From: root <root@localhost.localdomain>
Signed-off-by: Liu Bo <bo.li....@oracle.com>
---
Makefile | 4 +-
crc32c.h | 4 +-
disk-io.c | 2 +-
hash.h | 2 +-
xxhash.c | 448 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
xxhash.h | 171 +++++++++++++++++++++++
6 files changed, 626 insertions(+), 5 deletions(-)
create mode 100644 xxhash.c
create mode 100644 xxhash.h
diff --git a/Makefile b/Makefile
index 369df6c..1d70bc9 100644
--- a/Makefile
+++ b/Makefile
@@ -16,10 +16,10 @@ cmds_objects = cmds-subvolume.o cmds-filesystem.o
cmds-device.o cmds-scrub.o \
cmds-restore.o cmds-rescue.o chunk-recover.o super-recover.o \
cmds-property.o cmds-dedup.o
libbtrfs_objects = send-stream.o send-utils.o rbtree.o btrfs-list.o crc32c.o \
- uuid-tree.o
+ uuid-tree.o xxhash.o
libbtrfs_headers = send-stream.h send-utils.h send.h rbtree.h btrfs-list.h \
crc32c.h list.h kerncompat.h radix-tree.h extent-cache.h \
- extent_io.h ioctl.h ctree.h btrfsck.h
+ extent_io.h ioctl.h ctree.h btrfsck.h xxhash.h
TESTS = fsck-tests.sh
INSTALL = install
diff --git a/crc32c.h b/crc32c.h
index c552ef6..6dd0ce2 100644
--- a/crc32c.h
+++ b/crc32c.h
@@ -25,9 +25,11 @@
#include <btrfs/kerncompat.h>
#endif /* BTRFS_FLAT_INCLUDES */
+#include "xxhash.h"
+
u32 crc32c_le(u32 seed, unsigned char const *data, size_t length);
void crc32c_optimization_init(void);
-#define crc32c(seed, data, length) crc32c_le(seed, (unsigned char const
*)data, length)
+#define crc32c(seed, data, length) XXH32(data, length, 0)
#define btrfs_crc32c crc32c
#endif
diff --git a/disk-io.c b/disk-io.c
index 19b95a7..2c72f7f 100644
--- a/disk-io.c
+++ b/disk-io.c
@@ -67,7 +67,7 @@ u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32
seed, size_t len)
void btrfs_csum_final(u32 crc, char *result)
{
- *(__le32 *)result = ~cpu_to_le32(crc);
+ *(__le32 *)result = cpu_to_le32(crc);
}
static int __csum_tree_block_size(struct extent_buffer *buf, u16 csum_size,
diff --git a/hash.h b/hash.h
index c0b88a1..2d1a71d 100644
--- a/hash.h
+++ b/hash.h
@@ -22,6 +22,6 @@
static inline u64 btrfs_name_hash(const char *name, int len)
{
- return ~(crc32c((u32)(~0), name, len));
+ return crc32c((u32)(~0), name, len);
}
#endif
diff --git a/xxhash.c b/xxhash.c
new file mode 100644
index 0000000..f855a58
--- /dev/null
+++ b/xxhash.c
@@ -0,0 +1,448 @@
+/*
+xxHash - Fast Hash algorithm
+Copyright (C) 2012-2014, Yann Collet.
+BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+* Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+* 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.
+
+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
+OWNER 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.
+
+You can contact the author at :
+- xxHash source repository : http://code.google.com/p/xxhash/
+*/
+
+
+//**************************************
+// Tuning parameters
+//**************************************
+// Unaligned memory access is automatically enabled for "common" CPU, such as
x86.
+// For others CPU, the compiler will be more cautious, and insert extra code
to ensure aligned access is respected.
+// If you know your target CPU supports unaligned memory access, you want to
force this option manually to improve performance.
+// You can also enable this parameter if you know your input data will always
be aligned (boundaries of 4, for U32).
+#if defined(__ARM_FEATURE_UNALIGNED) || defined(__i386) || defined(_M_IX86) ||
defined(__x86_64__) || defined(_M_X64)
+# define XXH_USE_UNALIGNED_ACCESS 1
+#endif
+
+// XXH_ACCEPT_NULL_INPUT_POINTER :
+// If the input pointer is a null pointer, xxHash default behavior is to
trigger a memory access error, since it is a bad pointer.
+// When this option is enabled, xxHash output for null input pointers will be
the same as a null-length input.
+// This option has a very small performance cost (only measurable on small
inputs).
+// By default, this option is disabled. To enable it, uncomment below define :
+//#define XXH_ACCEPT_NULL_INPUT_POINTER 1
+
+// XXH_FORCE_NATIVE_FORMAT :
+// By default, xxHash library provides endian-independant Hash values, based
on little-endian convention.
+// Results are therefore identical for little-endian and big-endian CPU.
+// This comes at a performance cost for big-endian CPU, since some swapping is
required to emulate little-endian format.
+// Should endian-independance be of no importance for your application, you
may set the #define below to 1.
+// It will improve speed for Big-endian CPU.
+// This option has no impact on Little_Endian CPU.
+#define XXH_FORCE_NATIVE_FORMAT 0
+
+
+//**************************************
+// Compiler Specific Options
+//**************************************
+#define FORCE_INLINE static inline __attribute__((always_inline))
+
+
+//**************************************
+// Includes & Memory related functions
+
+#include "xxhash.h"
+#include "kerncompat.h"
+#include <inttypes.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+
+
+
+//**************************************
+// Modify the local functions below should you wish to use some other memory
related routines
+
+FORCE_INLINE void* XXH_malloc(size_t s)
+{
+ return kmalloc(s, GFP_KERNEL);
+}
+
+FORCE_INLINE void XXH_free(void* p)
+{
+ kfree(p);
+}
+
+FORCE_INLINE void* XXH_memcpy(void* dest, const void* src, size_t size)
+{
+ return memcpy(dest, src, size);
+}
+
+
+//**************************************
+// Basic Types
+//**************************************
+typedef unsigned char BYTE;
+typedef unsigned short U16;
+typedef unsigned int U32;
+typedef signed int S32;
+typedef unsigned long long U64;
+
+typedef struct _U32_S {
+ U32 v;
+} __attribute__ ((__packed__)) U32_S;
+
+#define A32(x) (((U32_S *)(x))->v)
+
+
+//***************************************
+// Compiler-specific Functions and Macros
+//***************************************
+
+// Note : although _rotl exists for minGW (GCC under windows), performance
seems poor
+#define XXH_rotl32(x,r) ((x << r) | (x >> (32 - r)))
+
+#define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
+
+#if GCC_VERSION >= 403
+ #define XXH_swap32 __builtin_bswap32
+#else
+ static inline U32 XXH_swap32 (U32 x)
+ {
+ return ((x << 24) & 0xff000000 ) |
+ ((x << 8) & 0x00ff0000 ) |
+ ((x >> 8) & 0x0000ff00 ) |
+ ((x >> 24) & 0x000000ff );
+ }
+#endif
+
+
+//**************************************
+// Constants
+//**************************************
+#define PRIME32_1 2654435761U
+#define PRIME32_2 2246822519U
+#define PRIME32_3 3266489917U
+#define PRIME32_4 668265263U
+#define PRIME32_5 374761393U
+
+
+//**************************************
+// Architecture Macros
+//**************************************
+typedef enum {
+ XXH_bigEndian=0,
+ XXH_littleEndian=1
+} XXH_endianess;
+
+#ifndef XXH_CPU_LITTLE_ENDIAN // It is possible to define
XXH_CPU_LITTLE_ENDIAN externally, for example using a compiler switch
+ static const int one = 1;
+# define XXH_CPU_LITTLE_ENDIAN (*(char*)(&one))
+#endif
+
+
+//**************************************
+// Macros
+//**************************************
+#define XXH_STATIC_ASSERT(c) { enum { XXH_static_assert = 1/(!!(c)) }; }
// use only *after* variable declarations
+
+
+//****************************
+// Memory reads
+//****************************
+typedef enum {
+ XXH_aligned,
+ XXH_unaligned
+} XXH_alignment;
+
+FORCE_INLINE U32 XXH_readLE32_align(const U32* ptr, XXH_endianess endian,
XXH_alignment align)
+{
+ if (align == XXH_unaligned)
+ return endian == XXH_littleEndian ? A32(ptr) : XXH_swap32(A32(ptr));
+ else
+ return endian == XXH_littleEndian ? *ptr : XXH_swap32(*ptr);
+}
+
+FORCE_INLINE U32 XXH_readLE32(const U32* ptr, XXH_endianess endian) {
+ return XXH_readLE32_align(ptr, endian, XXH_unaligned);
+}
+
+
+//****************************
+// Simple Hash Functions
+//****************************
+FORCE_INLINE U32 XXH32_endian_align(const void* input, int len, U32 seed,
XXH_endianess endian, XXH_alignment align)
+{
+ const BYTE* p = (const BYTE*)input;
+ const BYTE* const bEnd = p + len;
+ U32 h32;
+
+#ifdef XXH_ACCEPT_NULL_INPUT_POINTER
+ if (p==NULL) { len=0; p=(const BYTE*)(size_t)16; }
+#endif
+
+ if (len>=16) {
+ const BYTE* const limit = bEnd - 16;
+ U32 v1 = seed + PRIME32_1 + PRIME32_2;
+ U32 v2 = seed + PRIME32_2;
+ U32 v3 = seed + 0;
+ U32 v4 = seed - PRIME32_1;
+
+ do {
+ v1 += XXH_readLE32_align((const U32*)p, endian, align) *
PRIME32_2; v1 = XXH_rotl32(v1, 13); v1 *= PRIME32_1; p+=4;
+ v2 += XXH_readLE32_align((const U32*)p, endian, align) *
PRIME32_2; v2 = XXH_rotl32(v2, 13); v2 *= PRIME32_1; p+=4;
+ v3 += XXH_readLE32_align((const U32*)p, endian, align) *
PRIME32_2; v3 = XXH_rotl32(v3, 13); v3 *= PRIME32_1; p+=4;
+ v4 += XXH_readLE32_align((const U32*)p, endian, align) *
PRIME32_2; v4 = XXH_rotl32(v4, 13); v4 *= PRIME32_1; p+=4;
+ } while (p<=limit);
+
+ h32 = XXH_rotl32(v1, 1) + XXH_rotl32(v2, 7) + XXH_rotl32(v3,
12) + XXH_rotl32(v4, 18);
+ } else {
+ h32 = seed + PRIME32_5;
+ }
+
+ h32 += (U32)len;
+
+ while (p <= bEnd - 4) {
+ h32 += XXH_readLE32_align((const U32*)p, endian, align) *
PRIME32_3;
+ h32 = XXH_rotl32(h32, 17) * PRIME32_4 ;
+ p += 4;
+ }
+
+ while (p < bEnd) {
+ h32 += (*p) * PRIME32_5;
+ h32 = XXH_rotl32(h32, 11) * PRIME32_1 ;
+ p++;
+ }
+
+ h32 ^= h32 >> 15;
+ h32 *= PRIME32_2;
+ h32 ^= h32 >> 13;
+ h32 *= PRIME32_3;
+ h32 ^= h32 >> 16;
+
+ return h32;
+}
+
+
+U32 XXH32(const void* input, int len, U32 seed)
+{
+#if 0
+ // Simple version, good for code maintenance, but unfortunately slow
for small inputs
+ void* state = XXH32_init(seed);
+ XXH32_update(state, input, len);
+ return XXH32_digest(state);
+#else
+
+ XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
+
+ #if !defined(XXH_USE_UNALIGNED_ACCESS)
+ if ((((size_t)input) & 3)) { // Input is aligned, let's leverage the
speed advantage
+ if ((endian_detected == XXH_littleEndian) ||
XXH_FORCE_NATIVE_FORMAT)
+ return XXH32_endian_align(input, len, seed,
XXH_littleEndian, XXH_aligned);
+ else
+ return XXH32_endian_align(input, len, seed,
XXH_bigEndian, XXH_aligned);
+ }
+ #endif
+
+ if ((endian_detected == XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
+ return XXH32_endian_align(input, len, seed, XXH_littleEndian,
XXH_unaligned);
+ else
+ return XXH32_endian_align(input, len, seed, XXH_bigEndian,
XXH_unaligned);
+#endif
+}
+
+//****************************
+// Advanced Hash Functions
+//****************************
+
+struct XXH_state32_t {
+ U64 total_len;
+ U32 seed;
+ U32 v1;
+ U32 v2;
+ U32 v3;
+ U32 v4;
+ int memsize;
+ char memory[16];
+};
+
+
+int XXH32_sizeofState()
+{
+ XXH_STATIC_ASSERT(XXH32_SIZEOFSTATE >= sizeof(struct XXH_state32_t));
// A compilation error here means XXH32_SIZEOFSTATE is not large enough
+ return sizeof(struct XXH_state32_t);
+}
+
+
+XXH_errorcode XXH32_resetState(void* state_in, U32 seed)
+{
+ struct XXH_state32_t * state = (struct XXH_state32_t *) state_in;
+ state->seed = seed;
+ state->v1 = seed + PRIME32_1 + PRIME32_2;
+ state->v2 = seed + PRIME32_2;
+ state->v3 = seed + 0;
+ state->v4 = seed - PRIME32_1;
+ state->total_len = 0;
+ state->memsize = 0;
+ return XXH_OK;
+}
+
+
+void* XXH32_init (U32 seed)
+{
+ void* state = XXH_malloc(sizeof(struct XXH_state32_t));
+ XXH32_resetState(state, seed);
+ return state;
+}
+
+
+FORCE_INLINE XXH_errorcode XXH32_update_endian (void* state_in, const void*
input, int len, XXH_endianess endian)
+{
+ struct XXH_state32_t * state = (struct XXH_state32_t *) state_in;
+ const BYTE* p = (const BYTE*)input;
+ const BYTE* const bEnd = p + len;
+
+#ifdef XXH_ACCEPT_NULL_INPUT_POINTER
+ if (input == NULL)
+ return XXH_ERROR;
+#endif
+
+ state->total_len += len;
+
+ if (state->memsize + len < 16) { // fill in tmp buffer
+ XXH_memcpy(state->memory + state->memsize, input, len);
+ state->memsize += len;
+ return XXH_OK;
+ }
+
+ if (state->memsize) // some data left from previous update
+ {
+ XXH_memcpy(state->memory + state->memsize, input,
16-state->memsize);
+ {
+ const U32* p32 = (const U32*)state->memory;
+ state->v1 += XXH_readLE32(p32, endian) * PRIME32_2;
state->v1 = XXH_rotl32(state->v1, 13); state->v1 *= PRIME32_1; p32++;
+ state->v2 += XXH_readLE32(p32, endian) * PRIME32_2;
state->v2 = XXH_rotl32(state->v2, 13); state->v2 *= PRIME32_1; p32++;
+ state->v3 += XXH_readLE32(p32, endian) * PRIME32_2;
state->v3 = XXH_rotl32(state->v3, 13); state->v3 *= PRIME32_1; p32++;
+ state->v4 += XXH_readLE32(p32, endian) * PRIME32_2;
state->v4 = XXH_rotl32(state->v4, 13); state->v4 *= PRIME32_1; p32++;
+ }
+ p += 16-state->memsize;
+ state->memsize = 0;
+ }
+
+ if (p <= bEnd-16) {
+ const BYTE* const limit = bEnd - 16;
+ U32 v1 = state->v1;
+ U32 v2 = state->v2;
+ U32 v3 = state->v3;
+ U32 v4 = state->v4;
+
+ do {
+ v1 += XXH_readLE32((const U32*)p, endian) * PRIME32_2; v1 =
XXH_rotl32(v1, 13); v1 *= PRIME32_1; p+=4;
+ v2 += XXH_readLE32((const U32*)p, endian) * PRIME32_2; v2 =
XXH_rotl32(v2, 13); v2 *= PRIME32_1; p+=4;
+ v3 += XXH_readLE32((const U32*)p, endian) * PRIME32_2; v3 =
XXH_rotl32(v3, 13); v3 *= PRIME32_1; p+=4;
+ v4 += XXH_readLE32((const U32*)p, endian) * PRIME32_2; v4 =
XXH_rotl32(v4, 13); v4 *= PRIME32_1; p+=4;
+ } while (p<=limit);
+
+ state->v1 = v1;
+ state->v2 = v2;
+ state->v3 = v3;
+ state->v4 = v4;
+ }
+
+ if (p < bEnd) {
+ XXH_memcpy(state->memory, p, bEnd-p);
+ state->memsize = (int)(bEnd-p);
+ }
+
+ return XXH_OK;
+}
+
+XXH_errorcode XXH32_update(void* state_in, const void* input, int len)
+{
+ XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
+
+ if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
+ return XXH32_update_endian(state_in, input, len,
XXH_littleEndian);
+ else
+ return XXH32_update_endian(state_in, input, len, XXH_bigEndian);
+}
+
+
+
+FORCE_INLINE U32 XXH32_intermediateDigest_endian (void* state_in,
XXH_endianess endian)
+{
+ struct XXH_state32_t * state = (struct XXH_state32_t *) state_in;
+ const BYTE * p = (const BYTE*)state->memory;
+ BYTE* bEnd = (BYTE*)state->memory + state->memsize;
+ U32 h32;
+
+ if (state->total_len >= 16) {
+ h32 = XXH_rotl32(state->v1, 1) + XXH_rotl32(state->v2, 7) +
XXH_rotl32(state->v3, 12) + XXH_rotl32(state->v4, 18);
+ } else {
+ h32 = state->seed + PRIME32_5;
+ }
+
+ h32 += (U32)state->total_len;
+
+ while (p <= bEnd - 4) {
+ h32 += XXH_readLE32((const U32*)p, endian) * PRIME32_3;
+ h32 = XXH_rotl32(h32, 17) * PRIME32_4;
+ p+=4;
+ }
+
+ while (p<bEnd) {
+ h32 += (*p) * PRIME32_5;
+ h32 = XXH_rotl32(h32, 11) * PRIME32_1;
+ p++;
+ }
+
+ h32 ^= h32 >> 15;
+ h32 *= PRIME32_2;
+ h32 ^= h32 >> 13;
+ h32 *= PRIME32_3;
+ h32 ^= h32 >> 16;
+
+ return h32;
+}
+
+
+U32 XXH32_intermediateDigest (void* state_in)
+{
+ XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
+
+ if ((endian_detected == XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
+ return XXH32_intermediateDigest_endian(state_in,
XXH_littleEndian);
+ else
+ return XXH32_intermediateDigest_endian(state_in, XXH_bigEndian);
+}
+
+
+U32 XXH32_digest (void* state_in)
+{
+ U32 h32 = XXH32_intermediateDigest(state_in);
+
+ XXH_free(state_in);
+
+ return h32;
+}
diff --git a/xxhash.h b/xxhash.h
new file mode 100644
index 0000000..97a1bb2
--- /dev/null
+++ b/xxhash.h
@@ -0,0 +1,171 @@
+/*
+ xxHash - Fast Hash algorithm
+ Header File
+ Copyright (C) 2012-2014, Yann Collet.
+ BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are
+ met:
+
+ * Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ * 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.
+
+ 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
+ OWNER 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.
+
+ You can contact the author at :
+ - xxHash source repository : http://code.google.com/p/xxhash/
+*/
+
+/* Notice extracted from xxHash homepage :
+
+xxHash is an extremely fast Hash algorithm, running at RAM speed limits.
+It also successfully passes all tests from the SMHasher suite.
+
+Comparison (single thread, Windows Seven 32 bits, using SMHasher on a Core 2
Duo @3GHz)
+
+Name Speed Q.Score Author
+xxHash 5.4 GB/s 10
+CrapWow 3.2 GB/s 2 Andrew
+MumurHash 3a 2.7 GB/s 10 Austin Appleby
+SpookyHash 2.0 GB/s 10 Bob Jenkins
+SBox 1.4 GB/s 9 Bret Mulvey
+Lookup3 1.2 GB/s 9 Bob Jenkins
+SuperFastHash 1.2 GB/s 1 Paul Hsieh
+CityHash64 1.05 GB/s 10 Pike & Alakuijala
+FNV 0.55 GB/s 5 Fowler, Noll, Vo
+CRC32 0.43 GB/s 9
+MD5-32 0.33 GB/s 10 Ronald L. Rivest
+SHA1-32 0.28 GB/s 10
+
+Q.Score is a measure of quality of the hash function.
+It depends on successfully passing SMHasher test set.
+10 is a perfect score.
+*/
+
+#pragma once
+
+#ifndef __XXHASH__
+#define __XXHASH__
+
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
+
+//****************************
+// Type
+//****************************
+typedef enum {
+ XXH_OK=0,
+ XXH_ERROR
+} XXH_errorcode;
+
+
+
+//****************************
+// Simple Hash Functions
+//****************************
+
+/*
+XXH32() :
+ Calculate the 32-bits hash of sequence of length "len" stored at memory
address "input".
+ The memory between input & input+len must be valid (allocated and
read-accessible).
+ "seed" can be used to alter the result predictably.
+ This function successfully passes all SMHasher tests.
+ Speed on Core 2 Duo @ 3 GHz (single thread, SMHasher benchmark) : 5.4 GB/s
+ Note that "len" is type "int", which means it is limited to 2^31-1.
+ If your data is larger, use the advanced functions below.
+*/
+unsigned int XXH32 (const void* input, int len, unsigned int seed);
+
+
+
+//****************************
+// Advanced Hash Functions
+//****************************
+
+void* XXH32_init (unsigned int seed);
+XXH_errorcode XXH32_update (void* state, const void* input, int len);
+unsigned int XXH32_digest (void* state);
+
+/*
+These functions calculate the xxhash of an input provided in several small
packets,
+as opposed to an input provided as a single block.
+
+It must be started with :
+void* XXH32_init()
+The function returns a pointer which holds the state of calculation.
+
+This pointer must be provided as "void* state" parameter for XXH32_update().
+XXH32_update() can be called as many times as necessary.
+The user must provide a valid (allocated) input.
+The function returns an error code, with 0 meaning OK, and any other value
meaning there is an error.
+Note that "len" is type "int", which means it is limited to 2^31-1.
+If your data is larger, it is recommended to chunk your data into blocks
+of size for example 2^30 (1GB) to avoid any "int" overflow issue.
+
+Finally, you can end the calculation anytime, by using XXH32_digest().
+This function returns the final 32-bits hash.
+You must provide the same "void* state" parameter created by XXH32_init().
+Memory will be freed by XXH32_digest().
+*/
+
+
+int XXH32_sizeofState(void);
+XXH_errorcode XXH32_resetState(void* state, unsigned int seed);
+
+#define XXH32_SIZEOFSTATE 48
+typedef struct { long long ll[(XXH32_SIZEOFSTATE+(sizeof(long
long)-1))/sizeof(long long)]; } XXH32_stateSpace_t;
+/*
+These functions allow user application to make its own allocation for state.
+
+XXH32_sizeofState() is used to know how much space must be allocated for the
xxHash 32-bits state.
+Note that the state must be aligned to access 'long long' fields. Memory must
be allocated and referenced by a pointer.
+This pointer must then be provided as 'state' into XXH32_resetState(), which
initializes the state.
+
+For static allocation purposes (such as allocation on stack, or freestanding
systems without malloc()),
+use the structure XXH32_stateSpace_t, which will ensure that memory space is
large enough and correctly aligned to access 'long long' fields.
+*/
+
+
+unsigned int XXH32_intermediateDigest (void* state);
+/*
+This function does the same as XXH32_digest(), generating a 32-bit hash,
+but preserve memory context.
+This way, it becomes possible to generate intermediate hashes, and then
continue feeding data with XXH32_update().
+To free memory context, use XXH32_digest(), or free().
+*/
+
+
+
+//****************************
+// Deprecated function names
+//****************************
+// The following translations are provided to ease code transition
+// You are encouraged to no longer this function names
+#define XXH32_feed XXH32_update
+#define XXH32_result XXH32_digest
+#define XXH32_getIntermediateResult XXH32_intermediateDigest
+
+
+
+#if defined (__cplusplus)
+}
+#endif
+
+#endif
--
1.7.7
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