gecko-dev/modules/libimg/gifcom/dllcompat.cpp

/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * The contents of this file are subject to the Netscape Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/NPL/
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is Netscape
 * Communications Corporation.  Portions created by Netscape are
 * Copyright (C) 1998 Netscape Communications Corporation. All
 * Rights Reserved.
 *
 * Contributor(s): 
 */
/*
 * The purpose of this file is to help phase out XP_ library
 * from the image library. In general, XP_ data structures and
 * functions will be replaced with the PR_ or PL_ equivalents.
 * In cases where the PR_ or PL_ equivalents don't yet exist,
 * this file (and its header equivalent) will play the role 
 * of the XP_ library.
 */

/* This file has func's from
xpcompat that are needed by
the local dll. So far, 
 1> Mac stuff.
*/
#include "prtypes.h"
#include "prlog.h"
#include "prmem.h"

#include "nsCRT.h"
//#include "xp_mcom.h"

PR_BEGIN_EXTERN_C
int MK_UNABLE_TO_LOCATE_FILE = -1;
int MK_OUT_OF_MEMORY = -2;
	
PR_END_EXTERN_C



#if defined(XP_MAC)

#ifndef UNIXMINUSMACTIME
#define UNIXMINUSMACTIME 2082844800UL
#endif

/* prototypes for local routines */
static void  shortsort(char *lo, char *hi, unsigned width,
                int ( *comp)(const void *, const void *));
static void  swap(char *p, char *q, unsigned int width);

/* this parameter defines the cutoff between using quick sort and
   insertion sort for arrays; arrays with lengths shorter or equal to the
   below value use insertion sort */

#define CUTOFF 8            /* testing shows that this is good value */


/***
*XP_QSORT(base, num, wid, comp) - quicksort function for sorting arrays
*
*Purpose:
*       quicksort the array of elements
*       side effects:  sorts in place
*
*Entry:
*       char *base = pointer to base of array
*       unsigned num  = number of elements in the array
*       unsigned width = width in bytes of each array element
*       int (*comp)() = pointer to function returning analog of strcmp for
*               strings, but supplied by user for comparing the array elements.
*               it accepts 2 pointers to elements and returns neg if 1<2, 0 if
*               1=2, pos if 1>2.
*
*Exit:
*       returns void
*
*Exceptions:
*
*******************************************************************************/

/* sort the array between lo and hi (inclusive) */

void XP_QSORT (
    void *base,
    size_t num,
    size_t width,
    int ( *comp)(const void *, const void *)
    )
{
    char *lo, *hi;              /* ends of sub-array currently sorting */
    char *mid;                  /* points to middle of subarray */
    char *loguy, *higuy;        /* traveling pointers for partition step */
    unsigned size;              /* size of the sub-array */
    char *lostk[30], *histk[30];
    int stkptr;                 /* stack for saving sub-array to be processed */

    /* Note: the number of stack entries required is no more than
       1 + log2(size), so 30 is sufficient for any array */

    if (num < 2 || width == 0)
        return;                 /* nothing to do */

    stkptr = 0;                 /* initialize stack */

    lo = (char*)base;
    hi = (char *)base + width * (num-1);        /* initialize limits */

    /* this entry point is for pseudo-recursion calling: setting
       lo and hi and jumping to here is like recursion, but stkptr is
       prserved, locals aren't, so we preserve stuff on the stack */
recurse:

    size = (hi - lo) / width + 1;        /* number of el's to sort */

    /* below a certain size, it is faster to use a O(n^2) sorting method */
    if (size <= CUTOFF) {
         shortsort(lo, hi, width, comp);
    }
    else {
        /* First we pick a partititioning element.  The efficiency of the
           algorithm demands that we find one that is approximately the
           median of the values, but also that we select one fast.  Using
           the first one produces bad performace if the array is already
           sorted, so we use the middle one, which would require a very
           wierdly arranged array for worst case performance.  Testing shows
           that a median-of-three algorithm does not, in general, increase
           performance. */

        mid = lo + (size / 2) * width;      /* find middle element */
        swap(mid, lo, width);               /* swap it to beginning of array */

        /* We now wish to partition the array into three pieces, one
           consisiting of elements <= partition element, one of elements
           equal to the parition element, and one of element >= to it.  This
           is done below; comments indicate conditions established at every
           step. */

        loguy = lo;
        higuy = hi + width;

        /* Note that higuy decreases and loguy increases on every iteration,
           so loop must terminate. */
        for (;;) {
            /* lo <= loguy < hi, lo < higuy <= hi + 1,
               A[i] <= A[lo] for lo <= i <= loguy,
               A[i] >= A[lo] for higuy <= i <= hi */

            do  {
                loguy += width;
            } while (loguy <= hi && comp(loguy, lo) <= 0);

            /* lo < loguy <= hi+1, A[i] <= A[lo] for lo <= i < loguy,
               either loguy > hi or A[loguy] > A[lo] */

            do  {
                higuy -= width;
            } while (higuy > lo && comp(higuy, lo) >= 0);

            /* lo-1 <= higuy <= hi, A[i] >= A[lo] for higuy < i <= hi,
               either higuy <= lo or A[higuy] < A[lo] */

            if (higuy < loguy)
                break;

            /* if loguy > hi or higuy <= lo, then we would have exited, so
               A[loguy] > A[lo], A[higuy] < A[lo],
               loguy < hi, highy > lo */

            swap(loguy, higuy, width);

            /* A[loguy] < A[lo], A[higuy] > A[lo]; so condition at top
               of loop is re-established */
        }

        /*     A[i] >= A[lo] for higuy < i <= hi,
               A[i] <= A[lo] for lo <= i < loguy,
               higuy < loguy, lo <= higuy <= hi
           implying:
               A[i] >= A[lo] for loguy <= i <= hi,
               A[i] <= A[lo] for lo <= i <= higuy,
               A[i] = A[lo] for higuy < i < loguy */

        swap(lo, higuy, width);     /* put partition element in place */

        /* OK, now we have the following:
              A[i] >= A[higuy] for loguy <= i <= hi,
              A[i] <= A[higuy] for lo <= i < higuy
              A[i] = A[lo] for higuy <= i < loguy    */

        /* We've finished the partition, now we want to sort the subarrays
           [lo, higuy-1] and [loguy, hi].
           We do the smaller one first to minimize stack usage.
           We only sort arrays of length 2 or more.*/

        if ( higuy - 1 - lo >= hi - loguy ) {
            if (lo + width < higuy) {
                lostk[stkptr] = lo;
                histk[stkptr] = higuy - width;
                ++stkptr;
            }                           /* save big recursion for later */

            if (loguy < hi) {
                lo = loguy;
                goto recurse;           /* do small recursion */
            }
        }
        else {
            if (loguy < hi) {
                lostk[stkptr] = loguy;
                histk[stkptr] = hi;
                ++stkptr;               /* save big recursion for later */
            }

            if (lo + width < higuy) {
                hi = higuy - width;
                goto recurse;           /* do small recursion */
            }
        }
    }

    /* We have sorted the array, except for any pending sorts on the stack.
       Check if there are any, and do them. */

    --stkptr;
    if (stkptr >= 0) {
        lo = lostk[stkptr];
        hi = histk[stkptr];
        goto recurse;           /* pop subarray from stack */
    }
    else
        return;                 /* all subarrays done */
}


/***
*shortsort(hi, lo, width, comp) - insertion sort for sorting short arrays
*
*Purpose:
*       sorts the sub-array of elements between lo and hi (inclusive)
*       side effects:  sorts in place
*       assumes that lo < hi
*
*Entry:
*       char *lo = pointer to low element to sort
*       char *hi = pointer to high element to sort
*       unsigned width = width in bytes of each array element
*       int (*comp)() = pointer to function returning analog of strcmp for
*               strings, but supplied by user for comparing the array elements.
*               it accepts 2 pointers to elements and returns neg if 1<2, 0 if
*               1=2, pos if 1>2.
*
*Exit:
*       returns void
*
*Exceptions:
*
*******************************************************************************/

static void  shortsort (
    char *lo,
    char *hi,
    unsigned width,
    int ( *comp)(const void *, const void *)
    )
{
    char *p, *max;

    /* Note: in assertions below, i and j are alway inside original bound of
       array to sort. */

    while (hi > lo) {
        /* A[i] <= A[j] for i <= j, j > hi */
        max = lo;
        for (p = lo+width; p <= hi; p += width) {
            /* A[i] <= A[max] for lo <= i < p */
            if (comp(p, max) > 0) {
                max = p;
            }
            /* A[i] <= A[max] for lo <= i <= p */
        }

        /* A[i] <= A[max] for lo <= i <= hi */

        swap(max, hi, width);

        /* A[i] <= A[hi] for i <= hi, so A[i] <= A[j] for i <= j, j >= hi */

        hi -= width;

        /* A[i] <= A[j] for i <= j, j > hi, loop top condition established */
    }
    /* A[i] <= A[j] for i <= j, j > lo, which implies A[i] <= A[j] for i < j,
       so array is sorted */
}


/***
*swap(a, b, width) - swap two elements
*
*Purpose:
*       swaps the two array elements of size width
*
*Entry:
*       char *a, *b = pointer to two elements to swap
*       unsigned width = width in bytes of each array element
*
*Exit:
*       returns void
*
*Exceptions:
*
*******************************************************************************/

static void  swap (
    char *a,
    char *b,
    unsigned width
    )
{
    char tmp;

    if ( a != b )
        /* Do the swap one character at a time to avoid potential alignment
           problems. */
        while ( width-- ) {
            tmp = *a;
            *a++ = *b;
            *b++ = tmp;
        }
}

#endif /* XP_MAC */
#ifdef XP_MAC
#include <OSUtils.h>
#include <time.h>

static void MyReadLocation(MachineLocation * loc)
{
	static MachineLocation storedLoc;	// InsideMac, OSUtilities, page 4-20
	static Boolean didReadLocation = FALSE;
	if (!didReadLocation)
	{	
		ReadLocation(&storedLoc);
		didReadLocation = TRUE;
	}
	*loc = storedLoc;
}

// current local time = GMTDelta() + GMT
// GMT = local time - GMTDelta()
static long GMTDelta()
{
	MachineLocation loc;
	long gmtDelta;
	
	MyReadLocation(&loc);
	gmtDelta = loc.u.gmtDelta & 0x00FFFFFF;
	if ((gmtDelta & 0x00800000) != 0)
		gmtDelta |= 0xFF000000;
	return gmtDelta;
}

// This routine simulates stdclib time(), time in seconds since 1.1.1970
// The time is in GMT
time_t GetTimeMac()
{
	unsigned long maclocal;
	// Get Mac local time
	GetDateTime(&maclocal); 
	// Get Mac GMT	
	maclocal -= GMTDelta();
	// return unix GMT
	return (maclocal - UNIXMINUSMACTIME);
}

// Returns the GMT times
time_t Mactime(time_t *timer)
{
	time_t t = GetTimeMac();
	if (timer != NULL)
		*timer = t;
	return t;
}
#endif /* XP_MAC */