| #include <u.h> |
| #include <libc.h> |
| #include <flate.h> |
| #include "zlib.h" |
| |
| 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; |
| } |