zutil.c
上传用户:zlt_tm
上传日期:2007-01-06
资源大小:214k
文件大小:5k
- /* zutil.c -- target dependent utility functions for the compression library
- * Copyright (C) 1995-1998 Jean-loup Gailly.
- * For conditions of distribution and use, see copyright notice in zlib.h
- */
- /* @(#) $Id$ */
- #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, "%sn", 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 */
- return (voidpf)calloc(items, size);
- }
- void zcfree (opaque, ptr)
- voidpf opaque;
- voidpf ptr;
- {
- free(ptr);
- if (opaque) return; /* make compiler happy */
- }
- #endif /* MY_ZCALLOC */