ref: a3dc4d80a899b28130729721b90a0506e44b8d76
dir: /sys/src/libflate/inflatezlib.c/
#include <u.h> #include <libc.h> #include <flate.h> #include "zlib.h" typedef struct ZWrite ZWrite; struct ZWrite { ulong adler; void *wr; int (*w)(void*, void*, int); }; static int zlwrite(void *vzw, void *buf, int n) { ZWrite *zw; zw = vzw; zw->adler = adler32(zw->adler, buf, n); n = (*zw->w)(zw->wr, buf, n); if(n <= 0) return n; return n; } int inflatezlib(void *wr, int (*w)(void*, void*, int), void *getr, int (*get)(void*)) { ZWrite zw; ulong v; int c, i; c = (*get)(getr); if(c < 0) return FlateInputFail; i = (*get)(getr); if(i < 0) return FlateInputFail; if(((c << 8) | i) % 31) return FlateCorrupted; if((c & ZlibMeth) != ZlibDeflate || (c & ZlibCInfo) > ZlibWin32k) return FlateCorrupted; zw.wr = wr; zw.w = w; zw.adler = 1; i = inflate(&zw, zlwrite, getr, get); if(i != FlateOk) return i; v = 0; for(i = 0; i < 4; i++){ c = (*get)(getr); if(c < 0) return FlateInputFail; v = (v << 8) | c; } if(zw.adler != v) return FlateCorrupted; return FlateOk; }