components/safe_json_parser/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 "components/safe_json_parser/safe_json_parser.h"
   6
   7 #include <string>
   8
   9 #include "base/strings/utf_string_conversions.h"
  10 #include "base/thread_task_runner_handle.h"
  11 #include "base/tuple.h"
  12 #include "base/values.h"
  13 #include "components/safe_json_parser/safe_json_parser_messages.h"
  14 #include "content/public/browser/browser_thread.h"
  15 #include "content/public/browser/utility_process_host.h"
  16 #include "grit/components_strings.h"
  17 #include "ipc/ipc_message_macros.h"
  18 #include "ui/base/l10n/l10n_util.h"
  19
  20 using content::BrowserThread;
  21 using content::UtilityProcessHost;
  22
  23 namespace safe_json_parser {
  24
  25 SafeJsonParser::SafeJsonParser(const std::string& unsafe_json,
  26                                const SuccessCallback& success_callback,
  27                                const ErrorCallback& error_callback)
  28     : unsafe_json_(unsafe_json),
  29       success_callback_(success_callback),
  30       error_callback_(error_callback) {
  31 }
  32
  33 void SafeJsonParser::Start() {
  34   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  35   BrowserThread::PostTask(
  36       BrowserThread::IO, FROM_HERE,
  37       base::Bind(&SafeJsonParser::StartWorkOnIOThread, this));
  38 }
  39
  40 SafeJsonParser::~SafeJsonParser() {
  41 }
  42
  43 void SafeJsonParser::StartWorkOnIOThread() {
  44   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  45   UtilityProcessHost* host = UtilityProcessHost::Create(
  46       this, base::ThreadTaskRunnerHandle::Get().get());
  47   host->SetName(
  48       l10n_util::GetStringUTF16(IDS_UTILITY_PROCESS_JSON_PARSER_NAME));
  49   host->Send(new SafeJsonParserMsg_ParseJSON(unsafe_json_));
  50 }
  51
  52 void SafeJsonParser::OnJSONParseSucceeded(const base::ListValue& wrapper) {
  53   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  54   const base::Value* value = NULL;
  55   CHECK(wrapper.Get(0, &value));
  56
  57   parsed_json_.reset(value->DeepCopy());
  58   ReportResults();
  59 }
  60
  61 void SafeJsonParser::OnJSONParseFailed(const std::string& error_message) {
  62   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  63   error_ = error_message;
  64   ReportResults();
  65 }
  66
  67 void SafeJsonParser::ReportResults() {
  68   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  69
  70   BrowserThread::PostTask(
  71       BrowserThread::UI, FROM_HERE,
  72       base::Bind(&SafeJsonParser::ReportResultOnUIThread, this));
  73 }
  74
  75 void SafeJsonParser::ReportResultOnUIThread() {
  76   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  77   if (error_.empty() && parsed_json_) {
  78     if (!success_callback_.is_null())
  79       success_callback_.Run(parsed_json_.Pass());
  80   } else {
  81     if (!error_callback_.is_null())
  82       error_callback_.Run(error_);
  83   }
  84 }
  85
  86 bool SafeJsonParser::OnMessageReceived(const IPC::Message& message) {
  87   bool handled = true;
  88   IPC_BEGIN_MESSAGE_MAP(SafeJsonParser, message)
  89     IPC_MESSAGE_HANDLER(SafeJsonParserHostMsg_ParseJSON_Succeeded,
  90                         OnJSONParseSucceeded)
  91     IPC_MESSAGE_HANDLER(SafeJsonParserHostMsg_ParseJSON_Failed,
  92                         OnJSONParseFailed)
  93     IPC_MESSAGE_UNHANDLED(handled = false)
  94   IPC_END_MESSAGE_MAP()
  95   return handled;
  96 }
  97
  98 }  // namespace safe_json_parser