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author | phajdan.jr@chromium.org <phajdan.jr@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98> | 2010-02-19 09:43:08 +0000 |
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committer | phajdan.jr@chromium.org <phajdan.jr@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98> | 2010-02-19 09:43:08 +0000 |
commit | 052313bd2f8ef1f994d65be5a5615bb2e9aa19f9 (patch) | |
tree | 883e79cee1112b90bd82890f6bffaf84688bb15f /chrome/common/important_file_writer.h | |
parent | f98f581eb3999563a71e8cf35c68420951c9f4e1 (diff) | |
download | chromium_src-052313bd2f8ef1f994d65be5a5615bb2e9aa19f9.zip chromium_src-052313bd2f8ef1f994d65be5a5615bb2e9aa19f9.tar.gz chromium_src-052313bd2f8ef1f994d65be5a5615bb2e9aa19f9.tar.bz2 |
Move pref_{member,service} and important_file_writer from chrome/common
to chrome/browser.
This is a part of an effort to remove bad dependency of chrome/common
on chrome/browser.
TEST=unit_tests and ui_tests, just moving code
BUG=none
Review URL: http://codereview.chromium.org/621004
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@39428 0039d316-1c4b-4281-b951-d872f2087c98
Diffstat (limited to 'chrome/common/important_file_writer.h')
-rw-r--r-- | chrome/common/important_file_writer.h | 104 |
1 files changed, 0 insertions, 104 deletions
diff --git a/chrome/common/important_file_writer.h b/chrome/common/important_file_writer.h deleted file mode 100644 index 4b70622..0000000 --- a/chrome/common/important_file_writer.h +++ /dev/null @@ -1,104 +0,0 @@ -// Copyright (c) 2009 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. - -#ifndef CHROME_COMMON_IMPORTANT_FILE_WRITER_H_ -#define CHROME_COMMON_IMPORTANT_FILE_WRITER_H_ - -#include <string> - -#include "base/basictypes.h" -#include "base/file_path.h" -#include "base/non_thread_safe.h" -#include "base/time.h" -#include "base/timer.h" - -namespace base { -class Thread; -} - -// Helper to ensure that a file won't be corrupted by the write (for example on -// application crash). Consider a naive way to save an important file F: -// -// 1. Open F for writing, truncating it. -// 2. Write new data to F. -// -// It's good when it works, but it gets very bad if step 2. doesn't complete. -// It can be caused by a crash, a computer hang, or a weird I/O error. And you -// end up with a broken file. -// -// To be safe, we don't start with writing directly to F. Instead, we write to -// to a temporary file. Only after that write is successful, we rename the -// temporary file to target filename. -// -// If you want to know more about this approach and ext3/ext4 fsync issues, see -// http://valhenson.livejournal.com/37921.html -class ImportantFileWriter : public NonThreadSafe { - public: - // Used by ScheduleSave to lazily provide the data to be saved. Allows us - // to also batch data serializations. - class DataSerializer { - public: - virtual ~DataSerializer() {} - - // Should put serialized string in |data| and return true on successful - // serialization. Will be called on the same thread on which - // ImportantFileWriter has been created. - virtual bool SerializeData(std::string* data) = 0; - }; - - // Initialize the writer. - // |path| is the name of file to write. - // All non-const methods, ctor and dtor must be called on the same thread. - explicit ImportantFileWriter(const FilePath& path); - - // You have to ensure that there are no pending writes at the moment - // of destruction. - ~ImportantFileWriter(); - - FilePath path() const { return path_; } - - // Returns true if there is a scheduled write pending which has not yet - // been started. - bool HasPendingWrite() const; - - // Save |data| to target filename. Does not block. If there is a pending write - // scheduled by ScheduleWrite, it is cancelled. - void WriteNow(const std::string& data); - - // Schedule a save to target filename. Data will be serialized and saved - // to disk after the commit interval. If another ScheduleWrite is issued - // before that, only one serialization and write to disk will happen, and - // the most recent |serializer| will be used. This operation does not block. - // |serializer| should remain valid through the lifetime of - // ImportantFileWriter. - void ScheduleWrite(DataSerializer* serializer); - - // Serialize data pending to be saved and execute write on backend thread. - void DoScheduledWrite(); - - base::TimeDelta commit_interval() const { - return commit_interval_; - } - - void set_commit_interval(const base::TimeDelta& interval) { - commit_interval_ = interval; - } - - private: - // Path being written to. - const FilePath path_; - - // Timer used to schedule commit after ScheduleWrite. - base::OneShotTimer<ImportantFileWriter> timer_; - - // Serializer which will provide the data to be saved. - DataSerializer* serializer_; - - // Time delta after which scheduled data will be written to disk. - base::TimeDelta commit_interval_; - - DISALLOW_COPY_AND_ASSIGN(ImportantFileWriter); -}; - -#endif // CHROME_COMMON_IMPORTANT_FILE_WRITER_H_ |