9e0f0a73dc
There's no need to differentiate between an actual Zone and its scope. Instead we bind the lifetime of the Zone memory to the lifetime of the Zone itself, which is way easier to understand than having to dig through the code looking for zone scopes. Depends on https://codereview.chromium.org/17826004/ R=danno@chromium.org BUG= Review URL: https://codereview.chromium.org/17827005 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15337 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
810 lines
27 KiB
C++
810 lines
27 KiB
C++
// Copyright 2011 the V8 project authors. All rights reserved.
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are
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// met:
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//
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// * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// * Redistributions in binary form must reproduce the above
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// copyright notice, this list of conditions and the following
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// disclaimer in the documentation and/or other materials provided
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// with the distribution.
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// * Neither the name of Google Inc. nor the names of its
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// contributors may be used to endorse or promote products derived
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// from this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#ifndef V8_JSON_PARSER_H_
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#define V8_JSON_PARSER_H_
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#include "v8.h"
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#include "char-predicates-inl.h"
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#include "v8conversions.h"
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#include "messages.h"
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#include "spaces-inl.h"
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#include "token.h"
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namespace v8 {
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namespace internal {
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// A simple json parser.
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template <bool seq_ascii>
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class JsonParser BASE_EMBEDDED {
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public:
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static Handle<Object> Parse(Handle<String> source) {
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return JsonParser(source).ParseJson();
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}
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static const int kEndOfString = -1;
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private:
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explicit JsonParser(Handle<String> source)
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: source_(source),
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source_length_(source->length()),
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isolate_(source->map()->GetHeap()->isolate()),
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factory_(isolate_->factory()),
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zone_(isolate_),
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object_constructor_(isolate_->native_context()->object_function(),
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isolate_),
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position_(-1) {
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FlattenString(source_);
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pretenure_ = (source_length_ >= kPretenureTreshold) ? TENURED : NOT_TENURED;
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// Optimized fast case where we only have ASCII characters.
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if (seq_ascii) {
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seq_source_ = Handle<SeqOneByteString>::cast(source_);
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}
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}
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// Parse a string containing a single JSON value.
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Handle<Object> ParseJson();
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inline void Advance() {
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position_++;
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if (position_ >= source_length_) {
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c0_ = kEndOfString;
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} else if (seq_ascii) {
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c0_ = seq_source_->SeqOneByteStringGet(position_);
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} else {
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c0_ = source_->Get(position_);
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}
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}
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// The JSON lexical grammar is specified in the ECMAScript 5 standard,
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// section 15.12.1.1. The only allowed whitespace characters between tokens
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// are tab, carriage-return, newline and space.
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inline void AdvanceSkipWhitespace() {
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do {
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Advance();
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} while (c0_ == ' ' || c0_ == '\t' || c0_ == '\n' || c0_ == '\r');
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}
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inline void SkipWhitespace() {
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while (c0_ == ' ' || c0_ == '\t' || c0_ == '\n' || c0_ == '\r') {
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Advance();
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}
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}
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inline uc32 AdvanceGetChar() {
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Advance();
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return c0_;
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}
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// Checks that current charater is c.
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// If so, then consume c and skip whitespace.
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inline bool MatchSkipWhiteSpace(uc32 c) {
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if (c0_ == c) {
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AdvanceSkipWhitespace();
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return true;
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}
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return false;
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}
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// A JSON string (production JSONString) is subset of valid JavaScript string
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// literals. The string must only be double-quoted (not single-quoted), and
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// the only allowed backslash-escapes are ", /, \, b, f, n, r, t and
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// four-digit hex escapes (uXXXX). Any other use of backslashes is invalid.
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Handle<String> ParseJsonString() {
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return ScanJsonString<false>();
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}
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bool ParseJsonString(Handle<String> expected) {
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int length = expected->length();
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if (source_->length() - position_ - 1 > length) {
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DisallowHeapAllocation no_gc;
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String::FlatContent content = expected->GetFlatContent();
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if (content.IsAscii()) {
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ASSERT_EQ('"', c0_);
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const uint8_t* input_chars = seq_source_->GetChars() + position_ + 1;
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const uint8_t* expected_chars = content.ToOneByteVector().start();
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for (int i = 0; i < length; i++) {
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uint8_t c0 = input_chars[i];
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if (c0 != expected_chars[i] ||
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c0 == '"' || c0 < 0x20 || c0 == '\\') {
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return false;
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}
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}
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if (input_chars[length] == '"') {
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position_ = position_ + length + 1;
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AdvanceSkipWhitespace();
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return true;
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}
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}
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}
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return false;
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}
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Handle<String> ParseJsonInternalizedString() {
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return ScanJsonString<true>();
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}
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template <bool is_internalized>
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Handle<String> ScanJsonString();
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// Creates a new string and copies prefix[start..end] into the beginning
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// of it. Then scans the rest of the string, adding characters after the
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// prefix. Called by ScanJsonString when reaching a '\' or non-ASCII char.
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template <typename StringType, typename SinkChar>
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Handle<String> SlowScanJsonString(Handle<String> prefix, int start, int end);
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// A JSON number (production JSONNumber) is a subset of the valid JavaScript
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// decimal number literals.
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// It includes an optional minus sign, must have at least one
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// digit before and after a decimal point, may not have prefixed zeros (unless
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// the integer part is zero), and may include an exponent part (e.g., "e-10").
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// Hexadecimal and octal numbers are not allowed.
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Handle<Object> ParseJsonNumber();
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// Parse a single JSON value from input (grammar production JSONValue).
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// A JSON value is either a (double-quoted) string literal, a number literal,
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// one of "true", "false", or "null", or an object or array literal.
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Handle<Object> ParseJsonValue();
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// Parse a JSON object literal (grammar production JSONObject).
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// An object literal is a squiggly-braced and comma separated sequence
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// (possibly empty) of key/value pairs, where the key is a JSON string
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// literal, the value is a JSON value, and the two are separated by a colon.
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// A JSON array doesn't allow numbers and identifiers as keys, like a
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// JavaScript array.
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Handle<Object> ParseJsonObject();
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// Parses a JSON array literal (grammar production JSONArray). An array
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// literal is a square-bracketed and comma separated sequence (possibly empty)
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// of JSON values.
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// A JSON array doesn't allow leaving out values from the sequence, nor does
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// it allow a terminal comma, like a JavaScript array does.
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Handle<Object> ParseJsonArray();
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// Mark that a parsing error has happened at the current token, and
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// return a null handle. Primarily for readability.
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inline Handle<Object> ReportUnexpectedCharacter() {
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return Handle<Object>::null();
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}
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inline Isolate* isolate() { return isolate_; }
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inline Factory* factory() { return factory_; }
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inline Handle<JSFunction> object_constructor() { return object_constructor_; }
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static const int kInitialSpecialStringLength = 1024;
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static const int kPretenureTreshold = 100 * 1024;
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private:
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Zone* zone() { return &zone_; }
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Handle<String> source_;
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int source_length_;
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Handle<SeqOneByteString> seq_source_;
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PretenureFlag pretenure_;
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Isolate* isolate_;
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Factory* factory_;
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Zone zone_;
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Handle<JSFunction> object_constructor_;
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uc32 c0_;
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int position_;
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};
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template <bool seq_ascii>
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Handle<Object> JsonParser<seq_ascii>::ParseJson() {
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// Advance to the first character (possibly EOS)
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AdvanceSkipWhitespace();
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Handle<Object> result = ParseJsonValue();
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if (result.is_null() || c0_ != kEndOfString) {
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// Some exception (for example stack overflow) is already pending.
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if (isolate_->has_pending_exception()) return Handle<Object>::null();
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// Parse failed. Current character is the unexpected token.
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const char* message;
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Factory* factory = this->factory();
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Handle<JSArray> array;
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switch (c0_) {
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case kEndOfString:
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message = "unexpected_eos";
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array = factory->NewJSArray(0);
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break;
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case '-':
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case '0':
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case '1':
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case '2':
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case '3':
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case '4':
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case '5':
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case '6':
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case '7':
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case '8':
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case '9':
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message = "unexpected_token_number";
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array = factory->NewJSArray(0);
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break;
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case '"':
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message = "unexpected_token_string";
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array = factory->NewJSArray(0);
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break;
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default:
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message = "unexpected_token";
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Handle<Object> name =
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LookupSingleCharacterStringFromCode(isolate_, c0_);
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Handle<FixedArray> element = factory->NewFixedArray(1);
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element->set(0, *name);
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array = factory->NewJSArrayWithElements(element);
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break;
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}
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MessageLocation location(factory->NewScript(source_),
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position_,
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position_ + 1);
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Handle<Object> result = factory->NewSyntaxError(message, array);
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isolate()->Throw(*result, &location);
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return Handle<Object>::null();
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}
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return result;
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}
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// Parse any JSON value.
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template <bool seq_ascii>
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Handle<Object> JsonParser<seq_ascii>::ParseJsonValue() {
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StackLimitCheck stack_check(isolate_);
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if (stack_check.HasOverflowed()) {
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isolate_->StackOverflow();
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return Handle<Object>::null();
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}
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if (c0_ == '"') return ParseJsonString();
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if ((c0_ >= '0' && c0_ <= '9') || c0_ == '-') return ParseJsonNumber();
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if (c0_ == '{') return ParseJsonObject();
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if (c0_ == '[') return ParseJsonArray();
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if (c0_ == 'f') {
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if (AdvanceGetChar() == 'a' && AdvanceGetChar() == 'l' &&
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AdvanceGetChar() == 's' && AdvanceGetChar() == 'e') {
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AdvanceSkipWhitespace();
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return factory()->false_value();
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}
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return ReportUnexpectedCharacter();
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}
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if (c0_ == 't') {
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if (AdvanceGetChar() == 'r' && AdvanceGetChar() == 'u' &&
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AdvanceGetChar() == 'e') {
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AdvanceSkipWhitespace();
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return factory()->true_value();
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}
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return ReportUnexpectedCharacter();
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}
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if (c0_ == 'n') {
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if (AdvanceGetChar() == 'u' && AdvanceGetChar() == 'l' &&
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AdvanceGetChar() == 'l') {
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AdvanceSkipWhitespace();
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return factory()->null_value();
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}
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return ReportUnexpectedCharacter();
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}
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return ReportUnexpectedCharacter();
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}
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// Parse a JSON object. Position must be right at '{'.
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template <bool seq_ascii>
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Handle<Object> JsonParser<seq_ascii>::ParseJsonObject() {
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HandleScope scope(isolate());
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Handle<JSObject> json_object =
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factory()->NewJSObject(object_constructor(), pretenure_);
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Handle<Map> map(json_object->map());
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ZoneList<Handle<Object> > properties(8, zone());
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ASSERT_EQ(c0_, '{');
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bool transitioning = true;
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AdvanceSkipWhitespace();
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if (c0_ != '}') {
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do {
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if (c0_ != '"') return ReportUnexpectedCharacter();
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int start_position = position_;
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Advance();
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uint32_t index = 0;
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if (c0_ >= '0' && c0_ <= '9') {
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// Maybe an array index, try to parse it.
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if (c0_ == '0') {
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// With a leading zero, the string has to be "0" only to be an index.
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Advance();
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} else {
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do {
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int d = c0_ - '0';
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if (index > 429496729U - ((d > 5) ? 1 : 0)) break;
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index = (index * 10) + d;
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Advance();
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} while (c0_ >= '0' && c0_ <= '9');
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}
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if (c0_ == '"') {
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// Successfully parsed index, parse and store element.
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AdvanceSkipWhitespace();
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if (c0_ != ':') return ReportUnexpectedCharacter();
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AdvanceSkipWhitespace();
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Handle<Object> value = ParseJsonValue();
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if (value.is_null()) return ReportUnexpectedCharacter();
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JSObject::SetOwnElement(json_object, index, value, kNonStrictMode);
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continue;
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}
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// Not an index, fallback to the slow path.
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}
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position_ = start_position;
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#ifdef DEBUG
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c0_ = '"';
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#endif
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Handle<String> key;
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Handle<Object> value;
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// Try to follow existing transitions as long as possible. Once we stop
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// transitioning, no transition can be found anymore.
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if (transitioning) {
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// First check whether there is a single expected transition. If so, try
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// to parse it first.
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bool follow_expected = false;
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Handle<Map> target;
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if (seq_ascii) {
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key = JSObject::ExpectedTransitionKey(map);
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follow_expected = !key.is_null() && ParseJsonString(key);
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}
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// If the expected transition hits, follow it.
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if (follow_expected) {
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target = JSObject::ExpectedTransitionTarget(map);
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} else {
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// If the expected transition failed, parse an internalized string and
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// try to find a matching transition.
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key = ParseJsonInternalizedString();
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if (key.is_null()) return ReportUnexpectedCharacter();
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target = JSObject::FindTransitionToField(map, key);
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// If a transition was found, follow it and continue.
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transitioning = !target.is_null();
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}
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if (c0_ != ':') return ReportUnexpectedCharacter();
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AdvanceSkipWhitespace();
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value = ParseJsonValue();
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if (value.is_null()) return ReportUnexpectedCharacter();
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if (transitioning) {
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int descriptor = map->NumberOfOwnDescriptors();
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PropertyDetails details =
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target->instance_descriptors()->GetDetails(descriptor);
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Representation expected_representation = details.representation();
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if (value->FitsRepresentation(expected_representation)) {
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// If the target representation is double and the value is already
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// double, use the existing box.
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if (FLAG_track_double_fields &&
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value->IsSmi() &&
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expected_representation.IsDouble()) {
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value = factory()->NewHeapNumber(
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Handle<Smi>::cast(value)->value());
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}
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properties.Add(value, zone());
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map = target;
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continue;
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} else {
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transitioning = false;
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}
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}
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// Commit the intermediate state to the object and stop transitioning.
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JSObject::AllocateStorageForMap(json_object, map);
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int length = properties.length();
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for (int i = 0; i < length; i++) {
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Handle<Object> value = properties[i];
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json_object->FastPropertyAtPut(i, *value);
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}
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} else {
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key = ParseJsonInternalizedString();
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if (key.is_null() || c0_ != ':') return ReportUnexpectedCharacter();
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AdvanceSkipWhitespace();
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value = ParseJsonValue();
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if (value.is_null()) return ReportUnexpectedCharacter();
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}
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JSObject::SetLocalPropertyIgnoreAttributes(
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json_object, key, value, NONE);
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} while (MatchSkipWhiteSpace(','));
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if (c0_ != '}') {
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return ReportUnexpectedCharacter();
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}
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// If we transitioned until the very end, transition the map now.
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if (transitioning) {
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JSObject::AllocateStorageForMap(json_object, map);
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int length = properties.length();
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for (int i = 0; i < length; i++) {
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Handle<Object> value = properties[i];
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json_object->FastPropertyAtPut(i, *value);
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}
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}
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}
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AdvanceSkipWhitespace();
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return scope.CloseAndEscape(json_object);
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}
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// Parse a JSON array. Position must be right at '['.
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template <bool seq_ascii>
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Handle<Object> JsonParser<seq_ascii>::ParseJsonArray() {
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HandleScope scope(isolate());
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ZoneList<Handle<Object> > elements(4, zone());
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ASSERT_EQ(c0_, '[');
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AdvanceSkipWhitespace();
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if (c0_ != ']') {
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do {
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Handle<Object> element = ParseJsonValue();
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if (element.is_null()) return ReportUnexpectedCharacter();
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elements.Add(element, zone());
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} while (MatchSkipWhiteSpace(','));
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if (c0_ != ']') {
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return ReportUnexpectedCharacter();
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}
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}
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AdvanceSkipWhitespace();
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// Allocate a fixed array with all the elements.
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Handle<FixedArray> fast_elements =
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factory()->NewFixedArray(elements.length(), pretenure_);
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for (int i = 0, n = elements.length(); i < n; i++) {
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fast_elements->set(i, *elements[i]);
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}
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Handle<Object> json_array = factory()->NewJSArrayWithElements(
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fast_elements, FAST_ELEMENTS, pretenure_);
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return scope.CloseAndEscape(json_array);
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}
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template <bool seq_ascii>
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Handle<Object> JsonParser<seq_ascii>::ParseJsonNumber() {
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bool negative = false;
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int beg_pos = position_;
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if (c0_ == '-') {
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Advance();
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negative = true;
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}
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if (c0_ == '0') {
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Advance();
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// Prefix zero is only allowed if it's the only digit before
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// a decimal point or exponent.
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if ('0' <= c0_ && c0_ <= '9') return ReportUnexpectedCharacter();
|
|
} else {
|
|
int i = 0;
|
|
int digits = 0;
|
|
if (c0_ < '1' || c0_ > '9') return ReportUnexpectedCharacter();
|
|
do {
|
|
i = i * 10 + c0_ - '0';
|
|
digits++;
|
|
Advance();
|
|
} while (c0_ >= '0' && c0_ <= '9');
|
|
if (c0_ != '.' && c0_ != 'e' && c0_ != 'E' && digits < 10) {
|
|
SkipWhitespace();
|
|
return Handle<Smi>(Smi::FromInt((negative ? -i : i)), isolate());
|
|
}
|
|
}
|
|
if (c0_ == '.') {
|
|
Advance();
|
|
if (c0_ < '0' || c0_ > '9') return ReportUnexpectedCharacter();
|
|
do {
|
|
Advance();
|
|
} while (c0_ >= '0' && c0_ <= '9');
|
|
}
|
|
if (AsciiAlphaToLower(c0_) == 'e') {
|
|
Advance();
|
|
if (c0_ == '-' || c0_ == '+') Advance();
|
|
if (c0_ < '0' || c0_ > '9') return ReportUnexpectedCharacter();
|
|
do {
|
|
Advance();
|
|
} while (c0_ >= '0' && c0_ <= '9');
|
|
}
|
|
int length = position_ - beg_pos;
|
|
double number;
|
|
if (seq_ascii) {
|
|
Vector<const uint8_t> chars(seq_source_->GetChars() + beg_pos, length);
|
|
number = StringToDouble(isolate()->unicode_cache(),
|
|
Vector<const char>::cast(chars),
|
|
NO_FLAGS, // Hex, octal or trailing junk.
|
|
OS::nan_value());
|
|
} else {
|
|
Vector<uint8_t> buffer = Vector<uint8_t>::New(length);
|
|
String::WriteToFlat(*source_, buffer.start(), beg_pos, position_);
|
|
Vector<const uint8_t> result =
|
|
Vector<const uint8_t>(buffer.start(), length);
|
|
number = StringToDouble(isolate()->unicode_cache(),
|
|
// TODO(dcarney): Convert StringToDouble to uint_t.
|
|
Vector<const char>::cast(result),
|
|
NO_FLAGS, // Hex, octal or trailing junk.
|
|
0.0);
|
|
buffer.Dispose();
|
|
}
|
|
SkipWhitespace();
|
|
return factory()->NewNumber(number, pretenure_);
|
|
}
|
|
|
|
|
|
template <typename StringType>
|
|
inline void SeqStringSet(Handle<StringType> seq_str, int i, uc32 c);
|
|
|
|
template <>
|
|
inline void SeqStringSet(Handle<SeqTwoByteString> seq_str, int i, uc32 c) {
|
|
seq_str->SeqTwoByteStringSet(i, c);
|
|
}
|
|
|
|
template <>
|
|
inline void SeqStringSet(Handle<SeqOneByteString> seq_str, int i, uc32 c) {
|
|
seq_str->SeqOneByteStringSet(i, c);
|
|
}
|
|
|
|
template <typename StringType>
|
|
inline Handle<StringType> NewRawString(Factory* factory,
|
|
int length,
|
|
PretenureFlag pretenure);
|
|
|
|
template <>
|
|
inline Handle<SeqTwoByteString> NewRawString(Factory* factory,
|
|
int length,
|
|
PretenureFlag pretenure) {
|
|
return factory->NewRawTwoByteString(length, pretenure);
|
|
}
|
|
|
|
template <>
|
|
inline Handle<SeqOneByteString> NewRawString(Factory* factory,
|
|
int length,
|
|
PretenureFlag pretenure) {
|
|
return factory->NewRawOneByteString(length, pretenure);
|
|
}
|
|
|
|
|
|
// Scans the rest of a JSON string starting from position_ and writes
|
|
// prefix[start..end] along with the scanned characters into a
|
|
// sequential string of type StringType.
|
|
template <bool seq_ascii>
|
|
template <typename StringType, typename SinkChar>
|
|
Handle<String> JsonParser<seq_ascii>::SlowScanJsonString(
|
|
Handle<String> prefix, int start, int end) {
|
|
int count = end - start;
|
|
int max_length = count + source_length_ - position_;
|
|
int length = Min(max_length, Max(kInitialSpecialStringLength, 2 * count));
|
|
Handle<StringType> seq_string =
|
|
NewRawString<StringType>(factory(), length, pretenure_);
|
|
// Copy prefix into seq_str.
|
|
SinkChar* dest = seq_string->GetChars();
|
|
String::WriteToFlat(*prefix, dest, start, end);
|
|
|
|
while (c0_ != '"') {
|
|
// Check for control character (0x00-0x1f) or unterminated string (<0).
|
|
if (c0_ < 0x20) return Handle<String>::null();
|
|
if (count >= length) {
|
|
// We need to create a longer sequential string for the result.
|
|
return SlowScanJsonString<StringType, SinkChar>(seq_string, 0, count);
|
|
}
|
|
if (c0_ != '\\') {
|
|
// If the sink can contain UC16 characters, or source_ contains only
|
|
// ASCII characters, there's no need to test whether we can store the
|
|
// character. Otherwise check whether the UC16 source character can fit
|
|
// in the ASCII sink.
|
|
if (sizeof(SinkChar) == kUC16Size ||
|
|
seq_ascii ||
|
|
c0_ <= String::kMaxOneByteCharCode) {
|
|
SeqStringSet(seq_string, count++, c0_);
|
|
Advance();
|
|
} else {
|
|
// StringType is SeqOneByteString and we just read a non-ASCII char.
|
|
return SlowScanJsonString<SeqTwoByteString, uc16>(seq_string, 0, count);
|
|
}
|
|
} else {
|
|
Advance(); // Advance past the \.
|
|
switch (c0_) {
|
|
case '"':
|
|
case '\\':
|
|
case '/':
|
|
SeqStringSet(seq_string, count++, c0_);
|
|
break;
|
|
case 'b':
|
|
SeqStringSet(seq_string, count++, '\x08');
|
|
break;
|
|
case 'f':
|
|
SeqStringSet(seq_string, count++, '\x0c');
|
|
break;
|
|
case 'n':
|
|
SeqStringSet(seq_string, count++, '\x0a');
|
|
break;
|
|
case 'r':
|
|
SeqStringSet(seq_string, count++, '\x0d');
|
|
break;
|
|
case 't':
|
|
SeqStringSet(seq_string, count++, '\x09');
|
|
break;
|
|
case 'u': {
|
|
uc32 value = 0;
|
|
for (int i = 0; i < 4; i++) {
|
|
Advance();
|
|
int digit = HexValue(c0_);
|
|
if (digit < 0) {
|
|
return Handle<String>::null();
|
|
}
|
|
value = value * 16 + digit;
|
|
}
|
|
if (sizeof(SinkChar) == kUC16Size ||
|
|
value <= String::kMaxOneByteCharCode) {
|
|
SeqStringSet(seq_string, count++, value);
|
|
break;
|
|
} else {
|
|
// StringType is SeqOneByteString and we just read a non-ASCII char.
|
|
position_ -= 6; // Rewind position_ to \ in \uxxxx.
|
|
Advance();
|
|
return SlowScanJsonString<SeqTwoByteString, uc16>(seq_string,
|
|
0,
|
|
count);
|
|
}
|
|
}
|
|
default:
|
|
return Handle<String>::null();
|
|
}
|
|
Advance();
|
|
}
|
|
}
|
|
|
|
ASSERT_EQ('"', c0_);
|
|
// Advance past the last '"'.
|
|
AdvanceSkipWhitespace();
|
|
|
|
// Shrink seq_string length to count and return.
|
|
return SeqString::Truncate(seq_string, count);
|
|
}
|
|
|
|
|
|
template <bool seq_ascii>
|
|
template <bool is_internalized>
|
|
Handle<String> JsonParser<seq_ascii>::ScanJsonString() {
|
|
ASSERT_EQ('"', c0_);
|
|
Advance();
|
|
if (c0_ == '"') {
|
|
AdvanceSkipWhitespace();
|
|
return factory()->empty_string();
|
|
}
|
|
|
|
if (seq_ascii && is_internalized) {
|
|
// Fast path for existing internalized strings. If the the string being
|
|
// parsed is not a known internalized string, contains backslashes or
|
|
// unexpectedly reaches the end of string, return with an empty handle.
|
|
uint32_t running_hash = isolate()->heap()->HashSeed();
|
|
int position = position_;
|
|
uc32 c0 = c0_;
|
|
do {
|
|
if (c0 == '\\') {
|
|
c0_ = c0;
|
|
int beg_pos = position_;
|
|
position_ = position;
|
|
return SlowScanJsonString<SeqOneByteString, uint8_t>(source_,
|
|
beg_pos,
|
|
position_);
|
|
}
|
|
if (c0 < 0x20) return Handle<String>::null();
|
|
if (static_cast<uint32_t>(c0) >
|
|
unibrow::Utf16::kMaxNonSurrogateCharCode) {
|
|
running_hash =
|
|
StringHasher::AddCharacterCore(running_hash,
|
|
unibrow::Utf16::LeadSurrogate(c0));
|
|
running_hash =
|
|
StringHasher::AddCharacterCore(running_hash,
|
|
unibrow::Utf16::TrailSurrogate(c0));
|
|
} else {
|
|
running_hash = StringHasher::AddCharacterCore(running_hash, c0);
|
|
}
|
|
position++;
|
|
if (position >= source_length_) return Handle<String>::null();
|
|
c0 = seq_source_->SeqOneByteStringGet(position);
|
|
} while (c0 != '"');
|
|
int length = position - position_;
|
|
uint32_t hash = (length <= String::kMaxHashCalcLength)
|
|
? StringHasher::GetHashCore(running_hash) : length;
|
|
Vector<const uint8_t> string_vector(
|
|
seq_source_->GetChars() + position_, length);
|
|
StringTable* string_table = isolate()->heap()->string_table();
|
|
uint32_t capacity = string_table->Capacity();
|
|
uint32_t entry = StringTable::FirstProbe(hash, capacity);
|
|
uint32_t count = 1;
|
|
Handle<String> result;
|
|
while (true) {
|
|
Object* element = string_table->KeyAt(entry);
|
|
if (element == isolate()->heap()->undefined_value()) {
|
|
// Lookup failure.
|
|
result = factory()->InternalizeOneByteString(
|
|
seq_source_, position_, length);
|
|
break;
|
|
}
|
|
if (element != isolate()->heap()->the_hole_value() &&
|
|
String::cast(element)->IsOneByteEqualTo(string_vector)) {
|
|
result = Handle<String>(String::cast(element), isolate());
|
|
#ifdef DEBUG
|
|
uint32_t hash_field =
|
|
(hash << String::kHashShift) | String::kIsNotArrayIndexMask;
|
|
ASSERT_EQ(static_cast<int>(result->Hash()),
|
|
static_cast<int>(hash_field >> String::kHashShift));
|
|
#endif
|
|
break;
|
|
}
|
|
entry = StringTable::NextProbe(entry, count++, capacity);
|
|
}
|
|
position_ = position;
|
|
// Advance past the last '"'.
|
|
AdvanceSkipWhitespace();
|
|
return result;
|
|
}
|
|
|
|
int beg_pos = position_;
|
|
// Fast case for ASCII only without escape characters.
|
|
do {
|
|
// Check for control character (0x00-0x1f) or unterminated string (<0).
|
|
if (c0_ < 0x20) return Handle<String>::null();
|
|
if (c0_ != '\\') {
|
|
if (seq_ascii || c0_ <= String::kMaxOneByteCharCode) {
|
|
Advance();
|
|
} else {
|
|
return SlowScanJsonString<SeqTwoByteString, uc16>(source_,
|
|
beg_pos,
|
|
position_);
|
|
}
|
|
} else {
|
|
return SlowScanJsonString<SeqOneByteString, uint8_t>(source_,
|
|
beg_pos,
|
|
position_);
|
|
}
|
|
} while (c0_ != '"');
|
|
int length = position_ - beg_pos;
|
|
Handle<String> result = factory()->NewRawOneByteString(length, pretenure_);
|
|
uint8_t* dest = SeqOneByteString::cast(*result)->GetChars();
|
|
String::WriteToFlat(*source_, dest, beg_pos, position_);
|
|
|
|
ASSERT_EQ('"', c0_);
|
|
// Advance past the last '"'.
|
|
AdvanceSkipWhitespace();
|
|
return result;
|
|
}
|
|
|
|
} } // namespace v8::internal
|
|
|
|
#endif // V8_JSON_PARSER_H_
|