Libx xxHash

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    Data Structures

    struct  XXH64_canonical_t
     Canonical (big endian) representation of XXH64_hash_t. More...

    Typedefs

    typedef struct XXH64_state_s XXH64_state_t
     The opaque state struct for the XXH64 streaming API.

    Functions

    XXH64_hash_t XXH64 (const void *input, size_t length, XXH64_hash_t seed)
     Calculates the 64-bit hash of input using xxHash64.
    XXH64_state_t * XXH64_createState (void)
     Allocates an XXH64_state_t.
    XXH_errorcode XXH64_freeState (XXH64_state_t *statePtr)
     Frees an XXH64_state_t.
    void XXH64_copyState (XXH64_state_t *dst_state, const XXH64_state_t *src_state)
     Copies one XXH64_state_t to another.
    XXH_errorcode XXH64_reset (XXH64_state_t *statePtr, XXH64_hash_t seed)
     Resets an XXH64_state_t to begin a new hash.
    XXH_errorcode XXH64_update (XXH64_state_t *statePtr, const void *input, size_t length)
     Consumes a block of input to an XXH64_state_t.
    XXH64_hash_t XXH64_digest (const XXH64_state_t *statePtr)
     Returns the calculated hash value from an XXH64_state_t.
    void XXH64_canonicalFromHash (XXH64_canonical_t *dst, XXH64_hash_t hash)
     Converts an XXH64_hash_t to a big endian XXH64_canonical_t.
    XXH64_hash_t XXH64_hashFromCanonical (const XXH64_canonical_t *src)
     Converts an XXH64_canonical_t to a native XXH64_hash_t.

    Detailed Description

    Contains functions used in the classic 64-bit xxHash algorithm.

    Note
    XXH3 provides competitive speed for both 32-bit and 64-bit systems, and offers true 64/128 bit hash results. It provides better speed for systems with vector processing capabilities.

    Typedef Documentation

    ◆ XXH64_state_t

    typedef struct XXH64_state_s XXH64_state_t

    The opaque state struct for the XXH64 streaming API.

    See also
    XXH64_state_s for details.
    Streaming Example

    Function Documentation

    ◆ XXH64()

    XXH64_hash_t XXH64 ( const void * input,
    size_t length,
    XXH64_hash_t seed )

    Calculates the 64-bit hash of input using xxHash64.

    Parameters
    inputThe block of data to be hashed, at least length bytes in size.
    lengthThe length of input, in bytes.
    seedThe 64-bit seed to alter the hash's output predictably.
    Precondition
    The memory between input and input + length must be valid, readable, contiguous memory. However, if length is 0, input may be NULL. In C++, this also must be TriviallyCopyable.
    Returns
    The calculated 64-bit xxHash64 value.
    See also
    Single Shot Example for an example.

    ◆ XXH64_createState()

    XXH64_state_t * XXH64_createState ( void )

    Allocates an XXH64_state_t.

    Returns
    An allocated pointer of XXH64_state_t on success.
    NULL on failure.
    Note
    Must be freed with XXH64_freeState().
    See also
    Streaming Example

    ◆ XXH64_freeState()

    XXH_errorcode XXH64_freeState ( XXH64_state_t * statePtr)

    Frees an XXH64_state_t.

    Parameters
    statePtrA pointer to an XXH64_state_t allocated with XXH64_createState().
    Returns
    XXH_OK.
    Note
    statePtr must be allocated with XXH64_createState().
    See also
    Streaming Example

    ◆ XXH64_copyState()

    void XXH64_copyState ( XXH64_state_t * dst_state,
    const XXH64_state_t * src_state )

    Copies one XXH64_state_t to another.

    Parameters
    dst_stateThe state to copy to.
    src_stateThe state to copy from.
    Precondition
    dst_state and src_state must not be NULL and must not overlap.

    ◆ XXH64_reset()

    XXH_errorcode XXH64_reset ( XXH64_state_t * statePtr,
    XXH64_hash_t seed )

    Resets an XXH64_state_t to begin a new hash.

    Parameters
    statePtrThe state struct to reset.
    seedThe 64-bit seed to alter the hash result predictably.
    Precondition
    statePtr must not be NULL.
    Returns
    XXH_OK on success.
    XXH_ERROR on failure.
    Note
    This function resets and seeds a state. Call it before XXH64_update().
    See also
    Streaming Example

    ◆ XXH64_update()

    XXH_errorcode XXH64_update ( XXH64_state_t * statePtr,
    const void * input,
    size_t length )

    Consumes a block of input to an XXH64_state_t.

    Parameters
    statePtrThe state struct to update.
    inputThe block of data to be hashed, at least length bytes in size.
    lengthThe length of input, in bytes.
    Precondition
    statePtr must not be NULL.
    The memory between input and input + length must be valid, readable, contiguous memory. However, if length is 0, input may be NULL. In C++, this also must be TriviallyCopyable.
    Returns
    XXH_OK on success.
    XXH_ERROR on failure.
    Note
    Call this to incrementally consume blocks of data.
    See also
    Streaming Example

    ◆ XXH64_digest()

    XXH64_hash_t XXH64_digest ( const XXH64_state_t * statePtr)

    Returns the calculated hash value from an XXH64_state_t.

    Parameters
    statePtrThe state struct to calculate the hash from.
    Precondition
    statePtr must not be NULL.
    Returns
    The calculated 64-bit xxHash64 value from that state.
    Note
    Calling XXH64_digest() will not affect statePtr, so you can update, digest, and update again.
    See also
    Streaming Example

    ◆ XXH64_canonicalFromHash()

    void XXH64_canonicalFromHash ( XXH64_canonical_t * dst,
    XXH64_hash_t hash )

    Converts an XXH64_hash_t to a big endian XXH64_canonical_t.

    Parameters
    dstThe XXH64_canonical_t pointer to be stored to.
    hashThe XXH64_hash_t to be converted.
    Precondition
    dst must not be NULL.
    See also
    Canonical Representation Example

    ◆ XXH64_hashFromCanonical()

    XXH64_hash_t XXH64_hashFromCanonical ( const XXH64_canonical_t * src)

    Converts an XXH64_canonical_t to a native XXH64_hash_t.

    Parameters
    srcThe XXH64_canonical_t to convert.
    Precondition
    src must not be NULL.
    Returns
    The converted hash.
    See also
    Canonical Representation Example