blob: f1dfc763c3ceee41076343a29636beb540e0c7c4 [file] [log] [blame]
// Copyright 2020 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <memory>
#include <string>
#include <vector>
#include "base/files/file_path.h"
#include "base/observer_list.h"
#include "base/observer_list_types.h"
#include "croslog/log_entry.h"
#include "croslog/log_entry_reader.h"
#include "croslog/log_parser.h"
namespace croslog {
// Read logs from multiple files with merging the lines.
class Multiplexer : public LogLineReader::Observer {
class Observer : public base::CheckedObserver {
virtual void OnLogFileChanged() = 0;
Multiplexer(const Multiplexer&) = delete;
Multiplexer& operator=(const Multiplexer&) = delete;
// Add a source log file to read.
void AddSource(base::FilePath log_file,
std::unique_ptr<LogParser> parser,
bool install_change_watcher);
// Start watching changes from the currently watched files.
void StartWatchingFileChange();
// Read the next line from log.
MaybeLogEntry Forward();
// Read the previous line from log.
MaybeLogEntry Backward();
// Set the position to read next.
void SetLinesFromLast(uint32_t pos);
// Add a observer to retrieve file change events.
void AddObserver(Observer* obs);
// Remove a observer to retrieve file change events.
void RemoveObserver(Observer* obs);
struct LogSource {
LogSource(base::FilePath log_file,
std::unique_ptr<LogParser> parser_in,
bool install_change_watcher);
LogEntryReader reader;
MaybeLogEntry cache_next_forward;
MaybeLogEntry cache_next_backward;
void OnFileChanged(LogLineReader* reader) override;
std::vector<std::unique_ptr<LogSource>> sources_;
base::ObserverList<Observer> observers_;
} // namespace croslog