mqtt: string views in API and internal callbacks

* stateless callbacks for mqttRegister. no module uses the lambda / std
  func with captures or otherwise, so it is kind of pointless to have it
* make sure we know topic and payload length at all invocations and
  not constantly trying to re-parse the same string over and over again
* clean-up api related to string parsing and make sure we allow
  stringview as input
* clean-up id / unsigned number parsing to work with views instead of
  using a generic strto{,u}l; sometimes this works, sometimes doesn't.
  as noticed previously with IR implementation, it *will* parse until
  the '\0' is found in the input and we can't interpret parts of the
  string without doing a copy for the strtoul
* fixing additional bugs caught in ifan, leds, sensors and lights that
  were causing build failures. plus, more range-based parsing code for
  the same reason as described above

code/espurna/api.cpp

@@ -28,7 +28,7 @@ Copyright (C) 2020-2021 by Maxim Prokhorov <prokhorov dot max at outlook dot com
 
 // -----------------------------------------------------------------------------
 
-PathParts::PathParts(const String& path) :
+PathParts::PathParts(espurna::StringView path) :
     _path(path)
 {
     if (!_path.length()) {
@@ -40,7 +40,7 @@ PathParts::PathParts(const String& path) :
     size_t length { 0ul };
     size_t offset { 0ul };
 
-    const char* p { _path.c_str() };
+    const char* p { _path.begin() };
     if (*p == '\0') {
        goto error;
     }
@@ -193,43 +193,76 @@ error:
     return false;
 }
 
-#if WEB_SUPPORT
-
-String ApiRequest::wildcard(int index) const {
+espurna::StringView PathParts::wildcard(const PathParts& pattern, const PathParts& value, int index) {
     if (index < 0) {
         index = std::abs(index + 1);
     }
 
-    if (std::abs(index) >= _pattern.parts().size()) {
-        return _empty_string();
-    }
+    espurna::StringView out;
+
+    if (std::abs(index) < pattern.parts().size()) {
+        const auto& pattern_parts = pattern.parts();
+        int counter { 0 };
+
+        for (size_t part = 0; part < pattern.size(); ++part) {
+            const auto& lhs = pattern_parts[part];
+            const auto& rhs = value.parts()[part];
 
-    int counter { 0 };
-    auto& pattern = _pattern.parts();
+            const auto path = value.path();
 
-    for (unsigned int part = 0; part < pattern.size(); ++part) {
-        auto& lhs = pattern[part];
-        if (PathPart::Type::SingleWildcard == lhs.type) {
-            if (counter == index) {
-                auto& rhs = _parts.parts()[part];
-                return _parts.path().substring(rhs.offset, rhs.offset + rhs.length);
+            switch (lhs.type) {
+            case PathPart::Type::Value:
+            case PathPart::Type::Unknown:
+                break;
+
+            case PathPart::Type::SingleWildcard:
+                if (counter == index) {
+                    out = espurna::StringView(
+                        path.begin() + rhs.offset, path.begin() + rhs.offset + rhs.length);
+                    return out;
+                }
+                ++counter;
+                break;
+
+            case PathPart::Type::MultiWildcard:
+                if (counter == index) {
+                    out = espurna::StringView(
+                        path.begin() + rhs.offset, path.end());
+                }
+                return out;
             }
-            ++counter;
         }
     }
 
-    return _empty_string();
+    return out;
 }
 
-size_t ApiRequest::wildcards() const {
-    size_t result { 0ul };
-    for (auto& part : _pattern) {
-        if (PathPart::Type::SingleWildcard == part.type) {
-            ++result;
+size_t PathParts::wildcards(const PathParts& pattern) {
+    size_t out { 0 };
+
+    for (const auto& part : pattern) {
+        switch (part.type) {
+        case PathPart::Type::Unknown:
+        case PathPart::Type::Value:
+        case PathPart::Type::MultiWildcard:
+            break;
+        case PathPart::Type::SingleWildcard:
+            ++out;
+            break;
         }
     }
 
-    return result;
+    return out;
+}
+
+#if WEB_SUPPORT
+
+String ApiRequest::wildcard(int index) const {
+    return PathParts::wildcard(_pattern, _parts, index).toString();
+}
+
+size_t ApiRequest::wildcards() const {
+    return PathParts::wildcards(_pattern);
 }
 
 #endif
@@ -447,7 +480,7 @@ public:
     }
 
     void _handleGet(AsyncWebServerRequest* request, ApiRequest& apireq) {
-        DynamicJsonBuffer jsonBuffer(API_JSON_BUFFER_SIZE);
+        DynamicJsonBuffer jsonBuffer(BufferSize);
         JsonObject& root = jsonBuffer.createObject();
         if (!_get(apireq, root)) {
             request->send(500);
@@ -467,7 +500,7 @@ public:
     void _handlePut(AsyncWebServerRequest* request, uint8_t* data, size_t size) {
         // XXX: arduinojson v5 de-serializer will happily read garbage from raw ptr, since there's no length limit
         //      this is fixed in v6 though. for now, use a wrapper, but be aware that this actually uses more mem for the jsonbuffer
-        DynamicJsonBuffer jsonBuffer(API_JSON_BUFFER_SIZE);
+        DynamicJsonBuffer jsonBuffer(BufferSize);
         ReadOnlyStream stream(data, size);
 
         JsonObject& root = jsonBuffer.parseObject(stream);

code/espurna/api_impl.h

@@ -57,13 +57,15 @@ struct ApiRequest {
         });
     }
 
-    const String& param(const String& name) {
-        auto* result = _request.getParam(name, HTTP_PUT == _request.method());
+    espurna::StringView param(const String& name) {
+        const auto* result = _request.getParam(name, HTTP_PUT == _request.method());
+
+        espurna::StringView out;
         if (result) {
-            return result->value();
+            out = result->value();
         }
 
-        return _empty_string();
+        return out;
     }
 
     void send(const String& payload) {
@@ -86,7 +88,7 @@ struct ApiRequest {
     }
 
     String part(size_t index) const {
-        return _parts[index];
+        return _parts[index].toString();
     }
 
     // Only works when pattern cointains '+', retrieving the part at the same index from the real path
@@ -95,11 +97,6 @@ struct ApiRequest {
     size_t wildcards() const;
 
 private:
-    const String& _empty_string() const {
-        static const String string;
-        return string;
-    }
-
     bool _done { false };
 
     AsyncWebServerRequest& _request;

code/espurna/api_path.h

@@ -9,9 +9,10 @@ Copyright (C) 2021 by Maxim Prokhorov <prokhorov dot max at outlook dot com>
 #pragma once
 
 #include <Arduino.h>
-
 #include <vector>
 
+#include "types.h"
+
 // -----------------------------------------------------------------------------
 
 struct PathPart {
@@ -33,8 +34,8 @@ struct PathParts {
     PathParts() = delete;
     PathParts(const PathParts&) = delete;
 
-    explicit PathParts(const String& path);
-    PathParts(const String& path, Parts&& parts) :
+    explicit PathParts(espurna::StringView path);
+    PathParts(espurna::StringView path, Parts&& parts) :
         _path(path),
         _parts(std::move(parts)),
         _ok(_parts.size())
@@ -44,7 +45,7 @@ struct PathParts {
         PathParts(other._path, std::move(other._parts))
     {}
 
-    PathParts(const String& path, PathParts&& other) noexcept :
+    PathParts(espurna::StringView path, PathParts&& other) noexcept :
         _path(path),
         _parts(std::move(other._parts)),
         _ok(other._ok)
@@ -62,12 +63,19 @@ struct PathParts {
         _parts.reserve(size);
     }
 
-    String operator[](size_t index) const {
-        auto& part = _parts[index];
-        return _path.substring(part.offset, part.offset + part.length);
+    espurna::StringView operator[](size_t index) const {
+        return get(_parts[index]);
     }
 
-    const String& path() const {
+    espurna::StringView back() const {
+        return get(_parts.back());
+    }
+
+    espurna::StringView front() const {
+        return get(_parts.front());
+    }
+
+    espurna::StringView path() const {
         return _path;
     }
 
@@ -88,11 +96,20 @@ struct PathParts {
     }
 
     bool match(const PathParts& path) const;
-    bool match(const String& path) const {
+    bool match(espurna::StringView path) const {
         return match(PathParts(path));
     }
 
+    static espurna::StringView wildcard(const PathParts& pattern, const PathParts& value, int index);
+    static size_t wildcards(const PathParts& pattern);
+
 private:
+    espurna::StringView get(const PathPart& part) const {
+        return espurna::StringView(
+            _path.begin() + part.offset,
+            _path.begin() + part.offset + part.length);
+    }
+
     PathPart& emplace_back(PathPart part) {
         _parts.push_back(part);
         return _parts.back();
@@ -106,7 +123,7 @@ private:
         });
     }
 
-    const String& _path;
+    espurna::StringView _path;
     Parts _parts;
     bool _ok { false };
 };

code/espurna/button.cpp

@@ -773,7 +773,7 @@ namespace terminal {
 void button(::terminal::CommandContext&& ctx) {
     if (ctx.argv.size() == 2) {
         size_t id;
-        if (!tryParseId(ctx.argv[1], buttonCount, id)) {
+        if (!tryParseId(ctx.argv[1], buttonCount(), id)) {
             terminalError(ctx, F("Invalid button ID"));
             return;
         }

code/espurna/compat.h

@@ -6,17 +6,7 @@ COMPATIBILITY BETWEEN 2.3.0 and latest versions
 
 #pragma once
 
-#include "espurna.h"
-
-// -----------------------------------------------------------------------------
-
-inline constexpr bool isEspurnaMinimal() {
-#if defined(ESPURNA_MINIMAL_ARDUINO_OTA) || defined(ESPURNA_MINIMAL_WEBUI)
-    return true;
-#else
-    return false;
-#endif
-}
+#include <Arduino.h>
 
 // -----------------------------------------------------------------------------
 // Core version 2.4.2 and higher changed the cont_t structure to a pointer:
@@ -106,21 +96,32 @@ using std::isnan;
 // -----------------------------------------------------------------------------
 // various backports for C++11, since we still use it with gcc v4.8
 // -----------------------------------------------------------------------------
-#if __cplusplus <= 201103L
 
 #include <memory>
+#include <type_traits>
+
 namespace std {
 
+#if __cplusplus < 202002L
+template <typename T>
+using remove_cvref = typename std::remove_cv<std::remove_reference<T>>::type;
+#endif
+
+#if __cplusplus < 201304L
 template<typename T, typename... Args>
 std::unique_ptr<T> make_unique(Args&&... args) {
     return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
 }
+#endif
 
+#if __cplusplus < 201603L
 template <typename T>
 constexpr const T& clamp(const T& value, const T& low, const T& high) {
     return (value < low) ? low : (high < value) ? high : value;
 }
+#endif
 
+#if __cplusplus < 201411L
 template <typename T, size_t Size>
 constexpr size_t size(const T (&)[Size]) {
     return Size;
@@ -140,16 +141,10 @@ template <typename T>
 constexpr auto cend(const T& value) -> decltype(std::end(value)) {
     return std::end(value);
 }
-
-template <typename T>
-constexpr std::reverse_iterator<T> make_reverse_iterator(T iterator) {
-    return std::reverse_iterator<T>(iterator);
-}
+#endif
 
 } // namespace std
 
-#endif
-
 // Same as min and max, force same type arguments
 #undef constrain
 

code/espurna/curtain_kingart.cpp

@@ -349,21 +349,21 @@ void _KACurtainResult() {
 #if MQTT_SUPPORT
 
 //------------------------------------------------------------------------------
-void _curtainMQTTCallback(unsigned int type, const char* topic, char* payload) {
+void _curtainMQTTCallback(unsigned int type, espurna::StringView topic, espurna::StringView payload) {
     if (type == MQTT_CONNECT_EVENT) {
         mqttSubscribe(MQTT_TOPIC_CURTAIN);
     } else if (type == MQTT_MESSAGE_EVENT) {
         // Match topic
-        const String t = mqttMagnitude(topic);
+        const auto t = mqttMagnitude(topic);
         if (t.equals(MQTT_TOPIC_CURTAIN)) {
-            if (strcmp(payload, "pause") == 0) {
+            if (payload == "pause") {
                 _KACurtainSet(CURTAIN_BUTTON_PAUSE);
-            } else  if (strcmp(payload, "on") == 0) {
+            } else if (payload == "on") {
                 _KACurtainSet(CURTAIN_BUTTON_OPEN);
-            } else  if (strcmp(payload, "off") == 0) {
+            } else if (payload == "off") {
                 _KACurtainSet(CURTAIN_BUTTON_CLOSE);
             } else {
-                _curtain_position_set = String(payload).toInt();
+                _curtain_position_set = payload.toString().toInt();
                 _KACurtainSet(CURTAIN_BUTTON_UNKNOWN, _curtain_position_set);
             }
         }

code/espurna/domoticz.cpp

@@ -282,7 +282,7 @@ void unsubscribe() {
     mqttUnsubscribeRaw(settings::topicOut().c_str());
 }
 
-void callback(unsigned int type, const char* topic, char* payload) {
+void callback(unsigned int type, espurna::StringView topic, espurna::StringView payload) {
     if (!enabled()) {
         return;
     }
@@ -296,10 +296,10 @@ void callback(unsigned int type, const char* topic, char* payload) {
     }
 
     if (type == MQTT_MESSAGE_EVENT) {
-        auto out = settings::topicOut();
-        if (out.equals(topic)) {
+        const auto out = settings::topicOut();
+        if (topic == out) {
             DynamicJsonBuffer jsonBuffer(1024);
-            JsonObject& root = jsonBuffer.parseObject(payload);
+            JsonObject& root = jsonBuffer.parseObject(payload.begin());
             if (!root.success()) {
                 DEBUG_MSG_P(PSTR("[DOMOTICZ] Error parsing data\n"));
                 return;

code/espurna/garland.cpp

@@ -329,11 +329,11 @@ bool executeCommand(const String& command) {
             one_color_palette.reset(new Palette("Color", {root[MQTT_PAYLOAD_PALETTE].as<uint32_t>()}));
             newPalette = one_color_palette.get();
         } else {
-            auto palette = root[MQTT_PAYLOAD_PALETTE].as<const char*>();
+            auto palette = root[MQTT_PAYLOAD_PALETTE].as<String>();
             bool palette_found = false;
             for (size_t i = 0; i < pals.size(); ++i) {
                 auto pal_name = pals[i].name();
-                if (strcmp(palette, pal_name) == 0) {
+                if (palette = pal_name) {
                     newPalette = &pals[i];
                     palette_found = true;
                     scene_setup_required = true;
@@ -341,9 +341,9 @@ bool executeCommand(const String& command) {
                 }
             }
             if (!palette_found) {
-                uint32_t color = (uint32_t)strtoul(palette, NULL, 0);
-                if (color != 0) {
-                    one_color_palette.reset(new Palette("Color", {color}));
+                const auto result = parseUnsigned(palette);
+                if (result.ok) {
+                    one_color_palette.reset(new Palette("Color", {result.value}));
                     newPalette = one_color_palette.get();
                 }
             }
@@ -409,17 +409,14 @@ void garlandLoop(void) {
 }
 
 //------------------------------------------------------------------------------
-void garlandMqttCallback(unsigned int type, const char* topic, char* payload) {
+void garlandMqttCallback(unsigned int type, espurna::StringView topic, espurna::StringView payload) {
     if (type == MQTT_CONNECT_EVENT) {
         mqttSubscribe(MQTT_TOPIC_GARLAND);
     }
 
     if (type == MQTT_MESSAGE_EVENT) {
-        // Match topic
-        String t = mqttMagnitude(topic);
-
+        auto t = mqttMagnitude(topic);
         if (t.equals(MQTT_TOPIC_GARLAND)) {
-            // Parse JSON input
             DynamicJsonBuffer jsonBuffer;
             JsonObject& root = jsonBuffer.parseObject(payload);
             if (!root.success()) {
@@ -433,7 +430,7 @@ void garlandMqttCallback(unsigned int type, const char* topic, char* payload) {
             }
 
             if (command == MQTT_COMMAND_IMMEDIATE) {
-                _immediate_command = payload;
+                _immediate_command = payload.toString();
             } else if (command == MQTT_COMMAND_RESET) {
                 std::queue<String> empty_queue;
                 std::swap(_command_queue, empty_queue);
@@ -444,9 +441,9 @@ void garlandMqttCallback(unsigned int type, const char* topic, char* payload) {
                 setDefault();
                 garlandEnabled(true);
             } else if (command == MQTT_COMMAND_QUEUE) {
-                _command_queue.push(payload);
+                _command_queue.push(payload.toString());
             } else if (command == MQTT_COMMAND_SEQUENCE) {
-                _command_sequence.push_back(payload);
+                _command_sequence.push_back(payload.toString());
             }
         }
     }
@@ -674,18 +671,19 @@ byte Anim::rngb() {
 //------------------------------------------------------------------------------
 
 void garlandEnabled(bool enabled) {
-    _garland_enabled = enabled;
     setSetting(NAME_GARLAND_ENABLED, _garland_enabled);
-    if (!_garland_enabled) {
-        schedule_function([]() {
+    if (_garland_enabled != enabled) {
+        espurnaRegisterOnceUnique([]() {
             pixels.clear();
             pixels.show();
         });
     }
 
+    _garland_enabled = enabled;
+
 #if WEB_SUPPORT
-    wsPost([](JsonObject& root) {
-        root["garlandEnabled"] = _garland_enabled;
+    wsPost([enabled](JsonObject& root) {
+        root["garlandEnabled"] = enabled;
     });
 #endif
 }

code/espurna/homeassistant.cpp

@@ -316,7 +316,7 @@ struct RelayContext {
 
 RelayContext makeRelayContext() {
     return {
-        mqttTopic(MQTT_TOPIC_STATUS, false),
+        mqttTopic(MQTT_TOPIC_STATUS),
         quote(mqttPayloadStatus(true)),
         quote(mqttPayloadStatus(false)),
         quote(relayPayload(PayloadStatus::On).toString()),
@@ -372,8 +372,8 @@ public:
             json[F("pl_off")] = _relay.payload_off.c_str();
             json[F("uniq_id")] = uniqueId();
             json[F("name")] = _ctx.name() + ' ' + _index;
-            json[F("stat_t")] = mqttTopic(MQTT_TOPIC_RELAY, _index, false);
-            json[F("cmd_t")] = mqttTopic(MQTT_TOPIC_RELAY, _index, true);
+            json[F("stat_t")] = mqttTopic(MQTT_TOPIC_RELAY, _index);
+            json[F("cmd_t")] = mqttTopicSetter(MQTT_TOPIC_RELAY, _index);
             json.printTo(_message);
         }
         return _message;
@@ -477,10 +477,10 @@ public:
 
             json[F("name")] = _ctx.name() + ' ' + F("Light");
 
-            json[F("stat_t")] = mqttTopic(MQTT_TOPIC_LIGHT_JSON, false);
-            json[F("cmd_t")] = mqttTopic(MQTT_TOPIC_LIGHT_JSON, true);
+            json[F("stat_t")] = mqttTopic(MQTT_TOPIC_LIGHT_JSON);
+            json[F("cmd_t")] = mqttTopicSetter(MQTT_TOPIC_LIGHT_JSON);
 
-            json[F("avty_t")] = mqttTopic(MQTT_TOPIC_STATUS, false);
+            json[F("avty_t")] = mqttTopic(MQTT_TOPIC_STATUS);
             json[F("pl_avail")] = quote(mqttPayloadStatus(true));
             json[F("pl_not_avail")] = quote(mqttPayloadStatus(false));
 
@@ -597,7 +597,7 @@ bool heartbeat(espurna::heartbeat::Mask mask) {
         String message;
         root.printTo(message);
 
-        String topic = mqttTopic(MQTT_TOPIC_LIGHT_JSON, false);
+        String topic = mqttTopic(MQTT_TOPIC_LIGHT_JSON);
         mqttSendRaw(topic.c_str(), message.c_str(), false);
     }
 
@@ -608,9 +608,9 @@ void publishLightJson() {
     heartbeat(static_cast<heartbeat::Mask>(heartbeat::Report::Light));
 }
 
-void receiveLightJson(char* payload) {
+void receiveLightJson(espurna::StringView payload) {
     DynamicJsonBuffer buffer(1024);
-    JsonObject& root = buffer.parseObject(payload);
+    JsonObject& root = buffer.parseObject(payload.begin());
     if (!root.success()) {
         return;
     }
@@ -719,7 +719,7 @@ public:
             json[F("uniq_id")] = uniqueId();
 
             json[F("name")] = _ctx.name() + ' ' + name() + ' ' + localId();
-            json[F("stat_t")] = mqttTopic(_info.topic, false);
+            json[F("stat_t")] = mqttTopic(_info.topic);
             json[F("unit_of_meas")] = magnitudeUnitsName(_info.units);
 
             json.printTo(_message);
@@ -1026,7 +1026,7 @@ void configure() {
     homeassistant::publishDiscovery();
 }
 
-void mqttCallback(unsigned int type, const char* topic, char* payload) {
+void mqttCallback(unsigned int type, StringView topic, StringView payload) {
     if (MQTT_DISCONNECT_EVENT == type) {
         if (internal::state == internal::State::Sent) {
             internal::state = internal::State::Pending;
@@ -1045,7 +1045,7 @@ void mqttCallback(unsigned int type, const char* topic, char* payload) {
 
 #if LIGHT_PROVIDER != LIGHT_PROVIDER_NONE
     if (type == MQTT_MESSAGE_EVENT) {
-        String t = ::mqttMagnitude(topic);
+        auto t = ::mqttMagnitude(topic);
         if (t.equals(MQTT_TOPIC_LIGHT_JSON)) {
             receiveLightJson(payload);
         }

code/espurna/ifan.cpp

@@ -69,7 +69,7 @@ String speedToPayload(FanSpeed speed) {
     return espurna::settings::internal::serialize(speed);
 }
 
-constexpr unsigned long DefaultSaveDelay { 1000ul };
+static constexpr auto DefaultSaveDelay = duration::Seconds{ 10 };
 
 // We expect to write a specific 'mask' via GPIO LOW & HIGH to set the speed
 // Sync up with the relay and write it on ON / OFF status events
@@ -96,25 +96,21 @@ constexpr int controlPin() {
 }
 
 struct Config {
-    Config() = default;
-    explicit Config(unsigned long save_, FanSpeed speed_) :
-        save(save_),
-        speed(speed_)
-    {}
-
-    unsigned long save { DefaultSaveDelay };
-    FanSpeed speed { FanSpeed::Off };
-    StatePins state_pins;
+    duration::Seconds save;
+    FanSpeed speed;
 };
 
 Config readSettings() {
-    return Config(
-        getSetting("fanSave", DefaultSaveDelay),
-        getSetting("fanSpeed", FanSpeed::Medium)
-    );
+    return Config{
+        .save = getSetting("fanSave", DefaultSaveDelay),
+        .speed = getSetting("fanSpeed", FanSpeed::Medium)};
 }
 
-Config config;
+StatePins state_pins;
+Config config {
+    .save = DefaultSaveDelay,
+    .speed = FanSpeed::Medium,
+};
 
 void configure() {
     config = readSettings();
@@ -127,10 +123,10 @@ void report(FanSpeed speed [[gnu::unused]]) {
 }
 
 void save(FanSpeed speed) {
-    static Ticker ticker;
+    static timer::SystemTimer ticker;
     config.speed = speed;
-    ticker.once_ms(config.save, []() {
-        auto value = speedToPayload(config.speed);
+    ticker.once(config.save, []() {
+        const auto value = speedToPayload(config.speed);
         setSetting("fanSpeed", value);
         DEBUG_MSG_P(PSTR("[IFAN] Saved speed setting \"%s\"\n"), value.c_str());
     });
@@ -217,13 +213,13 @@ void updateSpeed(FanSpeed speed) {
     updateSpeed(config, speed);
 }
 
-void updateSpeedFromPayload(const String& payload) {
-    updateSpeed(payloadToSpeed(payload));
+void updateSpeedFromPayload(StringView payload) {
+    updateSpeed(payloadToSpeed(payload.toString()));
 }
 
 #if MQTT_SUPPORT
 
-void onMqttEvent(unsigned int type, const char* topic, char* payload) {
+void onMqttEvent(unsigned int type, StringView topic, StringView payload) {
     switch (type) {
 
     case MQTT_CONNECT_EVENT:
@@ -245,9 +241,10 @@ void onMqttEvent(unsigned int type, const char* topic, char* payload) {
 
 class FanProvider : public RelayProviderBase {
 public:
-    explicit FanProvider(BasePinPtr&& pin, const Config& config, FanSpeedUpdate& callback) :
+    FanProvider(BasePinPtr&& pin, const Config& config, const StatePins& pins, FanSpeedUpdate& callback) :
         _pin(std::move(pin)),
-        _config(config)
+        _config(config),
+        _pins(pins)
     {
         callback = [this](FanSpeed speed) {
             change(speed);
@@ -265,8 +262,8 @@ public:
         auto state = stateFromSpeed(speed);
         DEBUG_MSG_P(PSTR("[IFAN] State mask: %s\n"), maskFromSpeed(speed));
 
-        for (size_t index = 0; index < _config.state_pins.size(); ++index) {
-            auto& pin = _config.state_pins[index].second;
+        for (size_t index = 0; index < _pins.size(); ++index) {
+            auto& pin = _pins[index].second;
             if (!pin) {
                 continue;
             }
@@ -282,6 +279,7 @@ public:
 private:
     BasePinPtr _pin;
     const Config& _config;
+    const StatePins& _pins;
 };
 
 #if TERMINAL_SUPPORT
@@ -314,19 +312,18 @@ void setup() {
 #endif
 
 void setup() {
-
-    config.state_pins = setupStatePins();
-    if (!config.state_pins.size()) {
+    state_pins = setupStatePins();
+    if (!state_pins.size()) {
         return;
     }
 
     configure();
-
     espurnaRegisterReload(configure);
 
     auto relay_pin = gpioRegister(controlPin());
     if (relay_pin) {
-        auto provider = std::make_unique<FanProvider>(std::move(relay_pin), config, onFanSpeedUpdate);
+        auto provider = std::make_unique<FanProvider>(
+            std::move(relay_pin), config, state_pins, onFanSpeedUpdate);
         if (!relayAdd(std::move(provider))) {
             DEBUG_MSG_P(PSTR("[IFAN] Could not add relay provider for GPIO%d\n"), controlPin());
             gpioUnlock(controlPin());

code/espurna/ir.cpp

@@ -418,33 +418,22 @@ private:
     Result _result;
 };
 
-// TODO: std::from_chars works directly with the view. not available with -std=c++11,
-//       and needs some care in regards to the code size
-
 template <typename T>
-T sized(StringView view) {
-    String value(view);
-
-    char* endp { nullptr };
-    unsigned long result { std::strtoul(value.c_str(), &endp, 10) };
-    if ((endp != value.c_str()) && (*endp == '\0')) {
-        constexpr unsigned long Boundary { 1ul << (sizeof(T) * 8) };
-        if (result < Boundary) {
-            return result;
-        }
+T sized(StringView value) {
+    const auto result = parseUnsigned(value, 10);
+    constexpr decltype(result.value) Boundary { 1ul << (sizeof(T) * 8) };
+    if (result.ok && (result.value < Boundary)) {
+        return result.value;
     }
 
     return 0;
 }
 
 template <>
-unsigned long sized(StringView view) {
-    String value(view);
-
-    char* endp { nullptr };
-    unsigned long result { std::strtoul(value.c_str(), &endp, 10) };
-    if ((endp != value.c_str()) && (*endp == '\0')) {
-        return result;
+unsigned long sized(StringView value) {
+    const auto result = parseUnsigned(value, 10);
+    if (result.ok) {
+        return result.value;
     }
 
     return 0;
@@ -1263,7 +1252,7 @@ bool publish_raw { build::rxRaw() };
 bool publish_simple { build::rxSimple() };
 bool publish_state { build::rxState() };
 
-void callback(unsigned int type, const char* topic, char* payload) {
+void callback(unsigned int type, StringView topic, StringView payload) {
     switch (type) {
 
     case MQTT_CONNECT_EVENT:
@@ -1273,15 +1262,13 @@ void callback(unsigned int type, const char* topic, char* payload) {
         break;
 
     case MQTT_MESSAGE_EVENT: {
-        StringView view{payload, payload + strlen(payload)};
-
-        String t = mqttMagnitude(topic);
+        auto t = mqttMagnitude(topic);
         if (t.equals(build::topicTxSimple())) {
-            ir::tx::enqueue(ir::simple::parse(view));
+            ir::tx::enqueue(ir::simple::parse(payload));
         } else if (t.equals(build::topicTxState())) {
-            ir::tx::enqueue(ir::state::parse(view));
+            ir::tx::enqueue(ir::state::parse(payload));
         } else if (t.equals(build::topicTxRaw())) {
-            ir::tx::enqueue(ir::raw::parse(view));
+            ir::tx::enqueue(ir::raw::parse(payload));
         }
 
         break;

code/espurna/led.cpp

@@ -362,11 +362,8 @@ bool Led::toggle() {
 
 #include "led_pattern.re.ipp"
 
-} // namespace
-
 namespace settings {
 namespace keys {
-namespace {
 
 alignas(4) static constexpr char Gpio[] PROGMEM = "ledGpio";
 alignas(4) static constexpr char Inverse[] PROGMEM = "ledInv";
@@ -374,11 +371,9 @@ alignas(4) static constexpr char Mode[] PROGMEM = "ledMode";
 alignas(4) static constexpr char Relay[] PROGMEM = "ledRelay";
 alignas(4) static constexpr char Pattern[] PROGMEM = "ledPattern";
 
-} // namespace
 } // namespace keys
 
 namespace options {
-namespace {
 
 using espurna::settings::options::Enumeration;
 
@@ -415,9 +410,9 @@ static constexpr Enumeration<LedMode> LedModeOptions[] PROGMEM {
 #endif
 };
 
-} // namespace
 } // namespace options
 } // namespace settings
+} // namespace
 } // namespace led
 
 // -----------------------------------------------------------------------------
@@ -445,9 +440,10 @@ String serialize(LedMode mode) {
 // -----------------------------------------------------------------------------
 
 namespace led {
-namespace build {
 namespace {
 
+namespace build {
+
 constexpr size_t LedsMax { 8ul };
 
 constexpr size_t preconfiguredLeds() {
@@ -531,11 +527,9 @@ constexpr bool inverse(size_t index) {
     );
 }
 
-} // namespace
 } // namespace build
 
 namespace settings {
-namespace {
 
 unsigned char pin(size_t id) {
     return getSetting({keys::Gpio, id}, build::pin(id));
@@ -567,7 +561,6 @@ void migrate(int version) {
     }
 }
 
-} // namespace
 } // namespace settings
 
 // For network-based modes, indefinitely cycle ON <-> OFF
@@ -590,18 +583,15 @@ LED_STATIC_DELAY(NetworkConfigInverse, 900, 100);
 LED_STATIC_DELAY(NetworkIdle, 500, 500);
 
 namespace internal {
-namespace {
 
 std::vector<Led> leds;
 bool update { false };
 
-} // namespace
 } // namespace internal
 
 namespace settings {
 namespace query {
 namespace internal {
-namespace {
 
 #define ID_VALUE(NAME)\
 String NAME (size_t id) {\
@@ -616,11 +606,8 @@ ID_VALUE(relay)
 
 #undef ID_VALUE
 
-} // namespace
 } // namespace internal
 
-namespace {
-
 static constexpr espurna::settings::query::IndexedSetting IndexedSettings[] PROGMEM {
     {keys::Gpio, internal::pin},
     {keys::Inverse, internal::inverse},
@@ -646,14 +633,12 @@ void setup() {
     });
 }
 
-} // namespace
 } // namespace query
 } // namespace settings
 
 #if RELAY_SUPPORT
 namespace relay {
 namespace internal {
-namespace {
 
 struct Link {
     Led& led;
@@ -697,11 +682,8 @@ size_t find(Led& led) {
     return RelaysMax;
 }
 
-} // namespace
 } // namespace internal
 
-namespace {
-
 void unlink(Led& led) {
     internal::unlink(led);
 }
@@ -730,12 +712,9 @@ bool areAnyOn() {
     return result;
 }
 
-} // namespace
 } // namespace relay
 #endif
 
-namespace {
-
 size_t count() {
     return internal::leds.size();
 }
@@ -794,8 +773,10 @@ void pattern(Led& led, Pattern&& other) {
 }
 
 void payload_status(Led& led, StringView payload) {
-    led.mode(LedMode::Manual);
     led.stop();
+    led.status(false);
+
+    led.mode(LedMode::Manual);
 
     const auto value = rpcParsePayload(payload);
     switch (value) {
@@ -957,13 +938,10 @@ void loop() {
     cancel();
 }
 
-} // namespace
-
 #if MQTT_SUPPORT
 namespace mqtt {
-namespace {
 
-void callback(unsigned int type, const char* topic, char* payload) {
+void callback(unsigned int type, StringView topic, StringView payload) {
     if (type == MQTT_CONNECT_EVENT) {
         mqttSubscribe(MQTT_TOPIC_LED "/+");
         return;
@@ -972,13 +950,13 @@ void callback(unsigned int type, const char* topic, char* payload) {
     // Only want `led/+/<MQTT_SETTER>`
     // We get the led ID from the `+`
     if (type == MQTT_MESSAGE_EVENT) {
-        const String magnitude = mqttMagnitude(topic);
+        const auto magnitude = mqttMagnitude(topic);
         if (!magnitude.startsWith(MQTT_TOPIC_LED)) {
             return;
         }
 
         size_t ledID;
-        if (tryParseId(mqttMagnitudeTail(magnitude, MQTT_TOPIC_LED), ledCount, ledID)) {
+        if (tryParseIdPath(magnitude, ledCount(), ledID)) {
             payload_status(internal::leds[ledID], payload);
         }
 
@@ -986,13 +964,11 @@ void callback(unsigned int type, const char* topic, char* payload) {
     }
 }
 
-} // namespace
 } // namespace mqtt
 #endif // MQTT_SUPPORT
 
 #if WEB_SUPPORT
 namespace web {
-namespace {
 
 bool onKeyCheck(StringView key, const JsonVariant&) {
     return settings::query::checkSamePrefix(key);
@@ -1009,20 +985,18 @@ void onConnected(JsonObject& root) {
     }
 }
 
-} // namespace
 } // namespace web
 #endif // WEB_SUPPORT
 
 #if TERMINAL_SUPPORT
 namespace terminal {
-namespace {
 
 alignas(4) static constexpr char Led[] PROGMEM = "LED";
 
 void led(::terminal::CommandContext&& ctx) {
     if (ctx.argv.size() > 1) {
         size_t id;
-        if (!tryParseId(ctx.argv[1], ledCount, id)) {
+        if (!tryParseId(ctx.argv[1], ledCount(), id)) {
             terminalError(ctx, F("Invalid ledID"));
             return;
         }
@@ -1056,12 +1030,9 @@ void setup() {
     espurna::terminal::add(Commands);
 }
 
-} // namespace
 } // namespace terminal
 #endif
 
-namespace {
-
 void setup() {
     migrateVersion(settings::migrate);
     internal::leds.reserve(build::preconfiguredLeds());
@@ -1107,7 +1078,7 @@ void setup() {
 
 } // namespace
 } // namespace led
-} // namespace led
+} // namespace espurna
 
 bool ledStatus(size_t id, bool status) {
     if (id < espurna::led::count()) {

code/espurna/led_pattern.re

@@ -13,8 +13,6 @@ Copyright (C) 2020-2021 by Maxim Prokhorov <prokhorov dot max at outlook dot com
 // And returns a list of Delay objects for the pattern
 
 Pattern::Pattern(espurna::StringView value) {
-    char buffer[16];
-
     const char* on1;
     const char* on2;
 
@@ -48,27 +46,28 @@ loop:
         wsp { goto loop; }
 
         @on1 num @on2 [,] @off1 num @off2 [,] @repeat1 num @repeat2 {
-            memcpy(buffer, on1, on2 - on1);
-            buffer[on2 - on1] = '\0';
-            espurna::duration::Milliseconds::rep on { strtoul(buffer, nullptr, 10) };
-
-            memcpy(buffer, off1, off2 - off1);
-            buffer[off2 - off1] = '\0';
-            espurna::duration::Milliseconds::rep off { strtoul(buffer, nullptr, 10) };
+            const auto on = parseUnsigned(StringView(on1, on2), 10);
+            if (!on.ok) {
+                return;
+            }
 
-            memcpy(buffer, repeat1, repeat2 - repeat1);
-            buffer[repeat2 - repeat1] = '\0';
+            const auto off = parseUnsigned(StringView(off1, off2), 10);
+            if (!off.ok) {
+                return;
+            }
 
             using Repeats = Delay::Repeats;
-            Repeats repeats { strtoul(buffer, nullptr, 10) };
-
             constexpr Repeats RepeatsMax { Delay::RepeatsMax };
-            _delays.emplace_back(
-                std::min(espurna::duration::Milliseconds(on), Delay::MillisecondsMax),
-                std::min(espurna::duration::Milliseconds(off), Delay::MillisecondsMax),
-                std::min(repeats, RepeatsMax));
+            const auto repeats = parseUnsigned(StringView(repeat1, repeat2), 10);
+            if (!repeats.ok) {
+                return;
+            }
 
-            if (repeats) {
+            _delays.emplace_back(
+                std::min(duration::Milliseconds(on.value), Delay::MillisecondsMax),
+                std::min(duration::Milliseconds(off.value), Delay::MillisecondsMax),
+                std::min(repeats.value, RepeatsMax));
+            if (repeats.value) {
                 goto loop;
             }
         }

code/espurna/led_pattern.re.ipp

@@ -1,5 +1,5 @@
-/* Generated by re2c 2.2 */
-#line 1 "espurna\\led_pattern.re"
+/* Generated by re2c 3.0 */
+#line 1 "espurna/led_pattern.re"
 /*
 
 LED MODULE
@@ -15,8 +15,6 @@ Copyright (C) 2020-2021 by Maxim Prokhorov <prokhorov dot max at outlook dot com
 // And returns a list of Delay objects for the pattern
 
 Pattern::Pattern(espurna::StringView value) {
-    char buffer[16];
-
     const char* on1;
     const char* on2;
 
@@ -31,127 +29,128 @@ Pattern::Pattern(espurna::StringView value) {
     const char* YYMARKER;
 
 loop:
-#line 35 "espurna\\led_pattern.re.ipp"
+#line 33 "espurna/led_pattern.re.ipp"
 const char *yyt1;const char *yyt2;const char *yyt3;
-#line 32 "espurna\\led_pattern.re"
+#line 30 "espurna/led_pattern.re"
 
 
-#line 40 "espurna\\led_pattern.re.ipp"
+#line 38 "espurna/led_pattern.re.ipp"
 	{
 		char yych;
 		yych = (char)*YYCURSOR;
 		switch (yych) {
-		case '\t':
-		case ' ': goto yy4;
-		case '0' ... '9':
-			yyt1 = YYCURSOR;
-			goto yy7;
-		default:
-			if (YYLIMIT <= YYCURSOR) goto yy18;
-			goto yy2;
+			case '\t':
+			case ' ': goto yy3;
+			case '0' ... '9':
+				yyt1 = YYCURSOR;
+				goto yy5;
+			default:
+				if (YYLIMIT <= YYCURSOR) goto yy13;
+				goto yy1;
 		}
-yy2:
+yy1:
 		++YYCURSOR;
-yy3:
-#line 46 "espurna\\led_pattern.re"
+yy2:
+#line 44 "espurna/led_pattern.re"
 		{ return; }
-#line 59 "espurna\\led_pattern.re.ipp"
-yy4:
+#line 57 "espurna/led_pattern.re.ipp"
+yy3:
 		yych = (char)*++YYCURSOR;
 		switch (yych) {
-		case '\t':
-		case ' ': goto yy4;
-		default: goto yy6;
+			case '\t':
+			case ' ': goto yy3;
+			default: goto yy4;
 		}
-yy6:
-#line 48 "espurna\\led_pattern.re"
+yy4:
+#line 46 "espurna/led_pattern.re"
 		{ goto loop; }
-#line 70 "espurna\\led_pattern.re.ipp"
-yy7:
+#line 68 "espurna/led_pattern.re.ipp"
+yy5:
 		yych = (char)*(YYMARKER = ++YYCURSOR);
 		switch (yych) {
-		case ',': goto yy8;
-		case '0' ... '9': goto yy10;
-		default: goto yy3;
+			case ',': goto yy6;
+			case '0' ... '9': goto yy8;
+			default: goto yy2;
 		}
-yy8:
+yy6:
 		yych = (char)*++YYCURSOR;
 		switch (yych) {
-		case '0' ... '9':
-			yyt2 = YYCURSOR;
-			goto yy12;
-		default: goto yy9;
+			case '0' ... '9':
+				yyt2 = YYCURSOR;
+				goto yy9;
+			default: goto yy7;
 		}
-yy9:
+yy7:
 		YYCURSOR = YYMARKER;
-		goto yy3;
-yy10:
+		goto yy2;
+yy8:
 		yych = (char)*++YYCURSOR;
 		switch (yych) {
-		case ',': goto yy8;
-		case '0' ... '9': goto yy10;
-		default: goto yy9;
+			case ',': goto yy6;
+			case '0' ... '9': goto yy8;
+			default: goto yy7;
 		}
-yy12:
+yy9:
 		yych = (char)*++YYCURSOR;
 		switch (yych) {
-		case ',': goto yy14;
-		case '0' ... '9': goto yy12;
-		default: goto yy9;
+			case ',': goto yy10;
+			case '0' ... '9': goto yy9;
+			default: goto yy7;
 		}
-yy14:
+yy10:
 		yych = (char)*++YYCURSOR;
 		switch (yych) {
-		case '0' ... '9':
-			yyt3 = YYCURSOR;
-			goto yy15;
-		default: goto yy9;
+			case '0' ... '9':
+				yyt3 = YYCURSOR;
+				goto yy11;
+			default: goto yy7;
 		}
-yy15:
+yy11:
 		yych = (char)*++YYCURSOR;
 		switch (yych) {
-		case '0' ... '9': goto yy15;
-		default: goto yy17;
+			case '0' ... '9': goto yy11;
+			default: goto yy12;
 		}
-yy17:
+yy12:
 		on1 = yyt1;
 		off1 = yyt2;
 		repeat1 = yyt3;
 		on2 = yyt2 - 1;
 		off2 = yyt3 - 1;
 		repeat2 = YYCURSOR;
-#line 50 "espurna\\led_pattern.re"
+#line 48 "espurna/led_pattern.re"
 		{
-            memcpy(buffer, on1, on2 - on1);
-            buffer[on2 - on1] = '\0';
-            espurna::duration::Milliseconds::rep on { strtoul(buffer, nullptr, 10) };
-
-            memcpy(buffer, off1, off2 - off1);
-            buffer[off2 - off1] = '\0';
-            espurna::duration::Milliseconds::rep off { strtoul(buffer, nullptr, 10) };
+            const auto on = parseUnsigned(StringView(on1, on2), 10);
+            if (!on.ok) {
+                return;
+            }
 
-            memcpy(buffer, repeat1, repeat2 - repeat1);
-            buffer[repeat2 - repeat1] = '\0';
+            const auto off = parseUnsigned(StringView(off1, off2), 10);
+            if (!off.ok) {
+                return;
+            }
 
             using Repeats = Delay::Repeats;
-            Repeats repeats { strtoul(buffer, nullptr, 10) };
-
             constexpr Repeats RepeatsMax { Delay::RepeatsMax };
-            _delays.emplace_back(
-                std::min(espurna::duration::Milliseconds(on), Delay::MillisecondsMax),
-                std::min(espurna::duration::Milliseconds(off), Delay::MillisecondsMax),
-                std::min(repeats, RepeatsMax));
+            const auto repeats = parseUnsigned(StringView(repeat1, repeat2), 10);
+            if (!repeats.ok) {
+                return;
+            }
 
-            if (repeats) {
+            _delays.emplace_back(
+                std::min(duration::Milliseconds(on.value), Delay::MillisecondsMax),
+                std::min(duration::Milliseconds(off.value), Delay::MillisecondsMax),
+                std::min(repeats.value, RepeatsMax));
+            if (repeats.value) {
                 goto loop;
             }
         }
-#line 150 "espurna\\led_pattern.re.ipp"
-yy18:
-#line 45 "espurna\\led_pattern.re"
+#line 149 "espurna/led_pattern.re.ipp"
+yy13:
+#line 43 "espurna/led_pattern.re"
 		{ return; }
-#line 154 "espurna\\led_pattern.re.ipp"
+#line 153 "espurna/led_pattern.re.ipp"
 	}
-#line 75 "espurna\\led_pattern.re"
+#line 74 "espurna/led_pattern.re"
 
 }

code/espurna/libs/URL.h

@@ -13,6 +13,8 @@
 #include <cstdint>
 #include <utility>
 
+#include "../types.h"
+
 class URL {
 public:
     URL() = default;
@@ -22,22 +24,19 @@ public:
     URL& operator=(const URL&) = default;
     URL& operator=(URL&&) = default;
 
-    URL(const String& string) {
+    explicit URL(espurna::StringView string) {
         _parse(string);
     }
 
-    URL(String&& string) {
-        _parse(std::move(string));
-    }
-
     String protocol;
     String host;
     String path;
     uint16_t port { 0 };
 
 private:
-    void _parse(String buffer) {
-        // cut the protocol part
+    void _parse(espurna::StringView string) {
+        auto buffer = string.toString();
+
         int index = buffer.indexOf("://");
         if (index > 0) {
             this->protocol = buffer.substring(0, index);

code/espurna/light.cpp

@@ -1019,33 +1019,59 @@ void _lightFromHexPayload(espurna::StringView payload) {
     }
 }
 
-void _lightFromCommaSeparatedPayload(espurna::StringView payload) {
-    constexpr size_t BufferSize { 16 };
-    if (payload.length() < BufferSize) {
-        char buffer[BufferSize] = {0};
-        std::copy(payload.begin(), payload.end(), buffer);
+template <typename T>
+const char* _lightForEachToken(espurna::StringView payload, char sep, T&& callback) {
+    const auto begin = payload.begin();
+    const auto end = payload.end();
+
+    auto it = begin;
+    for (auto last = it; it != end; ++it) {
+        last = it;
+        it = std::find(it, payload.end(), ',');
+        if (!callback(espurna::StringView(last, it))) {
+            break;
+        }
+        if (it == end) {
+            break;
+        }
+    }
 
-        auto it = _light_channels.begin();
-        char* tok = std::strtok(buffer, ",");
+    return it;
+}
 
-        while ((it != _light_channels.end()) && (tok != nullptr)) {
-            char* endp { nullptr };
-            auto value = std::strtol(tok, &endp, 10);
-            if ((endp == tok) || (*endp != '\0')) {
-                break;
+template <typename Begin, typename End>
+const char* _lightApplyForEachToken(espurna::StringView payload, char sep, Begin& it, End end) {
+    return _lightForEachToken(payload, sep,
+        [&](espurna::StringView token) {
+            if (it != end) {
+                const auto result = parseUnsigned(token, 10);
+                if (result.ok) {
+                    (*it) = result.value;
+                    ++it;
+                    return true;
+                }
             }
 
-            (*it) = value;
-            ++it;
+            return false;
+        });
+}
 
-            tok = std::strtok(nullptr, ",");
-        }
+void _lightFromCommaSeparatedPayload(espurna::StringView payload) {
+    const auto end = _light_channels.end();
 
-        // same as previous versions, set the rest to zeroes
-        while (it != _light_channels.end()) {
-            (*it) = 0;
-            ++it;
-        }
+    auto it = _light_channels.begin();
+    if (it == end) {
+        return;
+    }
+
+    // every channel value is separated by a comma
+    _lightApplyForEachToken(payload, ',', it, end);
+
+    // and fill the rest with zeroes
+    while (it != end) {
+        DEBUG_MSG_P(PSTR(":set %p with zero\n"), it);
+        (*it) = 0;
+        ++it;
     }
 }
 
@@ -1072,45 +1098,29 @@ void _lightFromRgbPayload(espurna::StringView payload) {
     _lightFromCommaSeparatedPayload(payload);
 }
 
-// HSV string is expected to be "H,S,V", where:
-// - H [0...360]
-// - S [0...100]
-// - V [0...100]
-
 void _lightFromHsvPayload(espurna::StringView payload) {
-    if (!_light_has_color || !payload.length() || (payload[0] == '\0')) {
+    if (!_light_has_color || !payload.length()) {
         return;
     }
 
-    constexpr size_t BufferSize { 16 };
-
-    if (payload.length() < BufferSize) {
-        char buffer[BufferSize] = {0};
-        std::copy(payload.begin(), payload.end(), buffer);
-
-        long values[3] {0, 0, 0};
-        char* tok = std::strtok(buffer, ",");
-
-        auto it = std::begin(values);
-        while ((it != std::end(values)) && (tok != nullptr)) {
-            char* endp { nullptr };
-            auto value = std::strtol(tok, &endp, 10);
-            if ((endp == tok) || (*endp != '\0')) {
-                break;
-            }
+    long hsv[3] {0, 0, 0};
+    auto it = std::begin(hsv);
 
-            (*it) = value;
-            ++it;
-
-            tok = std::strtok(nullptr, ",");
-        }
+    // HSV string is expected to be "H,S,V", where:
+    // - H [0...360]
+    // - S [0...100]
+    // - V [0...100]
+    const auto parsed = _lightApplyForEachToken(
+            payload, ',', it, std::end(hsv));
 
-        if (it != std::end(values)) {
-            return;
-        }
-
-        lightHsv({values[0], values[1], values[2]});
+    // discard partial or uneven payloads
+    if ((parsed != payload.end()) || (it != std::end(hsv))) {
+        return;
     }
+
+    // values are expected to be 'clamped' either
+    // in the call or in ctor of the helper object
+    lightHsv({hsv[0], hsv[1], hsv[2]});
 }
 
 // Thanks to Sacha Telgenhof for sharing this code in his AiLight library
@@ -1261,17 +1271,15 @@ String _lightRgbPayload() {
     return _lightRgbPayload(_lightToInputRgb());
 }
 
-void _lightFromGroupPayload(const char* payload) {
-    if (!payload || *payload == '\0') {
+void _lightFromGroupPayload(espurna::StringView payload) {
+    if (!payload.length()) {
         return;
     }
 
     constexpr size_t BufferSize { 32 };
-    const size_t PayloadLen { strlen(payload) };
-
-    if (PayloadLen < BufferSize) {
+    if (payload.length() < BufferSize) {
         char buffer[BufferSize] = {0};
-        std::copy(payload, payload + PayloadLen, buffer);
+        std::copy(payload.begin(), payload.end(), buffer);
 
         char* tok = std::strtok(buffer, ",");
         auto it = _light_channels.begin();
@@ -2001,7 +2009,8 @@ void _lightSaveSettings() {
     }
 
     for (size_t channel = 0; channel < _light_channels.size(); ++channel) {
-        espurna::light::settings::value(channel, _light_channels[channel].inputValue);
+        espurna::light::settings::value(
+            channel, _light_channels[channel].inputValue);
     }
 
     espurna::light::settings::brightness(_light_brightness);
@@ -2038,7 +2047,7 @@ bool _lightParsePayload(espurna::StringView payload) {
 }
 
 bool _lightTryParseChannel(espurna::StringView value, size_t& id) {
-    return tryParseId(value, lightChannels, id);
+    return tryParseIdPath(value, lightChannels(), id);
 }
 
 } // namespace
@@ -2049,6 +2058,18 @@ bool _lightTryParseChannel(espurna::StringView value, size_t& id) {
 
 namespace {
 
+bool _lightApiTransition(espurna::StringView payload) {
+    const auto result = parseUnsigned(payload, 10);
+    if (result.ok) {
+        lightTransition(
+                espurna::duration::Milliseconds(result.value),
+                _light_transition_step);
+        return true;
+    }
+
+    return false;
+}
+
 int _lightMqttReportMask() {
     return espurna::light::DefaultReport & ~(static_cast<int>(mqttForward() ? espurna::light::Report::None : espurna::light::Report::Mqtt));
 }
@@ -2081,7 +2102,7 @@ bool _lightMqttHeartbeat(espurna::heartbeat::Mask mask) {
     return mqttConnected();
 }
 
-void _lightMqttCallback(unsigned int type, const char* topic, char* payload) {
+void _lightMqttCallback(unsigned int type, espurna::StringView topic, espurna::StringView payload) {
     String mqtt_group_color = espurna::light::settings::mqttGroup();
 
     if (type == MQTT_CONNECT_EVENT) {
@@ -2113,14 +2134,14 @@ void _lightMqttCallback(unsigned int type, const char* topic, char* payload) {
 
     if (type == MQTT_MESSAGE_EVENT) {
         // Group color
-        if ((mqtt_group_color.length() > 0) && (mqtt_group_color.equals(topic))) {
+        if ((mqtt_group_color.length() > 0) && (topic == mqtt_group_color)) {
             _lightFromGroupPayload(payload);
             _lightUpdateFromMqttGroup();
             return;
         }
 
         // Match topic
-        String t = mqttMagnitude(topic);
+        auto t = mqttMagnitude(topic);
 
         // Color temperature in mireds
         if (t.equals(MQTT_TOPIC_MIRED)) {
@@ -2149,17 +2170,9 @@ void _lightMqttCallback(unsigned int type, const char* topic, char* payload) {
             return;
         }
 
-        // Transition setting
+        // Transition setting (persist)
         if (t.equals(MQTT_TOPIC_TRANSITION)) {
-            char* endp { nullptr };
-            auto result = strtoul(payload, &endp, 10);
-            if (!endp || (endp == payload)) {
-                return;
-            }
-
-            lightTransition(
-                espurna::duration::Milliseconds(result),
-                _light_transition_step);
+            _lightApiTransition(payload);
             return;
         }
 
@@ -2173,7 +2186,7 @@ void _lightMqttCallback(unsigned int type, const char* topic, char* payload) {
         // Channel
         if (t.startsWith(MQTT_TOPIC_CHANNEL)) {
             size_t id;
-            if (_lightTryParseChannel(mqttMagnitudeTail(t, MQTT_TOPIC_CHANNEL), id)) {
+            if (_lightTryParseChannel(t, id)) {
                 _lightAdjustChannel(id, payload);
                 _lightUpdateFromMqtt();
             }
@@ -2318,21 +2331,7 @@ void _lightApiSetup() {
             return true;
         },
         [](ApiRequest& request) {
-            auto value = request.param(F("value"));
-
-            const char* p { value.c_str() };
-            char* endp { nullptr };
-
-            auto result = strtoul(p, &endp, 10);
-            if (!endp || (endp == p)) {
-                return false;
-            }
-
-            lightTransition(
-                espurna::duration::Milliseconds(result),
-                _light_transition_step);
-
-            return true;
+            return _lightApiTransition(request.param(F("value")));
         }
     );
 
@@ -2448,10 +2447,10 @@ void _lightWebSocketOnAction(uint32_t client_id, const char* action, JsonObject&
             STRING_VIEW_INLINE(Hsv, "hsv");
 
             if (data.containsKey(Rgb)) {
-                _lightFromRgbPayload(data[Rgb].as<espurna::StringView>());
+                _lightFromRgbPayload(data[Rgb].as<String>());
                 lightUpdate();
             } else if (data.containsKey(Hsv)) {
-                _lightFromHsvPayload(data[Hsv].as<espurna::StringView>());
+                _lightFromHsvPayload(data[Hsv].as<String>());
                 lightUpdate();
             }
         }

code/espurna/mqtt.cpp

@@ -72,12 +72,12 @@ namespace {
 
 #if MQTT_LIBRARY == MQTT_LIBRARY_ASYNCMQTTCLIENT
 
-struct MqttPidCallback {
+struct MqttPidCallbackHandler {
     uint16_t pid;
-    mqtt_pid_callback_f run;
+    MqttPidCallback callback;
 };
 
-using MqttPidCallbacks = std::forward_list<MqttPidCallback>;
+using MqttPidCallbacks = std::forward_list<MqttPidCallbackHandler>;
 
 MqttPidCallbacks _mqtt_publish_callbacks;
 MqttPidCallbacks _mqtt_subscribe_callbacks;
@@ -91,7 +91,7 @@ espurna::duration::Seconds _mqtt_heartbeat_interval;
 String _mqtt_payload_online;
 String _mqtt_payload_offline;
 
-std::forward_list<mqtt_callback_f> _mqtt_callbacks;
+std::forward_list<MqttCallback> _mqtt_callbacks;
 
 } // namespace
 
@@ -124,17 +124,15 @@ namespace mqtt {
 namespace build {
 namespace {
 
-constexpr espurna::duration::Milliseconds SkipTime { MQTT_SKIP_TIME };
+static constexpr espurna::duration::Milliseconds SkipTime { MQTT_SKIP_TIME };
 
-constexpr espurna::duration::Milliseconds ReconnectDelayMin { MQTT_RECONNECT_DELAY_MIN };
-constexpr espurna::duration::Milliseconds ReconnectDelayMax { MQTT_RECONNECT_DELAY_MAX };
-constexpr espurna::duration::Milliseconds ReconnectStep { MQTT_RECONNECT_DELAY_STEP };
+static constexpr espurna::duration::Milliseconds ReconnectDelayMin { MQTT_RECONNECT_DELAY_MIN };
+static constexpr espurna::duration::Milliseconds ReconnectDelayMax { MQTT_RECONNECT_DELAY_MAX };
+static constexpr espurna::duration::Milliseconds ReconnectStep { MQTT_RECONNECT_DELAY_STEP };
 
-constexpr size_t MessageLogMax { 128ul };
+static constexpr size_t MessageLogMax { 128ul };
 
-const __FlashStringHelper* server() {
-    return F(MQTT_SERVER);
-}
+alignas(4) static constexpr char Server[] PROGMEM = MQTT_SERVER;
 
 constexpr uint16_t port() {
     return MQTT_PORT;
@@ -148,25 +146,12 @@ constexpr bool autoconnect() {
     return 1 == MQTT_AUTOCONNECT;
 }
 
-const __FlashStringHelper* topic() {
-    return F(MQTT_TOPIC);
-}
-
-const __FlashStringHelper* getter() {
-    return F(MQTT_GETTER);
-}
-
-const __FlashStringHelper* setter() {
-    return F(MQTT_SETTER);
-}
+alignas(4) static constexpr char Topic[] PROGMEM = MQTT_TOPIC;
+alignas(4) static constexpr char Getter[] PROGMEM = MQTT_GETTER;
+alignas(4) static constexpr char Setter[] PROGMEM = MQTT_SETTER;
 
-const __FlashStringHelper* user() {
-    return F(MQTT_USER);
-}
-
-const __FlashStringHelper* password() {
-    return F(MQTT_PASS);
-}
+alignas(4) static constexpr char User[] PROGMEM = MQTT_USER;
+alignas(4) static constexpr char Password[] PROGMEM = MQTT_PASS;
 
 constexpr int qos() {
     return MQTT_QOS;
@@ -176,8 +161,8 @@ constexpr bool retain() {
     return 1 == MQTT_RETAIN;
 }
 
-constexpr KeepAlive KeepaliveMin { 15 };
-constexpr KeepAlive KeepaliveMax{ KeepAlive::max() };
+static constexpr KeepAlive KeepaliveMin { 15 };
+static constexpr KeepAlive KeepaliveMax{ KeepAlive::max() };
 
 constexpr KeepAlive keepalive() {
     return KeepAlive { MQTT_KEEPALIVE };
@@ -186,29 +171,21 @@ constexpr KeepAlive keepalive() {
 static_assert(keepalive() >= KeepaliveMin, "");
 static_assert(keepalive() <= KeepaliveMax, "");
 
-const __FlashStringHelper* topicWill() {
-    return F(MQTT_TOPIC_STATUS);
-}
+alignas(4) static constexpr char TopicWill[] PROGMEM = MQTT_TOPIC_STATUS;
 
 constexpr bool json() {
     return 1 == MQTT_USE_JSON;
 }
 
-const __FlashStringHelper* topicJson() {
-    return F(MQTT_TOPIC_JSON);
-}
+static constexpr auto JsonDelay = espurna::duration::Milliseconds(MQTT_USE_JSON_DELAY);
+alignas(4) static constexpr char TopicJson[] PROGMEM = MQTT_TOPIC_JSON;
 
 constexpr espurna::duration::Milliseconds skipTime() {
     return espurna::duration::Milliseconds(MQTT_SKIP_TIME);
 }
 
-const __FlashStringHelper* payloadOnline() {
-    return F(MQTT_STATUS_ONLINE);
-}
-
-const __FlashStringHelper* payloadOffline() {
-    return F(MQTT_STATUS_OFFLINE);
-}
+alignas(4) static constexpr char PayloadOnline[] PROGMEM = MQTT_STATUS_ONLINE;
+alignas(4) static constexpr char PayloadOffline[] PROGMEM = MQTT_STATUS_OFFLINE;
 
 constexpr bool secure() {
     return 1 == MQTT_SSL_ENABLED;
@@ -218,9 +195,7 @@ int secureClientCheck() {
     return MQTT_SECURE_CLIENT_CHECK;
 }
 
-const __FlashStringHelper* fingerprint() {
-    return F(MQTT_SSL_FINGERPRINT);
-}
+alignas(4) static constexpr char Fingerprint[] PROGMEM = MQTT_SSL_FINGERPRINT;
 
 constexpr uint16_t mfln() {
     return MQTT_SECURE_CLIENT_MFLN;
@@ -272,7 +247,7 @@ alignas(4) static constexpr char SecureClientMfln[] PROGMEM = "mqttScMFLN";
 namespace {
 
 String server() {
-    return getSetting(keys::Server, build::server());
+    return getSetting(keys::Server, espurna::StringView(build::Server));
 }
 
 uint16_t port() {
@@ -288,23 +263,23 @@ bool autoconnect() {
 }
 
 String topic() {
-    return getSetting(keys::Topic, build::topic());
+    return getSetting(keys::Topic, espurna::StringView(build::Topic));
 }
 
 String getter() {
-    return getSetting(keys::Getter, build::getter());
+    return getSetting(keys::Getter, espurna::StringView(build::Getter));
 }
 
 String setter() {
-    return getSetting(keys::Setter, build::setter());
+    return getSetting(keys::Setter, espurna::StringView(build::Setter));
 }
 
 String user() {
-    return getSetting(keys::User, build::user());
+    return getSetting(keys::User, espurna::StringView(build::User));
 }
 
 String password() {
-    return getSetting(keys::Password, build::password());
+    return getSetting(keys::Password, espurna::StringView(build::Password));
 }
 
 int qos() {
@@ -326,7 +301,7 @@ String clientId() {
 }
 
 String topicWill() {
-    return getSetting(keys::TopicWill, build::topicWill());
+    return getSetting(keys::TopicWill, espurna::StringView(build::TopicWill));
 }
 
 bool json() {
@@ -334,7 +309,7 @@ bool json() {
 }
 
 String topicJson() {
-    return getSetting(keys::TopicJson, build::topicJson());
+    return getSetting(keys::TopicJson, espurna::StringView(build::TopicJson));
 }
 
 espurna::heartbeat::Mode heartbeatMode() {
@@ -350,11 +325,11 @@ espurna::duration::Milliseconds skipTime() {
 }
 
 String payloadOnline() {
-    return getSetting(keys::PayloadOnline, build::payloadOnline());
+    return getSetting(keys::PayloadOnline, espurna::StringView(build::PayloadOnline));
 }
 
 String payloadOffline() {
-    return getSetting(keys::PayloadOffline, build::payloadOffline());
+    return getSetting(keys::PayloadOffline, espurna::StringView(build::PayloadOffline));
 }
 
 [[gnu::unused]]
@@ -369,7 +344,7 @@ int secureClientCheck() {
 
 [[gnu::unused]]
 String fingerprint() {
-    return getSetting(keys::Fingerprint, build::fingerprint());
+    return getSetting(keys::Fingerprint, espurna::StringView(build::Fingerprint));
 }
 
 [[gnu::unused]]
@@ -487,13 +462,32 @@ static void _mqttApplySetting(Lhs& lhs, Rhs&& rhs) {
     }
 }
 
-template <typename Rhs>
-static void _mqttApplyTopic(String& lhs, Rhs&& rhs) {
-    auto topic = mqttTopic(rhs, false);
-    if (lhs != topic) {
-        mqttFlush();
-        lhs = std::move(topic);
+// Can't have **any** MQTT placeholders but our own `{magnitude}`
+bool _mqttValidTopicString(espurna::StringView value) {
+    size_t hash = 0;
+    size_t plus = 0;
+    for (auto it = value.begin(); it != value.end(); ++it) {
+        switch (*it) {
+        case '#':
+            ++hash;
+            break;
+        case '+':
+            ++plus;
+            break;
+        }
     }
+
+    return (hash <= 1) && (plus == 0);
+}
+
+bool _mqttApplyValidTopicString(String& lhs, String&& rhs) {
+    if (_mqttValidTopicString(rhs)) {
+        _mqttApplySetting(lhs, std::move(rhs));
+        return true;
+    }
+
+    mqttDisconnect();
+    return false;
 }
 
 } // namespace
@@ -715,6 +709,8 @@ void _mqttMdnsStop();
 
 void _mqttConfigure() {
 
+    _mqtt_enabled = false;
+
     // Make sure we have both the server to connect to things are enabled
     {
         _mqttApplySetting(_mqtt_settings.server, mqtt::settings::server());
@@ -734,7 +730,6 @@ void _mqttConfigure() {
                 _mqttMdnsSchedule();
             }
 #endif
-            _mqtt_enabled = false;
             return;
         }
     }
@@ -743,22 +738,34 @@ void _mqttConfigure() {
     {
         // Replace things inside curly braces (like {hostname}, {mac} etc.)
         auto topic = _mqttPlaceholders(mqtt::settings::topic());
+        if (!_mqttValidTopicString(topic)) {
+            mqttDisconnect();
+            return;
+        }
+
+        // Topic **must** end with some kind of word
         if (topic.endsWith("/")) {
             topic.remove(topic.length() - 1);
         }
 
+        // For simple topics, sssume right-hand side contains magnitude
         if (topic.indexOf("#") == -1) {
             topic.concat("/#");
         }
 
-        _mqttApplySetting(_mqtt_settings.topic, topic);
+        _mqttApplySetting(_mqtt_settings.topic, std::move(topic));
     }
 
     // Getter and setter
-    _mqttApplySetting(_mqtt_settings.getter, mqtt::settings::getter());
-    _mqttApplySetting(_mqtt_settings.setter, mqtt::settings::setter());
+    _mqttApplyValidTopicString(_mqtt_settings.getter, mqtt::settings::getter());
+    _mqttApplyValidTopicString(_mqtt_settings.setter, mqtt::settings::setter());
     _mqttApplySetting(_mqtt_forward,
-            !_mqtt_settings.setter.equals(_mqtt_settings.getter));
+        !_mqtt_settings.setter.equals(_mqtt_settings.getter));
+
+    // Last will aka status topic
+    // (note that *must* be after topic updates)
+    _mqttApplyValidTopicString(_mqtt_settings.will,
+        mqttTopic(mqtt::settings::topicWill()));
 
     // MQTT options
     _mqttApplySetting(_mqtt_settings.user, _mqttPlaceholders(mqtt::settings::user()));
@@ -770,12 +777,10 @@ void _mqttConfigure() {
     _mqttApplySetting(_mqtt_settings.retain, mqtt::settings::retain());
     _mqttApplySetting(_mqtt_settings.keepalive, mqtt::settings::keepalive());
 
-    _mqttApplyTopic(_mqtt_settings.will, mqtt::settings::topicWill());
-
     // MQTT JSON
     _mqttApplySetting(_mqtt_use_json, mqtt::settings::json());
     if (_mqtt_use_json) {
-        _mqttApplyTopic(_mqtt_settings.topic_json, mqtt::settings::topicJson());
+        _mqttApplyValidTopicString(_mqtt_settings.topic_json, mqtt::settings::topicJson());
     }
 
     // Heartbeat messages
@@ -1006,13 +1011,13 @@ void _mqttCommandsSetup() {
 
 namespace {
 
-void _mqttCallback(unsigned int type, const char* topic, char* payload) {
+void _mqttCallback(unsigned int type, espurna::StringView topic, espurna::StringView payload) {
     if (type == MQTT_CONNECT_EVENT) {
         mqttSubscribe(MQTT_TOPIC_ACTION);
     }
 
     if (type == MQTT_MESSAGE_EVENT) {
-        String t = mqttMagnitude(topic);
+        auto t = mqttMagnitude(topic);
         if (t.equals(MQTT_TOPIC_ACTION)) {
             rpcHandleAction(payload);
         }
@@ -1117,8 +1122,10 @@ void _mqttOnConnect() {
     systemHeartbeat(_mqttHeartbeat, _mqtt_heartbeat_mode, _mqtt_heartbeat_interval);
 
     // Notify all subscribers about the connection
-    for (auto& callback : _mqtt_callbacks) {
-        callback(MQTT_CONNECT_EVENT, nullptr, nullptr);
+    for (const auto callback : _mqtt_callbacks) {
+        callback(MQTT_CONNECT_EVENT,
+            espurna::StringView(),
+            espurna::StringView());
     }
 
     DEBUG_MSG_P(PSTR("[MQTT] Connected!\n"));
@@ -1136,8 +1143,10 @@ void _mqttOnDisconnect() {
     systemStopHeartbeat(_mqttHeartbeat);
 
     // Notify all subscribers about the disconnect
-    for (auto& callback : _mqtt_callbacks) {
-        callback(MQTT_DISCONNECT_EVENT, nullptr, nullptr);
+    for (const auto callback : _mqtt_callbacks) {
+        callback(MQTT_DISCONNECT_EVENT,
+            espurna::StringView(),
+            espurna::StringView());
     }
 
     DEBUG_MSG_P(PSTR("[MQTT] Disconnected!\n"));
@@ -1158,7 +1167,7 @@ void _mqttPidCallback(MqttPidCallbacks& callbacks, uint16_t pid) {
 
     while (it != end) {
         if ((*it).pid == pid) {
-            (*it).run();
+            (*it).callback();
             it = callbacks.erase_after(prev);
         } else {
             prev = it;
@@ -1191,29 +1200,38 @@ bool _mqttMaybeSkipRetained(char* topic) {
 // TODO: Current callback model does not allow to pass message length. Instead, implement a topic filter and record all subscriptions. That way we don't need to filter out events and could implement per-event callbacks.
 
 void _mqttOnMessageAsync(char* topic, char* payload, AsyncMqttClientMessageProperties, size_t len, size_t index, size_t total) {
-    if (!len || (len > MQTT_BUFFER_MAX_SIZE) || (total > MQTT_BUFFER_MAX_SIZE)) return;
-    if (_mqttMaybeSkipRetained(topic)) return;
+    static constexpr size_t BufferSize { MQTT_BUFFER_MAX_SIZE };
+    static_assert(BufferSize > 0, "");
 
-    static char message[((MQTT_BUFFER_MAX_SIZE + 1) + 31) & -32] = {0};
-    memmove(message + index, (char *) payload, len);
+    if (!len || (len > BufferSize) || (total > BufferSize)) {
+        return;
+    }
+
+    if (_mqttMaybeSkipRetained(topic)) {
+        return;
+    }
+
+    alignas(4) static char buffer[((BufferSize + 3) & ~3) + 4] = {0};
+    std::copy(payload, payload + len, buffer);
 
     // Not done yet
     if (total != (len + index)) {
         DEBUG_MSG_P(PSTR("[MQTT] Buffered %s => %u / %u bytes\n"), topic, len, total);
         return;
     }
-    message[len + index] = '\0';
+
+    buffer[len + index] = '\0';
     if (len < mqtt::build::MessageLogMax) {
-        DEBUG_MSG_P(PSTR("[MQTT] Received %s => %s\n"), topic, message);
+        DEBUG_MSG_P(PSTR("[MQTT] Received %s => %s\n"), topic, buffer);
     } else {
         DEBUG_MSG_P(PSTR("[MQTT] Received %s => (%u bytes)\n"), topic, len);
     }
 
-    // Call subscribers with the message buffer
-    for (auto& callback : _mqtt_callbacks) {
-        callback(MQTT_MESSAGE_EVENT, topic, message);
+    auto topic_view = espurna::StringView{ topic };
+    auto message_view = espurna::StringView{ &buffer[0], &buffer[total] };
+    for (const auto callback : _mqtt_callbacks) {
+        callback(MQTT_MESSAGE_EVENT, topic_view, message_view);
     }
-
 }
 
 #else
@@ -1247,89 +1265,91 @@ void _mqttOnMessage(char* topic, char* payload, unsigned int len) {
 // Public API
 // -----------------------------------------------------------------------------
 
-/**
-    Returns the magnitude part of a topic
-
-    @param topic the full MQTT topic
-    @return String object with the magnitude part.
-*/
-String mqttMagnitude(const char* topic) {
-    String output;
-
-    String pattern = _mqtt_settings.topic + _mqtt_settings.setter;
-    int position = pattern.indexOf("#");
-
-    if (position >= 0) {
-        String start = pattern.substring(0, position);
-        String end = pattern.substring(position + 1);
+// Return {magnitude} (aka #) part of the topic string
+// e.g.
+// * <TOPIC>/#/set - generic topic placement
+//           ^
+// * <LHS>/#/<RHS>/set - when {magnitude} is used
+//         ^
+// * #/<RHS>/set - when magnitude is at the start
+//   ^
+// * #/set - when *only* {magnitude} is used (or, empty topic string)
+//   ^
+// Depends on the topic and setter settings values.
+// Note that function is ignoring the fact that these strings may not contain the
+// root topic b/c MQTT handles that instead of us (and it's good idea to trust it).
+espurna::StringView mqttMagnitude(espurna::StringView topic) {
+    using espurna::StringView;
+    StringView out;
+
+    const auto pattern = _mqtt_settings.topic + _mqtt_settings.setter;
+    auto it = std::find(pattern.begin(), pattern.end(), '#');
+    if (it == pattern.end()) {
+        return out;
+    }
 
-        String magnitude(topic);
-        if (magnitude.startsWith(start) && magnitude.endsWith(end)) {
-            output = std::move(magnitude);
-            output.replace(start, "");
-            output.replace(end, "");
-        }
+    const auto start = StringView(pattern.begin(), it);
+    if (start.length()) {
+        topic = StringView(topic.begin() + start.length(), topic.end());
     }
 
-    return output;
-}
+    const auto end = StringView(it + 1, pattern.end());
+    if (end.length()) {
+        topic = StringView(topic.begin(), topic.end() - end.length());
+    }
 
-// Retrieve lefthand side of the extracted magnitude value
-espurna::StringView mqttMagnitudeTail(espurna::StringView magnitude, espurna::StringView topic) {
-    return espurna::StringView(magnitude.begin() + topic.length(), magnitude.end());
+    out = StringView(topic.begin(), topic.end());
+    return out;
 }
 
-/**
-    Returns a full MQTT topic from the magnitude
-
-    @param magnitude the magnitude part of the topic.
-    @param is_set whether to build a command topic (true)
-        or a state topic (false).
-    @return String full MQTT topic.
-*/
-String mqttTopic(const String& magnitude, bool is_set) {
-    String output;
-    output.reserve(magnitude.length()
+// Creates a proper MQTT topic for on the given 'magnitude'
+static String _mqttTopicWith(String magnitude) {
+    String out;
+    out.reserve(magnitude.length()
         + _mqtt_settings.topic.length()
         + _mqtt_settings.setter.length()
         + _mqtt_settings.getter.length());
 
-    output += _mqtt_settings.topic;
-    output.replace("#", magnitude);
-    output += is_set ? _mqtt_settings.setter : _mqtt_settings.getter;
+    out += _mqtt_settings.topic;
+    out.replace("#", magnitude);
 
-    return output;
+    return out;
 }
 
-String mqttTopic(const char* magnitude, bool is_set) {
-    return mqttTopic(String(magnitude), is_set);
+// When magnitude is a status topic aka getter
+static String _mqttTopicGetter(String magnitude) {
+    return _mqttTopicWith(magnitude) + _mqtt_settings.getter;
 }
 
-/**
-    Returns a full MQTT topic from the magnitude
+// When magnitude is an input topic aka setter
+String _mqttTopicSetter(String magnitude) {
+    return _mqttTopicWith(magnitude) + _mqtt_settings.setter;
+}
 
-    @param magnitude the magnitude part of the topic.
-    @param index index of the magnitude when more than one such magnitudes.
-    @param is_set whether to build a command topic (true)
-        or a state topic (false).
-    @return String full MQTT topic.
-*/
-String mqttTopic(const String& magnitude, unsigned int index, bool is_set) {
-    String output;
-    output.reserve(magnitude.length() + (sizeof(decltype(index)) * 4));
-    output += magnitude;
-    output += '/';
-    output += index;
-    return mqttTopic(output, is_set);
+// When magnitude is indexed, append its index to the topic
+static String _mqttTopicIndexed(String topic, size_t index) {
+    return topic + '/' + String(index, 10);
 }
 
-String mqttTopic(const char* magnitude, unsigned int index, bool is_set) {
-    return mqttTopic(String(magnitude), index, is_set);
+String mqttTopic(const String& magnitude) {
+    return _mqttTopicGetter(magnitude);
+}
+
+String mqttTopic(const String& magnitude, size_t index) {
+    return _mqttTopicGetter(_mqttTopicIndexed(magnitude, index));
+}
+
+String mqttTopicSetter(const String& magnitude) {
+    return _mqttTopicSetter(magnitude);
+}
+
+String mqttTopicSetter(const String& magnitude, size_t index) {
+    return _mqttTopicSetter(_mqttTopicIndexed(magnitude, index));
 }
 
 // -----------------------------------------------------------------------------
 
-uint16_t mqttSendRaw(const char * topic, const char * message, bool retain, int qos) {
+uint16_t mqttSendRaw(const char* topic, const char* message, bool retain, int qos) {
     if (_mqtt.connected()) {
         const unsigned int packetId {
 #if MQTT_LIBRARY == MQTT_LIBRARY_ASYNCMQTTCLIENT
@@ -1362,34 +1382,33 @@ uint16_t mqttSendRaw(const char * topic, const char * message, bool retain, int
     return false;
 }
 
-uint16_t mqttSendRaw(const char * topic, const char * message, bool retain) {
+uint16_t mqttSendRaw(const char* topic, const char* message, bool retain) {
     return mqttSendRaw(topic, message, retain, _mqtt_settings.qos);
 }
 
-uint16_t mqttSendRaw(const char * topic, const char * message) {
+uint16_t mqttSendRaw(const char* topic, const char* message) {
     return mqttSendRaw(topic, message, _mqtt_settings.retain);
 }
 
-bool mqttSend(const char * topic, const char * message, bool force, bool retain) {
+bool mqttSend(const char* topic, const char* message, bool force, bool retain) {
     if (!force && _mqtt_use_json) {
         mqttEnqueue(topic, message);
-        _mqtt_json_payload_flush.once(
-            espurna::duration::Milliseconds(MQTT_USE_JSON_DELAY), mqttFlush);
+        _mqtt_json_payload_flush.once(mqtt::build::JsonDelay, mqttFlush);
         return true;
     }
 
-    return mqttSendRaw(mqttTopic(topic, false).c_str(), message, retain) > 0;
+    return mqttSendRaw(mqttTopic(topic).c_str(), message, retain) > 0;
 }
 
-bool mqttSend(const char * topic, const char * message, bool force) {
+bool mqttSend(const char* topic, const char* message, bool force) {
     return mqttSend(topic, message, force, _mqtt_settings.retain);
 }
 
-bool mqttSend(const char * topic, const char * message) {
+bool mqttSend(const char* topic, const char* message) {
     return mqttSend(topic, message, false);
 }
 
-bool mqttSend(const char * topic, unsigned int index, const char * message, bool force, bool retain) {
+bool mqttSend(const char* topic, unsigned int index, const char* message, bool force, bool retain) {
     const size_t TopicLen { strlen(topic) };
     String out;
     out.reserve(TopicLen + 5);
@@ -1401,11 +1420,11 @@ bool mqttSend(const char * topic, unsigned int index, const char * message, bool
     return mqttSend(out.c_str(), message, force, retain);
 }
 
-bool mqttSend(const char * topic, unsigned int index, const char * message, bool force) {
+bool mqttSend(const char* topic, unsigned int index, const char* message, bool force) {
     return mqttSend(topic, index, message, force, _mqtt_settings.retain);
 }
 
-bool mqttSend(const char * topic, unsigned int index, const char * message) {
+bool mqttSend(const char* topic, unsigned int index, const char* message) {
     return mqttSend(topic, index, message, false);
 }
 
@@ -1467,7 +1486,7 @@ void mqttFlush() {
     mqttSendRaw(_mqtt_settings.topic_json.c_str(), output.c_str(), false);
 }
 
-void mqttEnqueue(const char* topic, const char* message) {
+void mqttEnqueue(espurna::StringView topic, espurna::StringView payload) {
     // Queue is not meant to send message "offline"
     // We must prevent the queue does not get full while offline
     if (_mqtt.connected()) {
@@ -1475,11 +1494,13 @@ void mqttEnqueue(const char* topic, const char* message) {
             mqttFlush();
         }
 
-        _mqtt_json_payload.remove_if([topic](const MqttPayload& payload) {
-            return payload.topic() == topic;
-        });
+        _mqtt_json_payload.remove_if(
+            [topic](const MqttPayload& payload) {
+                return topic == payload.topic();
+            });
 
-        _mqtt_json_payload.emplace_front(topic, message);
+        _mqtt_json_payload.emplace_front(
+            topic.toString(), payload.toString());
         ++_mqtt_json_payload_count;
     }
 }
@@ -1502,11 +1523,11 @@ uint16_t mqttSubscribeRaw(const char* topic) {
     return mqttSubscribeRaw(topic, _mqtt_settings.qos);
 }
 
-bool mqttSubscribe(const char * topic) {
-    return mqttSubscribeRaw(mqttTopic(topic, true).c_str(), _mqtt_settings.qos);
+bool mqttSubscribe(const char* topic) {
+    return mqttSubscribeRaw(mqttTopicSetter(topic).c_str(), _mqtt_settings.qos);
 }
 
-uint16_t mqttUnsubscribeRaw(const char * topic) {
+uint16_t mqttUnsubscribeRaw(const char* topic) {
     uint16_t pid { 0u };
     if (_mqtt.connected() && (strlen(topic) > 0)) {
         pid = _mqtt.unsubscribe(topic);
@@ -1516,8 +1537,8 @@ uint16_t mqttUnsubscribeRaw(const char * topic) {
     return pid;
 }
 
-bool mqttUnsubscribe(const char * topic) {
-    return mqttUnsubscribeRaw(mqttTopic(topic, true).c_str());
+bool mqttUnsubscribe(const char* topic) {
+    return mqttUnsubscribeRaw(mqttTopicSetter(topic).c_str());
 }
 
 // -----------------------------------------------------------------------------
@@ -1550,7 +1571,7 @@ bool mqttForward() {
 
     @param standalone function pointer
 */
-void mqttRegister(mqtt_callback_f callback) {
+void mqttRegister(MqttCallback callback) {
     _mqtt_callbacks.push_front(callback);
 }
 
@@ -1561,9 +1582,12 @@ void mqttRegister(mqtt_callback_f callback) {
 
     @param callable object
 */
-void mqttOnPublish(uint16_t pid, mqtt_pid_callback_f callback) {
-    auto callable = MqttPidCallback { pid, callback };
-    _mqtt_publish_callbacks.push_front(std::move(callable));
+void mqttOnPublish(uint16_t pid, MqttPidCallback callback) {
+    _mqtt_publish_callbacks.push_front(
+        MqttPidCallbackHandler{
+            .pid = pid,
+            .callback = std::move(callback),
+        });
 }
 
 /**
@@ -1571,9 +1595,12 @@ void mqttOnPublish(uint16_t pid, mqtt_pid_callback_f callback) {
 
     @param callable object
 */
-void mqttOnSubscribe(uint16_t pid, mqtt_pid_callback_f callback) {
-    auto callable = MqttPidCallback { pid, callback };
-    _mqtt_subscribe_callbacks.push_front(std::move(callable));
+void mqttOnSubscribe(uint16_t pid, MqttPidCallback callback) {
+    _mqtt_subscribe_callbacks.push_front(
+        MqttPidCallbackHandler{
+            .pid = pid,
+            .callback = std::move(callback),
+        });
 }
 
 #endif
@@ -1772,7 +1799,7 @@ void mqttSetup() {
             .onConnected(_mqttWebSocketOnConnected)
             .onKeyCheck(_mqttWebSocketOnKeyCheck);
 
-        mqttRegister([](unsigned int type, const char*, char*) {
+        mqttRegister([](unsigned int type, espurna::StringView, espurna::StringView) {
             if ((type == MQTT_CONNECT_EVENT) || (type == MQTT_DISCONNECT_EVENT)) {
                 wsPost(_mqttWebSocketOnData);
             }

code/espurna/mqtt.h

@@ -54,23 +54,24 @@ Updated secure client support by Niek van der Maas < mail at niekvandermaas dot
 #define MQTT_TOPIC_CMD              "cmd"
 #define MQTT_TOPIC_SCHEDULE         "schedule"
 
-using mqtt_callback_f = std::function<void(unsigned int type, const char* topic, char* payload)>;
-using mqtt_pid_callback_f = std::function<void()>;
-
 void mqttHeartbeat(espurna::heartbeat::Callback);
-void mqttRegister(mqtt_callback_f callback);
 
-void mqttOnPublish(uint16_t pid, mqtt_pid_callback_f);
-void mqttOnSubscribe(uint16_t pid, mqtt_pid_callback_f);
+// stateless callback; generally, registered once per module when calling setup()
+using MqttCallback = void(*)(unsigned int type, espurna::StringView topic, espurna::StringView payload);
+void mqttRegister(MqttCallback);
+
+// stateful callback for ACK'ed messages; should be used when waiting for certain messsage to be PUBlished
+using MqttPidCallback = std::function<void()>;
+void mqttOnPublish(uint16_t pid, MqttPidCallback);
+void mqttOnSubscribe(uint16_t pid, MqttPidCallback);
 
-String mqttTopic(const String& magnitude, bool is_set);
-String mqttTopic(const char* magnitude, bool is_set);
+String mqttTopic(const String& magnitude);
+String mqttTopic(const String& magnitude, size_t index);
 
-String mqttTopic(const String& magnitude, unsigned int index, bool is_set);
-String mqttTopic(const char* magnitude, unsigned int index, bool is_set);
+String mqttTopicSetter(const String& magnitude);
+String mqttTopicSetter(const String& magnitude, size_t index);
 
-String mqttMagnitude(const char* topic);
-espurna::StringView mqttMagnitudeTail(espurna::StringView magnitude, espurna::StringView topic);
+espurna::StringView mqttMagnitude(espurna::StringView topic);
 
 uint16_t mqttSendRaw(const char * topic, const char * message, bool retain, int qos);
 uint16_t mqttSendRaw(const char * topic, const char * message, bool retain);
@@ -94,7 +95,7 @@ bool mqttSend(const char * topic, unsigned int index, const char * message);
 void mqttSendStatus();
 void mqttFlush();
 
-void mqttEnqueue(const char* topic, const char* message);
+void mqttEnqueue(espurna::StringView topic, espurna::StringView payload);
 
 const String& mqttPayloadOnline();
 const String& mqttPayloadOffline();

code/espurna/ota_asynctcp.cpp

@@ -31,6 +31,7 @@ Copyright (C) 2016-2019 by Xose Pérez <xose dot perez at gmail dot com>
 
 #include <ESPAsyncTCP.h>
 
+namespace espurna {
 namespace ota {
 namespace asynctcp {
 namespace {
@@ -217,9 +218,9 @@ bool BasicHttpClient::connect() {
 
 // -----------------------------------------------------------------------------
 
-void clientFromUrl(URL&& url) {
+void clientFromUrl(URL url) {
     if (!url.protocol.equals("http") && !url.protocol.equals("https")) {
-        DEBUG_MSG_P(PSTR("[OTA] Incorrect URL specified\n"));
+        DEBUG_MSG_P(PSTR("[OTA] Unsupported protocol\n"));
         return;
     }
 
@@ -229,14 +230,16 @@ void clientFromUrl(URL&& url) {
         return;
     }
 
+    DEBUG_MSG_P(PSTR("[OTA] Connecting to %s:%hu\n"), url.host.c_str(), url.port);
+
     internal::client = std::make_unique<BasicHttpClient>(std::move(url));
     if (!internal::client->connect()) {
         DEBUG_MSG_P(PSTR("[OTA] Connection failed\n"));
     }
 }
 
-void clientFromUrl(const String& string) {
-    clientFromUrl(URL(string));
+void clientFromUrl(StringView payload) {
+    clientFromUrl(URL(payload));
 }
 
 #if TERMINAL_SUPPORT
@@ -257,22 +260,21 @@ static constexpr ::terminal::Command OtaCommands[] PROGMEM {
 };
 
 void terminalSetup() {
-    espurna::terminal::add(OtaCommands);
+    terminal::add(OtaCommands);
 }
 #endif // TERMINAL_SUPPORT
 
 #if OTA_MQTT_SUPPORT
 
-void mqttCallback(unsigned int type, const char* topic, char* payload) {
+void mqttCallback(unsigned int type, StringView topic, StringView payload) {
     if (type == MQTT_CONNECT_EVENT) {
         mqttSubscribe(MQTT_TOPIC_OTA);
         return;
     }
 
     if (type == MQTT_MESSAGE_EVENT) {
-        String t = mqttMagnitude(topic);
+        auto t = mqttMagnitude(topic);
         if (t.equals(MQTT_TOPIC_OTA)) {
-            DEBUG_MSG_P(PSTR("[OTA] Initiating from URL: %s\n"), payload);
             clientFromUrl(payload);
         }
         return;
@@ -284,6 +286,7 @@ void mqttCallback(unsigned int type, const char* topic, char* payload) {
 } // namespace
 } // namespace asynctcp
 } // namespace ota
+} // namespace espurna
 
 #endif
 
@@ -293,11 +296,11 @@ void otaClientSetup() {
     moveSetting("otafp", "otaFP");
 
 #if TERMINAL_SUPPORT
-    ota::asynctcp::terminalSetup();
+    espurna::ota::asynctcp::terminalSetup();
 #endif
 
 #if (MQTT_SUPPORT && OTA_MQTT_SUPPORT)
-    mqttRegister(ota::asynctcp::mqttCallback);
+    mqttRegister(espurna::ota::asynctcp::mqttCallback);
 #endif
 }
 

code/espurna/ota_httpupdate.cpp

@@ -22,7 +22,6 @@ Copyright (C) 2019 by Maxim Prokhorov <prokhorov dot max at outlook dot com>
 #include <ESP8266HTTPClient.h>
 #include <ESP8266httpUpdate.h>
 
-#include "libs/URL.h"
 #include "libs/TypeChecks.h"
 #include "libs/SecureClientHelpers.h"
 
@@ -44,6 +43,7 @@ namespace {
 
 // -----------------------------------------------------------------------------
 
+namespace espurna {
 namespace ota {
 namespace httpupdate {
 namespace {
@@ -144,7 +144,7 @@ void clientFromUrl(const String& url) {
     }
 #endif
 
-    DEBUG_MSG_P(PSTR("[OTA] Incorrect URL specified\n"));
+    DEBUG_MSG_P(PSTR("[OTA] Unsupported protocol\n"));
 }
 
 void clientFromInternalUrl() {
@@ -153,8 +153,8 @@ void clientFromInternalUrl() {
 }
 
 [[gnu::unused]]
-void clientQueueUrl(String url) {
-    internal::url = std::move(url);
+void clientQueueUrl(espurna::StringView url) {
+    internal::url = url.toString();
     espurnaRegisterOnceUnique(clientFromInternalUrl);
 }
 
@@ -182,16 +182,15 @@ void terminalSetup() {
 
 #if (MQTT_SUPPORT && OTA_MQTT_SUPPORT)
 
-void mqttCallback(unsigned int type, const char* topic, char* payload) {
+void mqttCallback(unsigned int type, StringView topic, StringView payload) {
     if (type == MQTT_CONNECT_EVENT) {
         mqttSubscribe(MQTT_TOPIC_OTA);
         return;
     }
 
     if (type == MQTT_MESSAGE_EVENT) {
-        const String t = mqttMagnitude(topic);
+        const auto t = mqttMagnitude(topic);
         if (!internal::url.length() && t.equals(MQTT_TOPIC_OTA)) {
-            DEBUG_MSG_P(PSTR("[OTA] Queuing from URL: %s\n"), payload);
             clientQueueUrl(payload);
         }
 
@@ -204,6 +203,7 @@ void mqttCallback(unsigned int type, const char* topic, char* payload) {
 } // namespace
 } // namespace httpupdate
 } // namespace ota
+} // namespace espurna
 
 // -----------------------------------------------------------------------------
 
@@ -211,11 +211,11 @@ void otaClientSetup() {
     moveSetting("otafp", "otaFP");
 
 #if TERMINAL_SUPPORT
-    ota::httpupdate::terminalSetup();
+    espurna::ota::httpupdate::terminalSetup();
 #endif
 
 #if (MQTT_SUPPORT && OTA_MQTT_SUPPORT)
-    mqttRegister(ota::httpupdate::mqttCallback);
+    mqttRegister(espurna::ota::httpupdate::mqttCallback);
 #endif
 }
 

code/espurna/relay.cpp

@@ -221,29 +221,29 @@ alignas(4) static constexpr char PayloadOn[] PROGMEM = RELAY_MQTT_ON;
 alignas(4) static constexpr char PayloadOff[] PROGMEM = RELAY_MQTT_OFF;
 alignas(4) static constexpr char PayloadToggle[] PROGMEM = RELAY_MQTT_TOGGLE;
 
-constexpr espurna::StringView mqttTopicSub(size_t index) {
+const StringView mqttTopicSub(size_t index) {
     return (
-        (index == 0) ? STRING_VIEW(RELAY1_MQTT_TOPIC_SUB) :
-        (index == 1) ? STRING_VIEW(RELAY2_MQTT_TOPIC_SUB) :
-        (index == 2) ? STRING_VIEW(RELAY3_MQTT_TOPIC_SUB) :
-        (index == 3) ? STRING_VIEW(RELAY4_MQTT_TOPIC_SUB) :
-        (index == 4) ? STRING_VIEW(RELAY5_MQTT_TOPIC_SUB) :
-        (index == 5) ? STRING_VIEW(RELAY6_MQTT_TOPIC_SUB) :
-        (index == 6) ? STRING_VIEW(RELAY7_MQTT_TOPIC_SUB) :
-        (index == 7) ? STRING_VIEW(RELAY8_MQTT_TOPIC_SUB) : ""
+        (index == 0) ? StringView(PSTR(RELAY1_MQTT_TOPIC_SUB)) :
+        (index == 1) ? StringView(PSTR(RELAY2_MQTT_TOPIC_SUB)) :
+        (index == 2) ? StringView(PSTR(RELAY3_MQTT_TOPIC_SUB)) :
+        (index == 3) ? StringView(PSTR(RELAY4_MQTT_TOPIC_SUB)) :
+        (index == 4) ? StringView(PSTR(RELAY5_MQTT_TOPIC_SUB)) :
+        (index == 5) ? StringView(PSTR(RELAY6_MQTT_TOPIC_SUB)) :
+        (index == 6) ? StringView(PSTR(RELAY7_MQTT_TOPIC_SUB)) :
+        (index == 7) ? StringView(PSTR(RELAY8_MQTT_TOPIC_SUB)) : ""
     );
 }
 
-constexpr espurna::StringView mqttTopicPub(size_t index) {
+const StringView mqttTopicPub(size_t index) {
     return (
-        (index == 0) ? STRING_VIEW(RELAY1_MQTT_TOPIC_PUB) :
-        (index == 1) ? STRING_VIEW(RELAY2_MQTT_TOPIC_PUB) :
-        (index == 2) ? STRING_VIEW(RELAY3_MQTT_TOPIC_PUB) :
-        (index == 3) ? STRING_VIEW(RELAY4_MQTT_TOPIC_PUB) :
-        (index == 4) ? STRING_VIEW(RELAY5_MQTT_TOPIC_PUB) :
-        (index == 5) ? STRING_VIEW(RELAY6_MQTT_TOPIC_PUB) :
-        (index == 6) ? STRING_VIEW(RELAY7_MQTT_TOPIC_PUB) :
-        (index == 7) ? STRING_VIEW(RELAY8_MQTT_TOPIC_PUB) : ""
+        (index == 0) ? StringView(PSTR(RELAY1_MQTT_TOPIC_PUB)) :
+        (index == 1) ? StringView(PSTR(RELAY2_MQTT_TOPIC_PUB)) :
+        (index == 2) ? StringView(PSTR(RELAY3_MQTT_TOPIC_PUB)) :
+        (index == 3) ? StringView(PSTR(RELAY4_MQTT_TOPIC_PUB)) :
+        (index == 4) ? StringView(PSTR(RELAY5_MQTT_TOPIC_PUB)) :
+        (index == 5) ? StringView(PSTR(RELAY6_MQTT_TOPIC_PUB)) :
+        (index == 6) ? StringView(PSTR(RELAY7_MQTT_TOPIC_PUB)) :
+        (index == 7) ? StringView(PSTR(RELAY8_MQTT_TOPIC_PUB)) : ""
     );
 }
 
@@ -1459,26 +1459,12 @@ Stream* StmProvider::_port = nullptr;
 // -----------------------------------------------------------------------------
 
 bool _relayTryParseId(espurna::StringView value, size_t& id) {
-    return tryParseId(value, relayCount, id);
+    return tryParseId(value, relayCount(), id);
 }
 
 [[gnu::unused]]
-bool _relayTryParseIdFromPath(espurna::StringView endpoint, size_t& id) {
-    const auto begin = std::make_reverse_iterator(endpoint.end());
-    const auto end = std::make_reverse_iterator(endpoint.begin());
-
-    auto next_slash = std::find(begin, end, '/');
-    if (next_slash == end) {
-        return false;
-    }
-
-    espurna::StringView tail { next_slash.base() + 1, endpoint.end() };
-    if ((*tail.begin()) == '\0') {
-        DEBUG_MSG_P(PSTR("[RELAY] relayID was not specified\n"));
-        return false;
-    }
-
-    return _relayTryParseId(tail, id);
+bool _relayTryParseIdFromPath(espurna::StringView value, size_t& id) {
+    return tryParseIdPath(value, relayCount(), id);
 }
 
 void _relayHandleStatus(size_t id, PayloadStatus status) {
@@ -2462,7 +2448,7 @@ bool _relayMqttHeartbeat(espurna::heartbeat::Mask mask) {
     return mqttConnected();
 }
 
-void _relayMqttHandleCustomTopic(const String& topic, espurna::StringView payload) {
+void _relayMqttHandleCustomTopic(espurna::StringView topic, espurna::StringView payload) {
     PathParts received(topic);
     for (auto& topic : _relay_custom_topics) {
         if (topic.match(received)) {
@@ -2487,10 +2473,8 @@ void _relayMqttHandleDisconnect() {
 
 } // namespace
 
-void relayMQTTCallback(unsigned int type, const char* topic, char* payload) {
-
+void relayMQTTCallback(unsigned int type, espurna::StringView topic, espurna::StringView payload) {
     static bool connected { false };
-
     if (!_relays.size()) {
         return;
     }
@@ -2504,7 +2488,7 @@ void relayMQTTCallback(unsigned int type, const char* topic, char* payload) {
     }
 
     if (type == MQTT_MESSAGE_EVENT) {
-        String t = mqttMagnitude(topic);
+        const auto t = mqttMagnitude(topic);
 
         auto is_relay = t.startsWith(MQTT_TOPIC_RELAY);
         auto is_pulse = t.startsWith(MQTT_TOPIC_PULSE);
@@ -2592,8 +2576,10 @@ static void _relayCommand(::terminal::CommandContext&& ctx) {
         return;
     }
 
+    ctx.output.println(id);
+
     if (ctx.argv.size() > 2) {
-        auto status = relayParsePayload(ctx.argv[2].c_str());
+        auto status = relayParsePayload(ctx.argv[2]);
         if (PayloadStatus::Unknown == status) {
             terminalError(ctx, F("Invalid status"));
             return;

code/espurna/relay_pulse.ipp

@@ -149,21 +149,19 @@ update_decimal:
     ++ptr;
 
     if (type != Type::Unknown) {
-        char* endp { nullptr };
-        uint32_t value = strtoul(token.c_str(), &endp, 10);
-
-        if (endp && (endp != token.c_str()) && endp[0] == '\0') {
+        const auto result = parseUnsigned(token, 10);
+        if (result.ok) {
             switch (type) {
             case Type::Hours: {
-                out += ::espurna::duration::Hours { value };
+                out += ::espurna::duration::Hours { result.value };
                 break;
             }
             case Type::Minutes: {
-                out += ::espurna::duration::Minutes { value };
+                out += ::espurna::duration::Minutes { result.value };
                 break;
             }
             case Type::Seconds: {
-                out += ::espurna::duration::Seconds { value };
+                out += ::espurna::duration::Seconds { result.value };
                 break;
             }
             case Type::Unknown:

code/espurna/rfbridge.cpp

@@ -351,24 +351,24 @@ String on(size_t id) {
     return getSetting({FPSTR(keys::On), id});
 }
 
-void store(const __FlashStringHelper* prefix, size_t id, const String& value) {
+void store(espurna::StringView prefix, size_t id, const String& value) {
     const espurna::settings::Key key(prefix, id);
     setSetting(key, value);
     DEBUG_MSG_P(PSTR("[RF] Saved %s => \"%s\"\n"), key.c_str(), value.c_str());
 }
 
 void off(size_t id, const String& value) {
-    store(FPSTR(keys::Off), id, value);
+    store(keys::Off, id, value);
 }
 
 void on(size_t id, const String& value) {
-    store(FPSTR(keys::On), id, value);
+    store(keys::On, id, value);
 }
 
 } // namespace settings
 } // namespace rfbridge
 
-void _rfbStore(size_t id, bool status, const String& code) {
+void _rfbStore(size_t id, bool status, String code) {
     if (status) {
         rfbridge::settings::on(id, code);
     } else {
@@ -494,20 +494,17 @@ bool _rfbCompare(const char* lhs, const char* rhs, size_t length) {
 // **always** expect full length code as input to simplify comparison
 // previous implementation tried to help MQTT / API requests to match based on the saved code,
 // thus requiring us to 'return' value from settings as the real code, replacing input
-RfbRelayMatch _rfbMatch(const char* code) {
+RfbRelayMatch _rfbMatch(espurna::StringView code) {
     RfbRelayMatch matched;
-
     if (!relayCount()) {
         return matched;
     }
 
-    const espurna::StringView codeView(code);
-
     // we gather all available options, as the kv store might be defined in any order
     // scan kvs only once, since we want both ON and OFF options and don't want to depend on the relayCount()
     espurna::settings::foreach_prefix(
-        [codeView, &matched](espurna::StringView prefix, String key, const espurna::settings::kvs_type::ReadResult& value) {
-            if (codeView.length() != value.length()) {
+        [code, &matched](espurna::StringView prefix, String key, const espurna::settings::kvs_type::ReadResult& value) {
+            if (code.length() != value.length()) {
                 return;
             }
 
@@ -520,7 +517,7 @@ RfbRelayMatch _rfbMatch(const char* code) {
                 return;
             }
 
-            if (!_rfbCompare(codeView.c_str(), value.read().c_str(), codeView.length())) {
+            if (!_rfbCompare(code.begin(), value.read().begin(), code.length())) {
                 return;
             }
 
@@ -550,11 +547,13 @@ RfbRelayMatch _rfbMatch(const char* code) {
     return matched;
 }
 
-void _rfbLearnFromString(std::unique_ptr<RfbLearn>& learn, const char* buffer) {
-    if (!learn) return;
+void _rfbLearnFromString(std::unique_ptr<RfbLearn>& learn, espurna::StringView buffer) {
+    if (!learn) {
+        return;
+    }
 
     DEBUG_MSG_P(PSTR("[RF] Learned relay ID %u after %u ms\n"), learn->id, millis() - learn->ts);
-    _rfbStore(learn->id, learn->status, buffer);
+    _rfbStore(learn->id, learn->status, buffer.toString());
 
     // Websocket update needs to happen right here, since the only time
     // we send these in bulk is at the very start of the connection
@@ -568,10 +567,10 @@ void _rfbLearnFromString(std::unique_ptr<RfbLearn>& learn, const char* buffer) {
     learn.reset(nullptr);
 }
 
-bool _rfbRelayHandler(const char* buffer, bool locked = false) {
+bool _rfbRelayHandler(espurna::StringView payload, bool locked = false) {
     bool result { false };
 
-    auto match = _rfbMatch(buffer);
+    const auto match = _rfbMatch(payload);
     if (match) {
         DEBUG_MSG_P(PSTR("[RF] Matched with the relay ID %u\n"), match.id());
         _rfb_relay_status_lock.set(match.id(), locked);
@@ -593,20 +592,24 @@ bool _rfbRelayHandler(const char* buffer, bool locked = false) {
     return result;
 }
 
-void _rfbLearnStartFromPayload(const char* payload) {
+void _rfbLearnStartFromPayload(espurna::StringView payload) {
     // The payload must be the `relayID,mode` (where mode is either 0 or 1)
-    const char* sep = strchr(payload, ',');
-    if (nullptr == sep) {
+    auto it = std::find(payload.begin(), payload.end(), ',');
+    if (it == payload.end()) {
         return;
     }
 
     // ref. RelaysMax, we only have up to 2 digits
+    if ((it + 1) == payload.end()) {
+        return;
+    }
+
     char relay[3] {0, 0, 0};
-    if ((sep - payload) > 2) {
+    if (std::distance(payload.begin(), it) > 2) {
         return;
     }
 
-    std::copy(payload, sep, relay);
+    std::copy(payload.begin(), it, relay);
 
     size_t id;
     if (!tryParseId(relay, relayCount, id)) {
@@ -614,13 +617,13 @@ void _rfbLearnStartFromPayload(const char* payload) {
         return;
     }
 
-    ++sep;
-    if ((*sep == '0') || (*sep == '1')) {
-        rfbLearn(id, (*sep != '0'));
+    ++it;
+    if ((*it == '0') || (*it == '1')) {
+        rfbLearn(id, (*it != '0'));
     }
 }
 
-void _rfbLearnFromReceived(std::unique_ptr<RfbLearn>& learn, const char* buffer) {
+void _rfbLearnFromReceived(std::unique_ptr<RfbLearn>& learn, espurna::StringView buffer) {
     if (millis() - learn->ts > RFB_LEARN_TIMEOUT) {
         DEBUG_MSG_P(PSTR("[RF] Learn timeout after %u ms\n"), millis() - learn->ts);
         learn.reset(nullptr);
@@ -643,9 +646,9 @@ void _rfbEnqueue(uint8_t (&code)[RfbParser::PayloadSizeBasic], unsigned char rep
     _rfb_message_queue.push_back(RfbMessage(code, repeats));
 }
 
-bool _rfbEnqueue(const char* code, size_t length, unsigned char repeats = 1u) {
+bool _rfbEnqueue(espurna::StringView code, unsigned char repeats = 1u) {
     uint8_t buffer[RfbParser::PayloadSizeBasic] { 0u };
-    if (hexDecode(code, length, buffer, sizeof(buffer))) {
+    if (hexDecode(code.begin(), code.length(), buffer, sizeof(buffer))) {
         _rfbEnqueue(buffer, repeats);
         return true;
     }
@@ -775,18 +778,29 @@ void _rfbReceiveImpl() {
 }
 
 // note that we don't care about queue here, just dump raw message as-is
-void _rfbSendRawFromPayload(const char * raw) {
-    auto rawlen = strlen(raw);
-    if (rawlen > (RfbParser::MessageSizeMax * 2)) return;
-    if ((rawlen < 6) || (rawlen & 1)) return;
+void _rfbSendRawFromPayload(espurna::StringView raw) {
+    if (raw.length() > (RfbParser::MessageSizeMax * 2)) {
+        return;
+    }
+
+    if ((raw.length() < 6) || (raw.length() & 1)) {
+        return;
+    }
 
-    DEBUG_MSG_P(PSTR("[RF] Sending RAW MESSAGE \"%s\"\n"), raw);
+    DEBUG_MSG_P(PSTR("[RF] Sending RAW MESSAGE \"%.*s\"\n"),
+            raw.length(), raw.begin());
 
     size_t bytes = 0;
     uint8_t message[RfbParser::MessageSizeMax] { 0u };
-    if ((bytes = hexDecode(raw, rawlen, message, sizeof(message)))) {
-        if (message[0] != CodeStart) return;
-        if (message[bytes - 1] != CodeEnd) return;
+    if ((bytes = hexDecode(raw.begin(), raw.length(), message, sizeof(message)))) {
+        if (message[0] != CodeStart) {
+            return;
+        }
+
+        if (message[bytes - 1] != CodeEnd) {
+            return;
+        }
+
         _rfbSendRaw(message, bytes);
     }
 }
@@ -836,9 +850,9 @@ void _rfbEnqueue(uint8_t protocol, uint16_t timing, uint8_t bits, RfbMessage::co
     _rfb_message_queue.push_back(RfbMessage{protocol, timing, bits, code, repeats});
 }
 
-void _rfbEnqueue(const char* message, size_t length, unsigned char repeats = 1u) {
+void _rfbEnqueue(espurna::StringView message, unsigned char repeats = 1u) {
     uint8_t buffer[RfbMessage::BufferSize] { 0u };
-    if (hexDecode(message, length, buffer, sizeof(buffer))) {
+    if (hexDecode(message.begin(), message.length(), buffer, sizeof(buffer))) {
         const auto bytes = _rfb_bytes_for_bits(buffer[4]);
 
         uint8_t raw_code[sizeof(RfbMessage::code_type)] { 0u };
@@ -997,52 +1011,49 @@ void _rfbSendQueued() {
 }
 
 // Check if the payload looks like a HEX code (plus comma, specifying the 'repeats' arg for the queue)
-void _rfbSendFromPayload(const char * payload) {
-    size_t len { strlen(payload) };
-    if (!len) {
+void _rfbSendFromPayload(espurna::StringView payload) {
+    if (!payload.length()) {
         return;
     }
 
     decltype(_rfb_repeats) repeats { _rfb_repeats };
 
-    const char* sep { strchr(payload, ',') };
-    if (sep) {
-        len -= strlen(sep);
-
-        sep += 1;
-        if ('\0' == *sep) return;
-        if ('-' == *sep) return;
+    auto it = std::find(payload.begin(), payload.end(), ',');
+    if (it != payload.end()) {
+        it += 1;
+        if ((it == payload.end()) || (*it == '\0') || (*it == '-')) {
+            return;
+        }
 
-        char *endptr = nullptr;
-        repeats = strtoul(sep, &endptr, 10);
-        if (endptr == payload || endptr[0] != '\0') {
+        const auto result = parseUnsigned(
+            espurna::StringView(it, payload.end()), 10);
+        if (!result.ok) {
             return;
         }
+
+        repeats = result.value;
     }
 
-    if (!len || (len & 1)) {
+    payload = espurna::StringView(it, payload.end());
+    if (!payload.length()) {
         return;
     }
 
-    DEBUG_MSG_P(PSTR("[RF] Enqueuing MESSAGE '%s' %u time(s)\n"), payload, repeats);
+    DEBUG_MSG_P(PSTR("[RF] Enqueuing MESSAGE '%.*s' %u time(s)\n"),
+            payload.length(), payload.begin(), repeats);
 
     // We postpone the actual sending until the loop, as we may've been called from MQTT or HTTP API
     // RFB_PROVIDER implementation should select the appropriate de-serialization function
-    _rfbEnqueue(payload, len, repeats);
+    _rfbEnqueue(payload, repeats);
 }
 
-void rfbSend(const char* code) {
+void rfbSend(espurna::StringView code) {
     _rfbSendFromPayload(code);
 }
 
-void rfbSend(const String& code) {
-    _rfbSendFromPayload(code.c_str());
-}
-
 #if MQTT_SUPPORT
 
-void _rfbMqttCallback(unsigned int type, const char* topic, char* payload) {
-
+void _rfbMqttCallback(unsigned int type, espurna::StringView topic, espurna::StringView payload) {
     if (type == MQTT_CONNECT_EVENT) {
 
 #if RELAY_SUPPORT
@@ -1060,8 +1071,7 @@ void _rfbMqttCallback(unsigned int type, const char* topic, char* payload) {
     }
 
     if (type == MQTT_MESSAGE_EVENT) {
-
-        String t = mqttMagnitude(topic);
+        auto t = mqttMagnitude(topic);
 
 #if RELAY_SUPPORT
         if (t.equals(MQTT_TOPIC_RFLEARN)) {
@@ -1138,7 +1148,7 @@ void _rfbApiSetup() {
     apiRegister(F(MQTT_TOPIC_RFRAW),
         apiOk, // just a stub, nothing to return
         [](ApiRequest& request) {
-            _rfbSendRawFromPayload(request.param(F("value")).c_str());
+            _rfbSendRawFromPayload(request.param(F("value")));
             return true;
         }
     );
@@ -1227,7 +1237,7 @@ static void _rfbCommandWrite(::terminal::CommandContext&& ctx) {
         terminalError(ctx, F("RFB.WRITE <PAYLOAD>"));
         return;
     }
-    _rfbSendRawFromPayload(ctx.argv[1].c_str());
+    _rfbSendRawFromPayload(ctx.argv[1]);
     terminalOK(ctx);
 }
 #endif

code/espurna/rpnrules.cpp

@@ -34,6 +34,7 @@ Copyright (C) 2019 by Xose Pérez <xose dot perez at gmail dot com>
 
 // -----------------------------------------------------------------------------
 
+namespace espurna {
 namespace rpnrules {
 namespace {
 
@@ -447,13 +448,37 @@ void subscribe() {
     }
 }
 
-void callback(unsigned int type, const char * topic, const char * payload) {
+rpn_value process_variable(espurna::StringView payload) {
+    auto tmp = std::make_unique<rpn_context>();
+
+    rpn_value out;
+    if (!rpn_process(*tmp, payload.begin())) {
+        return out;
+    }
+
+    if (rpn_stack_size(*tmp) != 1) {
+        return out;
+    }
+
+    out = rpn_stack_pop(*tmp);
+    return out;
+}
+
+void callback(unsigned int type, StringView topic, StringView payload) {
     if (type == MQTT_CONNECT_EVENT) {
         subscribe();
         return;
     }
 
     if (type == MQTT_MESSAGE_EVENT) {
+        if (!payload.length()) {
+            return;
+        }
+
+        if ((payload[0] == '&') || (payload[0] == '$')) {
+            return;
+        }
+
         size_t index { 0 };
         String rpnTopic;
 
@@ -464,20 +489,29 @@ void callback(unsigned int type, const char * topic, const char * payload) {
             }
 
             if (rpnTopic == topic) {
-                auto name = rpnrules::settings::name(index);
+                const auto name = rpnrules::settings::name(index);
                 if (!name.length()) {
                     break;
                 }
 
+                auto value = process_variable(payload);
+                if (value.isNull() || value.isError()) {
+                    return;
+                }
+
                 for (auto& variable : variables) {
                     if (variable.name == name) {
-                        variable.value = rpn_value{atof(payload)};
+                        variable.value = std::move(value);
                         return;
                     }
                 }
 
-                variables.emplace_front(Variable{
-                        std::move(name), rpn_value{atof(payload)}});
+                variables.emplace_front(
+                    Variable{
+                        .name = std::move(name),
+                        .value = std::move(value),
+                    });
+
                 return;
             }
         }
@@ -1340,9 +1374,10 @@ void setup() {
 
 } // namespace
 } // namespace rpnrules
+} // namespace espurna
 
 void rpnSetup() {
-    rpnrules::setup();
+    espurna::rpnrules::setup();
 }
 
 #endif // RPN_RULES_SUPPORT

code/espurna/scheduler.cpp

@@ -531,11 +531,15 @@ bool set(ApiRequest&, JsonObject& root) {
 
 namespace schedule {
 
+bool tryParseId(StringView value, size_t& out) {
+    return ::tryParseId(value, build::max(), out);
+}
+
 bool get(ApiRequest& req, JsonObject& root) {
     const auto param = req.wildcard(0);
 
     size_t id;
-    if (tryParseId(param, build::max, id)) {
+    if (tryParseId(param, id)) {
         print(root, settings::schedule(id));
         return true;
     }
@@ -547,7 +551,7 @@ bool set(ApiRequest& req, JsonObject& root) {
     const auto param = req.wildcard(0);
 
     size_t id;
-    if (tryParseId(param, build::max, id)) {
+    if (tryParseId(param, id)) {
         return api::set(root, id);
     }
 

code/espurna/sensor.cpp

@@ -2954,8 +2954,8 @@ ParseResult convert(StringView value) {
         return out;
     }
 
-    const auto begin = value.c_str();
-    const auto end = value.c_str() + value.length();
+    const auto begin = value.begin();
+    const auto end = value.end();
 
     String kwh_number;
 
@@ -2972,25 +2972,26 @@ ParseResult convert(StringView value) {
     KilowattHours::Type kwh { 0 };
     WattSeconds::Type ws { 0 };
 
-    char* endp { nullptr };
-    kwh = strtoul(kwh_number.c_str(), &endp, 10);
-    if (!endp || (endp == kwh_number.c_str())) {
+    const auto result = parseUnsigned(kwh_number, 10);
+    if (!result.ok) {
         return out;
     }
 
+    kwh = result.value;
+
     if ((it != end) && (*it == '+')) {
         ++it;
         if (it == end) {
             return out;
         }
 
-        String ws_number;
-        ws_number.concat(it, (end - it));
-
-        ws = strtoul(ws_number.c_str(), &endp, 10);
-        if (!endp || (endp == ws_number.c_str())) {
+        const auto result = parseUnsigned(
+                StringView(it, end), 10);
+        if (!result.ok) {
             return out;
         }
+
+        ws = result.value;
     }
 
     out = Energy {
@@ -3016,7 +3017,7 @@ void set(const Magnitude& magnitude, const Energy& energy) {
     }
 }
 
-void set(const Magnitude& magnitude, const String& payload) {
+void set(const Magnitude& magnitude, StringView payload) {
     if (!payload.length()) {
         return;
     }
@@ -3029,14 +3030,6 @@ void set(const Magnitude& magnitude, const String& payload) {
     set(magnitude, energy.value());
 }
 
-void set(const Magnitude& magnitude, const char* payload) {
-    if (!payload) {
-        return;
-    }
-
-    set(magnitude, String(payload));
-}
-
 Energy get(unsigned char index) {
     Energy result;
 
@@ -3547,28 +3540,16 @@ void setup() {
 } // namespace web
 #endif
 
-bool tryParseIndex(const char* p, unsigned char type, unsigned char& output) {
-    char* endp { nullptr };
-    const unsigned long result { strtoul(p, &endp, 10) };
-    if ((endp == p) || (*endp != '\0') || (result >= magnitude::count(type))) {
-        DEBUG_MSG_P(PSTR("[SENSOR] Invalid magnitude ID (%s)\n"), p);
-        return false;
-    }
-
-    output = result;
-    return true;
-}
-
 #if API_SUPPORT
 namespace api {
 namespace {
 
 template <typename T>
 bool tryHandle(ApiRequest& request, unsigned char type, T&& callback) {
-    unsigned char index { 0u };
+    size_t index = 0;
     if (request.wildcards()) {
-        auto index_param = request.wildcard(0);
-        if (!tryParseIndex(index_param.c_str(), type, index)) {
+        const auto param = request.wildcard(0);
+        if (!::tryParseId(param, magnitude::count(type), index)) {
             return false;
         }
     }
@@ -3634,7 +3615,7 @@ void setup() {
 namespace mqtt {
 namespace {
 
-void callback(unsigned int type, const char* topic, char* payload) {
+void callback(unsigned int type, StringView topic, StringView payload) {
     if (!magnitude::count(MAGNITUDE_ENERGY)) {
         return;
     }
@@ -3642,43 +3623,29 @@ void callback(unsigned int type, const char* topic, char* payload) {
     static const auto base = magnitude::topic(MAGNITUDE_ENERGY);
 
     switch (type) {
-
     case MQTT_MESSAGE_EVENT:
     {
-        String tail = mqttMagnitude(topic);
-        if (!tail.startsWith(base)) {
+        auto t = mqttMagnitude(topic);
+        if (!t.startsWith(base)) {
             break;
         }
 
-        for (auto ptr = tail.c_str(); ptr != tail.end(); ++ptr) {
-            if (*ptr != '/') {
-                continue;
-            }
-
-            ++ptr;
-            if (ptr == tail.end()) {
-                break;
-            }
-
-            unsigned char index;
-            if (!tryParseIndex(ptr, MAGNITUDE_ENERGY, index)) {
-                break;
-            }
+        size_t index;
+        if (!tryParseIdPath(t, magnitude::count(MAGNITUDE_ENERGY), index)) {
+            break;
+        }
 
-            const auto* magnitude = magnitude::find(MAGNITUDE_ENERGY, index);
-            if (magnitude) {
-                energy::set(*magnitude, static_cast<const char*>(payload));
-            }
+        const auto* magnitude = magnitude::find(MAGNITUDE_ENERGY, index);
+        if (magnitude) {
+            energy::set(*magnitude, payload.toString());
         }
 
         break;
     }
 
     case MQTT_CONNECT_EVENT:
-    {
         mqttSubscribe((base + F("/+")).c_str());
         break;
-    }
 
     }
 }

code/espurna/settings.cpp

@@ -244,7 +244,7 @@ bool convert(const String& value) {
 
 template <>
 uint32_t convert(const String& value) {
-    return parseUnsigned(value);
+    return parseUnsigned(value).value;
 }
 
 String serialize(uint32_t value, int base) {
@@ -526,7 +526,7 @@ void moveSettings(const String& from, const String& to) {
     for (size_t index = 0; index < 100; ++index) {
         const auto keys = SettingsKeyPair{
             .from = {from, index},
-            .to = {to, index}
+            .to = {to, index},
         };
 
         const auto result = espurna::settings::get(keys.from.value());
@@ -571,24 +571,23 @@ String getSetting(const String& key) {
 }
 
 String getSetting(const __FlashStringHelper* key) {
-    return getSetting(String(key));
+    return getSetting(espurna::settings::Key(key));
 }
 
 String getSetting(const char* key) {
-    return getSetting(String(key));
+    return getSetting(espurna::settings::Key(key));
 }
 
 String getSetting(const espurna::settings::Key& key) {
-    static const String defaultValue("");
-    return getSetting(key, defaultValue);
+    return getSetting(key, espurna::StringView(""));
 }
 
 String getSetting(const espurna::settings::Key& key, const char* defaultValue) {
-    return getSetting(key, String(defaultValue));
+    return getSetting(key, espurna::StringView(defaultValue));
 }
 
 String getSetting(const espurna::settings::Key& key, const __FlashStringHelper* defaultValue) {
-    return getSetting(key, String(defaultValue));
+    return getSetting(key, espurna::StringView(defaultValue));
 }
 
 String getSetting(const espurna::settings::Key& key, const String& defaultValue) {
@@ -601,21 +600,29 @@ String getSetting(const espurna::settings::Key& key, const String& defaultValue)
 }
 
 String getSetting(const espurna::settings::Key& key, String&& defaultValue) {
+    String out;
+
     auto result = espurna::settings::get(key.value());
     if (result) {
-        return std::move(result).get();
+        out = std::move(result).get();
+    } else {
+        out = std::move(defaultValue);
     }
 
-    return std::move(defaultValue);
+    return out;
 }
 
 String getSetting(const espurna::settings::Key& key, espurna::StringView defaultValue) {
+    String out;
+
     auto result = espurna::settings::get(key.value());
     if (result) {
-        return std::move(result).get();
+        out = std::move(result).get();
+    } else {
+        out = defaultValue.toString();
     }
 
-    return String(defaultValue);
+    return out;
 }
 
 bool delSetting(const String& key) {

code/espurna/settings_helpers.h

@@ -41,6 +41,10 @@ public:
         _key(std::move(key))
     {}
 
+    Key(StringView key) :
+        Key(key.toString())
+    {}
+
     Key(const String& prefix, size_t index) :
         _key(prefix)
     {
@@ -53,6 +57,10 @@ public:
         _key += index;
     }
 
+    Key(StringView key, size_t index) :
+        Key(key.toString(), index)
+    {}
+
     Key(const char* prefix, size_t index) :
         _key(prefix)
     {

code/espurna/telnet.cpp

@@ -45,6 +45,14 @@ namespace espurna {
 namespace telnet {
 namespace {
 
+constexpr bool isEspurnaMinimal() {
+#if defined(ESPURNA_MINIMAL_ARDUINO_OTA) || defined(ESPURNA_MINIMAL_WEBUI)
+    return true;
+#else
+    return false;
+#endif
+}
+
 namespace build {
 
 constexpr size_t ClientsMax { TELNET_MAX_CLIENTS };
@@ -929,7 +937,7 @@ void connect_url(String url) {
 }
 
 void setup() {
-    mqttRegister([](unsigned int type, const char* topic, const char* payload) {
+    mqttRegister([](unsigned int type, StringView topic, StringView payload) {
         switch (type) {
         case MQTT_CONNECT_EVENT:
             mqttSubscribe(MQTT_TOPIC_TELNET_REVERSE);
@@ -938,7 +946,7 @@ void setup() {
         case MQTT_MESSAGE_EVENT: {
             auto t = mqttMagnitude(topic);
             if (t.equals(MQTT_TOPIC_TELNET_REVERSE)) {
-                connect_url(payload);
+                connect_url(payload.toString());
             }
             break;
         }

code/espurna/terminal.cpp

@@ -459,19 +459,24 @@ void setup() {
 namespace mqtt {
 
 void setup() {
-    mqttRegister([](unsigned int type, const char* topic, char* payload) {
+    mqttRegister([](unsigned int type, StringView topic, StringView payload) {
         if (type == MQTT_CONNECT_EVENT) {
             mqttSubscribe(MQTT_TOPIC_CMD);
             return;
         }
 
         if (type == MQTT_MESSAGE_EVENT) {
-            String t = mqttMagnitude(topic);
-            if (!t.startsWith(MQTT_TOPIC_CMD)) return;
-            if (!strlen(payload)) return;
+            auto t = mqttMagnitude(topic);
+            if (!t.startsWith(MQTT_TOPIC_CMD)) {
+                return;
+            }
 
-            auto line = String(payload);
-            if (!line.endsWith("\r\n") && !line.endsWith("\n")) {
+            if (!payload.length()) {
+                return;
+            }
+
+            auto line = payload.toString();
+            if (!payload.endsWith("\r\n") && !payload.endsWith("\n")) {
                 line += '\n';
             }
 
@@ -481,14 +486,13 @@ void setup() {
             // TODO: or, at least, make it growable on-demand and cap at MSS?
             // TODO: PrintLine<...> instead of one giant blob?
 
-            auto cmd = std::make_shared<String>(std::move(line));
-
-            espurnaRegisterOnce([cmd]() {
+            auto ptr = std::make_shared<String>(std::move(line));
+            espurnaRegisterOnce([ptr]() {
                 PrintString out(TCP_MSS);
-                api_find_and_call(*cmd, out);
+                api_find_and_call(*ptr, out);
 
                 if (out.length()) {
-                    static const auto topic = mqttTopic(MQTT_TOPIC_CMD, false);
+                    static const auto topic = mqttTopic(MQTT_TOPIC_CMD);
                     mqttSendRaw(topic.c_str(), out.c_str(), false);
                 }
             });

code/espurna/terminal_parsing.h

@@ -80,7 +80,7 @@ struct LineBuffer {
         }
 
         return Result{
-            .line = StringView(nullptr),
+            .line = StringView(),
             .overflow = _overflow };
     }
 
@@ -164,7 +164,7 @@ struct LineView {
             }
         }
 
-        return StringView{nullptr};
+        return StringView();
     }
 
     explicit operator bool() const {

code/espurna/thermostat.cpp

@@ -176,7 +176,7 @@ bool _thermostatMqttHeartbeat(espurna::heartbeat::Mask mask) {
     return mqttConnected();
 }
 
-void thermostatMqttCallback(unsigned int type, const char* topic, char* payload) {
+void thermostatMqttCallback(unsigned int type, espurna::StringView topic, espurna::StringView payload) {
 
     if (type == MQTT_CONNECT_EVENT) {
       mqttSubscribeRaw(thermostat_remote_sensor_topic.c_str());
@@ -184,24 +184,22 @@ void thermostatMqttCallback(unsigned int type, const char* topic, char* payload)
     }
 
     if (type == MQTT_MESSAGE_EVENT) {
-
-        // Match topic
-        String t = mqttMagnitude(topic);
-
-        if (strcmp(topic, thermostat_remote_sensor_topic.c_str()) != 0
-         && !t.equals(MQTT_TOPIC_HOLD_TEMP))
+        auto t = mqttMagnitude(topic);
+        if ((topic != thermostat_remote_sensor_topic)
+            && !t.equals(MQTT_TOPIC_HOLD_TEMP))
+        {
            return;
+        }
 
-        // Parse JSON input
         DynamicJsonBuffer jsonBuffer;
-        JsonObject& root = jsonBuffer.parseObject(payload);
+        JsonObject& root = jsonBuffer.parseObject(payload.begin());
         if (!root.success()) {
             DEBUG_MSG_P(PSTR("[THERMOSTAT] Error parsing data\n"));
             return;
         }
 
-        // Check rempte sensor temperature
-        if (strcmp(topic, thermostat_remote_sensor_topic.c_str()) == 0) {
+        // Check remote sensor temperature
+        if (topic == thermostat_remote_sensor_topic) {
             if (root.containsKey(magnitudeTopic(MAGNITUDE_TEMPERATURE))) {
                 String remote_temp = root[magnitudeTopic(MAGNITUDE_TEMPERATURE)];
                 _remote_temp.temp = remote_temp.toFloat();

code/espurna/thingspeak.cpp

@@ -94,7 +94,7 @@ String apiKey() {
 }
 
 String address() {
-    return getSetting(FPSTR(keys::Address), FPSTR(build::ApiKey));
+    return getSetting(FPSTR(keys::Address), FPSTR(build::Address));
 }
 
 #if RELAY_SUPPORT
@@ -362,7 +362,7 @@ public:
     }
 
     bool send(const String& address, const String& data, Completion completion) {
-        _address = address;
+        _address = URL(address);
         return send(data, completion);
     }
 

code/espurna/types.cpp

@@ -116,11 +116,9 @@ bool StringView::equals(StringView other) const {
 
 bool StringView::equalsIgnoreCase(StringView other) const {
     if (other._len == _len) {
-        if (inFlash(_ptr) || inFlash(other._ptr)) {
-            if (_ptr == other._ptr) {
-                return true;
-            }
-
+        if (inFlash(_ptr) && inFlash(other._ptr) && (_ptr == other._ptr)) {
+            return true;
+        } else if (inFlash(_ptr) || inFlash(other._ptr)) {
             String copy;
             const char* ptr = _ptr;
             if (inFlash(_ptr)) {
@@ -137,4 +135,20 @@ bool StringView::equalsIgnoreCase(StringView other) const {
     return false;
 }
 
+bool StringView::startsWith(StringView other) const {
+    if (other._len <= _len) {
+        return StringView(begin(), begin() + other._len).equals(other);
+    }
+
+    return false;
+}
+
+bool StringView::endsWith(StringView other) const {
+    if (other._len <= _len) {
+        return StringView(end() - other._len, end()).equals(other);
+    }
+
+    return false;
+}
+
 } // namespace espurna

code/espurna/types.h

@@ -12,6 +12,8 @@ Copyright (C) 2019-2021 by Maxim Prokhorov <prokhorov dot max at outlook dot com
 
 #include <memory>
 
+#include "compat.h"
+
 // missing in our original header
 extern "C" int memcmp_P(const void*, const void*, size_t);
 
@@ -52,10 +54,7 @@ struct Callback {
     Callback& operator=(Callback&& other) noexcept;
 
     template <typename T>
-    using remove_cvref = typename std::remove_cv<std::remove_reference<T>>::type;
-
-    template <typename T>
-    using is_callback = std::is_same<remove_cvref<T>, Callback>;
+    using is_callback = std::is_same<std::remove_cvref<T>, Callback>;
 
     template <typename T>
     using is_type = std::is_same<T, Type>;
@@ -212,6 +211,8 @@ struct StringView {
     StringView() noexcept = default;
     ~StringView() = default;
 
+    StringView(std::nullptr_t) = delete;
+
     constexpr StringView(const StringView&) noexcept = default;
     constexpr StringView(StringView&&) noexcept = default;
 
@@ -246,11 +247,6 @@ struct StringView {
         _len(strlen_P(_ptr))
     {}
 
-    explicit constexpr StringView(std::nullptr_t) noexcept :
-        _ptr(nullptr),
-        _len(0)
-    {}
-
     StringView(const String& string) noexcept :
         StringView(string.c_str(), string.length())
     {}
@@ -301,6 +297,9 @@ struct StringView {
     bool equals(StringView) const;
     bool equalsIgnoreCase(StringView) const;
 
+    bool startsWith(StringView) const;
+    bool endsWith(StringView) const;
+
 private:
 #if defined(HOST_MOCK)
     constexpr static bool inFlash(const char*) {

code/espurna/uartmqtt.cpp

@@ -125,7 +125,7 @@ String serialize(Span bytes, bool encode) {
 // have time to send the previously buffered data.
 void send(String data) {
     mqttSendRaw(
-        mqttTopic(MQTT_TOPIC_UARTIN, false).c_str(),
+        mqttTopic(MQTT_TOPIC_UARTIN).c_str(),
         data.c_str(), false, 0);
 }
 
@@ -238,7 +238,7 @@ void write(Print& print, uint8_t termination, bool decode) {
 }
 
 
-void mqtt_callback(unsigned int type, const char* topic, const char* payload) {
+void mqtt_callback(unsigned int type, StringView topic, StringView payload) {
     static constexpr char Subscription[] = MQTT_TOPIC_UARTOUT;
 
     switch (type) {
@@ -248,7 +248,7 @@ void mqtt_callback(unsigned int type, const char* topic, const char* payload) {
     case MQTT_MESSAGE_EVENT:
         const auto t = mqttMagnitude(topic);
         if (t.equals(Subscription)) {
-            enqueue(payload);
+            enqueue(payload.toString());
         }
         break;
     }

code/espurna/utils.cpp

@@ -13,16 +13,127 @@ Copyright (C) 2017-2019 by Xose Pérez <xose dot perez at gmail dot com>
 #include <limits>
 #include <random>
 
-bool tryParseId(espurna::StringView value, TryParseIdFunc limit, size_t& out) {
-    static_assert(std::numeric_limits<size_t>::max() >= std::numeric_limits<unsigned long>::max(), "");
+// We can only return small values (max 'z' aka 122)
+static constexpr uint8_t InvalidByte { 255u };
 
-    char* endp { nullptr };
-    out = strtoul(value.begin(), &endp, 10); // TODO from_chars
-    if ((endp == value.begin()) || (*endp != '\0') || (out >= limit())) {
-        return false;
+static uint8_t bin_char2byte(char c) {
+    switch (c) {
+    case '0'...'1':
+        return (c - '0');
     }
 
-    return true;
+    return InvalidByte;
+}
+
+static uint8_t oct_char2byte(char c) {
+    switch (c) {
+    case '0'...'7':
+        return (c - '0');
+    }
+
+    return InvalidByte;
+}
+
+static uint8_t dec_char2byte(char c) {
+    switch (c) {
+    case '0'...'9':
+        return (c - '0');
+    }
+
+    return InvalidByte;
+}
+
+static uint8_t hex_char2byte(char c) {
+    switch (c) {
+    case '0'...'9':
+        return (c - '0');
+    case 'a'...'f':
+        return 10 + (c - 'a');
+    case 'A'...'F':
+        return 10 + (c - 'A');
+    }
+
+    return InvalidByte;
+}
+
+static ParseUnsignedResult parseUnsignedImpl(espurna::StringView value, int base) {
+    auto out = ParseUnsignedResult{
+        .ok = false,
+        .value = 0,
+    };
+
+    using Char2Byte = uint8_t(*)(char);
+    Char2Byte char2byte = nullptr;
+
+    switch (base) {
+    case 2:
+        char2byte = bin_char2byte;
+        break;
+    case 8:
+        char2byte = oct_char2byte;
+        break;
+    case 10:
+        char2byte = dec_char2byte;
+        break;
+    case 16:
+        char2byte = hex_char2byte;
+        break;
+    }
+
+    if (!char2byte) {
+        return out;
+    }
+
+    for (auto it = value.begin(); it != value.end(); ++it) {
+        const auto digit = char2byte(*it);
+        if (digit == InvalidByte) {
+            out.ok = false;
+            goto err;
+        }
+
+        const auto value = out.value;
+        out.value = (out.value * uint32_t(base)) + digit;
+        // TODO explicitly set the output bit width?
+        if (value > out.value) {
+            out.ok = false;
+            goto err;
+        }
+
+        out.ok = true;
+    }
+
+err:
+    return out;
+}
+
+bool tryParseId(espurna::StringView value, size_t limit, size_t& out) {
+    using T = std::remove_cvref<decltype(out)>::type;
+    static_assert(std::is_same<T, size_t>::value, "");
+
+    if (value.length()) {
+        const auto result = parseUnsignedImpl(value, 10);
+        if (result.ok && (result.value < limit)) {
+            out = result.value;
+            return true;
+        }
+    }
+
+    return false;
+}
+
+bool tryParseIdPath(espurna::StringView value, size_t limit, size_t& out) {
+    if (value.length()) {
+        const auto before_begin = value.begin() - 1;
+        for (auto it = value.end() - 1; it != before_begin; --it) {
+            if ((*it) == '/') {
+                return tryParseId(
+                    espurna::StringView(it + 1, value.end()),
+                    limit, out);
+            }
+        }
+    }
+
+    return false;
 }
 
 String prettyDuration(espurna::duration::Seconds seconds) {
@@ -187,37 +298,15 @@ char* strnstr(const char* buffer, const char* token, size_t n) {
   return nullptr;
 }
 
-namespace {
-
-uint32_t parseUnsignedImpl(const String& value, int base) {
-    const char* ptr { value.c_str() };
-    char* endp { nullptr };
-
-    // invalidate the whole string when invalid chars are detected
-    // while this does not return a 'result' type, we can't know
-    // whether 0 was the actual decoded number or not
-    const auto result = strtoul(ptr, &endp, base);
-    if (endp == ptr || endp[0] != '\0') {
-        return 0;
-    }
-
-    return result;
-}
-
-} // namespace
-
-uint32_t parseUnsigned(const String& value, int base) {
+ParseUnsignedResult parseUnsigned(espurna::StringView value, int base) {
     return parseUnsignedImpl(value, base);
 }
 
-uint32_t parseUnsigned(const String& value) {
-    if (!value.length()) {
-        return 0;
-    }
-
+ParseUnsignedResult parseUnsigned(espurna::StringView value) {
     int base = 10;
-    if (value.length() > 2) {
-        auto* ptr = value.c_str();
+
+    if (value.length() && (value.length() > 2)) {
+        const auto* ptr = value.begin();
         if (*ptr == '0') {
             switch (*(ptr + 1)) {
             case 'b':
@@ -231,9 +320,12 @@ uint32_t parseUnsigned(const String& value) {
                 break;
             }
         }
+
+        value = espurna::StringView(
+            value.begin() + 2, value.end());
     }
 
-    return parseUnsignedImpl((base == 10) ? value : value.substring(2), base);
+    return parseUnsignedImpl(value, base);
 }
 
 String formatUnsigned(uint32_t value, int base) {
@@ -322,34 +414,18 @@ size_t hexEncode(const uint8_t* in, size_t in_size, char* out, size_t out_size)
 
 // From an hexa char array ("A220EE...") to a byte array (half the size)
 uint8_t* hexDecode(const char* in_begin, const char* in_end, uint8_t* out_begin, uint8_t* out_end) {
-    // We can only return small values (max 'z' aka 122)
-    constexpr uint8_t InvalidByte { 255u };
-
-    auto char2byte = [](char ch) -> uint8_t {
-        switch (ch) {
-        case '0'...'9':
-            return (ch - '0');
-        case 'a'...'f':
-            return 10 + (ch - 'a');
-        case 'A'...'F':
-            return 10 + (ch - 'A');
-        }
-
-        return InvalidByte;
-    };
-
     constexpr uint8_t Shift { 4 };
 
     const char* in_ptr { in_begin };
     uint8_t* out_ptr { out_begin };
     while ((in_ptr != in_end) && (out_ptr != out_end)) {
-        uint8_t lhs = char2byte(*in_ptr);
+        uint8_t lhs = hex_char2byte(*in_ptr);
         if (lhs == InvalidByte) {
             break;
         }
         ++in_ptr;
 
-        uint8_t rhs = char2byte(*in_ptr);
+        uint8_t rhs = hex_char2byte(*in_ptr);
         if (rhs == InvalidByte) {
             break;
         }

code/espurna/utils.h

@@ -29,8 +29,13 @@ double roundTo(double num, unsigned char positions);
 bool almostEqual(double lhs, double rhs, int ulp);
 bool almostEqual(double lhs, double rhs);
 
-uint32_t parseUnsigned(const String&, int base);
-uint32_t parseUnsigned(const String&);
+struct ParseUnsignedResult {
+    bool ok;
+    uint32_t value;
+};
+
+ParseUnsignedResult parseUnsigned(espurna::StringView, int base);
+ParseUnsignedResult parseUnsigned(espurna::StringView);
 String formatUnsigned(uint32_t value, int base);
 
 char* hexEncode(const uint8_t* in_begin, const uint8_t* in_end, char* out_begin, char* out_end);
@@ -50,7 +55,7 @@ inline String hexEncode(uint8_t value) {
 uint8_t* hexDecode(const char* in_begin, const char* in_end, uint8_t* out_begin, uint8_t* out_end);
 size_t hexDecode(const char* in, size_t in_size, uint8_t* out, size_t out_size);
 
-using TryParseIdFunc = size_t(*)();
-bool tryParseId(espurna::StringView, TryParseIdFunc limit, size_t& out);
+bool tryParseId(espurna::StringView, size_t limit, size_t& out);
+bool tryParseIdPath(espurna::StringView, size_t limit, size_t& out);
 
 espurna::StringView stripNewline(espurna::StringView);

code/espurna/web_utils.h

@@ -48,6 +48,8 @@ struct StringTraits<::espurna::StringView, void> {
         return nullptr;
     }
 
+    // technically, we could've had append w/ strings only
+    // but, this also means append of char, which we could not do
     static const bool has_append = false;
     static const bool has_equals = true;
     static const bool should_duplicate = true;

code/test/unit/src/types/types.cpp

@@ -18,6 +18,17 @@ void test_view() {
         expected, view.begin(), view.length());
 }
 
+void test_view_nullptr() {
+    auto func = [](espurna::StringView view) {
+        TEST_ASSERT_EQUAL(0, view.length());
+        TEST_ASSERT_EQUAL(nullptr, view.begin());
+        TEST_ASSERT_EQUAL(nullptr, view.end());
+    };
+
+    static_assert(!std::is_convertible<std::nullptr_t, espurna::StringView>::value, "");
+    func(espurna::StringView());
+}
+
 void test_view_convert() {
     const String origin("12345");
     StringView view(origin);
@@ -40,6 +51,15 @@ void test_view_convert() {
     TEST_ASSERT(view.equals(copy_view));
 }
 
+void test_view_compare() {
+    StringView base("aaaa bbbb cccc dddd");
+
+    TEST_ASSERT(base.startsWith("aaaa"));
+    TEST_ASSERT(base.endsWith("dddd"));
+    TEST_ASSERT(base.equals("aaaa bbbb cccc dddd"));
+    TEST_ASSERT(base.equalsIgnoreCase("aaaa BBBB cccc DDDD"));
+}
+
 void test_callback_empty() {
     Callback callback;
     TEST_ASSERT(callback.isEmpty());
@@ -204,7 +224,9 @@ int main(int, char**) {
 
     using namespace espurna::test;
 	RUN_TEST(test_view);
+	RUN_TEST(test_view_nullptr);
 	RUN_TEST(test_view_convert);
+	RUN_TEST(test_view_compare);
 	RUN_TEST(test_callback_empty);
 	RUN_TEST(test_callback_simple);
 	RUN_TEST(test_callback_lambda);