root/src/unicode-inl.h
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// Copyright 2007-2010 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
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef V8_UNICODE_INL_H_
#define V8_UNICODE_INL_H_
#include "unicode.h"
namespace unibrow {
template <class T, int s> bool Predicate<T, s>::get(uchar code_point) {
CacheEntry entry = entries_[code_point & kMask];
if (entry.code_point_ == code_point) return entry.value_;
return CalculateValue(code_point);
}
template <class T, int s> bool Predicate<T, s>::CalculateValue(
uchar code_point) {
bool result = T::Is(code_point);
entries_[code_point & kMask] = CacheEntry(code_point, result);
return result;
}
template <class T, int s> int Mapping<T, s>::get(uchar c, uchar n,
uchar* result) {
CacheEntry entry = entries_[c & kMask];
if (entry.code_point_ == c) {
if (entry.offset_ == 0) {
return 0;
} else {
result[0] = c + entry.offset_;
return 1;
}
} else {
return CalculateValue(c, n, result);
}
}
template <class T, int s> int Mapping<T, s>::CalculateValue(uchar c, uchar n,
uchar* result) {
bool allow_caching = true;
int length = T::Convert(c, n, result, &allow_caching);
if (allow_caching) {
if (length == 1) {
entries_[c & kMask] = CacheEntry(c, result[0] - c);
return 1;
} else {
entries_[c & kMask] = CacheEntry(c, 0);
return 0;
}
} else {
return length;
}
}
unsigned Utf8::Encode(char* str, uchar c, int previous) {
static const int kMask = ~(1 << 6);
if (c <= kMaxOneByteChar) {
str[0] = c;
return 1;
} else if (c <= kMaxTwoByteChar) {
str[0] = 0xC0 | (c >> 6);
str[1] = 0x80 | (c & kMask);
return 2;
} else if (c <= kMaxThreeByteChar) {
if (Utf16::IsTrailSurrogate(c) &&
Utf16::IsLeadSurrogate(previous)) {
const int kUnmatchedSize = kSizeOfUnmatchedSurrogate;
return Encode(str - kUnmatchedSize,
Utf16::CombineSurrogatePair(previous, c),
Utf16::kNoPreviousCharacter) - kUnmatchedSize;
}
str[0] = 0xE0 | (c >> 12);
str[1] = 0x80 | ((c >> 6) & kMask);
str[2] = 0x80 | (c & kMask);
return 3;
} else {
str[0] = 0xF0 | (c >> 18);
str[1] = 0x80 | ((c >> 12) & kMask);
str[2] = 0x80 | ((c >> 6) & kMask);
str[3] = 0x80 | (c & kMask);
return 4;
}
}
uchar Utf8::ValueOf(const byte* bytes, unsigned length, unsigned* cursor) {
if (length <= 0) return kBadChar;
byte first = bytes[0];
// Characters between 0000 and 0007F are encoded as a single character
if (first <= kMaxOneByteChar) {
*cursor += 1;
return first;
}
return CalculateValue(bytes, length, cursor);
}
unsigned Utf8::Length(uchar c, int previous) {
if (c <= kMaxOneByteChar) {
return 1;
} else if (c <= kMaxTwoByteChar) {
return 2;
} else if (c <= kMaxThreeByteChar) {
if (Utf16::IsTrailSurrogate(c) &&
Utf16::IsLeadSurrogate(previous)) {
return kSizeOfUnmatchedSurrogate - kBytesSavedByCombiningSurrogates;
}
return 3;
} else {
return 4;
}
}
uchar CharacterStream::GetNext() {
uchar result = DecodeCharacter(buffer_, &cursor_);
if (remaining_ == 1) {
cursor_ = 0;
FillBuffer();
} else {
remaining_--;
}
return result;
}
#if __BYTE_ORDER == __LITTLE_ENDIAN
#define IF_LITTLE(expr) expr
#define IF_BIG(expr) ((void) 0)
#elif __BYTE_ORDER == __BIG_ENDIAN
#define IF_LITTLE(expr) ((void) 0)
#define IF_BIG(expr) expr
#else
#warning Unknown byte ordering
#endif
bool CharacterStream::EncodeAsciiCharacter(uchar c, byte* buffer,
unsigned capacity, unsigned& offset) {
if (offset >= capacity) return false;
buffer[offset] = c;
offset += 1;
return true;
}
bool CharacterStream::EncodeNonAsciiCharacter(uchar c, byte* buffer,
unsigned capacity, unsigned& offset) {
unsigned aligned = (offset + 0x3) & ~0x3;
if ((aligned + sizeof(uchar)) > capacity)
return false;
if (offset == aligned) {
IF_LITTLE(*reinterpret_cast<uchar*>(buffer + aligned) = (c << 8) | 0x80);
IF_BIG(*reinterpret_cast<uchar*>(buffer + aligned) = c | (1 << 31));
} else {
buffer[offset] = 0x80;
IF_LITTLE(*reinterpret_cast<uchar*>(buffer + aligned) = c << 8);
IF_BIG(*reinterpret_cast<uchar*>(buffer + aligned) = c);
}
offset = aligned + sizeof(uchar);
return true;
}
bool CharacterStream::EncodeCharacter(uchar c, byte* buffer, unsigned capacity,
unsigned& offset) {
if (c <= Utf8::kMaxOneByteChar) {
return EncodeAsciiCharacter(c, buffer, capacity, offset);
} else {
return EncodeNonAsciiCharacter(c, buffer, capacity, offset);
}
}
uchar CharacterStream::DecodeCharacter(const byte* buffer, unsigned* offset) {
byte b = buffer[*offset];
if (b <= Utf8::kMaxOneByteChar) {
(*offset)++;
return b;
} else {
unsigned aligned = (*offset + 0x3) & ~0x3;
*offset = aligned + sizeof(uchar);
IF_LITTLE(return *reinterpret_cast<const uchar*>(buffer + aligned) >> 8);
IF_BIG(return *reinterpret_cast<const uchar*>(buffer + aligned) &
~(1 << 31));
}
}
#undef IF_LITTLE
#undef IF_BIG
template <class R, class I, unsigned s>
void InputBuffer<R, I, s>::FillBuffer() {
buffer_ = R::ReadBlock(input_, util_buffer_, s, &remaining_, &offset_);
}
template <class R, class I, unsigned s>
void InputBuffer<R, I, s>::Rewind() {
Reset(input_);
}
template <class R, class I, unsigned s>
void InputBuffer<R, I, s>::Reset(unsigned position, I input) {
input_ = input;
remaining_ = 0;
cursor_ = 0;
offset_ = position;
buffer_ = R::ReadBlock(input_, util_buffer_, s, &remaining_, &offset_);
}
template <class R, class I, unsigned s>
void InputBuffer<R, I, s>::Reset(I input) {
Reset(0, input);
}
template <class R, class I, unsigned s>
void InputBuffer<R, I, s>::Seek(unsigned position) {
offset_ = position;
buffer_ = R::ReadBlock(input_, util_buffer_, s, &remaining_, &offset_);
}
template <unsigned s>
Utf8InputBuffer<s>::Utf8InputBuffer(const char* data, unsigned length)
: InputBuffer<Utf8, Buffer<const char*>, s>(Buffer<const char*>(data,
length)) {
}
} // namespace unibrow
#endif // V8_UNICODE_INL_H_