Adding upstream version 14.2.21.upstream/14.2.21upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1074 insertions, 0 deletions

diff --git a/src/rocksdb/util/xxhash.cc b/src/rocksdb/util/xxhash.cc
new file mode 100644
index 00000000..2ec95a63
--- /dev/null
+++ b/src/rocksdb/util/xxhash.cc
@@ -0,0 +1,1074 @@
+/*
+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
+//**************************************
+/*!XXH_FORCE_MEMORY_ACCESS :
+ * By default, access to unaligned memory is controlled by `memcpy()`, which is
+ * safe and portable. Unfortunately, on some target/compiler combinations, the
+ * generated assembly is sub-optimal. The below switch allow to select different
+ * access method for improved performance. Method 0 (default) : use `memcpy()`.
+ * Safe and portable. Method 1 : `__packed` statement. It depends on compiler
+ * extension (ie, not portable). This method is safe if your compiler supports
+ * it, and *generally* as fast or faster than `memcpy`. Method 2 : direct
+ * access. This method doesn't depend on compiler but violate C standard. It can
+ * generate buggy code on targets which do not support unaligned memory
+ * accesses. But in some circumstances, it's the only known way to get the most
+ * performance (ie GCC + ARMv6) See http://stackoverflow.com/a/32095106/646947
+ * for details. Prefer these methods in priority order (0 > 1 > 2)
+ */
+
+#include "util/util.h"
+
+#ifndef XXH_FORCE_MEMORY_ACCESS /* can be defined externally, on command line \
+                                   for example */
+#if defined(__GNUC__) &&                                     \
+    (defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) ||  \
+     defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || \
+     defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__))
+#define XXH_FORCE_MEMORY_ACCESS 2
+#elif (defined(__INTEL_COMPILER) && !defined(_WIN32)) ||      \
+    (defined(__GNUC__) &&                                     \
+     (defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) ||  \
+      defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) || \
+      defined(__ARM_ARCH_7S__)))
+#define XXH_FORCE_MEMORY_ACCESS 1
+#endif
+#endif
+
+// 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-independent 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-independence 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
+
+/*!XXH_FORCE_ALIGN_CHECK :
+ * This is a minor performance trick, only useful with lots of very small keys.
+ * It means : check for aligned/unaligned input.
+ * The check costs one initial branch per hash;
+ * set it to 0 when the input is guaranteed to be aligned,
+ * or when alignment doesn't matter for performance.
+ */
+#ifndef XXH_FORCE_ALIGN_CHECK /* can be defined externally */
+#if defined(__i386) || defined(_M_IX86) || defined(__x86_64__) || \
+    defined(_M_X64)
+#define XXH_FORCE_ALIGN_CHECK 0
+#else
+#define XXH_FORCE_ALIGN_CHECK 1
+#endif
+#endif
+
+//**************************************
+// Compiler Specific Options
+//**************************************
+// Disable some Visual warning messages
+#ifdef _MSC_VER  // Visual Studio
+#  pragma warning(disable : 4127)      // disable: C4127: conditional expression is constant
+#  pragma warning(disable : 4804)      // disable: C4804: 'operation' : unsafe use of type 'bool' in operation (static assert line 313)
+#endif
+
+#ifdef _MSC_VER    // Visual Studio
+#  define FORCE_INLINE static __forceinline
+#else
+#  ifdef __GNUC__
+#    define FORCE_INLINE static inline __attribute__((always_inline))
+#  else
+#    define FORCE_INLINE static inline
+#  endif
+#endif
+
+
+//**************************************
+// Includes & Memory related functions
+//**************************************
+#include "xxhash.h"
+// Modify the local functions below should you wish to use some other memory related routines
+// for malloc(), free()
+#include <stdlib.h>
+FORCE_INLINE void* XXH_malloc(size_t s) { return malloc(s); }
+FORCE_INLINE void  XXH_free  (void* p)  { free(p); }
+// for memcpy()
+#include <string.h>
+FORCE_INLINE void* XXH_memcpy(void* dest, const void* src, size_t size) { return memcpy(dest,src,size); }
+#include <assert.h> /* assert */
+
+namespace rocksdb {
+//**************************************
+// Basic Types
+//**************************************
+#if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   // C99
+# include <stdint.h>
+  typedef uint8_t  BYTE;
+  typedef uint16_t U16;
+  typedef uint32_t U32;
+  typedef  int32_t S32;
+  typedef uint64_t U64;
+#else
+  typedef unsigned char      BYTE;
+  typedef unsigned short     U16;
+  typedef unsigned int       U32;
+  typedef   signed int       S32;
+  typedef unsigned long long U64;
+#endif
+
+#if defined(__GNUC__)  && !defined(XXH_USE_UNALIGNED_ACCESS)
+#  define _PACKED __attribute__ ((packed))
+#else
+#  define _PACKED
+#endif
+
+#if !defined(XXH_USE_UNALIGNED_ACCESS) && !defined(__GNUC__)
+#  ifdef __IBMC__
+#    pragma pack(1)
+#  else
+#    pragma pack(push, 1)
+#  endif
+#endif
+
+typedef struct _U32_S { U32 v; } _PACKED U32_S;
+
+#if !defined(XXH_USE_UNALIGNED_ACCESS) && !defined(__GNUC__)
+#  pragma pack(pop)
+#endif
+
+#define A32(x) (((U32_S *)(x))->v)
+
+#if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS == 2))
+
+/* Force direct memory access. Only works on CPU which support unaligned memory
+ * access in hardware */
+static U32 XXH_read32(const void* memPtr) { return *(const U32*)memPtr; }
+
+#elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS == 1))
+
+/* __pack instructions are safer, but compiler specific, hence potentially
+ * problematic for some compilers */
+/* currently only defined for gcc and icc */
+typedef union {
+  U32 u32;
+} __attribute__((packed)) unalign;
+static U32 XXH_read32(const void* ptr) { return ((const unalign*)ptr)->u32; }
+
+#else
+
+/* portable and safe solution. Generally efficient.
+ * see : http://stackoverflow.com/a/32095106/646947
+ */
+static U32 XXH_read32(const void* memPtr) {
+  U32 val;
+  memcpy(&val, memPtr, sizeof(val));
+  return val;
+}
+
+#endif /* XXH_FORCE_DIRECT_MEMORY_ACCESS */
+
+//***************************************
+// Compiler-specific Functions and Macros
+//***************************************
+#define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
+
+// Note : although _rotl exists for minGW (GCC under windows), performance seems poor
+#if defined(_MSC_VER)
+#  define XXH_rotl32(x,r) _rotl(x,r)
+#define XXH_rotl64(x, r) _rotl64(x, r)
+#else
+#  define XXH_rotl32(x,r) ((x << r) | (x >> (32 - r)))
+#define XXH_rotl64(x, r) ((x << r) | (x >> (64 - r)))
+#endif
+
+#if defined(_MSC_VER)     // Visual Studio
+#  define XXH_swap32 _byteswap_ulong
+#elif 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_align(const void* ptr, XXH_endianess endian,
+                                    XXH_alignment align) {
+  if (align == XXH_unaligned)
+    return endian == XXH_littleEndian ? XXH_read32(ptr)
+                                      : XXH_swap32(XXH_read32(ptr));
+  else
+    return endian == XXH_littleEndian ? *(const U32*)ptr
+                                      : XXH_swap32(*(const U32*)ptr);
+}
+
+FORCE_INLINE U32 XXH_readLE32(const U32* ptr, XXH_endianess endian) {
+  return XXH_readLE32_align(ptr, endian, XXH_unaligned);
+}
+
+//****************************
+// Simple Hash Functions
+//****************************
+#define XXH_get32bits(p) XXH_readLE32_align(p, endian, align)
+
+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;
+}
+
+/* *******************************************************************
+ *  64-bit hash functions
+ *********************************************************************/
+
+ #if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==2))
+
+ /* Force direct memory access. Only works on CPU which support unaligned memory access in hardware */
+ static U64 XXH_read64(const void* memPtr) { return *(const U64*) memPtr; }
+
+ #elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==1))
+
+ /* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
+ /* currently only defined for gcc and icc */
+ typedef union { U32 u32; U64 u64; } __attribute__((packed)) unalign64;
+ static U64 XXH_read64(const void* ptr) { return ((const unalign64*)ptr)->u64; }
+
+ #else
+
+ /* portable and safe solution. Generally efficient.
+  * see : http://stackoverflow.com/a/32095106/646947
+  */
+
+ static U64 XXH_read64(const void* memPtr)
+ {
+     U64 val;
+     memcpy(&val, memPtr, sizeof(val));
+     return val;
+ }
+#endif   /* XXH_FORCE_DIRECT_MEMORY_ACCESS */
+
+#if defined(_MSC_VER) /* Visual Studio */
+#define XXH_swap64 _byteswap_uint64
+#elif XXH_GCC_VERSION >= 403
+#define XXH_swap64 __builtin_bswap64
+#else
+static U64 XXH_swap64(U64 x) {
+  return ((x << 56) & 0xff00000000000000ULL) |
+         ((x << 40) & 0x00ff000000000000ULL) |
+         ((x << 24) & 0x0000ff0000000000ULL) |
+         ((x << 8) & 0x000000ff00000000ULL) |
+         ((x >> 8) & 0x00000000ff000000ULL) |
+         ((x >> 24) & 0x0000000000ff0000ULL) |
+         ((x >> 40) & 0x000000000000ff00ULL) |
+         ((x >> 56) & 0x00000000000000ffULL);
+}
+#endif
+
+FORCE_INLINE U64 XXH_readLE64_align(const void* ptr, XXH_endianess endian,
+                                    XXH_alignment align) {
+  if (align == XXH_unaligned)
+    return endian == XXH_littleEndian ? XXH_read64(ptr)
+                                      : XXH_swap64(XXH_read64(ptr));
+  else
+    return endian == XXH_littleEndian ? *(const U64*)ptr
+                                      : XXH_swap64(*(const U64*)ptr);
+}
+
+FORCE_INLINE U64 XXH_readLE64(const void* ptr, XXH_endianess endian) {
+  return XXH_readLE64_align(ptr, endian, XXH_unaligned);
+}
+
+static U64 XXH_readBE64(const void* ptr) {
+  return XXH_CPU_LITTLE_ENDIAN ? XXH_swap64(XXH_read64(ptr)) : XXH_read64(ptr);
+}
+
+/*======   xxh64   ======*/
+
+static const U64 PRIME64_1 =
+    11400714785074694791ULL; /* 0b1001111000110111011110011011000110000101111010111100101010000111
+                              */
+static const U64 PRIME64_2 =
+    14029467366897019727ULL; /* 0b1100001010110010101011100011110100100111110101001110101101001111
+                              */
+static const U64 PRIME64_3 =
+    1609587929392839161ULL; /* 0b0001011001010110011001111011000110011110001101110111100111111001
+                             */
+static const U64 PRIME64_4 =
+    9650029242287828579ULL; /* 0b1000010111101011110010100111011111000010101100101010111001100011
+                             */
+static const U64 PRIME64_5 =
+    2870177450012600261ULL; /* 0b0010011111010100111010110010111100010110010101100110011111000101
+                             */
+
+static U64 XXH64_round(U64 acc, U64 input) {
+  acc += input * PRIME64_2;
+  acc = XXH_rotl64(acc, 31);
+  acc *= PRIME64_1;
+  return acc;
+}
+
+static U64 XXH64_mergeRound(U64 acc, U64 val) {
+  val = XXH64_round(0, val);
+  acc ^= val;
+  acc = acc * PRIME64_1 + PRIME64_4;
+  return acc;
+}
+
+static U64 XXH64_avalanche(U64 h64) {
+  h64 ^= h64 >> 33;
+  h64 *= PRIME64_2;
+  h64 ^= h64 >> 29;
+  h64 *= PRIME64_3;
+  h64 ^= h64 >> 32;
+  return h64;
+}
+
+#define XXH_get64bits(p) XXH_readLE64_align(p, endian, align)
+
+static U64 XXH64_finalize(U64 h64, const void* ptr, size_t len,
+                          XXH_endianess endian, XXH_alignment align) {
+  const BYTE* p = (const BYTE*)ptr;
+
+#define PROCESS1_64          \
+  h64 ^= (*p++) * PRIME64_5; \
+  h64 = XXH_rotl64(h64, 11) * PRIME64_1;
+
+#define PROCESS4_64                           \
+  h64 ^= (U64)(XXH_get32bits(p)) * PRIME64_1; \
+  p += 4;                                     \
+  h64 = XXH_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;
+
+#define PROCESS8_64                                    \
+  {                                                    \
+    U64 const k1 = XXH64_round(0, XXH_get64bits(p));   \
+    p += 8;                                            \
+    h64 ^= k1;                                         \
+    h64 = XXH_rotl64(h64, 27) * PRIME64_1 + PRIME64_4; \
+  }
+
+  switch (len & 31) {
+    case 24:
+      PROCESS8_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 16:
+      PROCESS8_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 8:
+      PROCESS8_64;
+      return XXH64_avalanche(h64);
+
+    case 28:
+      PROCESS8_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 20:
+      PROCESS8_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 12:
+      PROCESS8_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 4:
+      PROCESS4_64;
+      return XXH64_avalanche(h64);
+
+    case 25:
+      PROCESS8_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 17:
+      PROCESS8_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 9:
+      PROCESS8_64;
+      PROCESS1_64;
+      return XXH64_avalanche(h64);
+
+    case 29:
+      PROCESS8_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 21:
+      PROCESS8_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 13:
+      PROCESS8_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 5:
+      PROCESS4_64;
+      PROCESS1_64;
+      return XXH64_avalanche(h64);
+
+    case 26:
+      PROCESS8_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 18:
+      PROCESS8_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 10:
+      PROCESS8_64;
+      PROCESS1_64;
+      PROCESS1_64;
+      return XXH64_avalanche(h64);
+
+    case 30:
+      PROCESS8_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 22:
+      PROCESS8_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 14:
+      PROCESS8_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 6:
+      PROCESS4_64;
+      PROCESS1_64;
+      PROCESS1_64;
+      return XXH64_avalanche(h64);
+
+    case 27:
+      PROCESS8_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 19:
+      PROCESS8_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 11:
+      PROCESS8_64;
+      PROCESS1_64;
+      PROCESS1_64;
+      PROCESS1_64;
+      return XXH64_avalanche(h64);
+
+    case 31:
+      PROCESS8_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 23:
+      PROCESS8_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 15:
+      PROCESS8_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 7:
+      PROCESS4_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 3:
+      PROCESS1_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 2:
+      PROCESS1_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 1:
+      PROCESS1_64;
+      FALLTHROUGH_INTENDED;
+      /* fallthrough */
+    case 0:
+      return XXH64_avalanche(h64);
+  }
+
+  /* impossible to reach */
+  assert(0);
+  return 0; /* unreachable, but some compilers complain without it */
+}
+
+FORCE_INLINE U64 XXH64_endian_align(const void* input, size_t len, U64 seed,
+                                    XXH_endianess endian, XXH_alignment align) {
+  const BYTE* p = (const BYTE*)input;
+  const BYTE* bEnd = p + len;
+  U64 h64;
+
+#if defined(XXH_ACCEPT_NULL_INPUT_POINTER) && \
+    (XXH_ACCEPT_NULL_INPUT_POINTER >= 1)
+  if (p == NULL) {
+    len = 0;
+    bEnd = p = (const BYTE*)(size_t)32;
+  }
+#endif
+
+  if (len >= 32) {
+    const BYTE* const limit = bEnd - 32;
+    U64 v1 = seed + PRIME64_1 + PRIME64_2;
+    U64 v2 = seed + PRIME64_2;
+    U64 v3 = seed + 0;
+    U64 v4 = seed - PRIME64_1;
+
+    do {
+      v1 = XXH64_round(v1, XXH_get64bits(p));
+      p += 8;
+      v2 = XXH64_round(v2, XXH_get64bits(p));
+      p += 8;
+      v3 = XXH64_round(v3, XXH_get64bits(p));
+      p += 8;
+      v4 = XXH64_round(v4, XXH_get64bits(p));
+      p += 8;
+    } while (p <= limit);
+
+    h64 = XXH_rotl64(v1, 1) + XXH_rotl64(v2, 7) + XXH_rotl64(v3, 12) +
+          XXH_rotl64(v4, 18);
+    h64 = XXH64_mergeRound(h64, v1);
+    h64 = XXH64_mergeRound(h64, v2);
+    h64 = XXH64_mergeRound(h64, v3);
+    h64 = XXH64_mergeRound(h64, v4);
+
+  } else {
+    h64 = seed + PRIME64_5;
+  }
+
+  h64 += (U64)len;
+
+  return XXH64_finalize(h64, p, len, endian, align);
+}
+
+unsigned long long XXH64(const void* input, size_t len,
+                         unsigned long long seed) {
+#if 0
+    /* Simple version, good for code maintenance, but unfortunately slow for small inputs */
+    XXH64_state_t state;
+    XXH64_reset(&state, seed);
+    XXH64_update(&state, input, len);
+    return XXH64_digest(&state);
+#else
+  XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
+
+  if (XXH_FORCE_ALIGN_CHECK) {
+    if ((((size_t)input) & 7) ==
+        0) { /* Input is aligned, let's leverage the speed advantage */
+      if ((endian_detected == XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
+        return XXH64_endian_align(input, len, seed, XXH_littleEndian,
+                                  XXH_aligned);
+      else
+        return XXH64_endian_align(input, len, seed, XXH_bigEndian, XXH_aligned);
+    }
+  }
+
+  if ((endian_detected == XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
+    return XXH64_endian_align(input, len, seed, XXH_littleEndian,
+                              XXH_unaligned);
+  else
+    return XXH64_endian_align(input, len, seed, XXH_bigEndian, XXH_unaligned);
+#endif
+}
+
+/*======   Hash Streaming   ======*/
+
+XXH64_state_t* XXH64_createState(void) {
+  return (XXH64_state_t*)XXH_malloc(sizeof(XXH64_state_t));
+}
+XXH_errorcode XXH64_freeState(XXH64_state_t* statePtr) {
+  XXH_free(statePtr);
+  return XXH_OK;
+}
+
+void XXH64_copyState(XXH64_state_t* dstState, const XXH64_state_t* srcState) {
+  memcpy(dstState, srcState, sizeof(*dstState));
+}
+
+XXH_errorcode XXH64_reset(XXH64_state_t* statePtr, unsigned long long seed) {
+  XXH64_state_t state; /* using a local state to memcpy() in order to avoid
+                          strict-aliasing warnings */
+  memset(&state, 0, sizeof(state));
+  state.v1 = seed + PRIME64_1 + PRIME64_2;
+  state.v2 = seed + PRIME64_2;
+  state.v3 = seed + 0;
+  state.v4 = seed - PRIME64_1;
+  /* do not write into reserved, planned to be removed in a future version */
+  memcpy(statePtr, &state, sizeof(state) - sizeof(state.reserved));
+  return XXH_OK;
+}
+
+FORCE_INLINE XXH_errorcode XXH64_update_endian(XXH64_state_t* state,
+                                               const void* input, size_t len,
+                                               XXH_endianess endian) {
+  if (input == NULL)
+#if defined(XXH_ACCEPT_NULL_INPUT_POINTER) && \
+    (XXH_ACCEPT_NULL_INPUT_POINTER >= 1)
+    return XXH_OK;
+#else
+    return XXH_ERROR;
+#endif
+
+  {
+    const BYTE* p = (const BYTE*)input;
+    const BYTE* const bEnd = p + len;
+
+    state->total_len += len;
+
+    if (state->memsize + len < 32) { /* fill in tmp buffer */
+      XXH_memcpy(((BYTE*)state->mem64) + state->memsize, input, len);
+      state->memsize += (U32)len;
+      return XXH_OK;
+    }
+
+    if (state->memsize) { /* tmp buffer is full */
+      XXH_memcpy(((BYTE*)state->mem64) + state->memsize, input,
+                 32 - state->memsize);
+      state->v1 =
+          XXH64_round(state->v1, XXH_readLE64(state->mem64 + 0, endian));
+      state->v2 =
+          XXH64_round(state->v2, XXH_readLE64(state->mem64 + 1, endian));
+      state->v3 =
+          XXH64_round(state->v3, XXH_readLE64(state->mem64 + 2, endian));
+      state->v4 =
+          XXH64_round(state->v4, XXH_readLE64(state->mem64 + 3, endian));
+      p += 32 - state->memsize;
+      state->memsize = 0;
+    }
+
+    if (p + 32 <= bEnd) {
+      const BYTE* const limit = bEnd - 32;
+      U64 v1 = state->v1;
+      U64 v2 = state->v2;
+      U64 v3 = state->v3;
+      U64 v4 = state->v4;
+
+      do {
+        v1 = XXH64_round(v1, XXH_readLE64(p, endian));
+        p += 8;
+        v2 = XXH64_round(v2, XXH_readLE64(p, endian));
+        p += 8;
+        v3 = XXH64_round(v3, XXH_readLE64(p, endian));
+        p += 8;
+        v4 = XXH64_round(v4, XXH_readLE64(p, endian));
+        p += 8;
+      } while (p <= limit);
+
+      state->v1 = v1;
+      state->v2 = v2;
+      state->v3 = v3;
+      state->v4 = v4;
+    }
+
+    if (p < bEnd) {
+      XXH_memcpy(state->mem64, p, (size_t)(bEnd - p));
+      state->memsize = (unsigned)(bEnd - p);
+    }
+  }
+
+  return XXH_OK;
+}
+
+XXH_errorcode XXH64_update(XXH64_state_t* state_in, const void* input,
+                           size_t len) {
+  XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
+
+  if ((endian_detected == XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
+    return XXH64_update_endian(state_in, input, len, XXH_littleEndian);
+  else
+    return XXH64_update_endian(state_in, input, len, XXH_bigEndian);
+}
+
+FORCE_INLINE U64 XXH64_digest_endian(const XXH64_state_t* state,
+                                     XXH_endianess endian) {
+  U64 h64;
+
+  if (state->total_len >= 32) {
+    U64 const v1 = state->v1;
+    U64 const v2 = state->v2;
+    U64 const v3 = state->v3;
+    U64 const v4 = state->v4;
+
+    h64 = XXH_rotl64(v1, 1) + XXH_rotl64(v2, 7) + XXH_rotl64(v3, 12) +
+          XXH_rotl64(v4, 18);
+    h64 = XXH64_mergeRound(h64, v1);
+    h64 = XXH64_mergeRound(h64, v2);
+    h64 = XXH64_mergeRound(h64, v3);
+    h64 = XXH64_mergeRound(h64, v4);
+  } else {
+    h64 = state->v3 /*seed*/ + PRIME64_5;
+  }
+
+  h64 += (U64)state->total_len;
+
+  return XXH64_finalize(h64, state->mem64, (size_t)state->total_len, endian,
+                        XXH_aligned);
+}
+
+unsigned long long XXH64_digest(const XXH64_state_t* state_in) {
+  XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
+
+  if ((endian_detected == XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
+    return XXH64_digest_endian(state_in, XXH_littleEndian);
+  else
+    return XXH64_digest_endian(state_in, XXH_bigEndian);
+}
+
+/*====== Canonical representation   ======*/
+
+void XXH64_canonicalFromHash(XXH64_canonical_t* dst, XXH64_hash_t hash) {
+  XXH_STATIC_ASSERT(sizeof(XXH64_canonical_t) == sizeof(XXH64_hash_t));
+  if (XXH_CPU_LITTLE_ENDIAN) hash = XXH_swap64(hash);
+  memcpy(dst, &hash, sizeof(*dst));
+}
+
+XXH64_hash_t XXH64_hashFromCanonical(const XXH64_canonical_t* src) {
+  return XXH_readBE64(src);
+}
+}  // namespace rocksdb