1// Copyright 2011 the V8 project authors. All rights reserved. 2// Redistribution and use in source and binary forms, with or without 3// modification, are permitted provided that the following conditions are 4// met: 5// 6// * Redistributions of source code must retain the above copyright 7// notice, this list of conditions and the following disclaimer. 8// * Redistributions in binary form must reproduce the above 9// copyright notice, this list of conditions and the following 10// disclaimer in the documentation and/or other materials provided 11// with the distribution. 12// * Neither the name of Google Inc. nor the names of its 13// contributors may be used to endorse or promote products derived 14// from this software without specific prior written permission. 15// 16// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 28#ifndef V8_SCANNER_CHARACTER_STREAMS_H_ 29#define V8_SCANNER_CHARACTER_STREAMS_H_ 30 31#include "scanner.h" 32 33namespace v8 { 34namespace internal { 35 36// A buffered character stream based on a random access character 37// source (ReadBlock can be called with pos_ pointing to any position, 38// even positions before the current). 39class BufferedUtf16CharacterStream: public Utf16CharacterStream { 40 public: 41 BufferedUtf16CharacterStream(); 42 virtual ~BufferedUtf16CharacterStream(); 43 44 virtual void PushBack(uc32 character); 45 46 protected: 47 static const unsigned kBufferSize = 512; 48 static const unsigned kPushBackStepSize = 16; 49 50 virtual unsigned SlowSeekForward(unsigned delta); 51 virtual bool ReadBlock(); 52 virtual void SlowPushBack(uc16 character); 53 54 virtual unsigned BufferSeekForward(unsigned delta) = 0; 55 virtual unsigned FillBuffer(unsigned position, unsigned length) = 0; 56 57 const uc16* pushback_limit_; 58 uc16 buffer_[kBufferSize]; 59}; 60 61 62// Generic string stream. 63class GenericStringUtf16CharacterStream: public BufferedUtf16CharacterStream { 64 public: 65 GenericStringUtf16CharacterStream(Handle<String> data, 66 unsigned start_position, 67 unsigned end_position); 68 virtual ~GenericStringUtf16CharacterStream(); 69 70 protected: 71 virtual unsigned BufferSeekForward(unsigned delta); 72 virtual unsigned FillBuffer(unsigned position, unsigned length); 73 74 Handle<String> string_; 75 unsigned start_position_; 76 unsigned length_; 77}; 78 79 80// Utf16 stream based on a literal UTF-8 string. 81class Utf8ToUtf16CharacterStream: public BufferedUtf16CharacterStream { 82 public: 83 Utf8ToUtf16CharacterStream(const byte* data, unsigned length); 84 virtual ~Utf8ToUtf16CharacterStream(); 85 86 protected: 87 virtual unsigned BufferSeekForward(unsigned delta); 88 virtual unsigned FillBuffer(unsigned char_position, unsigned length); 89 void SetRawPosition(unsigned char_position); 90 91 const byte* raw_data_; 92 unsigned raw_data_length_; // Measured in bytes, not characters. 93 unsigned raw_data_pos_; 94 // The character position of the character at raw_data[raw_data_pos_]. 95 // Not necessarily the same as pos_. 96 unsigned raw_character_position_; 97}; 98 99 100// UTF16 buffer to read characters from an external string. 101class ExternalTwoByteStringUtf16CharacterStream: public Utf16CharacterStream { 102 public: 103 ExternalTwoByteStringUtf16CharacterStream(Handle<ExternalTwoByteString> data, 104 int start_position, 105 int end_position); 106 virtual ~ExternalTwoByteStringUtf16CharacterStream(); 107 108 virtual void PushBack(uc32 character) { 109 ASSERT(buffer_cursor_ > raw_data_); 110 buffer_cursor_--; 111 pos_--; 112 } 113 114 protected: 115 virtual unsigned SlowSeekForward(unsigned delta) { 116 // Fast case always handles seeking. 117 return 0; 118 } 119 virtual bool ReadBlock() { 120 // Entire string is read at start. 121 return false; 122 } 123 Handle<ExternalTwoByteString> source_; 124 const uc16* raw_data_; // Pointer to the actual array of characters. 125}; 126 127} } // namespace v8::internal 128 129#endif // V8_SCANNER_CHARACTER_STREAMS_H_ 130