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ArrayWriter.c
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ArrayWriter.c
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/* vim: set expandtab ts=4 sw=4: */
/*
* You may redistribute this program and/or modify it under the terms of
* the GNU General Public License as published by the Free Software Foundation,
* either version 3 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, see <http://www.gnu.org/licenses/>.
*/
#include "io/ArrayWriter.h"
#include "util/Bits.h"
#include "util/Identity.h"
struct ArrayWriter_context {
struct Writer generic;
char* beginPointer;
char* pointer;
char* endPointer;
int returnCode;
Identity
};
/** @see Writer->write() */
static int write(struct Writer* writer, const void* toWrite, unsigned long length)
{
struct ArrayWriter_context* context = Identity_check((struct ArrayWriter_context*) writer);
/* If there was a previous failure then don't allow any more writing. */
if (context->returnCode != 0) {
return context->returnCode;
}
/* Prove that it doesn't run off the end of the buffer or roll over. */
if (context->pointer + length > context->endPointer
|| context->pointer + length < context->pointer)
{
context->returnCode = -1;
return -1;
}
Bits_memcpy(context->pointer, toWrite, length);
context->pointer += length;
context->generic.bytesWritten += length;
return 0;
}
/** @see ArrayWriter.h */
struct Writer* ArrayWriter_new(void* writeToBuffer,
unsigned long length,
struct Allocator* alloc)
{
struct ArrayWriter_context* context = Allocator_clone(alloc, (&(struct ArrayWriter_context) {
.generic = {
.write = write
},
.beginPointer = writeToBuffer,
.pointer = writeToBuffer,
.endPointer = (char*) writeToBuffer + length
}));
Identity_set(context);
return &context->generic;
}