Add Webserial (#444)

* Webserial

* Webserial

lib/MycilaWebSerial/src/MycilaWebSerial.h

@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright (C) 2023-2024 Mathieu Carbou
+ */
+#pragma once
+
+#if defined(ESP8266)
+#include "ESP8266WiFi.h"
+#elif defined(ESP32)
+#include "WiFi.h"
+#endif
+
+#include <Arduino.h>
+#include <ESPAsyncWebServer.h>
+#include <functional>
+
+#define WSL_VERSION          "6.3.0"
+#define WSL_VERSION_MAJOR    6
+#define WSL_VERSION_MINOR    3
+#define WSL_VERSION_REVISION 0
+
+#ifndef WSL_MAX_WS_CLIENTS
+#define WSL_MAX_WS_CLIENTS DEFAULT_MAX_WS_CLIENTS
+#endif
+
+// High performance mode:
+// - Low memory footprint (no stack allocation, no global buffer by default)
+// - Low latency (messages sent immediately to the WebSocket queue)
+// - High throughput (up to 20 messages per second, no locking mechanism)
+// Also recommended to tweak AsyncTCP and ESPAsyncWebServer settings, for example:
+//  -D CONFIG_ASYNC_TCP_QUEUE_SIZE=128  // AsyncTCP queue size
+//  -D CONFIG_ASYNC_TCP_RUNNING_CORE=1  // core for the async_task
+//  -D WS_MAX_QUEUED_MESSAGES=128       // WS message queue size
+
+typedef std::function<void(uint8_t* data, size_t len)> WSLMessageHandler;
+typedef std::function<void(const String& msg)> WSLStringMessageHandler;
+
+class WebSerialClass : public Print {
+  public:
+    void begin(AsyncWebServer* server, const char* url = "/webserial");
+    inline void setAuthentication(const char* username, const char* password) { setAuthentication(String(username), String(password)); }
+    void setAuthentication(const String& username, const String& password);
+    void onMessage(WSLMessageHandler recv);
+    void onMessage(WSLStringMessageHandler recv);
+    size_t write(uint8_t) override;
+    size_t write(const uint8_t* buffer, size_t size) override;
+
+    // A buffer (shared across cores) can be initialised with an initial capacity to be able to use any Print functions event those that are not buffered and would
+    // create a performance impact for WS calls. The goal of this buffer is to be used with lines ending with '\n', like log messages.
+    // The buffer size will eventually grow until a '\n' is found, then the message will be sent to the WS clients and a new buffer will be created.
+    // Set initialCapacity to 0 to disable buffering.
+    // Must be called before begin(): calling it after will erase the buffer and its content will be lost.
+    // The buffer is not enabled by default.
+    void setBuffer(size_t initialCapacity);
+
+  private:
+    // Server
+    AsyncWebServer* _server;
+    AsyncWebSocket* _ws;
+    WSLMessageHandler _recv = nullptr;
+    WSLStringMessageHandler _recvString = nullptr;
+    bool _authenticate = false;
+    String _username;
+    String _password;
+    size_t _initialBufferCapacity = 0;
+    String _buffer;
+    void _send(const uint8_t* buffer, size_t size);
+};
+
+extern WebSerialClass WebSerial;