text: // Copyright 2014 The Chromium 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 "chrome/browser/media/webrtc_log_util.h"
  
  #include "base/file_util.h"
  #include "base/files/file_enumerator.h"
  #include "base/logging.h"
  #include "base/time/time.h"
  #include "chrome/browser/browser_process.h"
  #include "chrome/browser/media/webrtc_log_list.h"
  #include "chrome/browser/profiles/profile.h"
  #include "chrome/browser/profiles/profile_manager.h"
  #include "content/public/browser/browser_thread.h"
  
  namespace {
  
  const int kDaysToKeepLogs = 5;
  
  // Remove any empty entries from the log list. One line is one log entry, see
  // WebRtcLogUploader::AddLocallyStoredLogInfoToUploadListFile for more
  // information about the format.
  void RemoveEmptyEntriesInLogList(std::string* log_list) {
    static const char kEmptyLine[] = ",,\n";
    size_t pos = 0;
    do {
      pos = log_list->find(kEmptyLine, pos);
      if (pos == std::string::npos)
        break;
      DCHECK(pos == 0 || (*log_list)[pos - 1] == '\n');
      log_list->erase(pos, arraysize(kEmptyLine) - 1);
    } while (true);
  }
  
  }  // namespace
  
  // static
  void WebRtcLogUtil::DeleteOldWebRtcLogFiles(const base::FilePath& log_dir) {
    DeleteOldAndRecentWebRtcLogFiles(log_dir, base::Time::Max());
  }
  
  // static
  void WebRtcLogUtil::DeleteOldAndRecentWebRtcLogFiles(
      const base::FilePath& log_dir,
      const base::Time& delete_begin_time) {
    DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::FILE));
  
    if (!base::PathExists(log_dir)) {
      // This will happen if no logs have been stored or uploaded.
      DVLOG(3) << "Could not find directory: " << log_dir.value();
      return;
    }
  
    const base::Time now = base::Time::Now();
    const base::TimeDelta time_to_keep_logs =
        base::TimeDelta::FromDays(kDaysToKeepLogs);
  
    base::FilePath log_list_path =
        WebRtcLogList::GetWebRtcLogListFileForDirectory(log_dir);
    std::string log_list;
    const bool update_log_list = base::PathExists(log_list_path);
    if (update_log_list) {
      bool read_ok = base::ReadFileToString(log_list_path, &log_list);
      DPCHECK(read_ok);
    }
  
    base::FileEnumerator log_files(log_dir, false, base::FileEnumerator::FILES);
    bool delete_ok = true;
    for (base::FilePath name = log_files.Next(); !name.empty();
         name = log_files.Next()) {
      if (name == log_list_path)
        continue;
      base::FileEnumerator::FileInfo file_info(log_files.GetInfo());
      base::TimeDelta file_age = now - file_info.GetLastModifiedTime();
      if (file_age > time_to_keep_logs ||
          (!delete_begin_time.is_max() &&
           file_info.GetLastModifiedTime() > delete_begin_time)) {
        if (!base::DeleteFile(name, false))
          delete_ok = false;
  
        // Remove the local ID from the log list file. The ID is guaranteed to be
        // unique.
        std::string id = file_info.GetName().RemoveExtension().MaybeAsASCII();
        size_t id_pos = log_list.find(id);
        if (id_pos == std::string::npos)
          continue;
        log_list.erase(id_pos, id.size());
      }
    }
  
    if (!delete_ok)
      LOG(WARNING) << "Could not delete all old WebRTC logs.";
  
    RemoveEmptyEntriesInLogList(&log_list);
  
    if (update_log_list) {
      int written = base::WriteFile(log_list_path, &log_list[0], log_list.size());
      DPCHECK(written == static_cast<int>(log_list.size()));
    }
  }
  
  // static
  void WebRtcLogUtil::DeleteOldWebRtcLogFilesForAllProfiles() {
    DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
  
    ProfileInfoCache& profile_cache =
        g_browser_process->profile_manager()->GetProfileInfoCache();
    size_t profiles_count = profile_cache.GetNumberOfProfiles();
    for (size_t i = 0; i < profiles_count; ++i) {
      content::BrowserThread::PostTask(
          content::BrowserThread::FILE,
          FROM_HERE,
          base::Bind(&DeleteOldWebRtcLogFiles,
                     WebRtcLogList::GetWebRtcLogDirectoryForProfile(
                         profile_cache.GetPathOfProfileAtIndex(i))));
    }
  }
  