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// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CHROME_BROWSER_SYNC_FILE_SYSTEM_LOCAL_LOCAL_FILE_SYNC_STATUS_H_
#define CHROME_BROWSER_SYNC_FILE_SYSTEM_LOCAL_LOCAL_FILE_SYNC_STATUS_H_
#include <stdint.h>
#include <map>
#include <set>
#include <utility>
#include "base/gtest_prod_util.h"
#include "base/observer_list.h"
#include "storage/browser/file_system/file_system_url.h"
namespace storage {
class FileSystemURL;
}
namespace sync_file_system {
// Represents local file sync status.
// This class is supposed to run only on IO thread.
//
// This class manages two important synchronization flags: writing (counter)
// and syncing (flag). Writing counter keeps track of which URL is in
// writing and syncing flag indicates which URL is in syncing.
//
// An entry can have multiple writers but sync is exclusive and cannot overwrap
// with any writes or syncs.
class LocalFileSyncStatus {
public:
using OriginAndType = std::pair<GURL, storage::FileSystemType>;
class Observer {
public:
Observer() = default;
Observer(const Observer&) = delete;
Observer& operator=(const Observer&) = delete;
virtual ~Observer() = default;
virtual void OnSyncEnabled(const storage::FileSystemURL& url) = 0;
virtual void OnWriteEnabled(const storage::FileSystemURL& url) = 0;
};
LocalFileSyncStatus();
LocalFileSyncStatus(const LocalFileSyncStatus&) = delete;
LocalFileSyncStatus& operator=(const LocalFileSyncStatus&) = delete;
~LocalFileSyncStatus();
// Increment writing counter for |url|.
// This should not be called if the |url| is not writable.
void StartWriting(const storage::FileSystemURL& url);
// Decrement writing counter for |url|.
void EndWriting(const storage::FileSystemURL& url);
// Start syncing for |url| and disable writing.
// This should not be called if |url| is in syncing or in writing.
void StartSyncing(const storage::FileSystemURL& url);
// Clears the syncing flag for |url| and enable writing.
void EndSyncing(const storage::FileSystemURL& url);
// Returns true if the |url| or its parent or child is in writing.
bool IsWriting(const storage::FileSystemURL& url) const;
// Returns true if the |url| is enabled for writing (i.e. not in syncing).
bool IsWritable(const storage::FileSystemURL& url) const;
// Returns true if the |url| is enabled for syncing (i.e. neither in
// syncing nor writing).
bool IsSyncable(const storage::FileSystemURL& url) const;
void AddObserver(Observer* observer);
void RemoveObserver(Observer* observer);
private:
FRIEND_TEST_ALL_PREFIXES(LocalFileSyncStatusTest, WritingOnPathsWithPeriod);
FRIEND_TEST_ALL_PREFIXES(LocalFileSyncStatusTest, SyncingOnPathsWithPeriod);
using PathSet = std::set<base::FilePath>;
using URLSet = std::map<OriginAndType, PathSet>;
using PathBucket = std::map<base::FilePath, int64_t>;
using URLBucket = std::map<OriginAndType, PathBucket>;
bool IsChildOrParentWriting(const storage::FileSystemURL& url) const;
bool IsChildOrParentSyncing(const storage::FileSystemURL& url) const;
// If this count is non-zero, then there are ongoing write operations.
URLBucket writing_;
// If this flag is set sync process is running on the file.
URLSet syncing_;
base::ObserverList<Observer>::UncheckedAndDanglingUntriaged observer_list_;
};
} // namespace sync_file_system
#endif // CHROME_BROWSER_SYNC_FILE_SYSTEM_LOCAL_LOCAL_FILE_SYNC_STATUS_H_
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