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/*
* BRLTTY - A background process providing access to the console screen (when in
* text mode) for a blind person using a refreshable braille display.
*
* Copyright (C) 1995-2010 by The BRLTTY Developers.
*
* BRLTTY comes with ABSOLUTELY NO WARRANTY.
*
* This is free software, placed 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. Please see the file LICENSE-GPL for details.
*
* Web Page: http://mielke.cc/brltty/
*
* This software is maintained by Dave Mielke <dave@mielke.cc>.
*/
#include "prologue.h"
#include <string.h>
#include "log.h"
#include "dataarea.h"
struct DataAreaStruct {
unsigned char *address;
size_t size;
size_t used;
};
void
resetDataArea (DataArea *area) {
area->address = NULL;
area->size = 0;
area->used = 0;
}
DataArea *
newDataArea (void) {
DataArea *area;
if ((area = malloc(sizeof(*area)))) resetDataArea(area);
return area;
}
void
destroyDataArea (DataArea *area) {
if (area->address) free(area->address);
free(area);
}
int
allocateDataItem (DataArea *area, DataOffset *offset, size_t size, unsigned int alignment) {
size_t newUsed = (area->used = (area->used + (alignment - 1)) / alignment * alignment) + size;
if (newUsed > area->size) {
size_t newSize = newUsed | 0XFFF;
unsigned char *newAddress = realloc(area->address, newSize);
if (!newAddress) {
LogPrint(LOG_ERR, "insufficient memory for data area");
return 0;
}
memset(newAddress+area->size, 0, newSize-area->size);
area->address = newAddress;
area->size = newSize;
}
if (offset) *offset = area->used;
area->used = newUsed;
return 1;
}
void *
getDataItem (DataArea *area, DataOffset offset) {
return area->address + offset;
}
size_t
getDataSize (DataArea *area) {
return area->used;
}
int
saveDataItem (DataArea *area, DataOffset *offset, const void *item, size_t size, int alignment) {
if (!allocateDataItem(area, offset, size, alignment)) return 0;
memcpy(getDataItem(area, *offset), item, size);
return 1;
}
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