wmaker/WINGs/data.c

/*
 *  WINGs WMData function library
 *
 *  Copyright (c) 1999-2003 Dan Pascu
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <string.h>
#include "WUtil.h"

typedef struct W_Data {
	unsigned length;	/* How many bytes we have */
	unsigned capacity;	/* How many bytes it can hold */
	unsigned growth;	/* How much to grow */
	void *bytes;		/* Actual data */
	unsigned retainCount;
	WMFreeDataProc *destructor;
	int format;		/* 0, 8, 16 or 32 */
} W_Data;

/* Creating and destroying data objects */

WMData *WMCreateDataWithCapacity(unsigned capacity)
{
	WMData *aData;

	aData = (WMData *) wmalloc(sizeof(WMData));

	if (capacity > 0)
		aData->bytes = wmalloc(capacity);
	else
		aData->bytes = NULL;

	aData->capacity = capacity;
	aData->growth = capacity / 2 > 0 ? capacity / 2 : 1;
	aData->length = 0;
	aData->retainCount = 1;
	aData->format = 0;
	aData->destructor = wfree;

	return aData;
}

WMData *WMCreateDataWithLength(unsigned length)
{
	WMData *aData;

	aData = WMCreateDataWithCapacity(length);
	if (length > 0) {
		aData->length = length;
	}

	return aData;
}

WMData *WMCreateDataWithBytes(void *bytes, unsigned length)
{
	WMData *aData;

	aData = WMCreateDataWithCapacity(length);
	aData->length = length;
	memcpy(aData->bytes, bytes, length);

	return aData;
}

WMData *WMCreateDataWithBytesNoCopy(void *bytes, unsigned length, WMFreeDataProc * destructor)
{
	WMData *aData;

	aData = (WMData *) wmalloc(sizeof(WMData));
	aData->length = length;
	aData->capacity = length;
	aData->growth = length / 2 > 0 ? length / 2 : 1;
	aData->bytes = bytes;
	aData->retainCount = 1;
	aData->format = 0;
	aData->destructor = destructor;

	return aData;
}

WMData *WMCreateDataWithData(WMData * aData)
{
	WMData *newData;

	if (aData->length > 0) {
		newData = WMCreateDataWithBytes(aData->bytes, aData->length);
	} else {
		newData = WMCreateDataWithCapacity(0);
	}
	newData->format = aData->format;

	return newData;
}

WMData *WMRetainData(WMData * aData)
{
	aData->retainCount++;
	return aData;
}

void WMReleaseData(WMData * aData)
{
	aData->retainCount--;
	if (aData->retainCount > 0)
		return;
	if (aData->bytes != NULL && aData->destructor != NULL) {
		aData->destructor(aData->bytes);
	}
	wfree(aData);
}

/* Adjusting capacity */

void WMSetDataCapacity(WMData * aData, unsigned capacity)
{
	if (aData->capacity != capacity) {
		aData->bytes = wrealloc(aData->bytes, capacity);
		aData->capacity = capacity;
		aData->growth = capacity / 2 > 0 ? capacity / 2 : 1;
	}
	if (aData->length > capacity) {
		aData->length = capacity;
	}
}

void WMSetDataLength(WMData * aData, unsigned length)
{
	if (length > aData->capacity) {
		WMSetDataCapacity(aData, length);
	}
	if (length > aData->length) {
		memset((unsigned char *)aData->bytes + aData->length, 0, length - aData->length);
	}
	aData->length = length;
}

void WMSetDataFormat(WMData * aData, unsigned format)
{
	aData->format = format;
}

void WMIncreaseDataLengthBy(WMData * aData, unsigned extraLength)
{
	WMSetDataLength(aData, aData->length + extraLength);
}

/* Accessing data */

const void *WMDataBytes(WMData * aData)
{
	return aData->bytes;
}

void WMGetDataBytes(WMData * aData, void *buffer)
{
	wassertr(aData->length > 0);

	memcpy(buffer, aData->bytes, aData->length);
}

unsigned WMGetDataFormat(WMData * aData)
{
	return aData->format;
}

void WMGetDataBytesWithLength(WMData * aData, void *buffer, unsigned length)
{
	wassertr(aData->length > 0);
	wassertr(length <= aData->length);

	memcpy(buffer, aData->bytes, length);
}

void WMGetDataBytesWithRange(WMData * aData, void *buffer, WMRange aRange)
{
	wassertr(aRange.position < aData->length);
	wassertr(aRange.count <= aData->length - aRange.position);

	memcpy(buffer, (unsigned char *)aData->bytes + aRange.position, aRange.count);
}

WMData *WMGetSubdataWithRange(WMData * aData, WMRange aRange)
{
	void *buffer;
	WMData *newData;

	if (aRange.count <= 0)
		return WMCreateDataWithCapacity(0);

	buffer = wmalloc(aRange.count);
	WMGetDataBytesWithRange(aData, buffer, aRange);
	newData = WMCreateDataWithBytesNoCopy(buffer, aRange.count, wfree);
	newData->format = aData->format;

	return newData;
}

/* Testing data */

Bool WMIsDataEqualToData(WMData * aData, WMData * anotherData)
{
	if (aData->length != anotherData->length)
		return False;
	else if (!aData->bytes && !anotherData->bytes)	/* both are empty */
		return True;
	else if (!aData->bytes || !anotherData->bytes)	/* one of them is empty */
		return False;
	return (memcmp(aData->bytes, anotherData->bytes, aData->length) == 0);
}

unsigned WMGetDataLength(WMData * aData)
{
	return aData->length;
}

/* Adding data */
void WMAppendDataBytes(WMData * aData, void *bytes, unsigned length)
{
	unsigned oldLength = aData->length;
	unsigned newLength = oldLength + length;

	if (newLength > aData->capacity) {
		unsigned nextCapacity = aData->capacity + aData->growth;
		unsigned nextGrowth = aData->capacity ? aData->capacity : 1;

		while (nextCapacity < newLength) {
			unsigned tmp = nextCapacity + nextGrowth;

			nextGrowth = nextCapacity;
			nextCapacity = tmp;
		}
		WMSetDataCapacity(aData, nextCapacity);
		aData->growth = nextGrowth;
	}
	memcpy((unsigned char *)aData->bytes + oldLength, bytes, length);
	aData->length = newLength;
}

void WMAppendData(WMData * aData, WMData * anotherData)
{
	if (anotherData->length > 0)
		WMAppendDataBytes(aData, anotherData->bytes, anotherData->length);
}

/* Modifying data */

void WMReplaceDataBytesInRange(WMData * aData, WMRange aRange, void *bytes)
{
	wassertr(aRange.position < aData->length);
	wassertr(aRange.count <= aData->length - aRange.position);

	memcpy((unsigned char *)aData->bytes + aRange.position, bytes, aRange.count);
}

void WMResetDataBytesInRange(WMData * aData, WMRange aRange)
{
	wassertr(aRange.position < aData->length);
	wassertr(aRange.count <= aData->length - aRange.position);

	memset((unsigned char *)aData->bytes + aRange.position, 0, aRange.count);
}

void WMSetData(WMData * aData, WMData * anotherData)
{
	unsigned length = anotherData->length;

	WMSetDataCapacity(aData, length);
	if (length > 0)
		memcpy(aData->bytes, anotherData->bytes, length);
	aData->length = length;
}

/* Storing data */