// Copyright 2011 the V8 project authors. 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. #ifndef V8_SCANNER_CHARACTER_STREAMS_H_ #define V8_SCANNER_CHARACTER_STREAMS_H_ #include "scanner.h" namespace v8 { namespace internal { // A buffered character stream based on a random access character // source (ReadBlock can be called with pos_ pointing to any position, // even positions before the current). class BufferedUtf16CharacterStream: public Utf16CharacterStream { public: BufferedUtf16CharacterStream(); virtual ~BufferedUtf16CharacterStream(); virtual void PushBack(uc32 character); protected: static const unsigned kBufferSize = 512; static const unsigned kPushBackStepSize = 16; virtual unsigned SlowSeekForward(unsigned delta); virtual bool ReadBlock(); virtual void SlowPushBack(uc16 character); virtual unsigned BufferSeekForward(unsigned delta) = 0; virtual unsigned FillBuffer(unsigned position, unsigned length) = 0; const uc16* pushback_limit_; uc16 buffer_[kBufferSize]; }; // Generic string stream. class GenericStringUtf16CharacterStream: public BufferedUtf16CharacterStream { public: GenericStringUtf16CharacterStream(Handle<String> data, unsigned start_position, unsigned end_position); virtual ~GenericStringUtf16CharacterStream(); protected: virtual unsigned BufferSeekForward(unsigned delta); virtual unsigned FillBuffer(unsigned position, unsigned length); Handle<String> string_; unsigned start_position_; unsigned length_; }; // Utf16 stream based on a literal UTF-8 string. class Utf8ToUtf16CharacterStream: public BufferedUtf16CharacterStream { public: Utf8ToUtf16CharacterStream(const byte* data, unsigned length); virtual ~Utf8ToUtf16CharacterStream(); protected: virtual unsigned BufferSeekForward(unsigned delta); virtual unsigned FillBuffer(unsigned char_position, unsigned length); void SetRawPosition(unsigned char_position); const byte* raw_data_; unsigned raw_data_length_; // Measured in bytes, not characters. unsigned raw_data_pos_; // The character position of the character at raw_data[raw_data_pos_]. // Not necessarily the same as pos_. unsigned raw_character_position_; }; // UTF16 buffer to read characters from an external string. class ExternalTwoByteStringUtf16CharacterStream: public Utf16CharacterStream { public: ExternalTwoByteStringUtf16CharacterStream(Handle<ExternalTwoByteString> data, int start_position, int end_position); virtual ~ExternalTwoByteStringUtf16CharacterStream(); virtual void PushBack(uc32 character) { ASSERT(buffer_cursor_ > raw_data_); buffer_cursor_--; pos_--; } protected: virtual unsigned SlowSeekForward(unsigned delta) { // Fast case always handles seeking. return 0; } virtual bool ReadBlock() { // Entire string is read at start. return false; } Handle<ExternalTwoByteString> source_; const uc16* raw_data_; // Pointer to the actual array of characters. }; } } // namespace v8::internal #endif // V8_SCANNER_CHARACTER_STREAMS_H_