New subroutine for generating a hash code from a string of characters:
xcall HASH, hashtype, key, cbkey, hash, status
hashtype specifies the type of hash to generate. Currently there are only two possibilities: 1=ELF, 2=DJB. ELF is one of the most commonly used hash algorithms in the UNIX world, and is tweaked for 32 bit processors. DJB (named after its creator Dan J. Bernstein) is thought to be one of the most efficient hash algorithms and is thought to work work well on very short keys, but may is considered somewhat weaker then the ELF algorithm (i.e. more likely to generate the same hash from different keys) when it comes to avalanche and permutation.
Parameter |
Type |
I/O |
Description |
|
|---|---|---|---|---|
hashtype |
Num |
in |
1=ELF, 2=DJB. See above |
|
key |
String or X |
in |
the source data from which the hash will be calculated. It can be any length. |
|
cbkey |
Num |
in |
optionally specifies the number of bytes to be considered in key. If 0, key is processed up to the first null byte or its physical length. |
|
hash |
String,8+ or b,4 |
out |
the generated hash. If string (8+ bytes), then it will be returned as 8 hex digits. If b,4, it will be returned as a 32 bit value. |
|
status |
Signed Num |
out |
indicates success or failure: |
|
>=0 |
success |
|||
-1 |
bad key type |
|||
-2 |
bad hash type |
|||
-3 |
bad has data type of size |
|||
