ltm rule command fasthash

iRule(1)		      BIG-IP TMSH Manual		      iRule(1)



fasthash
       Returns a hash for the specified string.

SYNOPSIS
       fasthash DATA

DESCRIPTION
       fasthash is guaranteed to return a high quality hash of the input as
       quickly as practical. The hash value returned is between 0 and 2^63-1
       inclusive (a positive integer).

       fasthash was added because there are many use cases (ie CARP) which
       need a hash of some value (ie URI) and which were using crc32 (which is
       a bad and slow hash function).

       Note: fasthash does not guarantee to provide the same hash value across
       different BIGIP versions and over BIGIP reboots. Do not use fasthash
       for long term and persistent storage.

       Syntax

       fasthash 

	    * Returns the numeric hash for the specified string

RETURN VALUE
       Returns the numeric hash for the specified string

VALID DURING
EXAMPLES
	when CLIENT_ACCEPTED {
	    set str "hello world"
	    log local0. "hash of $str is [fasthash $str]"
	}

HINTS
SEE ALSO
       crc32

CHANGE LOG
       @BIGIP-11.4.0 --First introduced the command.



BIG-IP				  2017-01-31			      iRule(1)