88 lines
2.2 KiB
C
88 lines
2.2 KiB
C
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/*
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* Copyright (c) 2007 Michael Niedermayer
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <inttypes.h>
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#include <errno.h>
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#include <string.h>
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static uint32_t state;
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static uint32_t ran(void)
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{
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return state = state * 1664525 + 1013904223;
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}
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static void checked_seek(FILE *stream, int64_t offset, int whence)
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{
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offset = fseek(stream, offset, whence);
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if (offset < 0) {
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fprintf(stderr, "seek failed\n");
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exit(1);
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}
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}
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int main(int argc, char **argv)
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{
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FILE *f;
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int count, maxburst, length;
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if (argc < 5) {
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printf("USAGE: trasher <filename> <count> <maxburst> <seed>\n");
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return 1;
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}
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f = fopen(argv[1], "rb+");
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if (!f) {
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perror(argv[1]);
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return 2;
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}
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count = atoi(argv[2]);
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maxburst = atoi(argv[3]);
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state = atoi(argv[4]);
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checked_seek(f, 0, SEEK_END);
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length = ftell(f);
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checked_seek(f, 0, SEEK_SET);
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while (count--) {
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int burst = 1 + ran() * (uint64_t) (abs(maxburst) - 1) / UINT32_MAX;
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int pos = ran() * (uint64_t) length / UINT32_MAX;
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checked_seek(f, pos, SEEK_SET);
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if (maxburst < 0)
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burst = -maxburst;
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if (pos + burst > length)
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continue;
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while (burst--) {
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int val = ran() * 256ULL / UINT32_MAX;
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if (maxburst < 0)
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val = 0;
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fwrite(&val, 1, 1, f);
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}
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}
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return 0;
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}
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