Wired GDataFileSystem::GetFile() method with internal cache.

chrome/browser/chromeos/gdata/gdata_file_system.h

 // 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_GDATA_FILE_SYSTEM_H_
 #define CHROME_BROWSER_CHROMEOS_GDATA_GDATA_FILE_SYSTEM_H_
 
 #include <sys/stat.h>
 
 #include <map>
@@ skipping 92 matching lines @@
  private:
   // FindFileDelegate overrides.
   virtual void OnDone(base::PlatformFileError error,
                       const FilePath& directory_path,
                       GDataFileBase* file) OVERRIDE;
 
   // File entry that was found.
   GDataFileBase* file_;
 };
 
+// Helper structure used for extracting key properties from GDataFile object.
+struct GDataFileProperties {
+  GDataFileProperties();
+  ~GDataFileProperties();
+
+  base::PlatformFileInfo file_info;
+  std::string resource_id;
+  std::string file_md5;
+  GURL content_url;
+  GURL edit_url;
+  bool is_hosted_document;
+};
+
 // GData file system abstraction layer.
 // The interface is defined to make GDataFileSystem mockable.
 class GDataFileSystemInterface {
  public:
   virtual ~GDataFileSystemInterface() {}
 
   // Used to notify events on the file system.
   class Observer {
    public:
     // Trigerred when a file has been pinned, after the cache state is
@@ skipping 11 matching lines @@
 
   // Enum defining GCache subdirectory location.
   enum CacheSubdir {  // This indexes into |cache_paths_| vector.
     CACHE_TYPE_META = 0,
     CACHE_TYPE_PINNED,
     CACHE_TYPE_OUTGOING,
     CACHE_TYPE_PERSISTENT,
     CACHE_TYPE_TMP,
   };
 
+  // Enum defining origin of a cached file.
+  enum CachedFileOrigin {
+    CACHED_FILE_FROM_SERVER = 0,
+    CACHED_FILE_LOCALLY_MODIFIED,
+  };
+
   // Authenticates the user by fetching the auth token as
   // needed. |callback| will be run with the error code and the auth
   // token, on the thread this function is run.
   //
   // Must be called on UI thread.
   virtual void Authenticate(const AuthStatusCallback& callback) = 0;
 
   // Finds file info by using virtual |file_path|. This call will also
   // retrieve and refresh file system content from server and disk cache.
   //
@@ skipping 111 matching lines @@
   // Gets the cache state of file corresponding to |resource_id| and |md5| if it
   // exists on disk.
   // Initializes cache if it has not been initialized.
   // Upon completion, |callback| is invoked on the thread where this method was
   // called with the cache state if file exists in cache or CACHE_STATE_NONE
   // otherwise.
   virtual void GetCacheState(const std::string& resource_id,
                              const std::string& md5,
                              const GetCacheStateCallback& callback) = 0;
 
-  // Finds file object by |file_path| and returns its |file_info|.
+  // Finds file object by |file_path| and returns its key |properties|.
   // Returns true if file was found.
   virtual bool GetFileInfoFromPath(const FilePath& gdata_file_path,
-                                   base::PlatformFileInfo* file_info) = 0;
+                                   GDataFileProperties* properties) = 0;
 
   // Returns the tmp sub-directory under gdata cache directory, i.e.
   // <user_profile_dir>/GCache/v1/tmp
   virtual FilePath GetGDataCacheTmpDirectory() = 0;
 
   // Fetches the user's Account Metadata to find out current quota information
   // and returns it to the callback.
   virtual void GetAvailableSpace(const GetAvailableSpaceCallback& callback) = 0;
 };
 
@@ skipping 34 matching lines @@
   GetProgressStatusList() OVERRIDE;
   virtual bool CancelOperation(const FilePath& file_path) OVERRIDE;
   virtual void AddOperationObserver(
       GDataOperationRegistry::Observer* observer) OVERRIDE;
   virtual void RemoveOperationObserver(
       GDataOperationRegistry::Observer* observer) OVERRIDE;
   virtual void GetCacheState(const std::string& resource_id,
                              const std::string& md5,
                              const GetCacheStateCallback& callback) OVERRIDE;
   virtual bool GetFileInfoFromPath(const FilePath& gdata_file_path,
-                                   base::PlatformFileInfo* file_info) OVERRIDE;
+                                   GDataFileProperties* properties) OVERRIDE;
   virtual FilePath GetGDataCacheTmpDirectory() OVERRIDE;
   virtual void GetAvailableSpace(
       const GetAvailableSpaceCallback& callback) OVERRIDE;
 
  private:
   friend class GDataUploader;
   friend class GDataFileSystemFactory;
   friend class GDataFileSystemTest;
   FRIEND_TEST_ALL_PREFIXES(GDataFileSystemTest,
                            FindFirstMissingParentDirectory);
@@ skipping 22 matching lines @@
                           const FileOperationCallback& callback);
     ~CreateDirectoryParams();
 
     const FilePath created_directory_path;
     const FilePath target_directory_path;
     const bool is_exclusive;
     const bool is_recursive;
     FileOperationCallback callback;
   };
 
+  // Defines set of parameters passed to intermediate callbacks during
+  // execution of GetFile() method.
+  struct GetFileFromCacheParams {
+    GetFileFromCacheParams(const FilePath& virtual_file_path,
+        const FilePath& local_tmp_path,
+        const GURL& content_url,
+        const std::string& resource_id,
+        const std::string& md5,
+        scoped_refptr<base::MessageLoopProxy> proxy,
+        const GetFileCallback& callback);
+    ~GetFileFromCacheParams();
+
+    FilePath virtual_file_path;
+    FilePath local_tmp_path;
+    GURL content_url;
+    std::string resource_id;
+    std::string md5;
+    scoped_refptr<base::MessageLoopProxy> proxy;
+    const GetFileCallback callback;
+  };
+
   // Callback similar to FileOperationCallback but with a given
   // |file_path|.
   typedef base::Callback<void(base::PlatformFileError error,
                               const FilePath& file_path)>
       FilePathUpdateCallback;
 
   GDataFileSystem(Profile* profile,
                   DocumentsServiceInterface* documents_service,
                   GDataSyncClientInterface* sync_client);
   virtual ~GDataFileSystem();
@@ skipping 126 matching lines @@
       const GURL& document_url);
 
   // Callback for handling directory create requests.
   void OnCreateDirectoryCompleted(
       const CreateDirectoryParams& params,
       GDataErrorCode status,
       scoped_ptr<base::Value> created_entry);
 
   // Callback for handling file downloading requests.
   void OnFileDownloaded(
-    const GetFileCallback& callback,
+    const GetFileFromCacheParams& params,
     GDataErrorCode status,
     const GURL& content_url,
-    const FilePath& temp_file);
+    const FilePath& downloaded_file_path);
+
+  // Callback for handling internal StoreToCache() calls after downloading
+  // file content.
+  void OnDownloadStoredToCache(base::PlatformFileError error,
+                               const std::string& resource_id,
+                               const std::string& md5);
 
   // Callback for handling file upload initialization requests.
   void OnUploadLocationReceived(
       const InitiateUploadCallback& callback,
       scoped_refptr<base::MessageLoopProxy> message_loop_proxy,
       GDataErrorCode code,
       const GURL& upload_location);
 
   // Callback for handling file upload resume requests.
   void OnResumeUpload(const ResumeUploadCallback& callback,
@@ skipping 99 matching lines @@
   // - provides absolute path for files to be cached or cached.
   // - updates the cached file on disk after user has edited it locally
   // - handles eviction when disk runs out of space
   // - uploads dirty files to gdata server.
   // - etc.
 
   // Returns absolute path of the file if it were cached or to be cached.
   FilePath GetCacheFilePath(const std::string& resource_id,
                             const std::string& md5,
                             CacheSubdir subdir_id,
-                            bool is_local);
+                            CachedFileOrigin file_orign);
 
   // Stores |source_path| corresponding to |resource_id| and |md5| to cache.
   // Initializes cache if it has not been initialized.
   // Upon completion, |callback| is invoked on the thread where this method was
   // called.
-  // TODO(kuan): When URLFetcher can save response to a specified file (as
-  // opposed to only temporary file currently), remove |source_path| parameter.
   void StoreToCache(const std::string& resource_id,
                     const std::string& md5,
                     const FilePath& source_path,
                     const CacheOperationCallback& callback);
 
   // Checks if file corresponding to |resource_id| and |md5| exist on disk and
   // can be accessed i.e. not corrupted by previous file operations that didn't
   // complete for whatever reasons.
   // Initializes cache if it has not been initialized.
   // Upon completion, |callback| is invoked on the thread where this method was
@@ skipping 85 matching lines @@
                       mode_t mode_bits,
                       const CacheOperationCallback& callback);
 
   // Helper function for OnFilePinned() and OnFileUnpinned().
   void OnCacheStatusModified(base::PlatformFileError error,
                              const std::string& resource_id,
                              const std::string& md5,
                              mode_t mode_bits,
                              const CacheOperationCallback& callback);
 
+  // Helper function for internally handling responses from GetFromCache()
+  // calls during processing of GetFile() request.
+  void OnGetFileFromCache(const GetFileFromCacheParams& params,
+                          base::PlatformFileError error,
+                          const std::string& resource_id,
+                          const std::string& md5,
+                          const FilePath& gdata_file_path,
+                          const FilePath& cache_file_path);
+
   // Callback for GetCacheState that gets cache state of file corresponding to
   // |resource_id| and |md5|.
   void OnGetCacheState(const std::string& resource_id,
                        const std::string& md5,
                        const GetCacheStateCallback& callback);
 
   // Cache internal helper functions.
 
   void GetFromCacheInternal(const std::string& resource_id,
                             const std::string& md5,
                             const FilePath& gdata_file_path,
                             const GetFromCacheCallback& callback);
 
   // Unsafe (unlocked) version of InitializeCacheIfnecessary method.
   void UnsafeInitializeCacheIfNecessary();
 
   // Helper function used to perform file search on the calling thread of
   // FindFileByPath() request.
   void FindFileByPathOnCallingThread(const FilePath& search_file_path,
                                      const FindFileCallback& callback);
 
-    scoped_ptr<GDataRootDirectory> root_;
+  scoped_ptr<GDataRootDirectory> root_;
 
   base::Lock lock_;
 
   // The profile hosts the GDataFileSystem.
   Profile* profile_;
 
   // The document service for the GDataFileSystem.
   scoped_ptr<DocumentsServiceInterface> documents_service_;
 
   // File content uploader.
@@ skipping 41 matching lines @@
   virtual ~GDataFileSystemFactory();
 
   // ProfileKeyedServiceFactory:
   virtual ProfileKeyedService* BuildServiceInstanceFor(
       Profile* profile) const OVERRIDE;
 };
 
 }  // namespace gdata
 
 #endif  // CHROME_BROWSER_CHROMEOS_GDATA_GDATA_FILE_SYSTEM_H_