Move the json-related files into a separate json directory. This hopefully al...

base/json_reader.cc

Index: base/json_reader.cc
===================================================================
--- base/json_reader.cc	(revision 29830)
+++ base/json_reader.cc	(working copy)
@@ -1,638 +0,0 @@
-// Copyright (c) 2009 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 "base/json_reader.h"
-
-#include "base/float_util.h"
-#include "base/logging.h"
-#include "base/scoped_ptr.h"
-#include "base/string_util.h"
-#include "base/utf_string_conversions.h"
-#include "base/values.h"
-
-static const JSONReader::Token kInvalidToken(JSONReader::Token::INVALID_TOKEN,
-                                             0, 0);
-static const int kStackLimit = 100;
-
-namespace {
-
-inline int HexToInt(wchar_t c) {
-  if ('0' <= c && c <= '9') {
-    return c - '0';
-  } else if ('A' <= c && c <= 'F') {
-    return c - 'A' + 10;
-  } else if ('a' <= c && c <= 'f') {
-    return c - 'a' + 10;
-  }
-  NOTREACHED();
-  return 0;
-}
-
-// A helper method for ParseNumberToken.  It reads an int from the end of
-// token.  The method returns false if there is no valid integer at the end of
-// the token.
-bool ReadInt(JSONReader::Token& token, bool can_have_leading_zeros) {
-  wchar_t first = token.NextChar();
-  int len = 0;
-
-  // Read in more digits
-  wchar_t c = first;
-  while ('\0' != c && '0' <= c && c <= '9') {
-    ++token.length;
-    ++len;
-    c = token.NextChar();
-  }
-  // We need at least 1 digit.
-  if (len == 0)
-    return false;
-
-  if (!can_have_leading_zeros && len > 1 && '0' == first)
-    return false;
-
-  return true;
-}
-
-// A helper method for ParseStringToken.  It reads |digits| hex digits from the
-// token. If the sequence if digits is not valid (contains other characters),
-// the method returns false.
-bool ReadHexDigits(JSONReader::Token& token, int digits) {
-  for (int i = 1; i <= digits; ++i) {
-    wchar_t c = *(token.begin + token.length + i);
-    if ('\0' == c)
-      return false;
-    if (!(('0' <= c && c <= '9') || ('a' <= c && c <= 'f') ||
-          ('A' <= c && c <= 'F'))) {
-      return false;
-    }
-  }
-
-  token.length += digits;
-  return true;
-}
-
-}  // anonymous namespace
-
-const char* JSONReader::kBadRootElementType =
-    "Root value must be an array or object.";
-const char* JSONReader::kInvalidEscape =
-    "Invalid escape sequence.";
-const char* JSONReader::kSyntaxError =
-    "Syntax error.";
-const char* JSONReader::kTrailingComma =
-    "Trailing comma not allowed.";
-const char* JSONReader::kTooMuchNesting =
-    "Too much nesting.";
-const char* JSONReader::kUnexpectedDataAfterRoot =
-    "Unexpected data after root element.";
-const char* JSONReader::kUnsupportedEncoding =
-    "Unsupported encoding. JSON must be UTF-8.";
-const char* JSONReader::kUnquotedDictionaryKey =
-    "Dictionary keys must be quoted.";
-
-/* static */
-Value* JSONReader::Read(const std::string& json,
-                        bool allow_trailing_comma) {
-  return ReadAndReturnError(json, allow_trailing_comma, NULL);
-}
-
-/* static */
-Value* JSONReader::ReadAndReturnError(const std::string& json,
-                                      bool allow_trailing_comma,
-                                      std::string *error_message_out) {
-  JSONReader reader = JSONReader();
-  Value* root = reader.JsonToValue(json, true, allow_trailing_comma);
-  if (root)
-    return root;
-
-  if (error_message_out)
-    *error_message_out = reader.error_message();
-
-  return NULL;
-}
-
-/* static */
-std::string JSONReader::FormatErrorMessage(int line, int column,
-                                           const char* description) {
-  return StringPrintf("Line: %i, column: %i, %s",
-                      line, column, description);
-}
-
-JSONReader::JSONReader()
-    : start_pos_(NULL), json_pos_(NULL), stack_depth_(0),
-      allow_trailing_comma_(false) {}
-
-Value* JSONReader::JsonToValue(const std::string& json, bool check_root,
-                               bool allow_trailing_comma) {
-  // The input must be in UTF-8.
-  if (!IsStringUTF8(json.c_str())) {
-    error_message_ = kUnsupportedEncoding;
-    return NULL;
-  }
-
-  // The conversion from UTF8 to wstring removes null bytes for us
-  // (a good thing).
-  std::wstring json_wide(UTF8ToWide(json));
-  start_pos_ = json_wide.c_str();
-
-  // When the input JSON string starts with a UTF-8 Byte-Order-Mark
-  // (0xEF, 0xBB, 0xBF), the UTF8ToWide() function converts it to a Unicode
-  // BOM (U+FEFF). To avoid the JSONReader::BuildValue() function from
-  // mis-treating a Unicode BOM as an invalid character and returning NULL,
-  // skip a converted Unicode BOM if it exists.
-  if (!json_wide.empty() && start_pos_[0] == 0xFEFF) {
-    ++start_pos_;
-  }
-
-  json_pos_ = start_pos_;
-  allow_trailing_comma_ = allow_trailing_comma;
-  stack_depth_ = 0;
-  error_message_.clear();
-
-  scoped_ptr<Value> root(BuildValue(check_root));
-  if (root.get()) {
-    if (ParseToken().type == Token::END_OF_INPUT) {
-      return root.release();
-    } else {
-      SetErrorMessage(kUnexpectedDataAfterRoot, json_pos_);
-    }
-  }
-
-  // Default to calling errors "syntax errors".
-  if (error_message_.empty())
-    SetErrorMessage(kSyntaxError, json_pos_);
-
-  return NULL;
-}
-
-Value* JSONReader::BuildValue(bool is_root) {
-  ++stack_depth_;
-  if (stack_depth_ > kStackLimit) {
-    SetErrorMessage(kTooMuchNesting, json_pos_);
-    return NULL;
-  }
-
-  Token token = ParseToken();
-  // The root token must be an array or an object.
-  if (is_root && token.type != Token::OBJECT_BEGIN &&
-      token.type != Token::ARRAY_BEGIN) {
-    SetErrorMessage(kBadRootElementType, json_pos_);
-    return NULL;
-  }
-
-  scoped_ptr<Value> node;
-
-  switch (token.type) {
-    case Token::END_OF_INPUT:
-    case Token::INVALID_TOKEN:
-      return NULL;
-
-    case Token::NULL_TOKEN:
-      node.reset(Value::CreateNullValue());
-      break;
-
-    case Token::BOOL_TRUE:
-      node.reset(Value::CreateBooleanValue(true));
-      break;
-
-    case Token::BOOL_FALSE:
-      node.reset(Value::CreateBooleanValue(false));
-      break;
-
-    case Token::NUMBER:
-      node.reset(DecodeNumber(token));
-      if (!node.get())
-        return NULL;
-      break;
-
-    case Token::STRING:
-      node.reset(DecodeString(token));
-      if (!node.get())
-        return NULL;
-      break;
-
-    case Token::ARRAY_BEGIN:
-      {
-        json_pos_ += token.length;
-        token = ParseToken();
-
-        node.reset(new ListValue());
-        while (token.type != Token::ARRAY_END) {
-          Value* array_node = BuildValue(false);
-          if (!array_node)
-            return NULL;
-          static_cast<ListValue*>(node.get())->Append(array_node);
-
-          // After a list value, we expect a comma or the end of the list.
-          token = ParseToken();
-          if (token.type == Token::LIST_SEPARATOR) {
-            json_pos_ += token.length;
-            token = ParseToken();
-            // Trailing commas are invalid according to the JSON RFC, but some
-            // consumers need the parsing leniency, so handle accordingly.
-            if (token.type == Token::ARRAY_END) {
-              if (!allow_trailing_comma_) {
-                SetErrorMessage(kTrailingComma, json_pos_);
-                return NULL;
-              }
-              // Trailing comma OK, stop parsing the Array.
-              break;
-            }
-          } else if (token.type != Token::ARRAY_END) {
-            // Unexpected value after list value.  Bail out.
-            return NULL;
-          }
-        }
-        if (token.type != Token::ARRAY_END) {
-          return NULL;
-        }
-        break;
-      }
-
-    case Token::OBJECT_BEGIN:
-      {
-        json_pos_ += token.length;
-        token = ParseToken();
-
-        node.reset(new DictionaryValue);
-        while (token.type != Token::OBJECT_END) {
-          if (token.type != Token::STRING) {
-            SetErrorMessage(kUnquotedDictionaryKey, json_pos_);
-            return NULL;
-          }
-          scoped_ptr<Value> dict_key_value(DecodeString(token));
-          if (!dict_key_value.get())
-            return NULL;
-
-          // Convert the key into a wstring.
-          std::wstring dict_key;
-          bool success = dict_key_value->GetAsString(&dict_key);
-          DCHECK(success);
-
-          json_pos_ += token.length;
-          token = ParseToken();
-          if (token.type != Token::OBJECT_PAIR_SEPARATOR)
-            return NULL;
-
-          json_pos_ += token.length;
-          token = ParseToken();
-          Value* dict_value = BuildValue(false);
-          if (!dict_value)
-            return NULL;
-          static_cast<DictionaryValue*>(node.get())->Set(dict_key, dict_value);
-
-          // After a key/value pair, we expect a comma or the end of the
-          // object.
-          token = ParseToken();
-          if (token.type == Token::LIST_SEPARATOR) {
-            json_pos_ += token.length;
-            token = ParseToken();
-            // Trailing commas are invalid according to the JSON RFC, but some
-            // consumers need the parsing leniency, so handle accordingly.
-            if (token.type == Token::OBJECT_END) {
-              if (!allow_trailing_comma_) {
-                SetErrorMessage(kTrailingComma, json_pos_);
-                return NULL;
-              }
-              // Trailing comma OK, stop parsing the Object.
-              break;
-            }
-          } else if (token.type != Token::OBJECT_END) {
-            // Unexpected value after last object value.  Bail out.
-            return NULL;
-          }
-        }
-        if (token.type != Token::OBJECT_END)
-          return NULL;
-
-        break;
-      }
-
-    default:
-      // We got a token that's not a value.
-      return NULL;
-  }
-  json_pos_ += token.length;
-
-  --stack_depth_;
-  return node.release();
-}
-
-JSONReader::Token JSONReader::ParseNumberToken() {
-  // We just grab the number here.  We validate the size in DecodeNumber.
-  // According   to RFC4627, a valid number is: [minus] int [frac] [exp]
-  Token token(Token::NUMBER, json_pos_, 0);
-  wchar_t c = *json_pos_;
-  if ('-' == c) {
-    ++token.length;
-    c = token.NextChar();
-  }
-
-  if (!ReadInt(token, false))
-    return kInvalidToken;
-
-  // Optional fraction part
-  c = token.NextChar();
-  if ('.' == c) {
-    ++token.length;
-    if (!ReadInt(token, true))
-      return kInvalidToken;
-    c = token.NextChar();
-  }
-
-  // Optional exponent part
-  if ('e' == c || 'E' == c) {
-    ++token.length;
-    c = token.NextChar();
-    if ('-' == c || '+' == c) {
-      ++token.length;
-      c = token.NextChar();
-    }
-    if (!ReadInt(token, true))
-      return kInvalidToken;
-  }
-
-  return token;
-}
-
-Value* JSONReader::DecodeNumber(const Token& token) {
-  const std::wstring num_string(token.begin, token.length);
-
-  int num_int;
-  if (StringToInt(WideToUTF16Hack(num_string), &num_int))
-    return Value::CreateIntegerValue(num_int);
-
-  double num_double;
-  if (StringToDouble(WideToUTF16Hack(num_string), &num_double) &&
-      base::IsFinite(num_double))
-    return Value::CreateRealValue(num_double);
-
-  return NULL;
-}
-
-JSONReader::Token JSONReader::ParseStringToken() {
-  Token token(Token::STRING, json_pos_, 1);
-  wchar_t c = token.NextChar();
-  while ('\0' != c) {
-    if ('\\' == c) {
-      ++token.length;
-      c = token.NextChar();
-      // Make sure the escaped char is valid.
-      switch (c) {
-        case 'x':
-          if (!ReadHexDigits(token, 2)) {
-            SetErrorMessage(kInvalidEscape, json_pos_ + token.length);
-            return kInvalidToken;
-          }
-          break;
-        case 'u':
-          if (!ReadHexDigits(token, 4)) {
-            SetErrorMessage(kInvalidEscape, json_pos_ + token.length);
-            return kInvalidToken;
-          }
-          break;
-        case '\\':
-        case '/':
-        case 'b':
-        case 'f':
-        case 'n':
-        case 'r':
-        case 't':
-        case 'v':
-        case '"':
-          break;
-        default:
-          SetErrorMessage(kInvalidEscape, json_pos_ + token.length);
-          return kInvalidToken;
-      }
-    } else if ('"' == c) {
-      ++token.length;
-      return token;
-    }
-    ++token.length;
-    c = token.NextChar();
-  }
-  return kInvalidToken;
-}
-
-Value* JSONReader::DecodeString(const Token& token) {
-  std::wstring decoded_str;
-  decoded_str.reserve(token.length - 2);
-
-  for (int i = 1; i < token.length - 1; ++i) {
-    wchar_t c = *(token.begin + i);
-    if ('\\' == c) {
-      ++i;
-      c = *(token.begin + i);
-      switch (c) {
-        case '"':
-        case '/':
-        case '\\':
-          decoded_str.push_back(c);
-          break;
-        case 'b':
-          decoded_str.push_back('\b');
-          break;
-        case 'f':
-          decoded_str.push_back('\f');
-          break;
-        case 'n':
-          decoded_str.push_back('\n');
-          break;
-        case 'r':
-          decoded_str.push_back('\r');
-          break;
-        case 't':
-          decoded_str.push_back('\t');
-          break;
-        case 'v':
-          decoded_str.push_back('\v');
-          break;
-
-        case 'x':
-          decoded_str.push_back((HexToInt(*(token.begin + i + 1)) << 4) +
-                                HexToInt(*(token.begin + i + 2)));
-          i += 2;
-          break;
-        case 'u':
-          decoded_str.push_back((HexToInt(*(token.begin + i + 1)) << 12 ) +
-                                (HexToInt(*(token.begin + i + 2)) << 8) +
-                                (HexToInt(*(token.begin + i + 3)) << 4) +
-                                HexToInt(*(token.begin + i + 4)));
-          i += 4;
-          break;
-
-        default:
-          // We should only have valid strings at this point.  If not,
-          // ParseStringToken didn't do it's job.
-          NOTREACHED();
-          return NULL;
-      }
-    } else {
-      // Not escaped
-      decoded_str.push_back(c);
-    }
-  }
-  return Value::CreateStringValue(decoded_str);
-}
-
-JSONReader::Token JSONReader::ParseToken() {
-  static const std::wstring kNullString(L"null");
-  static const std::wstring kTrueString(L"true");
-  static const std::wstring kFalseString(L"false");
-
-  EatWhitespaceAndComments();
-
-  Token token(Token::INVALID_TOKEN, 0, 0);
-  switch (*json_pos_) {
-    case '\0':
-      token.type = Token::END_OF_INPUT;
-      break;
-
-    case 'n':
-      if (NextStringMatch(kNullString))
-        token = Token(Token::NULL_TOKEN, json_pos_, 4);
-      break;
-
-    case 't':
-      if (NextStringMatch(kTrueString))
-        token = Token(Token::BOOL_TRUE, json_pos_, 4);
-      break;
-
-    case 'f':
-      if (NextStringMatch(kFalseString))
-        token = Token(Token::BOOL_FALSE, json_pos_, 5);
-      break;
-
-    case '[':
-      token = Token(Token::ARRAY_BEGIN, json_pos_, 1);
-      break;
-
-    case ']':
-      token = Token(Token::ARRAY_END, json_pos_, 1);
-      break;
-
-    case ',':
-      token = Token(Token::LIST_SEPARATOR, json_pos_, 1);
-      break;
-
-    case '{':
-      token = Token(Token::OBJECT_BEGIN, json_pos_, 1);
-      break;
-
-    case '}':
-      token = Token(Token::OBJECT_END, json_pos_, 1);
-      break;
-
-    case ':':
-      token = Token(Token::OBJECT_PAIR_SEPARATOR, json_pos_, 1);
-      break;
-
-    case '0':
-    case '1':
-    case '2':
-    case '3':
-    case '4':
-    case '5':
-    case '6':
-    case '7':
-    case '8':
-    case '9':
-    case '-':
-      token = ParseNumberToken();
-      break;
-
-    case '"':
-      token = ParseStringToken();
-      break;
-  }
-  return token;
-}
-
-bool JSONReader::NextStringMatch(const std::wstring& str) {
-  for (size_t i = 0; i < str.length(); ++i) {
-    if ('\0' == *json_pos_)
-      return false;
-    if (*(json_pos_ + i) != str[i])
-      return false;
-  }
-  return true;
-}
-
-void JSONReader::EatWhitespaceAndComments() {
-  while ('\0' != *json_pos_) {
-    switch (*json_pos_) {
-      case ' ':
-      case '\n':
-      case '\r':
-      case '\t':
-        ++json_pos_;
-        break;
-      case '/':
-        // TODO(tc): This isn't in the RFC so it should be a parser flag.
-        if (!EatComment())
-          return;
-        break;
-      default:
-        // Not a whitespace char, just exit.
-        return;
-    }
-  }
-}
-
-bool JSONReader::EatComment() {
-  if ('/' != *json_pos_)
-    return false;
-
-  wchar_t next_char = *(json_pos_ + 1);
-  if ('/' == next_char) {
-    // Line comment, read until \n or \r
-    json_pos_ += 2;
-    while ('\0' != *json_pos_) {
-      switch (*json_pos_) {
-        case '\n':
-        case '\r':
-          ++json_pos_;
-          return true;
-        default:
-          ++json_pos_;
-      }
-    }
-  } else if ('*' == next_char) {
-    // Block comment, read until */
-    json_pos_ += 2;
-    while ('\0' != *json_pos_) {
-      if ('*' == *json_pos_ && '/' == *(json_pos_ + 1)) {
-        json_pos_ += 2;
-        return true;
-      }
-      ++json_pos_;
-    }
-  } else {
-    return false;
-  }
-  return true;
-}
-
-void JSONReader::SetErrorMessage(const char* description,
-                                 const wchar_t* error_pos) {
-  int line_number = 1;
-  int column_number = 1;
-
-  // Figure out the line and column the error occured at.
-  for (const wchar_t* pos = start_pos_; pos != error_pos; ++pos) {
-    if (*pos == '\0') {
-      NOTREACHED();
-      return;
-    }
-
-    if (*pos == '\n') {
-      ++line_number;
-      column_number = 1;
-    } else {
-      ++column_number;
-    }
-  }
-
-  error_message_ = FormatErrorMessage(line_number, column_number, description);
-}