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#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;
}
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