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Diffstat (limited to 'chrome/browser/chromeos/gdata/drive_cache.h')
| -rw-r--r-- | chrome/browser/chromeos/gdata/drive_cache.h | 481 |
1 files changed, 481 insertions, 0 deletions
diff --git a/chrome/browser/chromeos/gdata/drive_cache.h b/chrome/browser/chromeos/gdata/drive_cache.h new file mode 100644 index 0000000..00715c6 --- /dev/null +++ b/chrome/browser/chromeos/gdata/drive_cache.h @@ -0,0 +1,481 @@ +// 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 CHROME_BROWSER_CHROMEOS_GDATA_DRIVE_CACHE_H_ +#define CHROME_BROWSER_CHROMEOS_GDATA_DRIVE_CACHE_H_ + +#include <map> +#include <string> +#include <vector> + +#include "base/callback.h" +#include "base/file_path.h" +#include "base/memory/scoped_ptr.h" +#include "base/memory/weak_ptr.h" +#include "base/observer_list.h" +#include "base/platform_file.h" +#include "chrome/browser/chromeos/gdata/gdata_errorcode.h" + +class Profile; + +namespace base { + +class SequencedTaskRunner; + +} // namespace base + +namespace gdata { + +class DriveCacheEntry; +class DriveCacheMetadata; + +// Callback for SetMountedStateOnUIThread and ClearAllOnUIThread. +typedef base::Callback<void(GDataFileError error, + const FilePath& file_path)> + ChangeCacheStateCallback; + +// Callback for completion of cache operation. +typedef base::Callback<void(GDataFileError error, + const std::string& resource_id, + const std::string& md5)> CacheOperationCallback; + +// Callback for GetFileFromCache. +typedef base::Callback<void(GDataFileError error, + const std::string& resource_id, + const std::string& md5, + const FilePath& cache_file_path)> + GetFileFromCacheCallback; + +// Callback for GetResourceIdsOfBacklogOnUIThread. +// |to_fetch| is for resource IDs of pinned-but-not-fetched files. +// |to_upload| is for resource IDs of dirty-but-not-uploaded files. +typedef base::Callback<void(const std::vector<std::string>& to_fetch, + const std::vector<std::string>& to_upload)> + GetResourceIdsOfBacklogCallback; + +// Callback for GetResourceIdsOfExistingPinnedFilesOnUIThread. +typedef base::Callback<void(const std::vector<std::string>& resource_ids)> + GetResourceIdsCallback; + +// Callback for GetCacheEntryOnUIThread. +// |success| indicates if the operation was successful. +// |cache_entry| is the obtained cache entry. On failure, |cache_state| is +// set to TEST_CACHE_STATE_NONE. +typedef base::Callback<void(bool success, const DriveCacheEntry& cache_entry)> + GetCacheEntryCallback; + +// DriveCache is used to maintain cache states of GDataFileSystem. +// +// All non-static public member functions, unless mentioned otherwise (see +// GetCacheFilePath() for example), should be called from the sequenced +// worker pool with the sequence token set by CreateDriveCacheOnUIThread(). This +// threading model is enforced by AssertOnSequencedWorkerPool(). +// +// TODO(hashimoto): Change threading model of this class to make public methods +// being called on UI thread unless mentioned otherwise. crbug.com/132926 +class DriveCache { + public: + // Enum defining GCache subdirectory location. + // This indexes into |DriveCache::cache_paths_| vector. + enum CacheSubDirectoryType { + CACHE_TYPE_META = 0, // Downloaded feeds. + CACHE_TYPE_PINNED, // Symlinks to files in persistent dir that are + // pinned, or to /dev/null for non-existent + // files. + CACHE_TYPE_OUTGOING, // Symlinks to files in persistent or tmp dir to + // be uploaded. + CACHE_TYPE_PERSISTENT, // Files that are pinned or modified locally, + // not evictable, hopefully. + CACHE_TYPE_TMP, // Files that don't meet criteria to be in + // persistent dir, and hence evictable. + CACHE_TYPE_TMP_DOWNLOADS, // Downloaded files. + CACHE_TYPE_TMP_DOCUMENTS, // Temporary JSON files for hosted documents. + NUM_CACHE_TYPES, // This must be at the end. + }; + + // Enum defining origin of a cached file. + enum CachedFileOrigin { + CACHED_FILE_FROM_SERVER = 0, + CACHED_FILE_LOCALLY_MODIFIED, + CACHED_FILE_MOUNTED, + }; + + // Enum defining type of file operation e.g. copy or move, etc. + enum FileOperationType { + FILE_OPERATION_MOVE = 0, + FILE_OPERATION_COPY, + }; + + // Used to notify events. All events are notified on UI thread. + class Observer { + public: + // Triggered when a file has been pinned successfully. + virtual void OnCachePinned(const std::string& resource_id, + const std::string& md5) {} + + // Triggered when a file has been unpinned successfully. + virtual void OnCacheUnpinned(const std::string& resource_id, + const std::string& md5) {} + + // Triggered when a dirty file has been committed (saved) successfully. + virtual void OnCacheCommitted(const std::string& resource_id) {} + + protected: + virtual ~Observer() {} + }; + + // Returns the sub-directory under gdata cache directory for the given sub + // directory type. Example: <user_profile_dir>/GCache/v1/tmp + // + // Can be called on any thread. + FilePath GetCacheDirectoryPath(CacheSubDirectoryType sub_dir_type) const; + + // Returns absolute path of the file if it were cached or to be cached. + // + // Can be called on any thread. + FilePath GetCacheFilePath(const std::string& resource_id, + const std::string& md5, + CacheSubDirectoryType sub_dir_type, + CachedFileOrigin file_orign) const; + + // Returns true if the given path is under gdata cache directory, i.e. + // <user_profile_dir>/GCache/v1 + // + // Can be called on any thread. + bool IsUnderDriveCacheDirectory(const FilePath& path) const; + + // Adds observer. + // Must be called on UI thread. + void AddObserver(Observer* observer); + + // Removes observer. + // Must be called on UI thread. + void RemoveObserver(Observer* observer); + + // Gets the cache entry by the given resource ID and MD5. + // See also GetCacheEntry(). + // + // Must be called on UI thread. |callback| is run on UI thread. + void GetCacheEntryOnUIThread( + const std::string& resource_id, + const std::string& md5, + const GetCacheEntryCallback& callback); + + // Gets the resource IDs of pinned-but-not-fetched files and + // dirty-but-not-uploaded files. + // + // Must be called on UI thread. |callback| is run on UI thread. + void GetResourceIdsOfBacklogOnUIThread( + const GetResourceIdsOfBacklogCallback& callback); + + // Gets the resource IDs of all existing (i.e. cached locally) pinned + // files, including pinned dirty files. + // + // Must be called on UI thread. |callback| is run on UI thread. + void GetResourceIdsOfExistingPinnedFilesOnUIThread( + const GetResourceIdsCallback& callback); + + // Gets the resource IDs of all files in the cache. + // + // Must be called on UI thread. |callback| is run on UI thread. + void GetResourceIdsOfAllFilesOnUIThread( + const GetResourceIdsCallback& callback); + + // Frees up disk space to store the given number of bytes, while keeping + // kMinFreSpace bytes on the disk, if needed. |has_enough_space| is + // updated to indicate if we have enough space. + void FreeDiskSpaceIfNeededFor(int64 num_bytes, + bool* has_enough_space); + + // Checks if file corresponding to |resource_id| and |md5| exists in cache. + void GetFileOnUIThread(const std::string& resource_id, + const std::string& md5, + const GetFileFromCacheCallback& callback); + + // Modifies cache state, which involves the following: + // - moves or copies (per |file_operation_type|) |source_path| + // to |dest_path| in the cache dir + // - if necessary, creates symlink + // - deletes stale cached versions of |resource_id| in + // |dest_path|'s directory. + void StoreOnUIThread(const std::string& resource_id, + const std::string& md5, + const FilePath& source_path, + FileOperationType file_operation_type, + const CacheOperationCallback& callback); + + // Modifies cache state, which involves the following: + // - moves |source_path| to |dest_path| in persistent dir if + // file is not dirty + // - creates symlink in pinned dir that references downloaded or locally + // modified file + void PinOnUIThread(const std::string& resource_id, + const std::string& md5, + const CacheOperationCallback& callback); + + // Modifies cache state, which involves the following: + // - moves |source_path| to |dest_path| in tmp dir if file is not dirty + // - deletes symlink from pinned dir + void UnpinOnUIThread(const std::string& resource_id, + const std::string& md5, + const CacheOperationCallback& callback); + + // Modifies cache state, which involves the following: + // - moves |source_path| to |dest_path|, where + // if we're mounting: |source_path| is the unmounted path and has .<md5> + // extension, and |dest_path| is the mounted path in persistent dir + // and has .<md5>.mounted extension; + // if we're unmounting: the opposite is true for the two paths, i.e. + // |dest_path| is the mounted path and |source_path| the unmounted path. + void SetMountedStateOnUIThread(const FilePath& file_path, + bool to_mount, + const ChangeCacheStateCallback& callback); + + // Modifies cache state, which involves the following: + // - moves |source_path| to |dest_path| in persistent dir, where + // |source_path| has .<md5> extension and |dest_path| has .local extension + // - if file is pinned, updates symlink in pinned dir to reference dirty file + void MarkDirtyOnUIThread(const std::string& resource_id, + const std::string& md5, + const GetFileFromCacheCallback& callback); + + // Modifies cache state, i.e. creates symlink in outgoing + // dir to reference dirty file in persistent dir. + void CommitDirtyOnUIThread(const std::string& resource_id, + const std::string& md5, + const CacheOperationCallback& callback); + + // Modifies cache state, which involves the following: + // - moves |source_path| to |dest_path| in persistent dir if + // file is pinned or tmp dir otherwise, where |source_path| has .local + // extension and |dest_path| has .<md5> extension + // - deletes symlink in outgoing dir + // - if file is pinned, updates symlink in pinned dir to reference + // |dest_path| + void ClearDirtyOnUIThread(const std::string& resource_id, + const std::string& md5, + const CacheOperationCallback& callback); + + // Does the following: + // - remove all delete stale cache versions corresponding to |resource_id| in + // persistent, tmp and pinned directories + // - remove entry corresponding to |resource_id| from cache map. + void RemoveOnUIThread(const std::string& resource_id, + const CacheOperationCallback& callback); + + // Does the following: + // - remove all the files in the cache directory. + // - re-create the |metadata_| instance. + void ClearAllOnUIThread(const ChangeCacheStateCallback& callback); + + // Utility method to call Initialize on UI thread. + void RequestInitializeOnUIThread(); + + // Utility method to call InitializeForTesting on UI thread. + void RequestInitializeOnUIThreadForTesting(); + + // Force a rescan of cache files, for testing. + void ForceRescanOnUIThreadForTesting(); + + // Gets the cache entry for file corresponding to |resource_id| and |md5| + // and returns true if entry exists in cache map. Otherwise, returns false. + // |md5| can be empty if only matching |resource_id| is desired, which may + // happen when looking for pinned entries where symlinks' filenames have no + // extension and hence no md5. + bool GetCacheEntry(const std::string& resource_id, + const std::string& md5, + DriveCacheEntry* entry); + + // Factory methods for DriveCache. + // |pool| and |sequence_token| are used to assert that the functions are + // called on the right sequenced worker pool with the right sequence token. + // + // For testing, the thread assertion can be disabled by passing NULL and + // the default value of SequenceToken. + static DriveCache* CreateDriveCacheOnUIThread( + const FilePath& cache_root_path, + base::SequencedTaskRunner* blocking_task_runner); + + // Deletes the cache. + void DestroyOnUIThread(); + + // Gets the cache root path (i.e. <user_profile_dir>/GCache/v1) from the + // profile. + // TODO(satorux): Write a unit test for this. + static FilePath GetCacheRootPath(Profile* profile); + + // Returns file paths for all the cache sub directories under + // |cache_root_path|. + static std::vector<FilePath> GetCachePaths(const FilePath& cache_root_path); + + // Creates cache directory and its sub-directories if they don't exist. + // TODO(glotov): take care of this when the setup and cleanup part is + // landed, noting that these directories need to be created for development + // in linux box and unittest. (http://crosbug.com/27577) + static bool CreateCacheDirectories( + const std::vector<FilePath>& paths_to_create); + + // Returns the type of the sub directory where the cache file is stored. + static CacheSubDirectoryType GetSubDirectoryType( + const DriveCacheEntry& cache_entry); + + private: + DriveCache(const FilePath& cache_root_path, + base::SequencedTaskRunner* blocking_task_runner); + virtual ~DriveCache(); + + // Checks whether the current thread is on the right sequenced worker pool + // with the right sequence ID. If not, DCHECK will fail. + void AssertOnSequencedWorkerPool(); + + // Initializes the cache. + void Initialize(); + + // Initializes the cache with in-memory cache for testing. + // The in-memory cache is used since it's faster than the db. + void InitializeForTesting(); + + // Deletes the cache. + void Destroy(); + + // Force a rescan of cache directories. + void ForceRescanForTesting(); + + // Used to implement GetResourceIdsOfBacklogOnUIThread. + void GetResourceIdsOfBacklog( + std::vector<std::string>* to_fetch, + std::vector<std::string>* to_upload); + + // Used to implement GetResourceIdsOfExistingPinnedFilesOnUIThread. + void GetResourceIdsOfExistingPinnedFiles( + std::vector<std::string>* resource_ids); + + // Used to implement GetResourceIdsOfAllFilesOnUIThread. + void GetResourceIdsOfAllFiles( + std::vector<std::string>* resource_ids); + + // Used to implement GetFileOnUIThread. + void GetFile(const std::string& resource_id, + const std::string& md5, + GDataFileError* error, + FilePath* cache_file_path); + + // Used to implement StoreOnUIThread. + void Store(const std::string& resource_id, + const std::string& md5, + const FilePath& source_path, + FileOperationType file_operation_type, + GDataFileError* error); + + // Used to implement PinOnUIThread. + void Pin(const std::string& resource_id, + const std::string& md5, + FileOperationType file_operation_type, + GDataFileError* error); + + // Used to implement UnpinOnUIThread. + void Unpin(const std::string& resource_id, + const std::string& md5, + FileOperationType file_operation_type, + GDataFileError* error); + + // Used to implement SetMountedStateOnUIThread. + void SetMountedState(const FilePath& file_path, + bool to_mount, + GDataFileError* error, + FilePath* cache_file_path); + + // Used to implement MarkDirtyOnUIThread. + void MarkDirty(const std::string& resource_id, + const std::string& md5, + FileOperationType file_operation_type, + GDataFileError* error, + FilePath* cache_file_path); + + // Used to implement CommitDirtyOnUIThread. + void CommitDirty(const std::string& resource_id, + const std::string& md5, + FileOperationType file_operation_type, + GDataFileError* error); + + // Used to implement ClearDirtyOnUIThread. + void ClearDirty(const std::string& resource_id, + const std::string& md5, + FileOperationType file_operation_type, + GDataFileError* error); + + // Used to implement RemoveOnUIThread. + void Remove(const std::string& resource_id, + GDataFileError* error); + + // Used to implement ClearAllUIThread. + void ClearAll(GDataFileError* error); + + // Runs callback and notifies the observers when file is pinned. + void OnPinned(GDataFileError* error, + const std::string& resource_id, + const std::string& md5, + const CacheOperationCallback& callback); + + // Runs callback and notifies the observers when file is unpinned. + void OnUnpinned(GDataFileError* error, + const std::string& resource_id, + const std::string& md5, + const CacheOperationCallback& callback); + + // Runs callback and notifies the observers when file is committed. + void OnCommitDirty(GDataFileError* error, + const std::string& resource_id, + const std::string& md5, + const CacheOperationCallback& callback); + + // Helper function to implement GetCacheEntryOnUIThread(). + void GetCacheEntryHelper(const std::string& resource_id, + const std::string& md5, + bool* success, + DriveCacheEntry* cache_entry); + + // The root directory of the cache (i.e. <user_profile_dir>/GCache/v1). + const FilePath cache_root_path_; + // Paths for all subdirectories of GCache, one for each + // DriveCache::CacheSubDirectoryType enum. + const std::vector<FilePath> cache_paths_; + scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_; + + // The cache state data. This member must be access only on the blocking pool. + scoped_ptr<DriveCacheMetadata> metadata_; + + // List of observers, this member must be accessed on UI thread. + ObserverList<Observer> observers_; + + // Note: This should remain the last member so it'll be destroyed and + // invalidate its weak pointers before any other members are destroyed. + base::WeakPtrFactory<DriveCache> weak_ptr_factory_; + DISALLOW_COPY_AND_ASSIGN(DriveCache); +}; + + +// The minimum free space to keep. GDataFileSystem::GetFileByPath() returns +// GDATA_FILE_ERROR_NO_SPACE if the available space is smaller than +// this value. +// +// Copied from cryptohome/homedirs.h. +// TODO(satorux): Share the constant. +const int64 kMinFreeSpace = 512 * 1LL << 20; + +// Interface class used for getting the free disk space. Only for testing. +class FreeDiskSpaceGetterInterface { + public: + virtual ~FreeDiskSpaceGetterInterface() {} + virtual int64 AmountOfFreeDiskSpace() const = 0; +}; + +// Sets the free disk space getter for testing. +// The existing getter is deleted. +void SetFreeDiskSpaceGetterForTesting( + FreeDiskSpaceGetterInterface* getter); + +} // namespace gdata + +#endif // CHROME_BROWSER_CHROMEOS_GDATA_DRIVE_CACHE_H_ |