| // 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. |
| |
| #include "content/browser/webui/url_data_source_impl.h" |
| |
| #include "base/bind.h" |
| #include "base/memory/ref_counted_memory.h" |
| #include "base/strings/string_util.h" |
| #include "content/browser/webui/url_data_manager_backend.h" |
| #include "content/public/browser/browser_thread.h" |
| #include "content/public/browser/url_data_source.h" |
| |
| namespace content { |
| |
| URLDataSourceImpl::URLDataSourceImpl(const std::string& source_name, |
| URLDataSource* source) |
| : source_name_(source_name), |
| backend_(NULL), |
| source_(source) { |
| } |
| |
| URLDataSourceImpl::~URLDataSourceImpl() { |
| } |
| |
| void URLDataSourceImpl::SendResponse( |
| int request_id, |
| base::RefCountedMemory* bytes) { |
| // Take a ref-pointer on entry so byte->Release() will always get called. |
| scoped_refptr<base::RefCountedMemory> bytes_ptr(bytes); |
| if (URLDataManager::IsScheduledForDeletion(this)) { |
| // We're scheduled for deletion. Servicing the request would result in |
| // this->AddRef being invoked, even though the ref count is 0 and 'this' is |
| // about to be deleted. If the AddRef were allowed through, when 'this' is |
| // released it would be deleted again. |
| // |
| // This scenario occurs with DataSources that make history requests. Such |
| // DataSources do a history query in |StartDataRequest| and the request is |
| // live until the object is deleted (history requests don't up the ref |
| // count). This means it's entirely possible for the DataSource to invoke |
| // |SendResponse| between the time when there are no more refs and the time |
| // when the object is deleted. |
| return; |
| } |
| BrowserThread::PostTask( |
| BrowserThread::IO, FROM_HERE, |
| base::Bind(&URLDataSourceImpl::SendResponseOnIOThread, this, request_id, |
| bytes_ptr)); |
| } |
| |
| void URLDataSourceImpl::SendResponseOnIOThread( |
| int request_id, |
| scoped_refptr<base::RefCountedMemory> bytes) { |
| DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO)); |
| if (backend_) |
| backend_->DataAvailable(request_id, bytes.get()); |
| } |
| |
| } // namespace content |