log to webui - initial version

src/web/WebLogService.h

@@ -0,0 +1,74 @@
+/*
+ * EMS-ESP - https://github.com/emsesp/EMS-ESP
+ * Copyright 2020  Paul Derbyshire
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef WebLogService_h
+#define WebLogService_h
+
+#include <ArduinoJson.h>
+#include <AsyncJson.h>
+#include <ESPAsyncWebServer.h>
+#include <SecurityManager.h>
+
+#include <uuid/log.h>
+
+#define EVENT_SOURCE_LOG_PATH "/es/log"
+
+namespace emsesp {
+
+class WebLogService : public uuid::log::Handler {
+  public:
+    static constexpr size_t MAX_LOG_MESSAGES = 50;
+
+    WebLogService(AsyncWebServer * server, SecurityManager * securityManager);
+
+    void             start();
+    uuid::log::Level log_level() const;
+    void             log_level(uuid::log::Level level);
+    size_t           maximum_log_messages() const;
+    void             maximum_log_messages(size_t count);
+    void             loop();
+
+    virtual void operator<<(std::shared_ptr<uuid::log::Message> message);
+
+  private:
+    AsyncEventSource _events;
+
+    class QueuedLogMessage {
+      public:
+        QueuedLogMessage(unsigned long id, std::shared_ptr<uuid::log::Message> && content);
+        ~QueuedLogMessage() = default;
+
+        unsigned long                                   id_;      // Sequential identifier for this log message
+        struct timeval                                  time_;    // Time message was received
+        const std::shared_ptr<const uuid::log::Message> content_; // Log message content
+    };
+
+    void forbidden(AsyncWebServerRequest * request);
+    void remove_queued_messages(uuid::log::Level level);
+    bool can_transmit();
+    void transmit(const QueuedLogMessage & message);
+
+    uint64_t                    last_transmit_        = 0;                // Last transmit time
+    size_t                      maximum_log_messages_ = MAX_LOG_MESSAGES; // Maximum number of log messages to buffer before they are output
+    unsigned long               log_message_id_       = 0;                // The next identifier to use for queued log messages
+    std::list<QueuedLogMessage> log_messages_;                            // Queued log messages, in the order they were received
+};
+
+} // namespace emsesp
+
+#endif