NAME
Protocol::Gearman - wire protocol support functions for Gearman
DESCRIPTION
This module provides the low-level functions required to implement a Gearman connection (either a client or a worker). It is used primarily by other modules in this distribution; it is not intended to be used directly.
For implementing a Gearman client or worker, see the modules
For a simple synchronous Gearman client or worker module for use during testing or similar, see
CONSTANTS
The following families of constants are defined, along with export tags:
TYPE_* (:types)
The request/response types
FUNCTIONS
( $type, $body ) = parse_packet( $bytes )
Attempts to parse a complete message packet from the given byte string. If it succeeds, it returns the type and data body, as an opaque byte string. If it fails it returns an empty list.
If successful, it will remove the bytes of the packet form the $bytes scalar, which must therefore be mutable.
If the byte string begins with some bytes that are not recognised as the Gearman packet magic for a response, the function will immediately throw an exception before modifying the string.
( $type, $body ) = recv_packet( $fh )
Attempts to read a complete packet from the given filehandle, blocking until it is available. The results are undefined if this function is called on a non-blocking filehandle.
If an IO error happens, an exception is thrown. If the first four bytes read are not recognised as the Gearman packet magic for a response, the function will immediately throw an exception. If either of these conditions happen, the filehandle should be considered no longer valid and should be closed.
$bytes = build_packet( $type, $body )
Returns a byte string containing a complete packet with the given fields.
send_packet( $fh, $type, $body )
Sends a complete packet to the given filehandle. If an IO error happens, an exception is thrown.
( $type, $body ) = pack_packet( $name, @args )
Given a name of a packet type (specified as a string as the name of one of the TYPE_* constants, without the leading TYPE_ prefix; case insignificant) returns the type value and the arguments for the packet packed into a body string. This is intended for passing directly into build_packet or send_packet:
send_packet $fh, pack_packet( SUBMIT_JOB => $func, $id, $arg );( $name, @args ) = unpack_packet( $type, $body )
Given a type code and body string, returns the type name and unpacked arguments from the body. This function is the reverse of pack_packet and is intended to be used on the result of parse_packet or recv_packet:
The returned $name will always be a fully-captialised type name, as one of the TYPE_* constants without the leading TYPE_ prefix.
This is intended for a given/when control block, or dynamic method dispatch:
my ( $name, @args ) = unpack_packet( recv_packet $fh );
$self->${\"handle_$name"}( @args )AUTHOR
Paul Evans <leonerd@leonerd.org.uk>