IndexedDB: Recycle cursor objects when calling continue().

content/renderer/indexed_db_dispatcher.cc

 // Copyright (c) 2011 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.
 
 #include "content/renderer/indexed_db_dispatcher.h"
 
 #include "content/common/indexed_db_messages.h"
 #include "content/renderer/render_thread_impl.h"
 #include "content/renderer/render_view_impl.h"
 #include "content/renderer/renderer_webidbcursor_impl.h"
@@ skipping 24 matching lines @@
 }
 
 IndexedDBDispatcher::~IndexedDBDispatcher() {
 }
 
 bool IndexedDBDispatcher::OnMessageReceived(const IPC::Message& msg) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(IndexedDBDispatcher, msg)
     IPC_MESSAGE_HANDLER(IndexedDBMsg_CallbacksSuccessIDBCursor,
                         OnSuccessOpenCursor)
+    IPC_MESSAGE_HANDLER(IndexedDBMsg_CallbacksSuccessCursorContinue,
+                        OnSuccessCursorContinue)
     IPC_MESSAGE_HANDLER(IndexedDBMsg_CallbacksSuccessIDBDatabase,
                         OnSuccessIDBDatabase)
     IPC_MESSAGE_HANDLER(IndexedDBMsg_CallbacksSuccessIndexedDBKey,
                         OnSuccessIndexedDBKey)
     IPC_MESSAGE_HANDLER(IndexedDBMsg_CallbacksSuccessIDBTransaction,
                         OnSuccessIDBTransaction)
     IPC_MESSAGE_HANDLER(IndexedDBMsg_CallbacksSuccessStringList,
                         OnSuccessStringList)
     IPC_MESSAGE_HANDLER(IndexedDBMsg_CallbacksSuccessSerializedScriptValue,
                         OnSuccessSerializedScriptValue)
@@ skipping 356 matching lines @@
     int32 response_id, const std::vector<string16>& value) {
   WebIDBCallbacks* callbacks = pending_callbacks_.Lookup(response_id);
   WebDOMStringList string_list;
   for (std::vector<string16>::const_iterator it = value.begin();
        it != value.end(); ++it)
       string_list.append(*it);
   callbacks->onSuccess(string_list);
   pending_callbacks_.Remove(response_id);
 }
 
 void IndexedDBDispatcher::OnSuccessSerializedScriptValue(

[michaeln, 2011/10/31 18:58:25]

When the cursor hits the end, what should it's key, value, and primaryKey
attributes reflect? I'm wondering what values should be stuff into the
RendererWebIDBCursorImpl instance at this time.

[hans, 2011/11/01 14:57:45]

That's a good question. The spec only says that the result when stepping a
cursor hits the end should be "null", and we do that. It doesn't say what should
happen with the old cursor object, though, if the user keeps a reference to it.

I don't have any strong views here.

     int32 response_id, const content::SerializedScriptValue& value) {
   WebIDBCallbacks* callbacks = pending_callbacks_.Lookup(response_id);
   callbacks->onSuccess(value);
   pending_callbacks_.Remove(response_id);
 }
 
 void IndexedDBDispatcher::OnSuccessOpenCursor(int32 repsonse_id,
-    int32 object_id, const IndexedDBKey& key, const IndexedDBKey& primaryKey,
+    int32 object_id, const IndexedDBKey& key, const IndexedDBKey& primary_key,
     const content::SerializedScriptValue& value) {
   WebIDBCallbacks* callbacks =
       pending_callbacks_.Lookup(repsonse_id);
-  callbacks->onSuccess(new RendererWebIDBCursorImpl(object_id, key,
-                       primaryKey, value));
+
+  RendererWebIDBCursorImpl* cursor = new RendererWebIDBCursorImpl(object_id);
+  cursors_[object_id] = cursor;
+  cursor->setKeyAndValue(key, primary_key, value);
+  callbacks->onSuccess(cursor);
+
   pending_callbacks_.Remove(repsonse_id);
 }
 
+void IndexedDBDispatcher::OnSuccessCursorContinue(
+    int32 response_id,
+    int32 cursor_id,
+    const IndexedDBKey& key,
+    const IndexedDBKey& primary_key,
+    const content::SerializedScriptValue& value) {
+
+  RendererWebIDBCursorImpl* cursor = cursors_[cursor_id];

[michaeln, 2011/10/31 18:58:25]

DCHECK(cursor)

[hans, 2011/11/01 14:57:45]

Done.

+  cursor->setKeyAndValue(key, primary_key, value);
+
+  WebIDBCallbacks* callbacks = pending_callbacks_.Lookup(response_id);
+  callbacks->onSuccessCursorContinue();
+
+  pending_callbacks_.Remove(response_id);
+}
+
 void IndexedDBDispatcher::OnBlocked(int32 response_id) {
   WebIDBCallbacks* callbacks = pending_callbacks_.Lookup(response_id);
   callbacks->onBlocked();
 }
 
 void IndexedDBDispatcher::OnError(int32 response_id, int code,
                                   const string16& message) {
   WebIDBCallbacks* callbacks = pending_callbacks_.Lookup(response_id);
   callbacks->onError(WebIDBDatabaseError(code, message));
   pending_callbacks_.Remove(response_id);
@@ skipping 15 matching lines @@
 
 void IndexedDBDispatcher::OnVersionChange(int32 database_id,
                                           const string16& newVersion) {
   WebIDBDatabaseCallbacks* callbacks =
       pending_database_callbacks_.Lookup(database_id);
   // callbacks would be NULL if a versionchange event is received after close
   // has been called.
   if (callbacks)
     callbacks->onVersionChange(newVersion);
 }
+
+void IndexedDBDispatcher::CursorDestroyed(int32 cursor_id) {
+  cursors_.erase(cursor_id);
+}