brintos

brintos / linux-shallow public Read only

0
0
Text · 2.7 KiB · 57027e0 Raw
115 lines · c
1// SPDX-License-Identifier: GPL-2.02 3#include <string.h>4 5#include "util/compress.h"6#include "util/debug.h"7 8int zstd_init(struct zstd_data *data, int level)9{10	data->comp_level = level;11	data->dstream = NULL;12	data->cstream = NULL;13	return 0;14}15 16int zstd_fini(struct zstd_data *data)17{18	if (data->dstream) {19		ZSTD_freeDStream(data->dstream);20		data->dstream = NULL;21	}22 23	if (data->cstream) {24		ZSTD_freeCStream(data->cstream);25		data->cstream = NULL;26	}27 28	return 0;29}30 31ssize_t zstd_compress_stream_to_records(struct zstd_data *data, void *dst, size_t dst_size,32				       void *src, size_t src_size, size_t max_record_size,33				       size_t process_header(void *record, size_t increment))34{35	size_t ret, size, compressed = 0;36	ZSTD_inBuffer input = { src, src_size, 0 };37	ZSTD_outBuffer output;38	void *record;39 40	if (!data->cstream) {41		data->cstream = ZSTD_createCStream();42		if (data->cstream == NULL) {43			pr_err("Couldn't create compression stream.\n");44			return -1;45		}46 47		ret = ZSTD_initCStream(data->cstream, data->comp_level);48		if (ZSTD_isError(ret)) {49			pr_err("Failed to initialize compression stream: %s\n",50				ZSTD_getErrorName(ret));51			return -1;52		}53	}54 55	while (input.pos < input.size) {56		record = dst;57		size = process_header(record, 0);58		compressed += size;59		dst += size;60		dst_size -= size;61		output = (ZSTD_outBuffer){ dst, (dst_size > max_record_size) ?62						max_record_size : dst_size, 0 };63		ret = ZSTD_compressStream(data->cstream, &output, &input);64		ZSTD_flushStream(data->cstream, &output);65		if (ZSTD_isError(ret)) {66			pr_err("failed to compress %ld bytes: %s\n",67				(long)src_size, ZSTD_getErrorName(ret));68			memcpy(dst, src, src_size);69			return src_size;70		}71		size = output.pos;72		size = process_header(record, size);73		compressed += size;74		dst += size;75		dst_size -= size;76	}77 78	return compressed;79}80 81size_t zstd_decompress_stream(struct zstd_data *data, void *src, size_t src_size,82			      void *dst, size_t dst_size)83{84	size_t ret;85	ZSTD_inBuffer input = { src, src_size, 0 };86	ZSTD_outBuffer output = { dst, dst_size, 0 };87 88	if (!data->dstream) {89		data->dstream = ZSTD_createDStream();90		if (data->dstream == NULL) {91			pr_err("Couldn't create decompression stream.\n");92			return 0;93		}94 95		ret = ZSTD_initDStream(data->dstream);96		if (ZSTD_isError(ret)) {97			pr_err("Failed to initialize decompression stream: %s\n",98				ZSTD_getErrorName(ret));99			return 0;100		}101	}102	while (input.pos < input.size) {103		ret = ZSTD_decompressStream(data->dstream, &output, &input);104		if (ZSTD_isError(ret)) {105			pr_err("failed to decompress (B): %zd -> %zd, dst_size %zd : %s\n",106			       src_size, output.size, dst_size, ZSTD_getErrorName(ret));107			break;108		}109		output.dst  = dst + output.pos;110		output.size = dst_size - output.pos;111	}112 113	return output.pos;114}115