Implement BoundedChannel and multithreaded logging infra

tooling/pipeline/includes/services/logging/channel_logger.h

@@ -0,0 +1,54 @@
+/**
+ * @file services/logging/channel_logger.h
+ * @brief Channel-backed producer for asynchronous pipeline logging.
+ *
+ * Intent: Decouple logging from synchronous I/O by forwarding entries to a
+ * bounded channel. LogConsumer drains the channel on a dedicated thread.
+ */
+
+#ifndef BIERGARTEN_PIPELINE_INCLUDES_SERVICES_LOGGING_CHANNEL_LOGGER_H_
+#define BIERGARTEN_PIPELINE_INCLUDES_SERVICES_LOGGING_CHANNEL_LOGGER_H_
+
+#include <string_view>
+
+#include "concurrency/bounded_channel.h"
+#include "services/logging/log_entry.h"
+#include "services/logging/logger.h"
+
+/**
+ * @class ChannelLogger
+ * @brief ILogger implementation that sends entries to a BoundedChannel.
+ *
+ * Non-copyable, non-movable. Holds a non-owning reference to the channel.
+ */
+class ChannelLogger final : public ILogger {
+ public:
+   /**
+    * @brief Construct a channel-backed logger.
+    *
+    * @param channel Reference to bounded channel for log entry transfer.
+    *                Channel must outlive this logger instance.
+    */
+   explicit ChannelLogger(BoundedChannel<LogEntry>& channel);
+
+   ChannelLogger(const ChannelLogger&) = delete;
+   ChannelLogger& operator=(const ChannelLogger&) = delete;
+   ChannelLogger(ChannelLogger&&) = delete;
+   ChannelLogger& operator=(ChannelLogger&&) = delete;
+
+   ~ChannelLogger() override = default;
+
+   /**
+    * @brief Queue a log entry for asynchronous processing.
+    *
+    * Blocks if the channel is full (backpressure). Returns immediately
+    * if the channel is closed.
+    */
+   void Log(LogLevel level, PipelinePhase phase,
+            std::string_view message) override;
+
+ private:
+   BoundedChannel<LogEntry>& channel_;
+};
+
+#endif  // BIERGARTEN_PIPELINE_INCLUDES_SERVICES_LOGGING_CHANNEL_LOGGER_H_