Import ZStandard v1.4.5

ZStandard is a modern, high performance, general compression algorithm.
It provides similar or better compression levels to GZIP, but with much
better performance. ZStandard provides a large selection of compression
levels to allow a storage administrator to select the preferred
performance/compression trade-off.

This commit imports the unmodified ZStandard single-file library which
will be used by ZFS.

The implementation of this new library is done with future updates of
zstd in mind. For this reason we integrated the code in a way, that does
not require modifications to the library. For more details, see
`module/zstd/README.md`.

The library is excluded from codecov calculation and cppcheck as
unaltered dependencies do not need full codecov or cppcheck.

Co-authored-by: Allan Jude <allanjude@freebsd.org>
Co-authored-by: Kjeld Schouten-Lebbing <kjeld@schouten-lebbing.nl>
Co-authored-by: Michael Niewöhner <foss@mniewoehner.de>
Signed-off-by: Allan Jude <allanjude@freebsd.org>
Signed-off-by: Kjeld Schouten-Lebbing <kjeld@schouten-lebbing.nl>
Signed-off-by: Michael Niewöhner <foss@mniewoehner.de>

Makefile.am

@@ -115,9 +115,11 @@ commitcheck:
 
 PHONY += cstyle
 cstyle:
-	@find ${top_srcdir} -name build -prune -o -type f -name '*.[hc]' \
+	@find ${top_srcdir} -name build -prune \
+		-o -type f -name '*.[hc]' \
 		! -name 'zfs_config.*' ! -name '*.mod.c' \
 		! -name 'opt_global.h' ! -name '*_if*.h' \
+		! -path './module/zstd/lib/*' \
 		-exec ${top_srcdir}/scripts/cstyle.pl -cpP {} \+
 
 filter_executable = -exec test -x '{}' \; -print

config/ax_code_coverage.m4

@@ -223,6 +223,7 @@ CODE_COVERAGE_GENHTML_OPTIONS ?= $(CODE_COVERAGE_GENHTML_OPTIONS_DEFAULT)
 # Add any folders you want to ignore here
 # Ignore tmp and tests themselves
 CODE_COVERAGE_IGNORE_PATTERN ?= "/tmp/*" "*/tests/*"
+CODE_COVERAGE_IGNORE_PATTERN += "*/module/zstd/lib/*"
 
 GITIGNOREFILES ?=
 GITIGNOREFILES += $(CODE_COVERAGE_OUTPUT_FILE) $(CODE_COVERAGE_OUTPUT_DIRECTORY)

cppcheck-suppressions.txt

@@ -4,3 +4,5 @@ uninitvar:module/os/freebsd/zfs/vdev_geom.c
 uninitvar:module/os/freebsd/zfs/zfs_vfsops.c
 uninitvar:module/os/freebsd/spl/spl_zone.c
 uninitvar:lib/libzutil/os/freebsd/zutil_import_os.c
+*:module/zstd/lib/zstd.c
+*:module/zstd/lib/zstd.h

module/zstd/lib/zstd_errors.h

@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
+ * 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.
+ */
+
+#ifndef ZSTD_ERRORS_H_398273423
+#define ZSTD_ERRORS_H_398273423
+
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
+/*===== dependency =====*/
+#include <stddef.h>   /* size_t */
+
+
+/* =====   ZSTDERRORLIB_API : control library symbols visibility   ===== */
+#ifndef ZSTDERRORLIB_VISIBILITY
+#  if defined(__GNUC__) && (__GNUC__ >= 4)
+#    define ZSTDERRORLIB_VISIBILITY __attribute__ ((visibility ("default")))
+#  else
+#    define ZSTDERRORLIB_VISIBILITY
+#  endif
+#endif
+#if defined(ZSTD_DLL_EXPORT) && (ZSTD_DLL_EXPORT==1)
+#  define ZSTDERRORLIB_API __declspec(dllexport) ZSTDERRORLIB_VISIBILITY
+#elif defined(ZSTD_DLL_IMPORT) && (ZSTD_DLL_IMPORT==1)
+#  define ZSTDERRORLIB_API __declspec(dllimport) ZSTDERRORLIB_VISIBILITY /* It isn't required but allows to generate better code, saving a function pointer load from the IAT and an indirect jump.*/
+#else
+#  define ZSTDERRORLIB_API ZSTDERRORLIB_VISIBILITY
+#endif
+
+/*-*********************************************
+ *  Error codes list
+ *-*********************************************
+ *  Error codes _values_ are pinned down since v1.3.1 only.
+ *  Therefore, don't rely on values if you may link to any version < v1.3.1.
+ *
+ *  Only values < 100 are considered stable.
+ *
+ *  note 1 : this API shall be used with static linking only.
+ *           dynamic linking is not yet officially supported.
+ *  note 2 : Prefer relying on the enum than on its value whenever possible
+ *           This is the only supported way to use the error list < v1.3.1
+ *  note 3 : ZSTD_isError() is always correct, whatever the library version.
+ **********************************************/
+typedef enum {
+  ZSTD_error_no_error = 0,
+  ZSTD_error_GENERIC  = 1,
+  ZSTD_error_prefix_unknown                = 10,
+  ZSTD_error_version_unsupported           = 12,
+  ZSTD_error_frameParameter_unsupported    = 14,
+  ZSTD_error_frameParameter_windowTooLarge = 16,
+  ZSTD_error_corruption_detected = 20,
+  ZSTD_error_checksum_wrong      = 22,
+  ZSTD_error_dictionary_corrupted      = 30,
+  ZSTD_error_dictionary_wrong          = 32,
+  ZSTD_error_dictionaryCreation_failed = 34,
+  ZSTD_error_parameter_unsupported   = 40,
+  ZSTD_error_parameter_outOfBound    = 42,
+  ZSTD_error_tableLog_tooLarge       = 44,
+  ZSTD_error_maxSymbolValue_tooLarge = 46,
+  ZSTD_error_maxSymbolValue_tooSmall = 48,
+  ZSTD_error_stage_wrong       = 60,
+  ZSTD_error_init_missing      = 62,
+  ZSTD_error_memory_allocation = 64,
+  ZSTD_error_workSpace_tooSmall= 66,
+  ZSTD_error_dstSize_tooSmall = 70,
+  ZSTD_error_srcSize_wrong    = 72,
+  ZSTD_error_dstBuffer_null   = 74,
+  /* following error codes are __NOT STABLE__, they can be removed or changed in future versions */
+  ZSTD_error_frameIndex_tooLarge = 100,
+  ZSTD_error_seekableIO          = 102,
+  ZSTD_error_dstBuffer_wrong     = 104,
+  ZSTD_error_maxCode = 120  /* never EVER use this value directly, it can change in future versions! Use ZSTD_isError() instead */
+} ZSTD_ErrorCode;
+
+/*! ZSTD_getErrorCode() :
+    convert a `size_t` function result into a `ZSTD_ErrorCode` enum type,
+    which can be used to compare with enum list published above */
+ZSTDERRORLIB_API ZSTD_ErrorCode ZSTD_getErrorCode(size_t functionResult);
+ZSTDERRORLIB_API const char* ZSTD_getErrorString(ZSTD_ErrorCode code);   /**< Same as ZSTD_getErrorName, but using a `ZSTD_ErrorCode` enum argument */
+
+
+#if defined (__cplusplus)
+}
+#endif
+
+#endif /* ZSTD_ERRORS_H_398273423 */

module/zstd/zstd-in.c

@@ -0,0 +1,68 @@
+/*
+ * BSD 3-Clause Clear License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its
+ * contributors may be used to endorse or promote products derived from this
+ * software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
+ * Copyright (c) 2019-2020, Michael Niewöhner
+ */
+
+#define	MEM_MODULE
+#define	XXH_NAMESPACE ZSTD_
+#define	XXH_PRIVATE_API
+#define	XXH_INLINE_ALL
+#define	ZSTD_LEGACY_SUPPORT 0
+#define	ZSTD_LIB_DICTBUILDER 0
+#define	ZSTD_LIB_DEPRECATED 0
+#define	ZSTD_NOBENCH
+
+#include "common/debug.c"
+#include "common/entropy_common.c"
+#include "common/error_private.c"
+#include "common/fse_decompress.c"
+#include "common/pool.c"
+#include "common/zstd_common.c"
+
+#include "compress/fse_compress.c"
+#include "compress/hist.c"
+#include "compress/huf_compress.c"
+#include "compress/zstd_compress_literals.c"
+#include "compress/zstd_compress_sequences.c"
+#include "compress/zstd_compress_superblock.c"
+#include "compress/zstd_compress.c"
+#include "compress/zstd_double_fast.c"
+#include "compress/zstd_fast.c"
+#include "compress/zstd_lazy.c"
+#include "compress/zstd_ldm.c"
+#include "compress/zstd_opt.c"
+
+#include "decompress/huf_decompress.c"
+#include "decompress/zstd_ddict.c"
+#include "decompress/zstd_decompress.c"
+#include "decompress/zstd_decompress_block.c"