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#ifndef V8_UNICODE_H_
#define V8_UNICODE_H_
#include <sys/types.h>
/**
* \file
* Definitions and convenience functions for working with unicode.
*/
namespace unibrow {
typedef unsigned int uchar;
typedef unsigned char byte;
/**
* The max length of the result of converting the case of a single
* character.
*/
const int kMaxMappingSize = 4;
template <class T, int size = 256>
class Predicate {
public:
inline Predicate() { }
inline bool get(uchar c);
private:
friend class Test;
bool CalculateValue(uchar c);
struct CacheEntry {
inline CacheEntry() : code_point_(0), value_(0) { }
inline CacheEntry(uchar code_point, bool value)
: code_point_(code_point),
value_(value) { }
uchar code_point_ : 21;
bool value_ : 1;
};
static const int kSize = size;
static const int kMask = kSize - 1;
CacheEntry entries_[kSize];
};
// A cache used in case conversion. It caches the value for characters
// that either have no mapping or map to a single character independent
// of context. Characters that map to more than one character or that
// map differently depending on context are always looked up.
template <class T, int size = 256>
class Mapping {
public:
inline Mapping() { }
inline int get(uchar c, uchar n, uchar* result);
private:
friend class Test;
int CalculateValue(uchar c, uchar n, uchar* result);
struct CacheEntry {
inline CacheEntry() : code_point_(kNoChar), offset_(0) { }
inline CacheEntry(uchar code_point, signed offset)
: code_point_(code_point),
offset_(offset) { }
uchar code_point_;
signed offset_;
static const int kNoChar = (1 << 21) - 1;
};
static const int kSize = size;
static const int kMask = kSize - 1;
CacheEntry entries_[kSize];
};
class UnicodeData {
private:
friend class Test;
static int GetByteCount();
static const uchar kMaxCodePoint;
};
// --- U t f 8 a n d 16 ---
template <typename Data>
class Buffer {
public:
inline Buffer(Data data, unsigned length) : data_(data), length_(length) { }
inline Buffer() : data_(0), length_(0) { }
Data data() { return data_; }
unsigned length() { return length_; }
private:
Data data_;
unsigned length_;
};
class Utf16 {
public:
static inline bool IsLeadSurrogate(int code) {
if (code == kNoPreviousCharacter) return false;
return (code & 0xfc00) == 0xd800;
}
static inline bool IsTrailSurrogate(int code) {
if (code == kNoPreviousCharacter) return false;
return (code & 0xfc00) == 0xdc00;
}
static inline int CombineSurrogatePair(uchar lead, uchar trail) {
return 0x10000 + ((lead & 0x3ff) << 10) + (trail & 0x3ff);
}
static const int kNoPreviousCharacter = -1;
static const uchar kMaxNonSurrogateCharCode = 0xffff;
// Encoding a single UTF-16 code unit will produce 1, 2 or 3 bytes
// of UTF-8 data. The special case where the unit is a surrogate
// trail produces 1 byte net, because the encoding of the pair is
// 4 bytes and the 3 bytes that were used to encode the lead surrogate
// can be reclaimed.
static const int kMaxExtraUtf8BytesForOneUtf16CodeUnit = 3;
// One UTF-16 surrogate is endoded (illegally) as 3 UTF-8 bytes.
// The illegality stems from the surrogate not being part of a pair.
static const int kUtf8BytesToCodeASurrogate = 3;
static inline uchar LeadSurrogate(int char_code) {
return 0xd800 + (((char_code - 0x10000) >> 10) & 0x3ff);
}
static inline uchar TrailSurrogate(int char_code) {
return 0xdc00 + (char_code & 0x3ff);
}
};
class Utf8 {
public:
static inline uchar Length(uchar chr, int previous);
static inline unsigned Encode(
char* out, uchar c, int previous);
static const byte* ReadBlock(Buffer<const char*> str, byte* buffer,
unsigned capacity, unsigned* chars_read, unsigned* offset);
static uchar CalculateValue(const byte* str,
unsigned length,
unsigned* cursor);
static const uchar kBadChar = 0xFFFD;
static const unsigned kMaxEncodedSize = 4;
static const unsigned kMaxOneByteChar = 0x7f;
static const unsigned kMaxTwoByteChar = 0x7ff;
static const unsigned kMaxThreeByteChar = 0xffff;
static const unsigned kMaxFourByteChar = 0x1fffff;
// A single surrogate is coded as a 3 byte UTF-8 sequence, but two together
// that match are coded as a 4 byte UTF-8 sequence.
static const unsigned kBytesSavedByCombiningSurrogates = 2;
static const unsigned kSizeOfUnmatchedSurrogate = 3;
private:
template <unsigned s> friend class Utf8InputBuffer;
friend class Test;
static inline uchar ValueOf(const byte* str,
unsigned length,
unsigned* cursor);
};
// --- C h a r a c t e r S t r e a m ---
class CharacterStream {
public:
inline uchar GetNext();
inline bool has_more() { return remaining_ != 0; }
// Note that default implementation is not efficient.
virtual void Seek(unsigned);
unsigned Length();
unsigned Utf16Length();
virtual ~CharacterStream() { }
static inline bool EncodeCharacter(uchar c, byte* buffer, unsigned capacity,
unsigned& offset);
static inline bool EncodeAsciiCharacter(uchar c, byte* buffer,
unsigned capacity, unsigned& offset);
static inline bool EncodeNonAsciiCharacter(uchar c, byte* buffer,
unsigned capacity, unsigned& offset);
static inline uchar DecodeCharacter(const byte* buffer, unsigned* offset);
virtual void Rewind() = 0;
protected:
virtual void FillBuffer() = 0;
// The number of characters left in the current buffer
unsigned remaining_;
// The current offset within the buffer
unsigned cursor_;
// The buffer containing the decoded characters.
const byte* buffer_;
};
// --- I n p u t B u f f e r ---
/**
* Provides efficient access to encoded characters in strings. It
* does so by reading characters one block at a time, rather than one
* character at a time, which gives string implementations an
* opportunity to optimize the decoding.
*/
template <class Reader, class Input = Reader*, unsigned kSize = 256>
class InputBuffer : public CharacterStream {
public:
virtual void Rewind();
inline void Reset(Input input);
void Seek(unsigned position);
inline void Reset(unsigned position, Input input);
protected:
InputBuffer() { }
explicit InputBuffer(Input input) { Reset(input); }
virtual void FillBuffer();
// A custom offset that can be used by the string implementation to
// mark progress within the encoded string.
unsigned offset_;
// The input string
Input input_;
// To avoid heap allocation, we keep an internal buffer to which
// the encoded string can write its characters. The string
// implementation is free to decide whether it wants to use this
// buffer or not.
byte util_buffer_[kSize];
};
// --- U t f 8 I n p u t B u f f e r ---
template <unsigned s = 256>
class Utf8InputBuffer : public InputBuffer<Utf8, Buffer<const char*>, s> {
public:
inline Utf8InputBuffer() { }
inline Utf8InputBuffer(const char* data, unsigned length);
inline void Reset(const char* data, unsigned length) {
InputBuffer<Utf8, Buffer<const char*>, s>::Reset(
Buffer<const char*>(data, length));
}
};
struct Uppercase {
static bool Is(uchar c);
};
struct Lowercase {
static bool Is(uchar c);
};
struct Letter {
static bool Is(uchar c);
};
struct Space {
static bool Is(uchar c);
};
struct Number {
static bool Is(uchar c);
};
struct WhiteSpace {
static bool Is(uchar c);
};
struct LineTerminator {
static bool Is(uchar c);
};
struct CombiningMark {
static bool Is(uchar c);
};
struct ConnectorPunctuation {
static bool Is(uchar c);
};
struct ToLowercase {
static const int kMaxWidth = 3;
static int Convert(uchar c,
uchar n,
uchar* result,
bool* allow_caching_ptr);
};
struct ToUppercase {
static const int kMaxWidth = 3;
static int Convert(uchar c,
uchar n,
uchar* result,
bool* allow_caching_ptr);
};
struct Ecma262Canonicalize {
static const int kMaxWidth = 1;
static int Convert(uchar c,
uchar n,
uchar* result,
bool* allow_caching_ptr);
};
struct Ecma262UnCanonicalize {
static const int kMaxWidth = 4;
static int Convert(uchar c,
uchar n,
uchar* result,
bool* allow_caching_ptr);
};
struct CanonicalizationRange {
static const int kMaxWidth = 1;
static int Convert(uchar c,
uchar n,
uchar* result,
bool* allow_caching_ptr);
};
} // namespace unibrow
#endif // V8_UNICODE_H_