Implement pipeline logging with bounded channels and orchestrator integration

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

@@ -0,0 +1,37 @@
+/**
+ * @file services/logging/channel_logger.h
+ * @brief Channel-backed implementation of the Logger interface.
+ *
+ * ChannelLogger constructs LogEntry values and forwards them to a
+ * BoundedChannel<LogEntry> for asynchronous consumption by LogConsumer.
+ * The channel is injected by reference; ChannelLogger does not own it.
+ */
+
+#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 final : public ILogger {
+ public:
+  explicit ChannelLogger(BoundedChannel<LogEntry>& channel);
+
+  ChannelLogger(const ChannelLogger&) = delete;
+  ChannelLogger& operator=(const ChannelLogger&) = delete;
+  ChannelLogger(ChannelLogger&&) = delete;
+  ChannelLogger& operator=(ChannelLogger&&) = delete;
+
+  ~ChannelLogger() override = default;
+
+  void Log(LogLevel level, PipelinePhase phase,
+           std::string_view message) override;
+
+ private:
+  BoundedChannel<LogEntry>& channel_;
+};
+
+#endif  // BIERGARTEN_PIPELINE_INCLUDES_SERVICES_LOGGING_CHANNEL_LOGGER_H_

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

@@ -0,0 +1,44 @@
+/**
+ * @file services/logging/log_consumer.h
+ * @brief Dedicated log drain worker for the pipeline logging channel.
+ *
+ * LogConsumer runs on its own thread, draining LogEntry items from a
+ * BoundedChannel<LogEntry> and forwarding them to spdlog. Exits cleanly
+ * when the channel is closed.
+ */
+
+#ifndef BIERGARTEN_PIPELINE_INCLUDES_SERVICES_LOGGING_LOG_CONSUMER_H_
+#define BIERGARTEN_PIPELINE_INCLUDES_SERVICES_LOGGING_LOG_CONSUMER_H_
+
+#include <spdlog/spdlog.h>
+
+#include <string>
+
+#include "concurrency/bounded_channel.h"
+#include "services/logging/log_entry.h"
+
+class LogConsumer {
+ public:
+  explicit LogConsumer(BoundedChannel<LogEntry>& channel);
+
+  LogConsumer(const LogConsumer&) = delete;
+  LogConsumer& operator=(const LogConsumer&) = delete;
+  LogConsumer(LogConsumer&&) = delete;
+  LogConsumer& operator=(LogConsumer&&) = delete;
+
+  /**
+   * @brief Drains the channel until it is closed.
+   *
+   * Intended to be run on a dedicated std::thread. Exits when:
+   *   - The channel is closed and the queue is fully drained.
+   */
+  void Run();
+
+ private:
+  BoundedChannel<LogEntry>& channel_;
+
+  static spdlog::level::level_enum ToSpdlogLevel(LogLevel level);
+  static std::string ToString(PipelinePhase phase);
+};
+
+#endif  // BIERGARTEN_PIPELINE_INCLUDES_SERVICES_LOGGING_LOG_CONSUMER_H_

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

@@ -0,0 +1,41 @@
+/**
+ * @file services/logging/log_entry.h
+ * @brief POD struct representing a single log event in the pipeline.
+ *
+ * LogEntry is produced by PipelineLogger and consumed by LogWorker via
+ * BoundedChannel<LogEntry>. All fields are value types so entries are
+ * safely movable across the channel without shared ownership.
+ */
+
+#ifndef BIERGARTEN_PIPELINE_INCLUDES_SERVICES_LOGGING_LOG_ENTRY_H_
+#define BIERGARTEN_PIPELINE_INCLUDES_SERVICES_LOGGING_LOG_ENTRY_H_
+
+#include <chrono>
+#include <string>
+
+enum class LogLevel {
+  Debug,
+  Info,
+  Warn,
+  Error,
+};
+
+enum class PipelinePhase {
+  Startup,
+  UserGeneration,
+  BreweryAndBeerGeneration,
+  CheckinGeneration,
+  RatingGeneration,
+  FollowGeneration,
+  Teardown,
+};
+
+struct LogEntry {
+  std::chrono::system_clock::time_point timestamp =
+      std::chrono::system_clock::now();
+  LogLevel level;
+  PipelinePhase phase;
+  std::string message;
+};
+
+#endif  // BIERGARTEN_PIPELINE_INCLUDES_SERVICES_LOGGING_LOG_ENTRY_H_

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

@@ -0,0 +1,31 @@
+/**
+ * @file services/logging/logger.h
+ * @brief Abstract interface for pipeline logging.
+ *
+ * Kept intentionally narrow. Components that need to log depend on Logger,
+ * not on PipelineLogger or any channel type.
+ */
+
+#ifndef BIERGARTEN_PIPELINE_INCLUDES_SERVICES_LOGGING_LOGGER_H_
+#define BIERGARTEN_PIPELINE_INCLUDES_SERVICES_LOGGING_LOGGER_H_
+
+#include <optional>
+#include <string>
+#include <string_view>
+
+#include "services/logging/log_entry.h"
+
+class ILogger {
+ public:
+  ILogger() = default;
+  ILogger(const ILogger&) = delete;
+  ILogger& operator=(const ILogger&) = delete;
+  ILogger(ILogger&&) = delete;
+  ILogger& operator=(ILogger&&) = delete;
+  virtual ~ILogger() = default;
+
+  virtual void Log(LogLevel level, PipelinePhase phase,
+                   std::string_view message) = 0;
+};
+
+#endif  // BIERGARTEN_PIPELINE_INCLUDES_SERVICES_LOGGING_LOGGER_H_