base/json/json_file_value_serializer.cc

   1 // Copyright (c) 2012 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 "base/json/json_file_value_serializer.h"
   6
   7 #include "base/file_util.h"
   8 #include "base/json/json_string_value_serializer.h"
   9 #include "base/logging.h"
  10
  11 using base::FilePath;
  12
  13 const char* JSONFileValueSerializer::kAccessDenied = "Access denied.";
  14 const char* JSONFileValueSerializer::kCannotReadFile = "Can't read file.";
  15 const char* JSONFileValueSerializer::kFileLocked = "File locked.";
  16 const char* JSONFileValueSerializer::kNoSuchFile = "File doesn't exist.";
  17
  18 bool JSONFileValueSerializer::Serialize(const base::Value& root) {
  19   return SerializeInternal(root, false);
  20 }
  21
  22 bool JSONFileValueSerializer::SerializeAndOmitBinaryValues(
  23     const base::Value& root) {
  24   return SerializeInternal(root, true);
  25 }
  26
  27 bool JSONFileValueSerializer::SerializeInternal(const base::Value& root,
  28                                                 bool omit_binary_values) {
  29   std::string json_string;
  30   JSONStringValueSerializer serializer(&json_string);
  31   serializer.set_pretty_print(true);
  32   bool result = omit_binary_values ?
  33       serializer.SerializeAndOmitBinaryValues(root) :
  34       serializer.Serialize(root);
  35   if (!result)
  36     return false;
  37
  38   int data_size = static_cast<int>(json_string.size());
  39   if (file_util::WriteFile(json_file_path_,
  40                            json_string.data(),
  41                            data_size) != data_size)
  42     return false;
  43
  44   return true;
  45 }
  46
  47 int JSONFileValueSerializer::ReadFileToString(std::string* json_string) {
  48   DCHECK(json_string);
  49   if (!base::ReadFileToString(json_file_path_, json_string)) {
  50 #if defined(OS_WIN)
  51     int error = ::GetLastError();
  52     if (error == ERROR_SHARING_VIOLATION || error == ERROR_LOCK_VIOLATION) {
  53       return JSON_FILE_LOCKED;
  54     } else if (error == ERROR_ACCESS_DENIED) {
  55       return JSON_ACCESS_DENIED;
  56     }
  57 #endif
  58     if (!base::PathExists(json_file_path_))
  59       return JSON_NO_SUCH_FILE;
  60     else
  61       return JSON_CANNOT_READ_FILE;
  62   }
  63   return JSON_NO_ERROR;
  64 }
  65
  66 const char* JSONFileValueSerializer::GetErrorMessageForCode(int error_code) {
  67   switch (error_code) {
  68     case JSON_NO_ERROR:
  69       return "";
  70     case JSON_ACCESS_DENIED:
  71       return kAccessDenied;
  72     case JSON_CANNOT_READ_FILE:
  73       return kCannotReadFile;
  74     case JSON_FILE_LOCKED:
  75       return kFileLocked;
  76     case JSON_NO_SUCH_FILE:
  77       return kNoSuchFile;
  78     default:
  79       NOTREACHED();
  80       return "";
  81   }
  82 }
  83
  84 base::Value* JSONFileValueSerializer::Deserialize(int* error_code,
  85                                                   std::string* error_str) {
  86   std::string json_string;
  87   int error = ReadFileToString(&json_string);
  88   if (error != JSON_NO_ERROR) {
  89     if (error_code)
  90       *error_code = error;
  91     if (error_str)
  92       *error_str = GetErrorMessageForCode(error);
  93     return NULL;
  94   }
  95
  96   JSONStringValueSerializer serializer(json_string);
  97   serializer.set_allow_trailing_comma(allow_trailing_comma_);
  98   return serializer.Deserialize(error_code, error_str);
  99 }