AppleWin/source/Tfe/tfesupp.cpp

/*
 * This file is a consolidation of functions required for tfe
 * emulation taken from the following files
 *
 * lib.c   - Library functions.
 * util.c  - Miscellaneous utility functions.
 * crc32.c
 *
 * Written by
 *  Andreas Boose <viceteam@t-online.de>
 *  Ettore Perazzoli <ettore@comm2000.it>
 *  Andreas Matthies <andreas.matthies@gmx.net>
 *  Tibor Biczo <crown@mail.matav.hu>
 *  Spiro Trikaliotis <Spiro.Trikaliotis@gmx.de>*
 *
 * This file is part of VICE, the Versatile Commodore Emulator.
 * See README for copyright notice.
 *
 *  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.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 *  02111-1307  USA.
 *
 */

#include <stdlib.h>
#include <string.h>

// Lib Stuff
/* #define LIB_DEBUG*/


#ifdef LIB_DEBUG
#define LIB_DEBUG_SIZE  0x10000
#define LIB_DEBUG_GUARD 0x1000
#endif

#define CRC32_POLY  0xedb88320
static unsigned long crc32_table[256];
static int crc32_is_initialized = 0;

void lib_free(void *ptr)
{
#ifdef LIB_DEBUG
    lib_debug_free(ptr, 1, 1);
#endif

#ifdef LIB_DEBUG
    lib_debug_libc_free(ptr);
#else
    free(ptr);
#endif
}

void *lib_malloc(size_t size)
{
#ifdef LIB_DEBUG
    void *ptr = lib_debug_libc_malloc(size);
#else
    void *ptr = malloc(size);
#endif

#ifndef __OS2__
    if (ptr == NULL && size > 0)
        exit(-1);
#endif
#ifdef LIB_DEBUG
    lib_debug_alloc(ptr, size, 3);
#endif

    return ptr;
}

/*-----------------------------------------------------------------------*/

/* Malloc enough space for `str', copy `str' into it and return its
   address.  */
char *lib_stralloc(const char *str)
{
    size_t size;
    char *ptr;

    if (str == NULL)
        exit(-1);

    size = strlen(str) + 1;
    ptr = (char *)lib_malloc(size);

    memcpy(ptr, str, size);
    return ptr;
}



/* Like realloc, but abort if not enough memory is available.  */
void *lib_realloc(void *ptr, size_t size)
{
#ifdef LIB_DEBUG
    void *new_ptr = lib_debug_libc_realloc(ptr, size);
#else
    void *new_ptr = realloc(ptr, size);
#endif

#ifndef __OS2__
    if (new_ptr == NULL)
        exit(-1);
#endif
#ifdef LIB_DEBUG
    lib_debug_free(ptr, 1, 0);
    lib_debug_alloc(new_ptr, size, 1);
#endif

    return new_ptr;
}

// Util Stuff

/* Set a new value to the dynamically allocated string *str.
   Returns `-1' if nothing has to be done.  */
int util_string_set(char **str, const char *new_value)
{
    if (*str == NULL) {
        if (new_value != NULL)
            *str = lib_stralloc(new_value);
    } else {
        if (new_value == NULL) {
            lib_free(*str);
            *str = NULL;
        } else {
            /* Skip copy if src and dest are already the same.  */
            if (strcmp(*str, new_value) == 0)
                return -1;

            *str = (char *)lib_realloc(*str, strlen(new_value) + 1);
            strcpy(*str, new_value);
        }
    }
    return 0;
}


// crc32 Stuff

unsigned long crc32_buf(const char *buffer, unsigned int len)
{
    int i, j;
    unsigned long crc, c;
    const char *p;

    if (!crc32_is_initialized) {
        for (i = 0; i < 256; i++) {
            c = (unsigned long) i;
            for (j = 0; j < 8; j++)
                c = c & 1 ? CRC32_POLY ^ (c >> 1) : c >> 1;
            crc32_table[i] = c;
        }
        crc32_is_initialized = 1;
    }

    crc = 0xffffffff;
    for (p = buffer; len > 0; ++p, --len)
        crc = (crc >> 8) ^ crc32_table[(crc ^ *p) & 0xff];
    
    return ~crc;
}