03cfc4363b
Review URL: https://chromiumcodereview.appspot.com/9600009 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11007 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
324 lines
11 KiB
C++
324 lines
11 KiB
C++
// 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.
|
|
|
|
#include "v8.h"
|
|
|
|
#include "scanner-character-streams.h"
|
|
|
|
#include "handles.h"
|
|
#include "unicode-inl.h"
|
|
|
|
namespace v8 {
|
|
namespace internal {
|
|
|
|
// ----------------------------------------------------------------------------
|
|
// BufferedUtf16CharacterStreams
|
|
|
|
BufferedUtf16CharacterStream::BufferedUtf16CharacterStream()
|
|
: Utf16CharacterStream(),
|
|
pushback_limit_(NULL) {
|
|
// Initialize buffer as being empty. First read will fill the buffer.
|
|
buffer_cursor_ = buffer_;
|
|
buffer_end_ = buffer_;
|
|
}
|
|
|
|
BufferedUtf16CharacterStream::~BufferedUtf16CharacterStream() { }
|
|
|
|
void BufferedUtf16CharacterStream::PushBack(uc32 character) {
|
|
if (character == kEndOfInput) {
|
|
pos_--;
|
|
return;
|
|
}
|
|
if (pushback_limit_ == NULL && buffer_cursor_ > buffer_) {
|
|
// buffer_ is writable, buffer_cursor_ is const pointer.
|
|
buffer_[--buffer_cursor_ - buffer_] = static_cast<uc16>(character);
|
|
pos_--;
|
|
return;
|
|
}
|
|
SlowPushBack(static_cast<uc16>(character));
|
|
}
|
|
|
|
|
|
void BufferedUtf16CharacterStream::SlowPushBack(uc16 character) {
|
|
// In pushback mode, the end of the buffer contains pushback,
|
|
// and the start of the buffer (from buffer start to pushback_limit_)
|
|
// contains valid data that comes just after the pushback.
|
|
// We NULL the pushback_limit_ if pushing all the way back to the
|
|
// start of the buffer.
|
|
|
|
if (pushback_limit_ == NULL) {
|
|
// Enter pushback mode.
|
|
pushback_limit_ = buffer_end_;
|
|
buffer_end_ = buffer_ + kBufferSize;
|
|
buffer_cursor_ = buffer_end_;
|
|
}
|
|
// Ensure that there is room for at least one pushback.
|
|
ASSERT(buffer_cursor_ > buffer_);
|
|
ASSERT(pos_ > 0);
|
|
buffer_[--buffer_cursor_ - buffer_] = character;
|
|
if (buffer_cursor_ == buffer_) {
|
|
pushback_limit_ = NULL;
|
|
} else if (buffer_cursor_ < pushback_limit_) {
|
|
pushback_limit_ = buffer_cursor_;
|
|
}
|
|
pos_--;
|
|
}
|
|
|
|
|
|
bool BufferedUtf16CharacterStream::ReadBlock() {
|
|
buffer_cursor_ = buffer_;
|
|
if (pushback_limit_ != NULL) {
|
|
// Leave pushback mode.
|
|
buffer_end_ = pushback_limit_;
|
|
pushback_limit_ = NULL;
|
|
// If there were any valid characters left at the
|
|
// start of the buffer, use those.
|
|
if (buffer_cursor_ < buffer_end_) return true;
|
|
// Otherwise read a new block.
|
|
}
|
|
unsigned length = FillBuffer(pos_, kBufferSize);
|
|
buffer_end_ = buffer_ + length;
|
|
return length > 0;
|
|
}
|
|
|
|
|
|
unsigned BufferedUtf16CharacterStream::SlowSeekForward(unsigned delta) {
|
|
// Leave pushback mode (i.e., ignore that there might be valid data
|
|
// in the buffer before the pushback_limit_ point).
|
|
pushback_limit_ = NULL;
|
|
return BufferSeekForward(delta);
|
|
}
|
|
|
|
// ----------------------------------------------------------------------------
|
|
// GenericStringUtf16CharacterStream
|
|
|
|
|
|
GenericStringUtf16CharacterStream::GenericStringUtf16CharacterStream(
|
|
Handle<String> data,
|
|
unsigned start_position,
|
|
unsigned end_position)
|
|
: string_(data),
|
|
length_(end_position) {
|
|
ASSERT(end_position >= start_position);
|
|
buffer_cursor_ = buffer_;
|
|
buffer_end_ = buffer_;
|
|
pos_ = start_position;
|
|
}
|
|
|
|
|
|
GenericStringUtf16CharacterStream::~GenericStringUtf16CharacterStream() { }
|
|
|
|
|
|
unsigned GenericStringUtf16CharacterStream::BufferSeekForward(unsigned delta) {
|
|
unsigned old_pos = pos_;
|
|
pos_ = Min(pos_ + delta, length_);
|
|
ReadBlock();
|
|
return pos_ - old_pos;
|
|
}
|
|
|
|
|
|
unsigned GenericStringUtf16CharacterStream::FillBuffer(unsigned from_pos,
|
|
unsigned length) {
|
|
if (from_pos >= length_) return 0;
|
|
if (from_pos + length > length_) {
|
|
length = length_ - from_pos;
|
|
}
|
|
String::WriteToFlat<uc16>(*string_, buffer_, from_pos, from_pos + length);
|
|
return length;
|
|
}
|
|
|
|
|
|
// ----------------------------------------------------------------------------
|
|
// Utf8ToUtf16CharacterStream
|
|
Utf8ToUtf16CharacterStream::Utf8ToUtf16CharacterStream(const byte* data,
|
|
unsigned length)
|
|
: BufferedUtf16CharacterStream(),
|
|
raw_data_(data),
|
|
raw_data_length_(length),
|
|
raw_data_pos_(0),
|
|
raw_character_position_(0) {
|
|
ReadBlock();
|
|
}
|
|
|
|
|
|
Utf8ToUtf16CharacterStream::~Utf8ToUtf16CharacterStream() { }
|
|
|
|
|
|
unsigned Utf8ToUtf16CharacterStream::BufferSeekForward(unsigned delta) {
|
|
unsigned old_pos = pos_;
|
|
unsigned target_pos = pos_ + delta;
|
|
SetRawPosition(target_pos);
|
|
pos_ = raw_character_position_;
|
|
ReadBlock();
|
|
return pos_ - old_pos;
|
|
}
|
|
|
|
|
|
unsigned Utf8ToUtf16CharacterStream::FillBuffer(unsigned char_position,
|
|
unsigned length) {
|
|
static const unibrow::uchar kMaxUtf16Character = 0xffff;
|
|
SetRawPosition(char_position);
|
|
if (raw_character_position_ != char_position) {
|
|
// char_position was not a valid position in the stream (hit the end
|
|
// while spooling to it).
|
|
return 0u;
|
|
}
|
|
unsigned i = 0;
|
|
while (i < length - 1) {
|
|
if (raw_data_pos_ == raw_data_length_) break;
|
|
unibrow::uchar c = raw_data_[raw_data_pos_];
|
|
if (c <= unibrow::Utf8::kMaxOneByteChar) {
|
|
raw_data_pos_++;
|
|
} else {
|
|
c = unibrow::Utf8::CalculateValue(raw_data_ + raw_data_pos_,
|
|
raw_data_length_ - raw_data_pos_,
|
|
&raw_data_pos_);
|
|
}
|
|
if (c > kMaxUtf16Character) {
|
|
buffer_[i++] = unibrow::Utf16::LeadSurrogate(c);
|
|
buffer_[i++] = unibrow::Utf16::TrailSurrogate(c);
|
|
} else {
|
|
buffer_[i++] = static_cast<uc16>(c);
|
|
}
|
|
}
|
|
raw_character_position_ = char_position + i;
|
|
return i;
|
|
}
|
|
|
|
|
|
static const byte kUtf8MultiByteMask = 0xC0;
|
|
static const byte kUtf8MultiByteCharStart = 0xC0;
|
|
static const byte kUtf8MultiByteCharFollower = 0x80;
|
|
|
|
|
|
#ifdef DEBUG
|
|
static bool IsUtf8MultiCharacterStart(byte first_byte) {
|
|
return (first_byte & kUtf8MultiByteMask) == kUtf8MultiByteCharStart;
|
|
}
|
|
#endif
|
|
|
|
|
|
static bool IsUtf8MultiCharacterFollower(byte later_byte) {
|
|
return (later_byte & kUtf8MultiByteMask) == kUtf8MultiByteCharFollower;
|
|
}
|
|
|
|
|
|
// Move the cursor back to point at the preceding UTF-8 character start
|
|
// in the buffer.
|
|
static inline void Utf8CharacterBack(const byte* buffer, unsigned* cursor) {
|
|
byte character = buffer[--*cursor];
|
|
if (character > unibrow::Utf8::kMaxOneByteChar) {
|
|
ASSERT(IsUtf8MultiCharacterFollower(character));
|
|
// Last byte of a multi-byte character encoding. Step backwards until
|
|
// pointing to the first byte of the encoding, recognized by having the
|
|
// top two bits set.
|
|
while (IsUtf8MultiCharacterFollower(buffer[--*cursor])) { }
|
|
ASSERT(IsUtf8MultiCharacterStart(buffer[*cursor]));
|
|
}
|
|
}
|
|
|
|
|
|
// Move the cursor forward to point at the next following UTF-8 character start
|
|
// in the buffer.
|
|
static inline void Utf8CharacterForward(const byte* buffer, unsigned* cursor) {
|
|
byte character = buffer[(*cursor)++];
|
|
if (character > unibrow::Utf8::kMaxOneByteChar) {
|
|
// First character of a multi-byte character encoding.
|
|
// The number of most-significant one-bits determines the length of the
|
|
// encoding:
|
|
// 110..... - (0xCx, 0xDx) one additional byte (minimum).
|
|
// 1110.... - (0xEx) two additional bytes.
|
|
// 11110... - (0xFx) three additional bytes (maximum).
|
|
ASSERT(IsUtf8MultiCharacterStart(character));
|
|
// Additional bytes is:
|
|
// 1 if value in range 0xC0 .. 0xDF.
|
|
// 2 if value in range 0xE0 .. 0xEF.
|
|
// 3 if value in range 0xF0 .. 0xF7.
|
|
// Encode that in a single value.
|
|
unsigned additional_bytes =
|
|
((0x3211u) >> (((character - 0xC0) >> 2) & 0xC)) & 0x03;
|
|
*cursor += additional_bytes;
|
|
ASSERT(!IsUtf8MultiCharacterFollower(buffer[1 + additional_bytes]));
|
|
}
|
|
}
|
|
|
|
|
|
// This can't set a raw position between two surrogate pairs, since there
|
|
// is no position in the UTF8 stream that corresponds to that. This assumes
|
|
// that the surrogate pair is correctly coded as a 4 byte UTF-8 sequence. If
|
|
// it is illegally coded as two 3 byte sequences then there is no problem here.
|
|
void Utf8ToUtf16CharacterStream::SetRawPosition(unsigned target_position) {
|
|
if (raw_character_position_ > target_position) {
|
|
// Spool backwards in utf8 buffer.
|
|
do {
|
|
int old_pos = raw_data_pos_;
|
|
Utf8CharacterBack(raw_data_, &raw_data_pos_);
|
|
raw_character_position_--;
|
|
ASSERT(old_pos - raw_data_pos_ <= 4);
|
|
// Step back over both code units for surrogate pairs.
|
|
if (old_pos - raw_data_pos_ == 4) raw_character_position_--;
|
|
} while (raw_character_position_ > target_position);
|
|
// No surrogate pair splitting.
|
|
ASSERT(raw_character_position_ == target_position);
|
|
return;
|
|
}
|
|
// Spool forwards in the utf8 buffer.
|
|
while (raw_character_position_ < target_position) {
|
|
if (raw_data_pos_ == raw_data_length_) return;
|
|
int old_pos = raw_data_pos_;
|
|
Utf8CharacterForward(raw_data_, &raw_data_pos_);
|
|
raw_character_position_++;
|
|
ASSERT(raw_data_pos_ - old_pos <= 4);
|
|
if (raw_data_pos_ - old_pos == 4) raw_character_position_++;
|
|
}
|
|
// No surrogate pair splitting.
|
|
ASSERT(raw_character_position_ == target_position);
|
|
}
|
|
|
|
|
|
// ----------------------------------------------------------------------------
|
|
// ExternalTwoByteStringUtf16CharacterStream
|
|
|
|
ExternalTwoByteStringUtf16CharacterStream::
|
|
~ExternalTwoByteStringUtf16CharacterStream() { }
|
|
|
|
|
|
ExternalTwoByteStringUtf16CharacterStream
|
|
::ExternalTwoByteStringUtf16CharacterStream(
|
|
Handle<ExternalTwoByteString> data,
|
|
int start_position,
|
|
int end_position)
|
|
: Utf16CharacterStream(),
|
|
source_(data),
|
|
raw_data_(data->GetTwoByteData(start_position)) {
|
|
buffer_cursor_ = raw_data_,
|
|
buffer_end_ = raw_data_ + (end_position - start_position);
|
|
pos_ = start_position;
|
|
}
|
|
|
|
} } // namespace v8::internal
|