chrome/browser/safe_json_parser.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/safe_json_parser.h"
   6
   7 #include "chrome/common/chrome_utility_messages.h"
   8 #include "content/public/browser/browser_thread.h"
   9 #include "content/public/browser/utility_process_host.h"
  10
  11 using content::BrowserThread;
  12 using content::UtilityProcessHost;
  13
  14 SafeJsonParser::SafeJsonParser(const std::string& unsafe_json,
  15                                const SuccessCallback& success_callback,
  16                                const ErrorCallback& error_callback)
  17     : unsafe_json_(unsafe_json),
  18       success_callback_(success_callback),
  19       error_callback_(error_callback) {}
  20
  21 void SafeJsonParser::Start() {
  22   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  23   BrowserThread::PostTask(
  24       BrowserThread::IO,
  25       FROM_HERE,
  26       base::Bind(&SafeJsonParser::StartWorkOnIOThread, this));
  27 }
  28
  29 SafeJsonParser::~SafeJsonParser() {}
  30
  31 void SafeJsonParser::StartWorkOnIOThread() {
  32   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  33   UtilityProcessHost* host =
  34       UtilityProcessHost::Create(this, base::MessageLoopProxy::current().get());
  35   host->Send(new ChromeUtilityMsg_ParseJSON(unsafe_json_));
  36 }
  37
  38 void SafeJsonParser::OnJSONParseSucceeded(const base::ListValue& wrapper) {
  39   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  40   const base::Value* value = NULL;
  41   CHECK(wrapper.Get(0, &value));
  42
  43   parsed_json_.reset(value->DeepCopy());
  44   ReportResults();
  45 }
  46
  47 void SafeJsonParser::OnJSONParseFailed(const std::string& error_message) {
  48   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  49   error_ = error_message;
  50   ReportResults();
  51 }
  52
  53 void SafeJsonParser::ReportResults() {
  54   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  55
  56   BrowserThread::PostTask(
  57       BrowserThread::UI,
  58       FROM_HERE,
  59       base::Bind(&SafeJsonParser::ReportResultOnUIThread, this));
  60 }
  61
  62 void SafeJsonParser::ReportResultOnUIThread() {
  63   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  64   if (error_.empty() && parsed_json_) {
  65     if (!success_callback_.is_null())
  66       success_callback_.Run(parsed_json_.Pass());
  67   } else {
  68     if (!error_callback_.is_null())
  69       error_callback_.Run(error_);
  70   }
  71 }
  72
  73 bool SafeJsonParser::OnMessageReceived(const IPC::Message& message) {
  74   bool handled = true;
  75   IPC_BEGIN_MESSAGE_MAP(SafeJsonParser, message)
  76     IPC_MESSAGE_HANDLER(ChromeUtilityHostMsg_ParseJSON_Succeeded,
  77                         OnJSONParseSucceeded)
  78     IPC_MESSAGE_HANDLER(ChromeUtilityHostMsg_ParseJSON_Failed,
  79                         OnJSONParseFailed)
  80     IPC_MESSAGE_UNHANDLED(handled = false)
  81   IPC_END_MESSAGE_MAP()
  82   return handled;
  83 }