MCUME/MCUME_teensy41/teensydoom/w_checksum.c

88 wiersze
2.2 KiB
C

//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// DESCRIPTION:
// Generate a checksum of the WAD directory.
//
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "m_misc.h"
#include "sha1.h"
#include "w_checksum.h"
#include "w_wad.h"
static wad_file_t **open_wadfiles = NULL;
static int num_open_wadfiles = 0;
static int GetFileNumber(wad_file_t *handle)
{
int i;
int result;
for (i=0; i<num_open_wadfiles; ++i)
{
if (open_wadfiles[i] == handle)
{
return i;
}
}
// Not found in list. This is a new file we haven't seen yet.
// Allocate another slot for this file.
open_wadfiles = realloc(open_wadfiles,
sizeof(wad_file_t *) * (num_open_wadfiles + 1));
open_wadfiles[num_open_wadfiles] = handle;
result = num_open_wadfiles;
++num_open_wadfiles;
return result;
}
static void ChecksumAddLump(sha1_context_t *sha1_context, lumpinfo_t *lump)
{
char buf[9];
M_StringCopy(buf, lump->name, sizeof(buf));
SHA1_UpdateString(sha1_context, buf);
SHA1_UpdateInt32(sha1_context, GetFileNumber(lump->wad_file));
SHA1_UpdateInt32(sha1_context, lump->position);
SHA1_UpdateInt32(sha1_context, lump->size);
}
void W_Checksum(sha1_digest_t digest)
{
sha1_context_t sha1_context;
unsigned int i;
SHA1_Init(&sha1_context);
num_open_wadfiles = 0;
// Go through each entry in the WAD directory, adding information
// about each entry to the SHA1 hash.
for (i=0; i<numlumps; ++i)
{
ChecksumAddLump(&sha1_context, &lumpinfo[i]);
}
SHA1_Final(digest, &sha1_context);
}