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| 1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. | |
| 2 // Use of this source code is governed by a BSD-style license that can be | |
| 3 // found in the LICENSE file. | |
| 4 | |
| 5 #include "chrome/common/important_file_writer.h" | |
| 6 | |
| 7 #include <stdio.h> | |
| 8 | |
| 9 #include <string> | |
| 10 | |
| 11 #include "base/bind.h" | |
| 12 #include "base/file_path.h" | |
| 13 #include "base/file_util.h" | |
| 14 #include "base/logging.h" | |
| 15 #include "base/message_loop_proxy.h" | |
| 16 #include "base/metrics/histogram.h" | |
| 17 #include "base/string_number_conversions.h" | |
| 18 #include "base/threading/thread.h" | |
| 19 #include "base/time.h" | |
| 20 | |
| 21 using base::TimeDelta; | |
| 22 | |
| 23 namespace { | |
| 24 | |
| 25 const int kDefaultCommitIntervalMs = 10000; | |
| 26 | |
| 27 enum TempFileFailure { | |
| 28 FAILED_CREATING, | |
| 29 FAILED_OPENING, | |
| 30 FAILED_CLOSING, | |
| 31 FAILED_WRITING, | |
| 32 FAILED_RENAMING, | |
| 33 TEMP_FILE_FAILURE_MAX | |
| 34 }; | |
| 35 | |
| 36 void LogFailure(const FilePath& path, TempFileFailure failure_code, | |
| 37 const std::string& message) { | |
| 38 UMA_HISTOGRAM_ENUMERATION("ImportantFile.TempFileFailures", failure_code, | |
| 39 TEMP_FILE_FAILURE_MAX); | |
| 40 DPLOG(WARNING) << "temp file failure: " << path.value() | |
| 41 << " : " << message; | |
| 42 } | |
| 43 | |
| 44 void WriteToDiskTask(const FilePath& path, const std::string& data) { | |
| 45 // Write the data to a temp file then rename to avoid data loss if we crash | |
| 46 // while writing the file. Ensure that the temp file is on the same volume | |
| 47 // as target file, so it can be moved in one step, and that the temp file | |
| 48 // is securely created. | |
| 49 FilePath tmp_file_path; | |
| 50 if (!file_util::CreateTemporaryFileInDir(path.DirName(), &tmp_file_path)) { | |
| 51 LogFailure(path, FAILED_CREATING, "could not create temporary file"); | |
| 52 return; | |
| 53 } | |
| 54 | |
| 55 int flags = base::PLATFORM_FILE_OPEN | base::PLATFORM_FILE_WRITE; | |
| 56 base::PlatformFile tmp_file = | |
| 57 base::CreatePlatformFile(tmp_file_path, flags, NULL, NULL); | |
| 58 if (tmp_file == base::kInvalidPlatformFileValue) { | |
| 59 LogFailure(path, FAILED_OPENING, "could not open temporary file"); | |
| 60 return; | |
| 61 } | |
| 62 | |
| 63 // If this happens in the wild something really bad is going on. | |
| 64 CHECK_LE(data.length(), static_cast<size_t>(kint32max)); | |
| 65 int bytes_written = base::WritePlatformFile( | |
| 66 tmp_file, 0, data.data(), static_cast<int>(data.length())); | |
| 67 base::FlushPlatformFile(tmp_file); // Ignore return value. | |
| 68 | |
| 69 if (!base::ClosePlatformFile(tmp_file)) { | |
| 70 LogFailure(path, FAILED_CLOSING, "failed to close temporary file"); | |
| 71 file_util::Delete(tmp_file_path, false); | |
| 72 return; | |
| 73 } | |
| 74 | |
| 75 if (bytes_written < static_cast<int>(data.length())) { | |
| 76 LogFailure(path, FAILED_WRITING, "error writing, bytes_written=" + | |
| 77 base::IntToString(bytes_written)); | |
| 78 file_util::Delete(tmp_file_path, false); | |
| 79 return; | |
| 80 } | |
| 81 | |
| 82 if (!file_util::ReplaceFile(tmp_file_path, path)) { | |
| 83 LogFailure(path, FAILED_RENAMING, "could not rename temporary file"); | |
| 84 file_util::Delete(tmp_file_path, false); | |
| 85 return; | |
| 86 } | |
| 87 } | |
| 88 | |
| 89 } // namespace | |
| 90 | |
| 91 ImportantFileWriter::ImportantFileWriter( | |
| 92 const FilePath& path, base::MessageLoopProxy* file_message_loop_proxy) | |
| 93 : path_(path), | |
| 94 file_message_loop_proxy_(file_message_loop_proxy), | |
| 95 serializer_(NULL), | |
| 96 commit_interval_(TimeDelta::FromMilliseconds( | |
| 97 kDefaultCommitIntervalMs)) { | |
| 98 DCHECK(CalledOnValidThread()); | |
| 99 DCHECK(file_message_loop_proxy_.get()); | |
| 100 } | |
| 101 | |
| 102 ImportantFileWriter::~ImportantFileWriter() { | |
| 103 // We're usually a member variable of some other object, which also tends | |
| 104 // to be our serializer. It may not be safe to call back to the parent object | |
| 105 // being destructed. | |
| 106 DCHECK(!HasPendingWrite()); | |
| 107 } | |
| 108 | |
| 109 bool ImportantFileWriter::HasPendingWrite() const { | |
| 110 DCHECK(CalledOnValidThread()); | |
| 111 return timer_.IsRunning(); | |
| 112 } | |
| 113 | |
| 114 void ImportantFileWriter::WriteNow(const std::string& data) { | |
| 115 DCHECK(CalledOnValidThread()); | |
| 116 if (data.length() > static_cast<size_t>(kint32max)) { | |
| 117 NOTREACHED(); | |
| 118 return; | |
| 119 } | |
| 120 | |
| 121 if (HasPendingWrite()) | |
| 122 timer_.Stop(); | |
| 123 | |
| 124 if (!file_message_loop_proxy_->PostTask( | |
| 125 FROM_HERE, base::Bind(&WriteToDiskTask, path_, data))) { | |
| 126 // Posting the task to background message loop is not expected | |
| 127 // to fail, but if it does, avoid losing data and just hit the disk | |
| 128 // on the current thread. | |
| 129 NOTREACHED(); | |
| 130 | |
| 131 WriteToDiskTask(path_, data); | |
| 132 } | |
| 133 } | |
| 134 | |
| 135 void ImportantFileWriter::ScheduleWrite(DataSerializer* serializer) { | |
| 136 DCHECK(CalledOnValidThread()); | |
| 137 | |
| 138 DCHECK(serializer); | |
| 139 serializer_ = serializer; | |
| 140 | |
| 141 if (!timer_.IsRunning()) { | |
| 142 timer_.Start(FROM_HERE, commit_interval_, this, | |
| 143 &ImportantFileWriter::DoScheduledWrite); | |
| 144 } | |
| 145 } | |
| 146 | |
| 147 void ImportantFileWriter::DoScheduledWrite() { | |
| 148 DCHECK(serializer_); | |
| 149 std::string data; | |
| 150 if (serializer_->SerializeData(&data)) { | |
| 151 WriteNow(data); | |
| 152 } else { | |
| 153 DLOG(WARNING) << "failed to serialize data to be saved in " | |
| 154 << path_.value(); | |
| 155 } | |
| 156 serializer_ = NULL; | |
| 157 } | |
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Chromium Code Reviews
Issue 11227026:
Move ImportantFileWriter to base/. It now has two consumers, base/prefs and chrome/. (Closed)
Base URL: svn://svn.chromium.org/chrome/trunk/src