diff options
Diffstat (limited to 'lib/xxhash.h')
-rw-r--r-- | lib/xxhash.h | 221 |
1 files changed, 128 insertions, 93 deletions
diff --git a/lib/xxhash.h b/lib/xxhash.h index 870a6d9..d6bad94 100644 --- a/lib/xxhash.h +++ b/lib/xxhash.h @@ -57,8 +57,8 @@ Q.Score is a measure of quality of the hash function. It depends on successfully passing SMHasher test set. 10 is a perfect score. -A 64-bits version, named XXH64, is available since r35. -It offers much better speed, but for 64-bits applications only. +A 64-bit version, named XXH64, is available since r35. +It offers much better speed, but for 64-bit applications only. Name Speed on 64 bits Speed on 32 bits XXH64 13.8 GB/s 1.9 GB/s XXH32 6.8 GB/s 6.0 GB/s @@ -80,18 +80,19 @@ typedef enum { XXH_OK=0, XXH_ERROR } XXH_errorcode; /* **************************** -* API modifier -******************************/ -/** XXH_PRIVATE_API -* This is useful to include xxhash functions in `static` mode -* in order to inline them, and remove their symbol from the public list. -* Methodology : -* #define XXH_PRIVATE_API -* #include "xxhash.h" -* `xxhash.c` is automatically included. -* It's not useful to compile and link it as a separate module. -*/ -#ifdef XXH_PRIVATE_API + * API modifier + ******************************/ +/** XXH_INLINE_ALL (and XXH_PRIVATE_API) + * This is useful to include xxhash functions in `static` mode + * in order to inline them, and remove their symbol from the public list. + * Inlining can offer dramatic performance improvement on small keys. + * Methodology : + * #define XXH_INLINE_ALL + * #include "xxhash.h" + * `xxhash.c` is automatically included. + * It's not useful to compile and link it as a separate module. + */ +#if defined(XXH_INLINE_ALL) || defined(XXH_PRIVATE_API) # ifndef XXH_STATIC_LINKING_ONLY # define XXH_STATIC_LINKING_ONLY # endif @@ -102,23 +103,24 @@ typedef enum { XXH_OK=0, XXH_ERROR } XXH_errorcode; # elif defined(_MSC_VER) # define XXH_PUBLIC_API static __inline # else -# define XXH_PUBLIC_API static /* this version may generate warnings for unused static functions; disable the relevant warning */ + /* this version may generate warnings for unused static functions */ +# define XXH_PUBLIC_API static # endif #else # define XXH_PUBLIC_API /* do nothing */ -#endif /* XXH_PRIVATE_API */ - -/*!XXH_NAMESPACE, aka Namespace Emulation : - -If you want to include _and expose_ xxHash functions from within your own library, -but also want to avoid symbol collisions with other libraries which may also include xxHash, - -you can use XXH_NAMESPACE, to automatically prefix any public symbol from xxhash library -with the value of XXH_NAMESPACE (therefore, avoid NULL and numeric values). - -Note that no change is required within the calling program as long as it includes `xxhash.h` : -regular symbol name will be automatically translated by this header. -*/ +#endif /* XXH_INLINE_ALL || XXH_PRIVATE_API */ + +/*! XXH_NAMESPACE, aka Namespace Emulation : + * + * If you want to include _and expose_ xxHash functions from within your own library, + * but also want to avoid symbol collisions with other libraries which may also include xxHash, + * + * you can use XXH_NAMESPACE, to automatically prefix any public symbol from xxhash library + * with the value of XXH_NAMESPACE (therefore, avoid NULL and numeric values). + * + * Note that no change is required within the calling program as long as it includes `xxhash.h` : + * regular symbol name will be automatically translated by this header. + */ #ifdef XXH_NAMESPACE # define XXH_CAT(A,B) A##B # define XXH_NAME2(A,B) XXH_CAT(A,B) @@ -149,18 +151,18 @@ regular symbol name will be automatically translated by this header. ***************************************/ #define XXH_VERSION_MAJOR 0 #define XXH_VERSION_MINOR 6 -#define XXH_VERSION_RELEASE 2 +#define XXH_VERSION_RELEASE 5 #define XXH_VERSION_NUMBER (XXH_VERSION_MAJOR *100*100 + XXH_VERSION_MINOR *100 + XXH_VERSION_RELEASE) XXH_PUBLIC_API unsigned XXH_versionNumber (void); /*-********************************************************************** -* 32-bits hash +* 32-bit hash ************************************************************************/ -typedef unsigned int XXH32_hash_t; +typedef unsigned int XXH32_hash_t; /*! XXH32() : - Calculate the 32-bits hash of sequence "length" bytes stored at memory address "input". + Calculate the 32-bit hash of sequence "length" bytes stored at memory address "input". The memory between input & input+length must be valid (allocated and read-accessible). "seed" can be used to alter the result predictably. Speed on Core 2 Duo @ 3 GHz (single thread, SMHasher benchmark) : 5.4 GB/s */ @@ -177,26 +179,25 @@ XXH_PUBLIC_API XXH_errorcode XXH32_update (XXH32_state_t* statePtr, const void* XXH_PUBLIC_API XXH32_hash_t XXH32_digest (const XXH32_state_t* statePtr); /* -These functions generate the xxHash of an input provided in multiple segments. -Note that, for small input, they are slower than single-call functions, due to state management. -For small input, prefer `XXH32()` and `XXH64()` . - -XXH state must first be allocated, using XXH*_createState() . - -Start a new hash by initializing state with a seed, using XXH*_reset(). - -Then, feed the hash state by calling XXH*_update() as many times as necessary. -Obviously, input must be allocated and read accessible. -The function returns an error code, with 0 meaning OK, and any other value meaning there is an error. - -Finally, a hash value can be produced anytime, by using XXH*_digest(). -This function returns the nn-bits hash as an int or long long. - -It's still possible to continue inserting input into the hash state after a digest, -and generate some new hashes later on, by calling again XXH*_digest(). - -When done, free XXH state space if it was allocated dynamically. -*/ + * Streaming functions generate the xxHash of an input provided in multiple segments. + * Note that, for small input, they are slower than single-call functions, due to state management. + * For small inputs, prefer `XXH32()` and `XXH64()`, which are better optimized. + * + * XXH state must first be allocated, using XXH*_createState() . + * + * Start a new hash by initializing state with a seed, using XXH*_reset(). + * + * Then, feed the hash state by calling XXH*_update() as many times as necessary. + * The function returns an error code, with 0 meaning OK, and any other value meaning there is an error. + * + * Finally, a hash value can be produced anytime, by using XXH*_digest(). + * This function returns the nn-bits hash as an int or long long. + * + * It's still possible to continue inserting input into the hash state after a digest, + * and generate some new hashes later on, by calling again XXH*_digest(). + * + * When done, free XXH state space if it was allocated dynamically. + */ /*====== Canonical representation ======*/ @@ -205,22 +206,22 @@ XXH_PUBLIC_API void XXH32_canonicalFromHash(XXH32_canonical_t* dst, XXH32_hash_t XXH_PUBLIC_API XXH32_hash_t XXH32_hashFromCanonical(const XXH32_canonical_t* src); /* Default result type for XXH functions are primitive unsigned 32 and 64 bits. -* The canonical representation uses human-readable write convention, aka big-endian (large digits first). -* These functions allow transformation of hash result into and from its canonical format. -* This way, hash values can be written into a file / memory, and remain comparable on different systems and programs. -*/ + * The canonical representation uses human-readable write convention, aka big-endian (large digits first). + * These functions allow transformation of hash result into and from its canonical format. + * This way, hash values can be written into a file / memory, and remain comparable on different systems and programs. + */ #ifndef XXH_NO_LONG_LONG /*-********************************************************************** -* 64-bits hash +* 64-bit hash ************************************************************************/ typedef unsigned long long XXH64_hash_t; /*! XXH64() : - Calculate the 64-bits hash of sequence of length "len" stored at memory address "input". + Calculate the 64-bit hash of sequence of length "len" stored at memory address "input". "seed" can be used to alter the result predictably. - This function runs faster on 64-bits systems, but slower on 32-bits systems (see benchmark). + This function runs faster on 64-bit systems, but slower on 32-bit systems (see benchmark). */ XXH_PUBLIC_API XXH64_hash_t XXH64 (const void* input, size_t length, unsigned long long seed); @@ -241,48 +242,82 @@ XXH_PUBLIC_API XXH64_hash_t XXH64_hashFromCanonical(const XXH64_canonical_t* src #endif /* XXH_NO_LONG_LONG */ + #ifdef XXH_STATIC_LINKING_ONLY /* ================================================================================================ - This section contains definitions which are not guaranteed to remain stable. + This section contains declarations which are not guaranteed to remain stable. They may change in future versions, becoming incompatible with a different version of the library. - They shall only be used with static linking. - Never use these definitions in association with dynamic linking ! + These declarations should only be used with static linking. + Never use them in association with dynamic linking ! =================================================================================================== */ -/* These definitions are only meant to allow allocation of XXH state - statically, on stack, or in a struct for example. - Do not use members directly. */ - - struct XXH32_state_s { - unsigned total_len_32; - unsigned large_len; - unsigned v1; - unsigned v2; - unsigned v3; - unsigned v4; - unsigned mem32[4]; /* buffer defined as U32 for alignment */ - unsigned memsize; - unsigned reserved; /* never read nor write, will be removed in a future version */ - }; /* typedef'd to XXH32_state_t */ - -#ifndef XXH_NO_LONG_LONG - struct XXH64_state_s { - unsigned long long total_len; - unsigned long long v1; - unsigned long long v2; - unsigned long long v3; - unsigned long long v4; - unsigned long long mem64[4]; /* buffer defined as U64 for alignment */ - unsigned memsize; - unsigned reserved[2]; /* never read nor write, will be removed in a future version */ - }; /* typedef'd to XXH64_state_t */ +/* These definitions are only present to allow + * static allocation of XXH state, on stack or in a struct for example. + * Never **ever** use members directly. */ + +#if !defined (__VMS) \ + && (defined (__cplusplus) \ + || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) ) +# include <stdint.h> + +struct XXH32_state_s { + uint32_t total_len_32; + uint32_t large_len; + uint32_t v1; + uint32_t v2; + uint32_t v3; + uint32_t v4; + uint32_t mem32[4]; + uint32_t memsize; + uint32_t reserved; /* never read nor write, might be removed in a future version */ +}; /* typedef'd to XXH32_state_t */ + +struct XXH64_state_s { + uint64_t total_len; + uint64_t v1; + uint64_t v2; + uint64_t v3; + uint64_t v4; + uint64_t mem64[4]; + uint32_t memsize; + uint32_t reserved[2]; /* never read nor write, might be removed in a future version */ +}; /* typedef'd to XXH64_state_t */ + +# else + +struct XXH32_state_s { + unsigned total_len_32; + unsigned large_len; + unsigned v1; + unsigned v2; + unsigned v3; + unsigned v4; + unsigned mem32[4]; + unsigned memsize; + unsigned reserved; /* never read nor write, might be removed in a future version */ +}; /* typedef'd to XXH32_state_t */ + +# ifndef XXH_NO_LONG_LONG /* remove 64-bit support */ +struct XXH64_state_s { + unsigned long long total_len; + unsigned long long v1; + unsigned long long v2; + unsigned long long v3; + unsigned long long v4; + unsigned long long mem64[4]; + unsigned memsize; + unsigned reserved[2]; /* never read nor write, might be removed in a future version */ +}; /* typedef'd to XXH64_state_t */ +# endif + +# endif + + +#if defined(XXH_INLINE_ALL) || defined(XXH_PRIVATE_API) +# include "xxhash.c" /* include xxhash function bodies as `static`, for inlining */ #endif -# ifdef XXH_PRIVATE_API -# include "xxhash.c" /* include xxhash function bodies as `static`, for inlining */ -# endif - #endif /* XXH_STATIC_LINKING_ONLY */ |