gdata: Implement CreateSnapshotFile() for files on gdata.

With this implemented, snapshot files are created on-the-fly
when files on gdata are accessed via File API.
The files on gdata are downloaded if not cached locally.

BUG=chromium-os:23516
TEST=click on large jpg files on gdata from the file manager, and they are displayed, with the following line in metadata_provider.js commented out, per kaznacheev's suggestion:

     contentURL: (result.contentUrl || '').replace(/\?.*$/gi, ''),

Review URL: https://chromiumcodereview.appspot.com/9692026

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@126572 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 79 insertions, 2 deletions

diff --git a/chrome/browser/chromeos/gdata/gdata_file_system_proxy.cc b/chrome/browser/chromeos/gdata/gdata_file_system_proxy.cc
index 6bce817..f1cdf8a 100644
--- a/chrome/browser/chromeos/gdata/gdata_file_system_proxy.cc
+++ b/chrome/browser/chromeos/gdata/gdata_file_system_proxy.cc
@@ -11,6 +11,7 @@
 #include "base/string_util.h"
 #include "base/values.h"
 #include "content/public/browser/browser_thread.h"
+#include "webkit/blob/shareable_file_reference.h"
 #include "webkit/fileapi/file_system_file_util_proxy.h"
 #include "webkit/fileapi/file_system_types.h"
 #include "webkit/fileapi/file_system_util.h"
@@ -24,6 +25,20 @@ namespace {
 const char kGDataRootDirectory[] = "gdata";
 const char kFeedField[] = "feed";
 
+// Helper function to run SnapshotFileCallback from
+// GDataFileSystemProxy::CreateSnapshotFile().
+void CallSnapshotFileCallback(
+    const FileSystemOperationInterface::SnapshotFileCallback& callback,
+    base::PlatformFileInfo file_info,
+    base::PlatformFileError error,
+    const FilePath& local_path) {
+  // TODO(satorux): We should use the last parameter
+  // (webkit_blob::ShareableFileReference) to create temporary JSON files
+  // on-the-fly for hosted documents so users can attach hosted files to web
+  // apps via File API. crosbug.com/27690
+  callback.Run(error, file_info, local_path, NULL);
+}
+
 }  // namespace
 
 namespace gdata {
@@ -276,6 +291,37 @@ void GDataFileSystemProxy::CreateDirectory(
   file_system_->CreateDirectory(file_path, exclusive, recursive, callback);
 }
 
+void GDataFileSystemProxy::CreateSnapshotFile(
+    const GURL& file_url,
+    const FileSystemOperationInterface::SnapshotFileCallback& callback) {
+  FilePath file_path;
+  if (!ValidateUrl(file_url, &file_path)) {
+    MessageLoopProxy::current()->PostTask(FROM_HERE,
+         base::Bind(callback,
+                    base::PLATFORM_FILE_ERROR_NOT_FOUND,
+                    base::PlatformFileInfo(),
+                    FilePath(),
+                    scoped_refptr<webkit_blob::ShareableFileReference>(NULL)));
+    return;
+  }
+
+  GDataFileBase* file = file_system_->GetGDataFileInfoFromPath(file_path);
+  if (!file) {
+    MessageLoopProxy::current()->PostTask(FROM_HERE,
+         base::Bind(callback,
+                    base::PLATFORM_FILE_ERROR_NOT_FOUND,
+                    base::PlatformFileInfo(),
+                    FilePath(),
+                    scoped_refptr<webkit_blob::ShareableFileReference>(NULL)));
+    return;
+  }
+
+  file_system_->GetFile(file_path,
+                        base::Bind(&CallSnapshotFileCallback,
+                                   callback,
+                                   file->file_info()));
+}
+
 // static.
 bool GDataFileSystemProxy::ValidateUrl(const GURL& url, FilePath* file_path) {
   // what platform you're on.
diff --git a/chrome/browser/chromeos/gdata/gdata_file_system_proxy.h b/chrome/browser/chromeos/gdata/gdata_file_system_proxy.h
index 63fa1fb..1a79889 100644
--- a/chrome/browser/chromeos/gdata/gdata_file_system_proxy.h
+++ b/chrome/browser/chromeos/gdata/gdata_file_system_proxy.h
@@ -42,6 +42,10 @@ class GDataFileSystemProxy : public fileapi::RemoteFileSystemProxyInterface {
       bool recursive,
       const fileapi::FileSystemOperationInterface::StatusCallback& callback)
           OVERRIDE;
+  virtual void CreateSnapshotFile(
+      const GURL& path,
+      const fileapi::FileSystemOperationInterface::SnapshotFileCallback&
+      callback) OVERRIDE;
   // TODO(zelidrag): More methods to follow as we implement other parts of FSO.
 
  private:
diff --git a/webkit/chromeos/fileapi/remote_file_system_operation.cc b/webkit/chromeos/fileapi/remote_file_system_operation.cc
index b84818a..83fcd5e 100644
--- a/webkit/chromeos/fileapi/remote_file_system_operation.cc
+++ b/webkit/chromeos/fileapi/remote_file_system_operation.cc
@@ -140,8 +140,11 @@ RemoteFileSystemOperation::AsFileSystemOperation() {
 void RemoteFileSystemOperation::CreateSnapshotFile(
     const GURL& path,
     const SnapshotFileCallback& callback) {
-  LOG(WARNING) << "No implementation for " << path.spec();
-  NOTIMPLEMENTED();
+  DCHECK(SetPendingOperationType(kOperationCreateSnapshotFile));
+  remote_proxy_->CreateSnapshotFile(
+      path,
+      base::Bind(&RemoteFileSystemOperation::DidCreateSnapshotFile,
+                 base::Owned(this), callback));
 }
 
 bool RemoteFileSystemOperation::SetPendingOperationType(OperationType type) {
@@ -193,4 +196,13 @@ void RemoteFileSystemOperation::DidFinishFileOperation(
   callback.Run(rv);
 }
 
+void RemoteFileSystemOperation::DidCreateSnapshotFile(
+    const SnapshotFileCallback& callback,
+    base::PlatformFileError result,
+    const base::PlatformFileInfo& file_info,
+    const FilePath& platform_path,
+    const scoped_refptr<webkit_blob::ShareableFileReference>& file_ref) {
+  callback.Run(result, file_info, platform_path, file_ref);
+}
+
 }  // namespace chromeos
diff --git a/webkit/chromeos/fileapi/remote_file_system_operation.h b/webkit/chromeos/fileapi/remote_file_system_operation.h
index 3cbd665..b167527 100644
--- a/webkit/chromeos/fileapi/remote_file_system_operation.h
+++ b/webkit/chromeos/fileapi/remote_file_system_operation.h
@@ -99,6 +99,13 @@ class RemoteFileSystemOperation : public fileapi::FileSystemOperationInterface {
       bool has_more);
   void DidFinishFileOperation(const StatusCallback& callback,
                               base::PlatformFileError rv);
+  void DidCreateSnapshotFile(
+      const SnapshotFileCallback& callback,
+      base::PlatformFileError result,
+      const base::PlatformFileInfo& file_info,
+      const FilePath& platform_path,
+      const scoped_refptr<webkit_blob::ShareableFileReference>& file_ref);
+
 
   scoped_refptr<fileapi::RemoteFileSystemProxyInterface> remote_proxy_;
   // A flag to make sure we call operation only once per instance.
diff --git a/webkit/chromeos/fileapi/remote_file_system_proxy.h b/webkit/chromeos/fileapi/remote_file_system_proxy.h
index d683282..c749982 100644
--- a/webkit/chromeos/fileapi/remote_file_system_proxy.h
+++ b/webkit/chromeos/fileapi/remote_file_system_proxy.h
@@ -58,6 +58,13 @@ class RemoteFileSystemProxyInterface :
       bool recursive,
       const FileSystemOperationInterface::StatusCallback& callback) = 0;
 
+  // Creates a local snapshot file for a given |path| and returns the
+  // metadata and platform path of the snapshot file via |callback|.
+  // See also FileSystemOperationInterface::CreateSnapshotFile().
+  virtual void CreateSnapshotFile(
+      const GURL& path,
+      const FileSystemOperationInterface::SnapshotFileCallback& callback) = 0;
+
   // TODO(zelidrag): More methods to follow as we implement other parts of FSO.
 };
 
diff --git a/webkit/fileapi/file_system_operation_interface.h b/webkit/fileapi/file_system_operation_interface.h
index 163f402..3bb785c 100644
--- a/webkit/fileapi/file_system_operation_interface.h
+++ b/webkit/fileapi/file_system_operation_interface.h
@@ -245,6 +245,7 @@ class FileSystemOperationInterface {
     kOperationNone,
     kOperationCreateFile,
     kOperationCreateDirectory,
+    kOperationCreateSnapshotFile,
     kOperationCopy,
     kOperationMove,
     kOperationDirectoryExists,