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// Copyright (c) 2000 Matthias Clasen
// See the file COPYING for copying permission.
#include "splib.h"
#ifdef SP_MULTI_BYTE
#include "Fixed4CodingSystem.h"
#include "macros.h"
#include "constant.h"
#ifdef SP_NAMESPACE
namespace SP_NAMESPACE {
#endif
class Fixed4Decoder : public Decoder {
public:
Fixed4Decoder(Boolean lsbFirst, Boolean lswFirst);
size_t decode(Char *to, const char *from, size_t fromLen,
const char **rest);
Boolean convertOffset(unsigned long &offset) const;
private:
// value for encoding error
enum { invalid = 0xfffd };
Boolean lsbFirst_;
Boolean lswFirst_;
};
class Fixed4Encoder : public Encoder {
public:
Fixed4Encoder();
~Fixed4Encoder();
void output(Char *, size_t, OutputByteStream *);
void output(const Char *, size_t, OutputByteStream *);
private:
void allocBuf(size_t);
char *buf_;
size_t bufSize_;
};
Decoder *Fixed4CodingSystem::makeDecoder(Boolean lsbFirst, Boolean lswFirst) const
{
return new Fixed4Decoder(lsbFirst, lswFirst);
}
Encoder *Fixed4CodingSystem::makeEncoder() const
{
return new Fixed4Encoder;
}
unsigned Fixed4CodingSystem::fixedBytesPerChar() const
{
return 4;
}
Fixed4Decoder::Fixed4Decoder(Boolean lsbFirst, Boolean lswFirst)
: Decoder(4), lsbFirst_(lsbFirst), lswFirst_(lswFirst)
{
}
size_t Fixed4Decoder::decode(Char *to, const char *from, size_t fromLen,
const char **rest)
{
#if 0
// FIXME for this optimization I need autoconf macros that tell
// me the byte order in 32bit words: 1234, 4321, 2143 or 3412.
// Look at the corresponding optimization in Fixed2Decoder.
if (sizeof(Char) == 4 && from == (char *)to) {
*rest = from + (fromLen & ~3);
for (size_t n = 0; n < fromLen/4; n++)
if (charMax < to[n])
to[n] = invalid;
return fromLen/4;
}
#endif
fromLen &= ~3;
*rest = from + fromLen;
// lsbFirst, lswFirst: 0123
// lsbFirst, !lswFirst: 2301
// !lsbFirst, lswFirst: 1032
// !lsbFirst, !lswFirst: 3210
size_t shift0 = 8*(!lsbFirst_ + 2*!lswFirst_);
size_t shift1 = 8*(lsbFirst_ + 2*!lswFirst_);
size_t shift2 = 8*(!lsbFirst_ + 2*lswFirst_);
size_t shift3 = 8*(lsbFirst_ + 2*lswFirst_);
for (size_t n = fromLen; n > 0; n -= 4) {
Unsigned32 c = ((unsigned char)from[0] << shift0)
+ ((unsigned char)from[1] << shift1)
+ ((unsigned char)from[2] << shift2)
+ ((unsigned char)from[3] << shift3);
*to++ = charMax < c ? invalid : c;
from += 4;
}
return fromLen/4;
}
Boolean Fixed4Decoder::convertOffset(unsigned long &n) const
{
n *= 4;
return true;
}
Fixed4Encoder::Fixed4Encoder()
: buf_(0), bufSize_(0)
{
}
Fixed4Encoder::~Fixed4Encoder()
{
delete [] buf_;
}
void Fixed4Encoder::allocBuf(size_t n)
{
if (bufSize_ < n) {
delete [] buf_;
buf_ = new char[bufSize_ = n];
}
}
void Fixed4Encoder::output(Char *s, size_t n, OutputByteStream *sb)
{
#ifdef SP_BIG_ENDIAN
if (sizeof(Char) == 4) {
sb->sputn((char *)s, n*4);
return;
}
#endif
ASSERT(sizeof(Char) >= 4);
char *p = (char *)s;
for (size_t i = 0; i < n; i++) {
Char c = s[i];
*p++ = (c >> 24) & 0xff;
*p++ = (c >> 16) & 0xff;
*p++ = (c >> 8) & 0xff;
*p++ = c & 0xff;
}
sb->sputn((char *)s, n*4);
}
void Fixed4Encoder::output(const Char *s, size_t n, OutputByteStream *sb)
{
#ifdef SP_BIG_ENDIAN
if (sizeof(Char) == 4) {
sb->sputn((char *)s, n*4);
return;
}
#endif
allocBuf(n*4);
for (size_t i = 0; i < n; i++) {
buf_[i*4] = (s[i] >> 24) & 0xff;
buf_[i*4 + 1] = (s[i] >> 16) & 0xff;
buf_[i*4 + 2] = (s[i] >> 8) & 0xff;
buf_[i*4 + 3] = s[i] & 0xff;
}
sb->sputn(buf_, n*4);
}
#ifdef SP_NAMESPACE
}
#endif
#else /* not SP_MULTI_BYTE */
#ifndef __GNUG__
static char non_empty_translation_unit; // sigh
#endif
#endif /* not SP_MULTI_BYTE */
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