1/* zutil.c -- target dependent utility functions for the compression library
2 * Copyright (C) 1995-1998 Jean-loup Gailly.
3 * For conditions of distribution and use, see copyright notice in zlib.h
4 */
5
6/* @(#) $Id: zutil.c,v 1.1 2001/11/09 01:48:02 mpl Exp $ */
7
8#include "zutil.h"
9
10struct internal_state      {int dummy;}; /* for buggy compilers */
11
12#ifndef STDC
13extern void exit OF((int));
14#endif
15
16const char *z_errmsg[10] = {
17"need dictionary",     /* Z_NEED_DICT       2  */
18"stream end",          /* Z_STREAM_END      1  */
19"",                    /* Z_OK              0  */
20"file error",          /* Z_ERRNO         (-1) */
21"stream error",        /* Z_STREAM_ERROR  (-2) */
22"data error",          /* Z_DATA_ERROR    (-3) */
23"insufficient memory", /* Z_MEM_ERROR     (-4) */
24"buffer error",        /* Z_BUF_ERROR     (-5) */
25"incompatible version",/* Z_VERSION_ERROR (-6) */
26""};
27
28
29const char * ZEXPORT zlibVersion()
30{
31    return ZLIB_VERSION;
32}
33
34#ifdef DEBUG
35
36#  ifndef verbose
37#    define verbose 0
38#  endif
39int z_verbose = verbose;
40
41void z_error (m)
42    char *m;
43{
44    fprintf(stderr, "%s\n", m);
45    exit(1);
46}
47#endif
48
49/* exported to allow conversion of error code to string for compress() and
50 * uncompress()
51 */
52const char * ZEXPORT zError(err)
53    int err;
54{
55    return ERR_MSG(err);
56}
57
58
59#ifndef HAVE_MEMCPY
60
61void zmemcpy(dest, source, len)
62    Bytef* dest;
63    const Bytef* source;
64    uInt  len;
65{
66    if (len == 0) return;
67    do {
68        *dest++ = *source++; /* ??? to be unrolled */
69    } while (--len != 0);
70}
71
72int zmemcmp(s1, s2, len)
73    const Bytef* s1;
74    const Bytef* s2;
75    uInt  len;
76{
77    uInt j;
78
79    for (j = 0; j < len; j++) {
80        if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
81    }
82    return 0;
83}
84
85void zmemzero(dest, len)
86    Bytef* dest;
87    uInt  len;
88{
89    if (len == 0) return;
90    do {
91        *dest++ = 0;  /* ??? to be unrolled */
92    } while (--len != 0);
93}
94#endif
95
96#ifdef __TURBOC__
97#if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__)
98/* Small and medium model in Turbo C are for now limited to near allocation
99 * with reduced MAX_WBITS and MAX_MEM_LEVEL
100 */
101#  define MY_ZCALLOC
102
103/* Turbo C malloc() does not allow dynamic allocation of 64K bytes
104 * and farmalloc(64K) returns a pointer with an offset of 8, so we
105 * must fix the pointer. Warning: the pointer must be put back to its
106 * original form in order to free it, use zcfree().
107 */
108
109#define MAX_PTR 10
110/* 10*64K = 640K */
111
112local int next_ptr = 0;
113
114typedef struct ptr_table_s {
115    voidpf org_ptr;
116    voidpf new_ptr;
117} ptr_table;
118
119local ptr_table table[MAX_PTR];
120/* This table is used to remember the original form of pointers
121 * to large buffers (64K). Such pointers are normalized with a zero offset.
122 * Since MSDOS is not a preemptive multitasking OS, this table is not
123 * protected from concurrent access. This hack doesn't work anyway on
124 * a protected system like OS/2. Use Microsoft C instead.
125 */
126
127voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
128{
129    voidpf buf = opaque; /* just to make some compilers happy */
130    ulg bsize = (ulg)items*size;
131
132    /* If we allocate less than 65520 bytes, we assume that farmalloc
133     * will return a usable pointer which doesn't have to be normalized.
134     */
135    if (bsize < 65520L) {
136        buf = farmalloc(bsize);
137        if (*(ush*)&buf != 0) return buf;
138    } else {
139        buf = farmalloc(bsize + 16L);
140    }
141    if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
142    table[next_ptr].org_ptr = buf;
143
144    /* Normalize the pointer to seg:0 */
145    *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
146    *(ush*)&buf = 0;
147    table[next_ptr++].new_ptr = buf;
148    return buf;
149}
150
151void  zcfree (voidpf opaque, voidpf ptr)
152{
153    int n;
154    if (*(ush*)&ptr != 0) { /* object < 64K */
155        farfree(ptr);
156        return;
157    }
158    /* Find the original pointer */
159    for (n = 0; n < next_ptr; n++) {
160        if (ptr != table[n].new_ptr) continue;
161
162        farfree(table[n].org_ptr);
163        while (++n < next_ptr) {
164            table[n-1] = table[n];
165        }
166        next_ptr--;
167        return;
168    }
169    ptr = opaque; /* just to make some compilers happy */
170    Assert(0, "zcfree: ptr not found");
171}
172#endif
173#endif /* __TURBOC__ */
174
175
176#if defined(M_I86) && !defined(__32BIT__)
177/* Microsoft C in 16-bit mode */
178
179#  define MY_ZCALLOC
180
181#if (!defined(_MSC_VER) || (_MSC_VER <= 600))
182#  define _halloc  halloc
183#  define _hfree   hfree
184#endif
185
186voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
187{
188    if (opaque) opaque = 0; /* to make compiler happy */
189    return _halloc((long)items, size);
190}
191
192void  zcfree (voidpf opaque, voidpf ptr)
193{
194    if (opaque) opaque = 0; /* to make compiler happy */
195    _hfree(ptr);
196}
197
198#endif /* MSC */
199
200
201#ifndef MY_ZCALLOC /* Any system without a special alloc function */
202
203#ifndef STDC
204extern voidp  calloc OF((uInt items, uInt size));
205extern void   free   OF((voidpf ptr));
206#endif
207
208voidpf zcalloc (opaque, items, size)
209    voidpf opaque;
210    unsigned items;
211    unsigned size;
212{
213    if (opaque) items += size - size; /* make compiler happy */
214    return (voidpf)calloc(items, size);
215}
216
217void  zcfree (opaque, ptr)
218    voidpf opaque;
219    voidpf ptr;
220{
221    free(ptr);
222    if (opaque) return; /* make compiler happy */
223}
224
225#endif /* MY_ZCALLOC */
226