int
deflatezlibblock(uchar *dst, int dsize, uchar *src, int ssize, int level, int debug)
{
ulong adler;
int n;
if(dsize < 6)
return FlateOutputFail;
n = deflateblock(dst + 2, dsize - 6, src, ssize, level, debug);
if(n < 0)
return n;
dst[0] = ZlibDeflate | ZlibWin32k;
/* bogus zlib encoding of compression level */
dst[1] = ((level > 2) + (level > 5) + (level > 8)) << 6;
/* header check field */
dst[1] |= 31 - ((dst[0] << 8) | dst[1]) % 31;
adler = adler32(1, src, ssize);
dst[n + 2] = adler >> 24;
dst[n + 3] = adler >> 16;
dst[n + 4] = adler >> 8;
dst[n + 5] = adler;
return n + 6;
}
ulong
writeBlock(uchar *b, int type)
{
uchar *cb, *ob;
int n;
PaqBlock bh;
uchar buf[BlockSize];
ulong offset;
offset = Boffset(out);
bh.magic = BlockMagic;
bh.size = blocksize;
bh.type = type;
bh.encoding = NoEnc;
bh.adler32 = adler32(0, b, blocksize);
ob = b;
if(!uflag) {
cb = emallocz(blocksize);
n = deflateblock(cb, blocksize, b, blocksize, 6, 0);
if(n > 0 && n < blocksize) {
bh.encoding = DeflateEnc;
bh.size = n;
ob = cb;
}
}
putBlock(buf, &bh);
outWrite(buf, sizeof(buf));
outWrite(ob, bh.size);
if(ob != b)
free(ob);
return offset;
}
