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 (base::WriteFile(json_file_path_, json_string.data(), data_size) !=
  40       data_size)
  41     return false;
  42
  43   return true;
  44 }
  45
  46 int JSONFileValueSerializer::ReadFileToString(std::string* json_string) {
  47   DCHECK(json_string);
  48   if (!base::ReadFileToString(json_file_path_, json_string)) {
  49 #if defined(OS_WIN)
  50     int error = ::GetLastError();
  51     if (error == ERROR_SHARING_VIOLATION || error == ERROR_LOCK_VIOLATION) {
  52       return JSON_FILE_LOCKED;
  53     } else if (error == ERROR_ACCESS_DENIED) {
  54       return JSON_ACCESS_DENIED;
  55     }
  56 #endif
  57     if (!base::PathExists(json_file_path_))
  58       return JSON_NO_SUCH_FILE;
  59     else
  60       return JSON_CANNOT_READ_FILE;
  61   }
  62   return JSON_NO_ERROR;
  63 }
  64
  65 const char* JSONFileValueSerializer::GetErrorMessageForCode(int error_code) {
  66   switch (error_code) {
  67     case JSON_NO_ERROR:
  68       return "";
  69     case JSON_ACCESS_DENIED:
  70       return kAccessDenied;
  71     case JSON_CANNOT_READ_FILE:
  72       return kCannotReadFile;
  73     case JSON_FILE_LOCKED:
  74       return kFileLocked;
  75     case JSON_NO_SUCH_FILE:
  76       return kNoSuchFile;
  77     default:
  78       NOTREACHED();
  79       return "";
  80   }
  81 }
  82
  83 base::Value* JSONFileValueSerializer::Deserialize(int* error_code,
  84                                                   std::string* error_str) {
  85   std::string json_string;
  86   int error = ReadFileToString(&json_string);
  87   if (error != JSON_NO_ERROR) {
  88     if (error_code)
  89       *error_code = error;
  90     if (error_str)
  91       *error_str = GetErrorMessageForCode(error);
  92     return NULL;
  93   }
  94
  95   JSONStringValueSerializer serializer(json_string);
  96   serializer.set_allow_trailing_comma(allow_trailing_comma_);
  97   return serializer.Deserialize(error_code, error_str);
  98 }