mirror of
https://github.com/bol-van/zapret.git
synced 2024-11-14 18:48:33 +05:00
83 lines
1.4 KiB
C
83 lines
1.4 KiB
C
#include "gzip.h"
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#define ZCHUNK 16384
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#define BUFMIN 128
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#define BUFCHUNK (1024*128)
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int z_readfile(FILE *F, char **buf, size_t *size)
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{
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z_stream zs;
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int r;
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unsigned char in[ZCHUNK];
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size_t bufsize;
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void *newbuf;
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memset(&zs, 0, sizeof(zs));
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*buf = NULL;
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bufsize = *size = 0;
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r = inflateInit2(&zs, 47);
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if (r != Z_OK) return r;
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do
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{
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zs.avail_in = fread(in, 1, sizeof(in), F);
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if (ferror(F))
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{
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r = Z_ERRNO;
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goto zerr;
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}
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if (!zs.avail_in) break;
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zs.next_in = in;
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do
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{
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if ((bufsize - *size) < BUFMIN)
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{
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bufsize += BUFCHUNK;
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newbuf = *buf ? realloc(*buf, bufsize) : malloc(bufsize);
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if (!newbuf)
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{
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r = Z_MEM_ERROR;
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goto zerr;
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}
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*buf = newbuf;
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}
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zs.avail_out = bufsize - *size;
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zs.next_out = (unsigned char*)(*buf + *size);
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r = inflate(&zs, Z_NO_FLUSH);
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if (r != Z_OK && r != Z_STREAM_END) goto zerr;
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*size = bufsize - zs.avail_out;
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} while (r == Z_OK && zs.avail_in);
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} while (r == Z_OK);
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if (*size < bufsize)
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{
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// free extra space
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if ((newbuf = realloc(*buf, *size))) *buf = newbuf;
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}
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inflateEnd(&zs);
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return Z_OK;
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zerr:
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inflateEnd(&zs);
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if (*buf)
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{
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free(*buf);
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*buf = NULL;
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}
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return r;
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}
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bool is_gzip(FILE* F)
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{
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unsigned char magic[2];
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bool b = !fseek(F, 0, SEEK_SET) && fread(magic, 1, 2, F) == 2 && magic[0] == 0x1F && magic[1] == 0x8B;
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fseek(F, 0, SEEK_SET);
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return b;
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}
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