Revert 288017 "Parse Drive API responses all at once in the bloc..."

trunk/src/google_apis/drive/drive_api_requests.cc

Index: trunk/src/google_apis/drive/drive_api_requests.cc
===================================================================
--- trunk/src/google_apis/drive/drive_api_requests.cc	(revision 288215)
+++ trunk/src/google_apis/drive/drive_api_requests.cc	(working copy)
@@ -11,6 +11,7 @@
 #include "base/sequenced_task_runner.h"
 #include "base/task_runner_util.h"
 #include "base/values.h"
+#include "google_apis/drive/drive_api_parser.h"
 #include "google_apis/drive/request_sender.h"
 #include "google_apis/drive/request_util.h"
 #include "google_apis/drive/time_util.h"
@@ -22,6 +23,70 @@
 const char kContentTypeApplicationJson[] = "application/json";
 const char kParentLinkKind[] = "drive#fileLink";
 
+// Parses the JSON value to a resource typed |T| and runs |callback| on the UI
+// thread once parsing is done.
+template<typename T>
+void ParseJsonAndRun(
+    const base::Callback<void(GDataErrorCode, scoped_ptr<T>)>& callback,
+    GDataErrorCode error,
+    scoped_ptr<base::Value> value) {
+  DCHECK(!callback.is_null());
+
+  scoped_ptr<T> resource;
+  if (value) {
+    resource = T::CreateFrom(*value);
+    if (!resource) {
+      // Failed to parse the JSON value, although the JSON value is available,
+      // so let the callback know the parsing error.
+      error = GDATA_PARSE_ERROR;
+    }
+  }
+
+  callback.Run(error, resource.Pass());
+}
+
+// Thin adapter of T::CreateFrom.
+template<typename T>
+scoped_ptr<T> ParseJsonOnBlockingPool(scoped_ptr<base::Value> value) {
+  return T::CreateFrom(*value);
+}
+
+// Runs |callback| with given |error| and |value|. If |value| is null,
+// overwrites |error| to GDATA_PARSE_ERROR.
+template<typename T>
+void ParseJsonOnBlockingPoolAndRunAfterBlockingPoolTask(
+    const base::Callback<void(GDataErrorCode, scoped_ptr<T>)>& callback,
+    GDataErrorCode error, scoped_ptr<T> value) {
+  if (!value)
+    error = GDATA_PARSE_ERROR;
+  callback.Run(error, value.Pass());
+}
+
+// Parses the JSON value to a resource typed |T| and runs |callback| on
+// blocking pool, and then run on the current thread.
+// TODO(hidehiko): Move this and ParseJsonAndRun defined above into base with
+// merging the tasks running on blocking pool into one.
+template<typename T>
+void ParseJsonOnBlockingPoolAndRun(
+    scoped_refptr<base::TaskRunner> blocking_task_runner,
+    const base::Callback<void(GDataErrorCode, scoped_ptr<T>)>& callback,
+    GDataErrorCode error,
+    scoped_ptr<base::Value> value) {
+  DCHECK(!callback.is_null());
+
+  if (!value) {
+    callback.Run(error, scoped_ptr<T>());
+    return;
+  }
+
+  base::PostTaskAndReplyWithResult(
+      blocking_task_runner,
+      FROM_HERE,
+      base::Bind(&ParseJsonOnBlockingPool<T>, base::Passed(&value)),
+      base::Bind(&ParseJsonOnBlockingPoolAndRunAfterBlockingPoolTask<T>,
+                 callback, error));
+}
+
 // Parses the JSON value to FileResource instance and runs |callback| on the
 // UI thread once parsing is done.
 // This is customized version of ParseJsonAndRun defined above to adapt the
@@ -61,16 +126,17 @@
 
 namespace drive {
 
-//============================ DriveApiPartialFieldRequest ====================
+//============================ DriveApiDataRequest ===========================
 
-DriveApiPartialFieldRequest::DriveApiPartialFieldRequest(
-    RequestSender* sender) : UrlFetchRequestBase(sender) {
+DriveApiDataRequest::DriveApiDataRequest(RequestSender* sender,
+                                         const GetDataCallback& callback)
+    : GetDataRequest(sender, callback) {
 }
 
-DriveApiPartialFieldRequest::~DriveApiPartialFieldRequest() {
+DriveApiDataRequest::~DriveApiDataRequest() {
 }
 
-GURL DriveApiPartialFieldRequest::GetURL() const {
+GURL DriveApiDataRequest::GetURL() const {
   GURL url = GetURLInternal();
   if (!fields_.empty())
     url = net::AppendOrReplaceQueryParameter(url, "fields", fields_);
@@ -83,7 +149,9 @@
     RequestSender* sender,
     const DriveApiUrlGenerator& url_generator,
     const FileResourceCallback& callback)
-    : DriveApiDataRequest<FileResource>(sender, callback),
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonAndRun<FileResource>, callback)),
       url_generator_(url_generator) {
   DCHECK(!callback.is_null());
 }
@@ -100,7 +168,9 @@
     RequestSender* sender,
     const DriveApiUrlGenerator& url_generator,
     const FileResourceCallback& callback)
-    : DriveApiDataRequest<FileResource>(sender, callback),
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonAndRun<FileResource>, callback)),
       url_generator_(url_generator) {
   DCHECK(!callback.is_null());
 }
@@ -121,7 +191,9 @@
     RequestSender* sender,
     const DriveApiUrlGenerator& url_generator,
     const FileResourceCallback& callback)
-    : DriveApiDataRequest<FileResource>(sender, callback),
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonAndRun<FileResource>, callback)),
       url_generator_(url_generator) {
   DCHECK(!callback.is_null());
 }
@@ -178,7 +250,9 @@
     RequestSender* sender,
     const DriveApiUrlGenerator& url_generator,
     const FileResourceCallback& callback)
-    : DriveApiDataRequest<FileResource>(sender, callback),
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonAndRun<FileResource>, callback)),
       url_generator_(url_generator),
       set_modified_date_(false),
       update_viewed_date_(true) {
@@ -246,7 +320,9 @@
     RequestSender* sender,
     const DriveApiUrlGenerator& url_generator,
     const FileResourceCallback& callback)
-    : DriveApiDataRequest<FileResource>(sender, callback),
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonAndRun<FileResource>, callback)),
       url_generator_(url_generator) {
   DCHECK(!callback.is_null());
 }
@@ -299,7 +375,11 @@
     RequestSender* sender,
     const DriveApiUrlGenerator& url_generator,
     const FileListCallback& callback)
-    : DriveApiDataRequest<FileList>(sender, callback),
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonOnBlockingPoolAndRun<FileList>,
+                     make_scoped_refptr(sender->blocking_task_runner()),
+                     callback)),
       url_generator_(url_generator),
       max_results_(100) {
   DCHECK(!callback.is_null());
@@ -316,7 +396,11 @@
 FilesListNextPageRequest::FilesListNextPageRequest(
     RequestSender* sender,
     const FileListCallback& callback)
-    : DriveApiDataRequest<FileList>(sender, callback) {
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonOnBlockingPoolAndRun<FileList>,
+                     make_scoped_refptr(sender->blocking_task_runner()),
+                     callback)) {
   DCHECK(!callback.is_null());
 }
 
@@ -361,7 +445,9 @@
     RequestSender* sender,
     const DriveApiUrlGenerator& url_generator,
     const FileResourceCallback& callback)
-    : DriveApiDataRequest<FileResource>(sender, callback),
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonAndRun<FileResource>, callback)),
       url_generator_(url_generator) {
   DCHECK(!callback.is_null());
 }
@@ -382,7 +468,9 @@
     RequestSender* sender,
     const DriveApiUrlGenerator& url_generator,
     const AboutResourceCallback& callback)
-    : DriveApiDataRequest<AboutResource>(sender, callback),
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonAndRun<AboutResource>, callback)),
       url_generator_(url_generator) {
   DCHECK(!callback.is_null());
 }
@@ -399,7 +487,11 @@
     RequestSender* sender,
     const DriveApiUrlGenerator& url_generator,
     const ChangeListCallback& callback)
-    : DriveApiDataRequest<ChangeList>(sender, callback),
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonOnBlockingPoolAndRun<ChangeList>,
+                     make_scoped_refptr(sender->blocking_task_runner()),
+                     callback)),
       url_generator_(url_generator),
       include_deleted_(true),
       max_results_(100),
@@ -419,7 +511,11 @@
 ChangesListNextPageRequest::ChangesListNextPageRequest(
     RequestSender* sender,
     const ChangeListCallback& callback)
-    : DriveApiDataRequest<ChangeList>(sender, callback) {
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonOnBlockingPoolAndRun<ChangeList>,
+                     make_scoped_refptr(sender->blocking_task_runner()),
+                     callback)) {
   DCHECK(!callback.is_null());
 }
 
@@ -437,7 +533,9 @@
     const DriveApiUrlGenerator& url_generator,
     bool use_internal_endpoint,
     const AppListCallback& callback)
-    : DriveApiDataRequest<AppList>(sender, callback),
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonAndRun<AppList>, callback)),
       url_generator_(url_generator),
       use_internal_endpoint_(use_internal_endpoint) {
   DCHECK(!callback.is_null());