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#include "buffer.h"
#include <string.h>
#include <stdlib.h>
#include <assert.h>
/********************************************************
Audio Tools, a module and set of tools for manipulating audio data
Copyright (C) 2007-2015 Brian Langenberger
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*******************************************************/
#ifndef MIN
#define MIN(x, y) ((x) < (y) ? (x) : (y))
#endif
#ifndef MAX
#define MAX(x, y) ((x) > (y) ? (x) : (y))
#endif
struct bs_buffer*
buf_new(void)
{
struct bs_buffer* stream = malloc(sizeof(struct bs_buffer));
stream->data = malloc(1);
stream->data_size = 1;
stream->window_start = 0;
stream->window_end = 0;
return stream;
}
void
buf_close(struct bs_buffer *stream)
{
free(stream->data);
free(stream);
}
void
buf_resize(struct bs_buffer *stream, unsigned additional_bytes)
{
/*only perform resize if space actually needed*/
if (additional_bytes > buf_unused_size(stream)) {
if (stream->window_start > 0) {
/*shift window down before extending buffer to add more space*/
if (buf_window_size(stream)) {
memmove(stream->data,
buf_window_start(stream),
buf_window_size(stream));
}
stream->window_end -= stream->window_start;
stream->window_start = 0;
}
while (additional_bytes > buf_unused_size(stream)) {
stream->data_size *= 2;
}
stream->data = realloc(stream->data, stream->data_size);
}
}
unsigned
buf_read(struct bs_buffer *stream, uint8_t *data, unsigned data_size)
{
const buf_size_t to_read = MIN(data_size, buf_window_size(stream));
memcpy(data, buf_window_start(stream), to_read);
stream->window_start += to_read;
return to_read;
}
unsigned
buf_skip(struct bs_buffer *stream, unsigned data_size)
{
const buf_size_t to_read = MIN(data_size, buf_window_size(stream));
stream->window_start += to_read;
return to_read;
}
void
buf_write(struct bs_buffer *stream, const uint8_t* data, unsigned data_size)
{
buf_resize(stream, data_size);
memcpy(buf_window_end(stream), data, (size_t)data_size);
stream->window_end += data_size;
}
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