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32 #include "core/inspector/JSONParser.h"
34 #include "platform/JSONValues.h"
35 #include "wtf/text/StringBuilder.h"
41 const int stackLimit = 1000;
58 const char* const nullString = "null";
59 const char* const trueString = "true";
60 const char* const falseString = "false";
62 template<typename CharType>
63 bool parseConstToken(const CharType* start, const CharType* end, const CharType** tokenEnd, const char* token)
65 while (start < end && *token != '\0' && *start++ == *token++) { }
72 template<typename CharType>
73 bool readInt(const CharType* start, const CharType* end, const CharType** tokenEnd, bool canHaveLeadingZeros)
77 bool haveLeadingZero = '0' == *start;
79 while (start < end && '0' <= *start && *start <= '9') {
85 if (!canHaveLeadingZeros && length > 1 && haveLeadingZero)
91 template<typename CharType>
92 bool parseNumberToken(const CharType* start, const CharType* end, const CharType** tokenEnd)
94 // We just grab the number here. We validate the size in DecodeNumber.
95 // According to RFC4627, a valid number is: [minus] int [frac] [exp]
102 if (!readInt(start, end, &start, false))
109 // Optional fraction part
113 if (!readInt(start, end, &start, true))
122 // Optional exponent part
123 if ('e' == c || 'E' == c) {
128 if ('-' == c || '+' == c) {
133 if (!readInt(start, end, &start, true))
141 template<typename CharType>
142 bool readHexDigits(const CharType* start, const CharType* end, const CharType** tokenEnd, int digits)
144 if (end - start < digits)
146 for (int i = 0; i < digits; ++i) {
147 CharType c = *start++;
148 if (!(('0' <= c && c <= '9') || ('a' <= c && c <= 'f') || ('A' <= c && c <= 'F')))
155 template<typename CharType>
156 bool parseStringToken(const CharType* start, const CharType* end, const CharType** tokenEnd)
158 while (start < end) {
159 CharType c = *start++;
162 // Make sure the escaped char is valid.
165 if (!readHexDigits(start, end, &start, 2))
169 if (!readHexDigits(start, end, &start, 4))
185 } else if ('"' == c) {
193 template<typename CharType>
194 Token parseToken(const CharType* start, const CharType* end, const CharType** tokenStart, const CharType** tokenEnd)
196 while (start < end && isSpaceOrNewline(*start))
206 if (parseConstToken(start, end, tokenEnd, nullString))
210 if (parseConstToken(start, end, tokenEnd, trueString))
214 if (parseConstToken(start, end, tokenEnd, falseString))
218 *tokenEnd = start + 1;
221 *tokenEnd = start + 1;
224 *tokenEnd = start + 1;
225 return ListSeparator;
227 *tokenEnd = start + 1;
230 *tokenEnd = start + 1;
233 *tokenEnd = start + 1;
234 return ObjectPairSeparator;
246 if (parseNumberToken(start, end, tokenEnd))
250 if (parseStringToken(start + 1, end, tokenEnd))
251 return StringLiteral;
257 template<typename CharType>
258 inline int hexToInt(CharType c)
260 if ('0' <= c && c <= '9')
262 if ('A' <= c && c <= 'F')
264 if ('a' <= c && c <= 'f')
266 ASSERT_NOT_REACHED();
270 template<typename CharType>
271 bool decodeString(const CharType* start, const CharType* end, StringBuilder* output)
273 while (start < end) {
304 c = (hexToInt(*start) << 4) +
305 hexToInt(*(start + 1));
309 c = (hexToInt(*start) << 12) +
310 (hexToInt(*(start + 1)) << 8) +
311 (hexToInt(*(start + 2)) << 4) +
312 hexToInt(*(start + 3));
323 template<typename CharType>
324 bool decodeString(const CharType* start, const CharType* end, String* output)
332 StringBuilder buffer;
333 buffer.reserveCapacity(end - start);
334 if (!decodeString(start, end, &buffer))
336 *output = buffer.toString();
340 template<typename CharType>
341 PassRefPtr<JSONValue> buildValue(const CharType* start, const CharType* end, const CharType** valueTokenEnd, int depth)
343 if (depth > stackLimit)
346 RefPtr<JSONValue> result;
347 const CharType* tokenStart;
348 const CharType* tokenEnd;
349 Token token = parseToken(start, end, &tokenStart, &tokenEnd);
354 result = JSONValue::null();
357 result = JSONBasicValue::create(true);
360 result = JSONBasicValue::create(false);
364 double value = charactersToDouble(tokenStart, tokenEnd - tokenStart, &ok);
367 result = JSONBasicValue::create(value);
370 case StringLiteral: {
372 bool ok = decodeString(tokenStart + 1, tokenEnd - 1, &value);
375 result = JSONString::create(value);
379 RefPtr<JSONArray> array = JSONArray::create();
381 token = parseToken(start, end, &tokenStart, &tokenEnd);
382 while (token != ArrayEnd) {
383 RefPtr<JSONValue> arrayNode = buildValue(start, end, &tokenEnd, depth + 1);
386 array->pushValue(arrayNode);
388 // After a list value, we expect a comma or the end of the list.
390 token = parseToken(start, end, &tokenStart, &tokenEnd);
391 if (token == ListSeparator) {
393 token = parseToken(start, end, &tokenStart, &tokenEnd);
394 if (token == ArrayEnd)
396 } else if (token != ArrayEnd) {
397 // Unexpected value after list value. Bail out.
401 if (token != ArrayEnd)
403 result = array.release();
407 RefPtr<JSONObject> object = JSONObject::create();
409 token = parseToken(start, end, &tokenStart, &tokenEnd);
410 while (token != ObjectEnd) {
411 if (token != StringLiteral)
414 if (!decodeString(tokenStart + 1, tokenEnd - 1, &key))
418 token = parseToken(start, end, &tokenStart, &tokenEnd);
419 if (token != ObjectPairSeparator)
423 RefPtr<JSONValue> value = buildValue(start, end, &tokenEnd, depth + 1);
426 object->setValue(key, value);
429 // After a key/value pair, we expect a comma or the end of the
431 token = parseToken(start, end, &tokenStart, &tokenEnd);
432 if (token == ListSeparator) {
434 token = parseToken(start, end, &tokenStart, &tokenEnd);
435 if (token == ObjectEnd)
437 } else if (token != ObjectEnd) {
438 // Unexpected value after last object value. Bail out.
442 if (token != ObjectEnd)
444 result = object.release();
449 // We got a token that's not a value.
452 *valueTokenEnd = tokenEnd;
453 return result.release();
456 template<typename CharType>
457 PassRefPtr<JSONValue> parseJSONInternal(const CharType* start, unsigned length)
459 const CharType* end = start + length;
460 const CharType *tokenEnd;
461 RefPtr<JSONValue> value = buildValue(start, end, &tokenEnd, 0);
462 if (!value || tokenEnd != end)
464 return value.release();
467 } // anonymous namespace
469 PassRefPtr<JSONValue> parseJSON(const String& json)
474 return parseJSONInternal(json.characters8(), json.length());
475 return parseJSONInternal(json.characters16(), json.length());