lib/zstd/zstd_compress_module.c

Source file repositories/reference/linux-study-clean/lib/zstd/zstd_compress_module.c

File Facts

System
Linux kernel
Corpus path
lib/zstd/zstd_compress_module.c
Extension
.c
Size
8973 bytes
Lines
287
Domain
Kernel Services
Bucket
lib
Inferred role
Kernel Services: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Shared kernel service surface used by multiple subsystems, including helpers, cryptography, virtualization support, and async I/O infrastructure.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/zstd.h>

#include "common/zstd_deps.h"
#include "common/zstd_internal.h"
#include "compress/zstd_compress_internal.h"

#define ZSTD_FORWARD_IF_ERR(ret)            \
	do {                                \
		size_t const __ret = (ret); \
		if (ZSTD_isError(__ret))    \
			return __ret;       \
	} while (0)

static size_t zstd_cctx_init(zstd_cctx *cctx, const zstd_parameters *parameters,
	unsigned long long pledged_src_size)
{
	ZSTD_FORWARD_IF_ERR(ZSTD_CCtx_reset(
		cctx, ZSTD_reset_session_and_parameters));
	ZSTD_FORWARD_IF_ERR(ZSTD_CCtx_setPledgedSrcSize(
		cctx, pledged_src_size));
	ZSTD_FORWARD_IF_ERR(ZSTD_CCtx_setParameter(
		cctx, ZSTD_c_windowLog, parameters->cParams.windowLog));
	ZSTD_FORWARD_IF_ERR(ZSTD_CCtx_setParameter(
		cctx, ZSTD_c_hashLog, parameters->cParams.hashLog));
	ZSTD_FORWARD_IF_ERR(ZSTD_CCtx_setParameter(
		cctx, ZSTD_c_chainLog, parameters->cParams.chainLog));
	ZSTD_FORWARD_IF_ERR(ZSTD_CCtx_setParameter(
		cctx, ZSTD_c_searchLog, parameters->cParams.searchLog));
	ZSTD_FORWARD_IF_ERR(ZSTD_CCtx_setParameter(
		cctx, ZSTD_c_minMatch, parameters->cParams.minMatch));
	ZSTD_FORWARD_IF_ERR(ZSTD_CCtx_setParameter(
		cctx, ZSTD_c_targetLength, parameters->cParams.targetLength));
	ZSTD_FORWARD_IF_ERR(ZSTD_CCtx_setParameter(
		cctx, ZSTD_c_strategy, parameters->cParams.strategy));
	ZSTD_FORWARD_IF_ERR(ZSTD_CCtx_setParameter(
		cctx, ZSTD_c_contentSizeFlag, parameters->fParams.contentSizeFlag));
	ZSTD_FORWARD_IF_ERR(ZSTD_CCtx_setParameter(
		cctx, ZSTD_c_checksumFlag, parameters->fParams.checksumFlag));
	ZSTD_FORWARD_IF_ERR(ZSTD_CCtx_setParameter(
		cctx, ZSTD_c_dictIDFlag, !parameters->fParams.noDictIDFlag));
	return 0;
}

int zstd_min_clevel(void)
{
	return ZSTD_minCLevel();
}
EXPORT_SYMBOL(zstd_min_clevel);

int zstd_max_clevel(void)
{
	return ZSTD_maxCLevel();
}
EXPORT_SYMBOL(zstd_max_clevel);

int zstd_default_clevel(void)
{
	return ZSTD_defaultCLevel();
}
EXPORT_SYMBOL(zstd_default_clevel);

size_t zstd_compress_bound(size_t src_size)
{
	return ZSTD_compressBound(src_size);
}
EXPORT_SYMBOL(zstd_compress_bound);

zstd_parameters zstd_get_params(int level,
	unsigned long long estimated_src_size)
{
	return ZSTD_getParams(level, estimated_src_size, 0);
}
EXPORT_SYMBOL(zstd_get_params);

zstd_compression_parameters zstd_get_cparams(int level,
	unsigned long long estimated_src_size, size_t dict_size)

Annotation

Implementation Notes