www.pudn.com > ZLib-check.rar > zutil.c

/* zutil.c -- target dependent utility functions for the compression library 
 * Copyright (C) 1995-2002 Jean-loup Gailly. 
 * For conditions of distribution and use, see copyright notice in zlib.h  
 */ 
 
/* @(#) $Id: zutil.c,v 1.1 2003/02/17 15:24:58 marcuso Exp $ */ 
 
#include "zutil.h" 
 
struct internal_state      {int dummy;}; /* for buggy compilers */ 
 
#ifndef STDC 
extern void exit OF((int)); 
#endif 
 
const char *z_errmsg[10] = { 
"need dictionary",     /* Z_NEED_DICT       2  */ 
"stream end",          /* Z_STREAM_END      1  */ 
"",                    /* Z_OK              0  */ 
"file error",          /* Z_ERRNO         (-1) */ 
"stream error",        /* Z_STREAM_ERROR  (-2) */ 
"data error",          /* Z_DATA_ERROR    (-3) */ 
"insufficient memory", /* Z_MEM_ERROR     (-4) */ 
"buffer error",        /* Z_BUF_ERROR     (-5) */ 
"incompatible version",/* Z_VERSION_ERROR (-6) */ 
""}; 
 
 
const char * ZEXPORT zlibVersion() 
{ 
    return ZLIB_VERSION; 
} 
 
#ifdef DEBUG 
 
#  ifndef verbose 
#    define verbose 0 
#  endif 
int z_verbose = verbose; 
 
void z_error (m) 
    char *m; 
{ 
    fprintf(stderr, "%s\n", m); 
    exit(1); 
} 
#endif 
 
/* exported to allow conversion of error code to string for compress() and 
 * uncompress() 
 */ 
const char * ZEXPORT zError(err) 
    int err; 
{ 
    return ERR_MSG(err); 
} 
 
 
#ifndef HAVE_MEMCPY 
 
void zmemcpy(dest, source, len) 
    Bytef* dest; 
    const Bytef* source; 
    uInt  len; 
{ 
    if (len == 0) return; 
    do { 
        *dest++ = *source++; /* ??? to be unrolled */ 
    } while (--len != 0); 
} 
 
int zmemcmp(s1, s2, len) 
    const Bytef* s1; 
    const Bytef* s2; 
    uInt  len; 
{ 
    uInt j; 
 
    for (j = 0; j < len; j++) { 
        if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1; 
    } 
    return 0; 
} 
 
void zmemzero(dest, len) 
    Bytef* dest; 
    uInt  len; 
{ 
    if (len == 0) return; 
    do { 
        *dest++ = 0;  /* ??? to be unrolled */ 
    } while (--len != 0); 
} 
#endif 
 
#ifdef __TURBOC__ 
#if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__) 
/* Small and medium model in Turbo C are for now limited to near allocation 
 * with reduced MAX_WBITS and MAX_MEM_LEVEL 
 */ 
#  define MY_ZCALLOC 
 
/* Turbo C malloc() does not allow dynamic allocation of 64K bytes 
 * and farmalloc(64K) returns a pointer with an offset of 8, so we 
 * must fix the pointer. Warning: the pointer must be put back to its 
 * original form in order to free it, use zcfree(). 
 */ 
 
#define MAX_PTR 10 
/* 10*64K = 640K */ 
 
local int next_ptr = 0; 
 
typedef struct ptr_table_s { 
    voidpf org_ptr; 
    voidpf new_ptr; 
} ptr_table; 
 
local ptr_table table[MAX_PTR]; 
/* This table is used to remember the original form of pointers 
 * to large buffers (64K). Such pointers are normalized with a zero offset. 
 * Since MSDOS is not a preemptive multitasking OS, this table is not 
 * protected from concurrent access. This hack doesn't work anyway on 
 * a protected system like OS/2. Use Microsoft C instead. 
 */ 
 
voidpf zcalloc (voidpf opaque, unsigned items, unsigned size) 
{ 
    voidpf buf = opaque; /* just to make some compilers happy */ 
    ulg bsize = (ulg)items*size; 
 
    /* If we allocate less than 65520 bytes, we assume that farmalloc 
     * will return a usable pointer which doesn't have to be normalized. 
     */ 
    if (bsize < 65520L) { 
        buf = farmalloc(bsize); 
        if (*(ush*)&buf != 0) return buf; 
    } else { 
        buf = farmalloc(bsize + 16L); 
    } 
    if (buf == NULL || next_ptr >= MAX_PTR) return NULL; 
    table[next_ptr].org_ptr = buf; 
 
    /* Normalize the pointer to seg:0 */ 
    *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4; 
    *(ush*)&buf = 0; 
    table[next_ptr++].new_ptr = buf; 
    return buf; 
} 
 
void  zcfree (voidpf opaque, voidpf ptr) 
{ 
    int n; 
    if (*(ush*)&ptr != 0) { /* object < 64K */ 
        farfree(ptr); 
        return; 
    } 
    /* Find the original pointer */ 
    for (n = 0; n < next_ptr; n++) { 
        if (ptr != table[n].new_ptr) continue; 
 
        farfree(table[n].org_ptr); 
        while (++n < next_ptr) { 
            table[n-1] = table[n]; 
        } 
        next_ptr--; 
        return; 
    } 
    ptr = opaque; /* just to make some compilers happy */ 
    Assert(0, "zcfree: ptr not found"); 
} 
#endif 
#endif /* __TURBOC__ */ 
 
 
#if defined(M_I86) && !defined(__32BIT__) 
/* Microsoft C in 16-bit mode */ 
 
#  define MY_ZCALLOC 
 
#if (!defined(_MSC_VER) || (_MSC_VER <= 600)) 
#  define _halloc  halloc 
#  define _hfree   hfree 
#endif 
 
voidpf zcalloc (voidpf opaque, unsigned items, unsigned size) 
{ 
    if (opaque) opaque = 0; /* to make compiler happy */ 
    return _halloc((long)items, size); 
} 
 
void  zcfree (voidpf opaque, voidpf ptr) 
{ 
    if (opaque) opaque = 0; /* to make compiler happy */ 
    _hfree(ptr); 
} 
 
#endif /* MSC */ 
 
 
#ifndef MY_ZCALLOC /* Any system without a special alloc function */ 
 
#ifndef STDC 
extern voidp  calloc OF((uInt items, uInt size)); 
extern void   free   OF((voidpf ptr)); 
#endif 
 
voidpf zcalloc (opaque, items, size) 
    voidpf opaque; 
    unsigned items; 
    unsigned size; 
{ 
    //if (opaque) items += size - size; /* make compiler happy */ 
	const unsigned int iAllocSize = items * size; 
	void* pMemory = malloc(iAllocSize); 
	memset(pMemory, 0, iAllocSize); 
    return pMemory; 
} 
 
void  zcfree (opaque, ptr) 
    voidpf opaque; 
    voidpf ptr; 
{ 
    free(ptr); 
} 
 
#endif /* MY_ZCALLOC */