ref: 95f206b1eab43f4e32119270151c44e46deae5d9
dir: /src/gzip/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 */ /* @(#) $Id$ */ #include "zutil.h" #ifndef STDC extern void exit OF((int)); #endif #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 */