/* zutil.c -- target dependent utility functions for the compression library
 * Copyright (C) 1995-2005, 2010 Jean-loup Gailly.
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/* @(#) $Id$ */

#include "zutil.h"

#ifndef NO_DUMMY_DECL
struct internal_state {
	int dummy;
};				/* for buggy compilers */
#endif

const char *const 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;
}

uLong ZEXPORT zlibCompileFlags()
{
	uLong flags;

	flags = 0;
	switch ((int)(sizeof(uInt))) {
	case 2:
		break;
	case 4:
		flags += 1;
		break;
	case 8:
		flags += 2;
		break;
	default:
		flags += 3;
	}
	switch ((int)(sizeof(uLong))) {
	case 2:
		break;
	case 4:
		flags += 1 << 2;
		break;
	case 8:
		flags += 2 << 2;
		break;
	default:
		flags += 3 << 2;
	}
	switch ((int)(sizeof(voidpf))) {
	case 2:
		break;
	case 4:
		flags += 1 << 4;
		break;
	case 8:
		flags += 2 << 4;
		break;
	default:
		flags += 3 << 4;
	}
	switch ((int)(sizeof(z_off_t))) {
	case 2:
		break;
	case 4:
		flags += 1 << 6;
		break;
	case 8:
		flags += 2 << 6;
		break;
	default:
		flags += 3 << 6;
	}
#ifdef DEBUG
	flags += 1 << 8;
#endif
#if defined(ASMV) || defined(ASMINF)
	flags += 1 << 9;
#endif
#ifdef ZLIB_WINAPI
	flags += 1 << 10;
#endif
#ifdef BUILDFIXED
	flags += 1 << 12;
#endif
#ifdef DYNAMIC_CRC_TABLE
	flags += 1 << 13;
#endif
#ifdef NO_GZCOMPRESS
	flags += 1L << 16;
#endif
#ifdef NO_GZIP
	flags += 1L << 17;
#endif
#ifdef PKZIP_BUG_WORKAROUND
	flags += 1L << 20;
#endif
#ifdef FASTEST
	flags += 1L << 21;
#endif
#ifdef STDC
#ifdef NO_vsnprintf
	flags += 1L << 25;
#ifdef HAS_vsprintf_void
	flags += 1L << 26;
#endif
#else
#ifdef HAS_vsnprintf_void
	flags += 1L << 26;
#endif
#endif
#else
	flags += 1L << 24;
#ifdef NO_snprintf
	flags += 1L << 25;
#ifdef HAS_sprintf_void
	flags += 1L << 26;
#endif
#else
#ifdef HAS_snprintf_void
	flags += 1L << 26;
#endif
#endif
#endif
	return flags;
}

#ifdef DEBUG

#ifndef verbose
#define verbose 0
#endif
int ZLIB_INTERNAL z_verbose = verbose;

void ZLIB_INTERNAL 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);
}

#if defined(_WIN32_WCE)
    /* The Microsoft C Run-Time Library for Windows CE doesn't have
     * errno.  We define it as a global variable to simplify porting.
     * Its value is always 0 and should not be used.
     */
int errno = 0;
#endif

#ifndef HAVE_MEMCPY

void ZLIB_INTERNAL 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 ZLIB_INTERNAL 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 ZLIB_INTERNAL zmemzero(dest, len)
Bytef *dest;
uInt len;
{
	if (len == 0)
		return;
	do {
		*dest++ = 0;	/* ??? to be unrolled */
	} while (--len != 0);
}
#endif

#ifdef SYS16BIT

#ifdef __TURBOC__
/* Turbo C in 16-bit mode */

#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 ZLIB_INTERNAL 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 ZLIB_INTERNAL 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				/* __TURBOC__ */

#ifdef M_I86
/* Microsoft C in 16-bit mode */

#define MY_ZCALLOC

#if (!defined(_MSC_VER) || (_MSC_VER <= 600))
#define _halloc  halloc
#define _hfree   hfree
#endif

voidpf ZLIB_INTERNAL zcalloc(voidpf opaque, uInt items, uInt size)
{
	if (opaque)
		opaque = 0;	/* to make compiler happy */
	return _halloc((long)items, size);
}

void ZLIB_INTERNAL zcfree(voidpf opaque, voidpf ptr)
{
	if (opaque)
		opaque = 0;	/* to make compiler happy */
	_hfree(ptr);
}

#endif				/* M_I86 */

#endif				/* SYS16BIT */

#ifndef MY_ZCALLOC		/* Any system without a special alloc function */

#ifndef STDC
extern voidp malloc OF((uInt size));
extern voidp calloc OF((uInt items, uInt size));
extern void free OF((voidpf ptr));
#endif

voidpf ZLIB_INTERNAL zcalloc(opaque, items, size)
voidpf opaque;
unsigned items;
unsigned size;
{
	if (opaque)
		items += size - size;	/* make compiler happy */
	return sizeof(uInt) > 2 ? (voidpf) malloc(items * size) :
	    (voidpf) calloc(items, size);
}

void ZLIB_INTERNAL zcfree(opaque, ptr)
voidpf opaque;
voidpf ptr;
{
	free(ptr);
	if (opaque)
		return;		/* make compiler happy */
}

#endif				/* MY_ZCALLOC */
