fhash_fnv Module

A module for Fowler–Noll–Vo (FNV) hashing

Implements the FNV 1a algorithm for 32bit hashes

Supports hashing of: - 32bit integers (scalar & 1D array) - 64bit integers (scalar & 1D array) - character(*), default kind

The lack of unsigned arithmetic in Fortran means that 64bit arithmetic is needed to perform 32bit hashing. Hashes are therefore returned as int64.


Uses


Contents

Interfaces

Functions


Interfaces

public interface fnv_1a

Generic interface to perform hashing

Usage:

 fnv_1a([seed],input)

where input is any of the supported types

  • private pure function fnv_1a_char_scalar(input) result(hash)

    Hash a single default kind character variable

    Arguments

    Type IntentOptional Attributes Name
    character(len=*), intent(in) :: input

    Return Value integer(kind=int64)

  • private pure function fnv_1a_char_scalar_seed(seed, input) result(hash)

    Hash a character(*) string of default kind

    Arguments

    Type IntentOptional Attributes Name
    integer(kind=int64), intent(in) :: seed
    character(len=*), intent(in) :: input

    Return Value integer(kind=int64)

  • private pure function fnv_1a_int32_scalar(input) result(hash)

    Hash a single 32bit integer

    Arguments

    Type IntentOptional Attributes Name
    integer(kind=int32), intent(in) :: input

    Return Value integer(kind=int64)

  • private pure function fnv_1a_int32_scalar_seed(seed, input) result(hash)

    Hash a single 32bit integer with a starting seed

    Arguments

    Type IntentOptional Attributes Name
    integer(kind=int64), intent(in) :: seed
    integer(kind=int32), intent(in) :: input

    Return Value integer(kind=int64)

  • private pure function fnv_1a_int32_1d(input) result(hash)

    Hash a 1D array of 32bit integers

    Arguments

    Type IntentOptional Attributes Name
    integer(kind=int32), intent(in) :: input(:)

    Return Value integer(kind=int64)

  • private pure function fnv_1a_int32_1d_seed(seed, input) result(hash)

    Hash a 1D array of 32bit integers with a starting seed

    Arguments

    Type IntentOptional Attributes Name
    integer(kind=int64), intent(in) :: seed
    integer(kind=int32), intent(in) :: input(:)

    Return Value integer(kind=int64)

  • private pure function fnv_1a_int64_scalar(input) result(hash)

    Hash a single 64bit integer

    Arguments

    Type IntentOptional Attributes Name
    integer(kind=int64), intent(in) :: input

    Return Value integer(kind=int64)

  • private pure function fnv_1a_int64_scalar_seed(seed, input) result(hash)

    Hash a single 64bit integer with a starting seed

    Arguments

    Type IntentOptional Attributes Name
    integer(kind=int64), intent(in) :: seed
    integer(kind=int64), intent(in) :: input

    Return Value integer(kind=int64)

  • private pure function fnv_1a_int64_1d(input) result(hash)

    Hash a 1D array of 64bit integers

    Arguments

    Type IntentOptional Attributes Name
    integer(kind=int64), intent(in) :: input(:)

    Return Value integer(kind=int64)

  • private pure function fnv_1a_int64_1d_seed(seed, input) result(hash)

    Hash a 1D array of 64bit integers with a starting seed

    Arguments

    Type IntentOptional Attributes Name
    integer(kind=int64), intent(in) :: seed
    integer(kind=int64), intent(in) :: input(:)

    Return Value integer(kind=int64)


Functions

public function hash_string(hash_value) result(str)

Help fcn to convert hash to hex representation

Arguments

Type IntentOptional Attributes Name
integer(kind=int64), intent(in) :: hash_value

Return Value character(len=:), allocatable