v/vlib/hash/fnv1a/fnv1a.v

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module fnv1a
// This module implements a FNV-1a hash.
// (see https://en.wikipedia.org/wiki/FowlerNollVo_hash_function)
const (
fnv64_prime = u64(1099511628211)
fnv64_offset_basis = u64(14695981039346656037)
fnv32_offset_basis = u32(2166136261)
fnv32_prime = u32(16777619)
)
// sum32 returns a fnv1a hash of the string, described by `data`
[direct_array_access; inline]
pub fn sum32_string(data string) u32 {
mut hash := fnv1a.fnv32_offset_basis
for i in 0 .. data.len {
hash = (hash ^ u32(data[i])) * fnv1a.fnv32_prime
}
return hash
}
// sum32 returns a fnv1a hash of the memory block, described by the dynamic
// byte array `data`.
[direct_array_access; inline]
pub fn sum32(data []byte) u32 {
mut hash := fnv1a.fnv32_offset_basis
for i in 0 .. data.len {
hash = (hash ^ u32(data[i])) * fnv1a.fnv32_prime
}
return hash
}
// sum32_bytes returns a fnv1a hash of the struct `s`.
[direct_array_access; inline]
pub fn sum32_struct<T>(s &T) u32 {
bp := unsafe { &byte(s) }
sz := int(sizeof(T))
mut hash := fnv1a.fnv32_offset_basis
for i in 0 .. sz {
hash = unsafe { (hash ^ u32(bp[i])) * fnv1a.fnv32_prime }
}
return hash
}
// sum32_bytes returns a fnv1a hash of `data_len` bytes starting at
// the address in the given &byte pointer `data`.
[direct_array_access; inline; unsafe]
pub fn sum32_bytes(data &byte, data_len int) u32 {
mut hash := fnv1a.fnv32_offset_basis
for i in 0 .. data_len {
hash = unsafe { (hash ^ u32(data[i])) * fnv1a.fnv32_prime }
}
return hash
}
// sum64 returns a fnv1a hash of the string, described by `data`
[direct_array_access; inline]
pub fn sum64_string(data string) u64 {
mut hash := fnv1a.fnv64_offset_basis
for i in 0 .. data.len {
hash = (hash ^ u64(data[i])) * fnv1a.fnv64_prime
}
return hash
}
// sum64 returns a fnv1a hash of the memory block, described by the dynamic
// byte array `data`.
[direct_array_access; inline]
pub fn sum64(data []byte) u64 {
mut hash := fnv1a.fnv64_offset_basis
for i in 0 .. data.len {
hash = (hash ^ u64(data[i])) * fnv1a.fnv64_prime
}
return hash
}
// sum64_bytes returns a fnv1a hash of `data_len` bytes starting at
// the address in the given &byte pointer `data`.
[direct_array_access; inline; unsafe]
pub fn sum64_bytes(data &byte, data_len int) u64 {
mut hash := fnv1a.fnv64_offset_basis
for i in 0 .. data_len {
hash = unsafe { (hash ^ u64(data[i])) * fnv1a.fnv64_prime }
}
return hash
}
// sum64_bytes returns a fnv1a hash of the struct `s`.
[direct_array_access; inline]
pub fn sum64_struct<T>(s &T) u64 {
bp := unsafe { &byte(s) }
sz := int(sizeof(T))
mut hash := fnv1a.fnv64_offset_basis
for i in 0 .. sz {
hash = unsafe { (hash ^ u64(bp[i])) * fnv1a.fnv64_prime }
}
return hash
}