incubator-nuttx/libs/libc/stream/lib_lzfcompress.c

144 lines
4.6 KiB
C

/****************************************************************************
* libs/libc/stream/lib_lzfcompress.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <unistd.h>
#include <nuttx/streams.h>
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: lzfoutstream_flush
****************************************************************************/
static int lzfoutstream_flush(FAR struct lib_outstream_s *this)
{
FAR struct lib_lzfoutstream_s *stream =
(FAR struct lib_lzfoutstream_s *)this;
FAR struct lzf_header_s *header;
size_t outlen;
if (stream->offset > 0)
{
outlen = lzf_compress(stream->in, stream->offset,
&stream->out[LZF_MAX_HDR_SIZE],
stream->offset, stream->state, &header);
if (outlen > 0)
{
stream->backend->puts(stream->backend, header, outlen);
}
stream->offset = 0;
}
return stream->backend->flush(stream->backend);
}
/****************************************************************************
* Name: lzfoutstream_puts
****************************************************************************/
static int lzfoutstream_puts(FAR struct lib_outstream_s *this,
FAR const void *buf, int len)
{
FAR struct lib_lzfoutstream_s *stream =
(FAR struct lib_lzfoutstream_s *)this;
FAR struct lzf_header_s *header;
FAR const char *ptr = buf;
size_t total = len;
size_t copyin;
size_t outlen;
int ret;
while (total > 0)
{
copyin = stream->offset + total > LZF_STREAM_BLOCKSIZE ?
LZF_STREAM_BLOCKSIZE - stream->offset : total;
memcpy(stream->in + stream->offset, ptr, copyin);
ptr += copyin;
stream->offset += copyin;
this->nput += copyin;
total -= copyin;
if (stream->offset == LZF_STREAM_BLOCKSIZE)
{
outlen = lzf_compress(stream->in, stream->offset,
&stream->out[LZF_MAX_HDR_SIZE],
stream->offset, stream->state,
&header);
if (outlen > 0)
{
ret = stream->backend->puts(stream->backend, header, outlen);
if (ret < 0)
{
return ret;
}
}
stream->offset = 0;
}
}
return len;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: lib_lzfoutstream
*
* Description:
* LZF compressed pipeline stream
*
* Input Parameters:
* stream - User allocated, uninitialized instance of struct
* lib_lzfoutstream_s to be initialized.
* backend - Stream backend port.
*
* Returned Value:
* None (User allocated instance initialized).
*
****************************************************************************/
void lib_lzfoutstream(FAR struct lib_lzfoutstream_s *stream,
FAR struct lib_outstream_s *backend)
{
if (stream == NULL || backend == NULL)
{
return;
}
memset(stream, 0, sizeof(*stream));
stream->public.puts = lzfoutstream_puts;
stream->public.flush = lzfoutstream_flush;
stream->backend = backend;
}