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// SPDX-License-Identifier: GPL-2.0
#include <string.h>
#include "util/compress.h"
#include "util/debug.h"
int zstd_init(struct zstd_data *data, int level)
{
size_t ret;
data->dstream = ZSTD_createDStream();
if (data->dstream == NULL) {
pr_err("Couldn't create decompression stream.\n");
return -1;
}
ret = ZSTD_initDStream(data->dstream);
if (ZSTD_isError(ret)) {
pr_err("Failed to initialize decompression stream: %s\n", ZSTD_getErrorName(ret));
return -1;
}
if (!level)
return 0;
data->cstream = ZSTD_createCStream();
if (data->cstream == NULL) {
pr_err("Couldn't create compression stream.\n");
return -1;
}
ret = ZSTD_initCStream(data->cstream, level);
if (ZSTD_isError(ret)) {
pr_err("Failed to initialize compression stream: %s\n", ZSTD_getErrorName(ret));
return -1;
}
return 0;
}
int zstd_fini(struct zstd_data *data)
{
if (data->dstream) {
ZSTD_freeDStream(data->dstream);
data->dstream = NULL;
}
if (data->cstream) {
ZSTD_freeCStream(data->cstream);
data->cstream = NULL;
}
return 0;
}
size_t zstd_compress_stream_to_records(struct zstd_data *data, void *dst, size_t dst_size,
void *src, size_t src_size, size_t max_record_size,
size_t process_header(void *record, size_t increment))
{
size_t ret, size, compressed = 0;
ZSTD_inBuffer input = { src, src_size, 0 };
ZSTD_outBuffer output;
void *record;
while (input.pos < input.size) {
record = dst;
size = process_header(record, 0);
compressed += size;
dst += size;
dst_size -= size;
output = (ZSTD_outBuffer){ dst, (dst_size > max_record_size) ?
max_record_size : dst_size, 0 };
ret = ZSTD_compressStream(data->cstream, &output, &input);
ZSTD_flushStream(data->cstream, &output);
if (ZSTD_isError(ret)) {
pr_err("failed to compress %ld bytes: %s\n",
(long)src_size, ZSTD_getErrorName(ret));
memcpy(dst, src, src_size);
return src_size;
}
size = output.pos;
size = process_header(record, size);
compressed += size;
dst += size;
dst_size -= size;
}
return compressed;
}
size_t zstd_decompress_stream(struct zstd_data *data, void *src, size_t src_size,
void *dst, size_t dst_size)
{
size_t ret;
ZSTD_inBuffer input = { src, src_size, 0 };
ZSTD_outBuffer output = { dst, dst_size, 0 };
while (input.pos < input.size) {
ret = ZSTD_decompressStream(data->dstream, &output, &input);
if (ZSTD_isError(ret)) {
pr_err("failed to decompress (B): %ld -> %ld : %s\n",
src_size, output.size, ZSTD_getErrorName(ret));
break;
}
output.dst = dst + output.pos;
output.size = dst_size - output.pos;
}
return output.pos;
}
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