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

chrome/browser/chromeos/gdata/gdata_file_system.h

Index: chrome/browser/chromeos/gdata/gdata_file_system.h
diff --git a/chrome/browser/chromeos/gdata/gdata_file_system.h b/chrome/browser/chromeos/gdata/gdata_file_system.h
index e34d1dda23a3ffbc8e17b00d99538638c70cb38a..59fe639bd4d19b2b3ea2437a6ec0cf0b6e5ce7ea 100644
--- a/chrome/browser/chromeos/gdata/gdata_file_system.h
+++ b/chrome/browser/chromeos/gdata/gdata_file_system.h
@@ -268,10 +268,14 @@ class GDataFileSystem : public ProfileKeyedService {
                      const std::string& md5,
                      const GetCacheStateCallback& callback);
 
-  // Finds file object by |file_path| and returns its |file_info|.
-  // Returns true if file was found.
+  // Finds file object by |file_path| and returns its |file_info| and optionally
+  // its |resource_id|, |md5| and |content_url| properties. Returns true if file
+  // was found.
   bool GetFileInfoFromPath(const FilePath& gdata_file_path,
-                           base::PlatformFileInfo* file_info);
+                           base::PlatformFileInfo* file_info,
+                           std::string* resource_id,
+                           std::string* md5,
+                           GURL* content_url);
 
   // Returns the tmp sub-directory under gdata cache directory, i.e.
   // <user_profile_dir>/GCache/v1/tmp
@@ -321,6 +325,27 @@ class GDataFileSystem : public ProfileKeyedService {
     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,
@@ -456,10 +481,16 @@ class GDataFileSystem : public ProfileKeyedService {
 
   // 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(
@@ -585,8 +616,6 @@ class GDataFileSystem : public ProfileKeyedService {
   // 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,
@@ -692,6 +721,15 @@ class GDataFileSystem : public ProfileKeyedService {
                              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,
@@ -713,7 +751,7 @@ class GDataFileSystem : public ProfileKeyedService {
   void FindFileByPathOnCallingThread(const FilePath& search_file_path,
                                      const FindFileCallback& callback);
 
-    scoped_ptr<GDataRootDirectory> root_;
+  scoped_ptr<GDataRootDirectory> root_;
 
   base::Lock lock_;