| Index: base/files/important_file_writer.h
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| diff --git a/base/files/important_file_writer.h b/base/files/important_file_writer.h
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| deleted file mode 100644
|
| index 99f1a7c6814753ec9b1d63a85930399eddb0eeab..0000000000000000000000000000000000000000
|
| --- a/base/files/important_file_writer.h
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| +++ /dev/null
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| @@ -1,140 +0,0 @@
|
| -// Copyright (c) 2012 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 BASE_FILES_IMPORTANT_FILE_WRITER_H_
|
| -#define BASE_FILES_IMPORTANT_FILE_WRITER_H_
|
| -
|
| -#include <string>
|
| -
|
| -#include "base/base_export.h"
|
| -#include "base/basictypes.h"
|
| -#include "base/callback.h"
|
| -#include "base/files/file_path.h"
|
| -#include "base/memory/ref_counted.h"
|
| -#include "base/threading/non_thread_safe.h"
|
| -#include "base/time/time.h"
|
| -#include "base/timer/timer.h"
|
| -
|
| -namespace base {
|
| -
|
| -class SequencedTaskRunner;
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| -class Thread;
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| -
|
| -// 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:
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| -//
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| -// 1. Open F for writing, truncating it.
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| -// 2. Write new data to F.
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| -//
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| -// It's good when it works, but it gets very bad if step 2. doesn't complete.
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| -// It can be caused by a crash, a computer hang, or a weird I/O error. And you
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| -// end up with a broken file.
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| -//
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| -// To be safe, we don't start with writing directly to F. Instead, we write to
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| -// to a temporary file. Only after that write is successful, we rename the
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| -// temporary file to target filename.
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| -//
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| -// If you want to know more about this approach and ext3/ext4 fsync issues, see
|
| -// http://valhenson.livejournal.com/37921.html
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| -class BASE_EXPORT ImportantFileWriter : public NonThreadSafe {
|
| - public:
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| - // Used by ScheduleSave to lazily provide the data to be saved. Allows us
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| - // to also batch data serializations.
|
| - class BASE_EXPORT DataSerializer {
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| - public:
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| - // Should put serialized string in |data| and return true on successful
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| - // serialization. Will be called on the same thread on which
|
| - // ImportantFileWriter has been created.
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| - virtual bool SerializeData(std::string* data) = 0;
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| -
|
| - protected:
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| - virtual ~DataSerializer() {}
|
| - };
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| -
|
| - // Save |data| to |path| in an atomic manner (see the class comment above).
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| - // Blocks and writes data on the current thread.
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| - static bool WriteFileAtomically(const FilePath& path,
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| - const std::string& data);
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| -
|
| - // Initialize the writer.
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| - // |path| is the name of file to write.
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| - // |task_runner| is the SequencedTaskRunner instance where on which we will
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| - // execute file I/O operations.
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| - // All non-const methods, ctor and dtor must be called on the same thread.
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| - ImportantFileWriter(
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| - const FilePath& path,
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| - const scoped_refptr<base::SequencedTaskRunner>& task_runner);
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| -
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| - // You have to ensure that there are no pending writes at the moment
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| - // of destruction.
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| - ~ImportantFileWriter();
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| -
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| - const FilePath& path() const { return path_; }
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| -
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| - // Returns true if there is a scheduled write pending which has not yet
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| - // been started.
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| - bool HasPendingWrite() const;
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| -
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| - // Save |data| to target filename. Does not block. If there is a pending write
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| - // scheduled by ScheduleWrite, it is cancelled.
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| - void WriteNow(scoped_ptr<std::string> data);
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| -
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| - // Schedule a save to target filename. Data will be serialized and saved
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| - // to disk after the commit interval. If another ScheduleWrite is issued
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| - // before that, only one serialization and write to disk will happen, and
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| - // the most recent |serializer| will be used. This operation does not block.
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| - // |serializer| should remain valid through the lifetime of
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| - // ImportantFileWriter.
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| - void ScheduleWrite(DataSerializer* serializer);
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| -
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| - // Serialize data pending to be saved and execute write on backend thread.
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| - void DoScheduledWrite();
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| -
|
| - // Registers |on_next_successful_write| to be called once, on the next
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| - // successful write event. Only one callback can be set at once.
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| - void RegisterOnNextSuccessfulWriteCallback(
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| - const base::Closure& on_next_successful_write);
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| -
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| - TimeDelta commit_interval() const {
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| - return commit_interval_;
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| - }
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| -
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| - void set_commit_interval(const TimeDelta& interval) {
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| - commit_interval_ = interval;
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| - }
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| -
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| - private:
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| - // Helper method for WriteNow().
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| - bool PostWriteTask(const Callback<bool()>& task);
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| -
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| - // If |result| is true and |on_next_successful_write_| is set, invokes
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| - // |on_successful_write_| and then resets it; no-ops otherwise.
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| - void ForwardSuccessfulWrite(bool result);
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| -
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| - // Invoked once and then reset on the next successful write event.
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| - base::Closure on_next_successful_write_;
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| -
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| - // Path being written to.
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| - const FilePath path_;
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| -
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| - // TaskRunner for the thread on which file I/O can be done.
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| - const scoped_refptr<base::SequencedTaskRunner> task_runner_;
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| -
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| - // Timer used to schedule commit after ScheduleWrite.
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| - OneShotTimer<ImportantFileWriter> timer_;
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| -
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| - // Serializer which will provide the data to be saved.
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| - DataSerializer* serializer_;
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| -
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| - // Time delta after which scheduled data will be written to disk.
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| - TimeDelta commit_interval_;
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| -
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| - WeakPtrFactory<ImportantFileWriter> weak_factory_;
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| -
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| - DISALLOW_COPY_AND_ASSIGN(ImportantFileWriter);
|
| -};
|
| -
|
| -} // namespace base
|
| -
|
| -#endif // BASE_FILES_IMPORTANT_FILE_WRITER_H_
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|
|