blob: 0b89cfed87fa7b2e22574ab0b5f5d4739b79b7e9
| 1 | /* |
| 2 | * Copyright (c) 2007 Michael Niedermayer |
| 3 | * |
| 4 | * This file is part of FFmpeg. |
| 5 | * |
| 6 | * FFmpeg is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU Lesser General Public |
| 8 | * License as published by the Free Software Foundation; either |
| 9 | * version 2.1 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * FFmpeg is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | * Lesser General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Lesser General Public |
| 17 | * License along with FFmpeg; if not, write to the Free Software |
| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 19 | */ |
| 20 | |
| 21 | #include <stdio.h> |
| 22 | #include <stdlib.h> |
| 23 | #include <inttypes.h> |
| 24 | #include <errno.h> |
| 25 | #include <string.h> |
| 26 | |
| 27 | static uint32_t state; |
| 28 | static uint32_t ran(void) |
| 29 | { |
| 30 | return state = state * 1664525 + 1013904223; |
| 31 | } |
| 32 | |
| 33 | static void checked_seek(FILE *stream, int64_t offset, int whence) |
| 34 | { |
| 35 | offset = fseek(stream, offset, whence); |
| 36 | if (offset < 0) { |
| 37 | fprintf(stderr, "seek failed\n"); |
| 38 | exit(1); |
| 39 | } |
| 40 | } |
| 41 | |
| 42 | int main(int argc, char **argv) |
| 43 | { |
| 44 | FILE *f; |
| 45 | int count, maxburst, length; |
| 46 | |
| 47 | if (argc < 5) { |
| 48 | printf("USAGE: trasher <filename> <count> <maxburst> <seed>\n"); |
| 49 | return 1; |
| 50 | } |
| 51 | |
| 52 | f = fopen(argv[1], "rb+"); |
| 53 | if (!f) { |
| 54 | perror(argv[1]); |
| 55 | return 2; |
| 56 | } |
| 57 | count = atoi(argv[2]); |
| 58 | maxburst = atoi(argv[3]); |
| 59 | state = atoi(argv[4]); |
| 60 | |
| 61 | checked_seek(f, 0, SEEK_END); |
| 62 | length = ftell(f); |
| 63 | checked_seek(f, 0, SEEK_SET); |
| 64 | |
| 65 | while (count--) { |
| 66 | int burst = 1 + ran() * (uint64_t) (abs(maxburst) - 1) / UINT32_MAX; |
| 67 | int pos = ran() * (uint64_t) length / UINT32_MAX; |
| 68 | checked_seek(f, pos, SEEK_SET); |
| 69 | |
| 70 | if (maxburst < 0) |
| 71 | burst = -maxburst; |
| 72 | |
| 73 | if (pos + burst > length) |
| 74 | continue; |
| 75 | |
| 76 | while (burst--) { |
| 77 | int val = ran() * 256ULL / UINT32_MAX; |
| 78 | |
| 79 | if (maxburst < 0) |
| 80 | val = 0; |
| 81 | |
| 82 | fwrite(&val, 1, 1, f); |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | return 0; |
| 87 | } |
| 88 |