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/*
* Copyright (C) 2010 Google Inc. All rights reserved.
* Copyright (C) 2014 University of Washington. All rights reserved.
* Copyright (C) 2017-2019 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include <wtf/JSONValues.h>
#include <wtf/text/StringBuilder.h>
namespace WTF {
namespace JSONImpl {
namespace {
static const int stackLimit = 1000;
enum class Token {
ObjectBegin,
ObjectEnd,
ArrayBegin,
ArrayEnd,
String,
Number,
BoolTrue,
BoolFalse,
Null,
ListSeparator,
ObjectPairSeparator,
Invalid,
};
const char* const nullString = "null";
const char* const trueString = "true";
const char* const falseString = "false";
bool parseConstToken(const UChar* start, const UChar* end, const UChar** tokenEnd, const char* token)
{
while (start < end && *token != '\0' && *start++ == *token++) { }
if (*token != '\0')
return false;
*tokenEnd = start;
return true;
}
bool readInt(const UChar* start, const UChar* end, const UChar** tokenEnd, bool canHaveLeadingZeros)
{
if (start == end)
return false;
bool haveLeadingZero = '0' == *start;
int length = 0;
while (start < end && '0' <= *start && *start <= '9') {
++start;
++length;
}
if (!length)
return false;
if (!canHaveLeadingZeros && length > 1 && haveLeadingZero)
return false;
*tokenEnd = start;
return true;
}
bool parseNumberToken(const UChar* start, const UChar* end, const UChar** tokenEnd)
{
// We just grab the number here. We validate the size in DecodeNumber.
// According to RFC 4627, a valid number is: [minus] int [frac] [exp]
if (start == end)
return false;
UChar c = *start;
if ('-' == c)
++start;
if (!readInt(start, end, &start, false))
return false;
if (start == end) {
*tokenEnd = start;
return true;
}
// Optional fraction part.
c = *start;
if ('.' == c) {
++start;
if (!readInt(start, end, &start, true))
return false;
if (start == end) {
*tokenEnd = start;
return true;
}
c = *start;
}
// Optional exponent part.
if ('e' == c || 'E' == c) {
++start;
if (start == end)
return false;
c = *start;
if ('-' == c || '+' == c) {
++start;
if (start == end)
return false;
}
if (!readInt(start, end, &start, true))
return false;
}
*tokenEnd = start;
return true;
}
bool readHexDigits(const UChar* start, const UChar* end, const UChar** tokenEnd, int digits)
{
if (end - start < digits)
return false;
for (int i = 0; i < digits; ++i) {
if (!isASCIIHexDigit(*start++))
return false;
}
*tokenEnd = start;
return true;
}
bool parseStringToken(const UChar* start, const UChar* end, const UChar** tokenEnd)
{
while (start < end) {
UChar c = *start++;
if ('\\' == c && start < end) {
c = *start++;
// Make sure the escaped char is valid.
switch (c) {
case 'x':
if (!readHexDigits(start, end, &start, 2))
return false;
break;
case 'u':
if (!readHexDigits(start, end, &start, 4))
return false;
break;
case '\\':
case '/':
case 'b':
case 'f':
case 'n':
case 'r':
case 't':
case 'v':
case '"':
break;
default:
return false;
}
} else if ('"' == c) {
*tokenEnd = start;
return true;
}
}
return false;
}
Token parseToken(const UChar* start, const UChar* end, const UChar** tokenStart, const UChar** tokenEnd)
{
while (start < end && isSpaceOrNewline(*start))
++start;
if (start == end)
return Token::Invalid;
*tokenStart = start;
switch (*start) {
case 'n':
if (parseConstToken(start, end, tokenEnd, nullString))
return Token::Null;
break;
case 't':
if (parseConstToken(start, end, tokenEnd, trueString))
return Token::BoolTrue;
break;
case 'f':
if (parseConstToken(start, end, tokenEnd, falseString))
return Token::BoolFalse;
break;
case '[':
*tokenEnd = start + 1;
return Token::ArrayBegin;
case ']':
*tokenEnd = start + 1;
return Token::ArrayEnd;
case ',':
*tokenEnd = start + 1;
return Token::ListSeparator;
case '{':
*tokenEnd = start + 1;
return Token::ObjectBegin;
case '}':
*tokenEnd = start + 1;
return Token::ObjectEnd;
case ':':
*tokenEnd = start + 1;
return Token::ObjectPairSeparator;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
case '-':
if (parseNumberToken(start, end, tokenEnd))
return Token::Number;
break;
case '"':
if (parseStringToken(start + 1, end, tokenEnd))
return Token::String;
break;
}
return Token::Invalid;
}
bool decodeString(const UChar* start, const UChar* end, StringBuilder& output)
{
while (start < end) {
UChar c = *start++;
if ('\\' != c) {
output.append(c);
continue;
}
if (UNLIKELY(start >= end))
return false;
c = *start++;
switch (c) {
case '"':
case '/':
case '\\':
break;
case 'b':
c = '\b';
break;
case 'f':
c = '\f';
break;
case 'n':
c = '\n';
break;
case 'r':
c = '\r';
break;
case 't':
c = '\t';
break;
case 'v':
c = '\v';
break;
case 'x':
if (UNLIKELY(start + 1 >= end))
return false;
c = toASCIIHexValue(start[0], start[1]);
start += 2;
break;
case 'u':
if (UNLIKELY(start + 3 >= end))
return false;
c = toASCIIHexValue(start[0], start[1]) << 8 | toASCIIHexValue(start[2], start[3]);
start += 4;
break;
default:
return false;
}
output.append(c);
}
return true;
}
bool decodeString(const UChar* start, const UChar* end, String& output)
{
if (start == end) {
output = emptyString();
return true;
}
if (start > end)
return false;
StringBuilder buffer;
buffer.reserveCapacity(end - start);
if (!decodeString(start, end, buffer))
return false;
output = buffer.toString();
return true;
}
RefPtr<JSON::Value> buildValue(const UChar* start, const UChar* end, const UChar** valueTokenEnd, int depth)
{
if (depth > stackLimit)
return nullptr;
RefPtr<JSON::Value> result;
const UChar* tokenStart;
const UChar* tokenEnd;
Token token = parseToken(start, end, &tokenStart, &tokenEnd);
switch (token) {
case Token::Invalid:
return nullptr;
case Token::Null:
result = JSON::Value::null();
break;
case Token::BoolTrue:
result = JSON::Value::create(true);
break;
case Token::BoolFalse:
result = JSON::Value::create(false);
break;
case Token::Number: {
bool ok;
double value = charactersToDouble(tokenStart, tokenEnd - tokenStart, &ok);
if (!ok)
return nullptr;
result = JSON::Value::create(value);
break;
}
case Token::String: {
String value;
bool ok = decodeString(tokenStart + 1, tokenEnd - 1, value);
if (!ok)
return nullptr;
result = JSON::Value::create(value);
break;
}
case Token::ArrayBegin: {
Ref<JSON::Array> array = JSON::Array::create();
start = tokenEnd;
token = parseToken(start, end, &tokenStart, &tokenEnd);
while (token != Token::ArrayEnd) {
RefPtr<JSON::Value> arrayNode = buildValue(start, end, &tokenEnd, depth + 1);
if (!arrayNode)
return nullptr;
array->pushValue(WTFMove(arrayNode));
// After a list value, we expect a comma or the end of the list.
start = tokenEnd;
token = parseToken(start, end, &tokenStart, &tokenEnd);
if (token == Token::ListSeparator) {
start = tokenEnd;
token = parseToken(start, end, &tokenStart, &tokenEnd);
if (token == Token::ArrayEnd)
return nullptr;
} else if (token != Token::ArrayEnd) {
// Unexpected value after list value. Bail out.
return nullptr;
}
}
if (token != Token::ArrayEnd)
return nullptr;
result = WTFMove(array);
break;
}
case Token::ObjectBegin: {
Ref<JSON::Object> object = JSON::Object::create();
start = tokenEnd;
token = parseToken(start, end, &tokenStart, &tokenEnd);
while (token != Token::ObjectEnd) {
if (token != Token::String)
return nullptr;
String key;
if (!decodeString(tokenStart + 1, tokenEnd - 1, key))
return nullptr;
start = tokenEnd;
token = parseToken(start, end, &tokenStart, &tokenEnd);
if (token != Token::ObjectPairSeparator)
return nullptr;
start = tokenEnd;
RefPtr<JSON::Value> value = buildValue(start, end, &tokenEnd, depth + 1);
if (!value)
return nullptr;
object->setValue(key, WTFMove(value));
start = tokenEnd;
// After a key/value pair, we expect a comma or the end of the
// object.
token = parseToken(start, end, &tokenStart, &tokenEnd);
if (token == Token::ListSeparator) {
start = tokenEnd;
token = parseToken(start, end, &tokenStart, &tokenEnd);
if (token == Token::ObjectEnd)
return nullptr;
} else if (token != Token::ObjectEnd) {
// Unexpected value after last object value. Bail out.
return nullptr;
}
}
if (token != Token::ObjectEnd)
return nullptr;
result = WTFMove(object);
break;
}
default:
// We got a token that's not a value.
return nullptr;
}
*valueTokenEnd = tokenEnd;
return result;
}
inline void appendDoubleQuotedString(StringBuilder& builder, StringView string)
{
builder.append('"');
for (UChar codeUnit : string.codeUnits()) {
switch (codeUnit) {
case '\b':
builder.appendLiteral("\\b");
continue;
case '\f':
builder.appendLiteral("\\f");
continue;
case '\n':
builder.appendLiteral("\\n");
continue;
case '\r':
builder.appendLiteral("\\r");
continue;
case '\t':
builder.appendLiteral("\\t");
continue;
case '\\':
builder.appendLiteral("\\\\");
continue;
case '"':
builder.appendLiteral("\\\"");
continue;
}
// We escape < and > to prevent script execution.
if (codeUnit >= 32 && codeUnit < 127 && codeUnit != '<' && codeUnit != '>') {
builder.append(codeUnit);
continue;
}
// We could encode characters >= 127 as UTF-8 instead of \u escape sequences.
// We could handle surrogates here if callers wanted that; for now we just
// write them out as a \u sequence, so a surrogate pair appears as two of them.
builder.appendLiteral("\\u");
builder.append(upperNibbleToASCIIHexDigit(codeUnit >> 8));
builder.append(lowerNibbleToASCIIHexDigit(codeUnit >> 8));
builder.append(upperNibbleToASCIIHexDigit(codeUnit));
builder.append(lowerNibbleToASCIIHexDigit(codeUnit));
}
builder.append('"');
}
} // anonymous namespace
Ref<Value> Value::null()
{
return adoptRef(*new Value);
}
Ref<Value> Value::create(bool value)
{
return adoptRef(*new Value(value));
}
Ref<Value> Value::create(int value)
{
return adoptRef(*new Value(value));
}
Ref<Value> Value::create(double value)
{
return adoptRef(*new Value(value));
}
Ref<Value> Value::create(const String& value)
{
return adoptRef(*new Value(value));
}
Ref<Value> Value::create(const char* value)
{
return adoptRef(*new Value(value));
}
bool Value::asValue(RefPtr<Value>& value)
{
value = this;
return true;
}
bool Value::asObject(RefPtr<Object>&)
{
return false;
}
bool Value::asArray(RefPtr<Array>&)
{
return false;
}
bool Value::parseJSON(const String& jsonInput, RefPtr<Value>& output)
{
// FIXME: This whole file should just use StringView instead of UChar/length and avoid upconverting.
auto characters = StringView(jsonInput).upconvertedCharacters();
const UChar* start = characters;
const UChar* end = start + jsonInput.length();
const UChar* tokenEnd;
auto result = buildValue(start, end, &tokenEnd, 0);
if (!result)
return false;
for (const UChar* valueEnd = tokenEnd; valueEnd < end; ++valueEnd) {
if (!isSpaceOrNewline(*valueEnd))
return false;
}
output = WTFMove(result);
return true;
}
String Value::toJSONString() const
{
StringBuilder result;
result.reserveCapacity(512);
writeJSON(result);
return result.toString();
}
bool Value::asBoolean(bool& output) const
{
if (type() != Type::Boolean)
return false;
output = m_value.boolean;
return true;
}
bool Value::asDouble(double& output) const
{
if (type() != Type::Double)
return false;
output = m_value.number;
return true;
}
bool Value::asDouble(float& output) const
{
if (type() != Type::Double)
return false;
output = static_cast<float>(m_value.number);
return true;
}
bool Value::asInteger(int& output) const
{
if (type() != Type::Integer && type() != Type::Double)
return false;
output = static_cast<int>(m_value.number);
return true;
}
bool Value::asInteger(unsigned& output) const
{
if (type() != Type::Integer && type() != Type::Double)
return false;
output = static_cast<unsigned>(m_value.number);
return true;
}
bool Value::asInteger(long& output) const
{
if (type() != Type::Integer && type() != Type::Double)
return false;
output = static_cast<long>(m_value.number);
return true;
}
bool Value::asInteger(long long& output) const
{
if (type() != Type::Integer && type() != Type::Double)
return false;
output = static_cast<long long>(m_value.number);
return true;
}
bool Value::asInteger(unsigned long& output) const
{
if (type() != Type::Integer && type() != Type::Double)
return false;
output = static_cast<unsigned long>(m_value.number);
return true;
}
bool Value::asInteger(unsigned long long& output) const
{
if (type() != Type::Integer && type() != Type::Double)
return false;
output = static_cast<unsigned long long>(m_value.number);
return true;
}
bool Value::asString(String& output) const
{
if (type() != Type::String)
return false;
output = m_value.string;
return true;
}
void Value::writeJSON(StringBuilder& output) const
{
switch (m_type) {
case Type::Null:
output.appendLiteral("null");
break;
case Type::Boolean:
if (m_value.boolean)
output.appendLiteral("true");
else
output.appendLiteral("false");
break;
case Type::String:
appendDoubleQuotedString(output, m_value.string);
break;
case Type::Double:
case Type::Integer: {
if (!std::isfinite(m_value.number))
output.appendLiteral("null");
else
output.appendECMAScriptNumber(m_value.number);
break;
}
default:
ASSERT_NOT_REACHED();
}
}
size_t Value::memoryCost() const
{
size_t memoryCost = sizeof(this);
if (m_type == Type::String && m_value.string)
memoryCost += m_value.string->sizeInBytes();
return memoryCost;
}
ObjectBase::~ObjectBase()
{
}
bool ObjectBase::asObject(RefPtr<Object>& output)
{
COMPILE_ASSERT(sizeof(Object) == sizeof(ObjectBase), cannot_cast);
output = static_cast<Object*>(this);
return true;
}
Object* ObjectBase::openAccessors()
{
COMPILE_ASSERT(sizeof(Object) == sizeof(ObjectBase), cannot_cast);
return static_cast<Object*>(this);
}
size_t ObjectBase::memoryCost() const
{
size_t memoryCost = Value::memoryCost();
for (const auto& entry : m_map) {
memoryCost += entry.key.sizeInBytes();
if (entry.value)
memoryCost += entry.value->memoryCost();
}
return memoryCost;
}
bool ObjectBase::getBoolean(const String& name, bool& output) const
{
RefPtr<Value> value;
if (!getValue(name, value))
return false;
return value->asBoolean(output);
}
bool ObjectBase::getString(const String& name, String& output) const
{
RefPtr<Value> value;
if (!getValue(name, value))
return false;
return value->asString(output);
}
bool ObjectBase::getObject(const String& name, RefPtr<Object>& output) const
{
RefPtr<Value> value;
if (!getValue(name, value))
return false;
return value->asObject(output);
}
bool ObjectBase::getArray(const String& name, RefPtr<Array>& output) const
{
RefPtr<Value> value;
if (!getValue(name, value))
return false;
return value->asArray(output);
}
bool ObjectBase::getValue(const String& name, RefPtr<Value>& output) const
{
Dictionary::const_iterator findResult = m_map.find(name);
if (findResult == m_map.end())
return false;
output = findResult->value;
return true;
}
void ObjectBase::remove(const String& name)
{
m_map.remove(name);
m_order.removeFirst(name);
}
void ObjectBase::writeJSON(StringBuilder& output) const
{
output.append('{');
for (size_t i = 0; i < m_order.size(); ++i) {
auto findResult = m_map.find(m_order[i]);
ASSERT(findResult != m_map.end());
if (i)
output.append(',');
appendDoubleQuotedString(output, findResult->key);
output.append(':');
findResult->value->writeJSON(output);
}
output.append('}');
}
ObjectBase::ObjectBase()
: Value(Type::Object)
, m_map()
, m_order()
{
}
ArrayBase::~ArrayBase()
{
}
bool ArrayBase::asArray(RefPtr<Array>& output)
{
COMPILE_ASSERT(sizeof(ArrayBase) == sizeof(Array), cannot_cast);
output = static_cast<Array*>(this);
return true;
}
void ArrayBase::writeJSON(StringBuilder& output) const
{
output.append('[');
for (Vector<RefPtr<Value>>::const_iterator it = m_map.begin(); it != m_map.end(); ++it) {
if (it != m_map.begin())
output.append(',');
(*it)->writeJSON(output);
}
output.append(']');
}
ArrayBase::ArrayBase()
: Value(Type::Array)
, m_map()
{
}
RefPtr<Value> ArrayBase::get(size_t index) const
{
RELEASE_ASSERT_WITH_SECURITY_IMPLICATION(index < m_map.size());
return m_map[index];
}
Ref<Object> Object::create()
{
return adoptRef(*new Object);
}
Ref<Array> Array::create()
{
return adoptRef(*new Array);
}
size_t ArrayBase::memoryCost() const
{
size_t memoryCost = Value::memoryCost();
for (const auto& item : m_map) {
if (item)
memoryCost += item->memoryCost();
}
return memoryCost;
}
} // namespace JSONImpl
} // namespace WTF