README

Protocol

Description

The PHPMQ message protocol

Installation

composer require php-mq/protocol

Usage

Message headers

Each message sent from a client to the endpoint must have a leading header line which defines:

A flag that identifies the line as message header
A number that identifies the version of the message protocol
The type of the message (see message types) (3 bytes)
The number of the following packages (see packet types)

Example:

H0100102

means:

PACKET-ID | VERSION | MSG-TYPE | PACKAGE COUNT
        H |      01 |      001 |            02

So a header always has a length of 8 byte.

Message types

001 - Client sends a message (client to server)
002 - Client wants to consume messages (consume request)
003 - Server dispatches a message (server to client)
004 - Client acknowledges a message (acknowledgement)
005 - Client wants to re-queue a message (pop from queue, append to queue)
006 - Client sends a dead letter for a message (remove message from queue)

Packet headers

Each data package in a message is preceded by a package header with defines:

A flag that identifies the line as package header
A number that identifies the package type
The length of the following package content

Example:

P01000000000000000000000000000000256

means:

PACKET-ID | PKG-TYPE | CONTENT-LENGTH (as int)
        P |       01 |                     256

So a package header always has a length of 32 byte.

Please note: The content length has a length of 32 bytes and is filled up with zeros.

Packet types

All

PKG-Type	Meaning
01	Queue name
02	Message content
03	Message ID
04	Count of message for consumption
05	Time to live of message (TTL)

For messages from client to endpoint

01 - Queue name
02 - Message content
05 - Message TTL

For messages from endpoint to client

01 - Queue name
02 - Message content
03 - Message ID
05 - Message TTL

For Consumption

01 - Queue name
04 - Count of messages the client wants to consume from the queue

For message acknowledgment

01 - Queue name
03 - Message ID

For message re-queue

01 - Queue name
03 - Message ID
05 - Message TTL

For dead letter

01 - Queue name
03 - Message ID

Full message examples

Send a message

Client sends a new message with content "Hello World" for queue "Foo" to server with a TTL of 3600 seconds.

H0100103
P0100000000000000000000000000003
Foo
P0200000000000000000000000000011
Hello World
P0500000000000000000000000000004
3600

Consume messages

Client wants to consume 5 messages from queue "Foo".

H0100202
P0100000000000000000000000000003
Foo
P0400000000000000000000000000001
5

Dispatch a message

Server sends the message above to the client 300 seconds later.

H0100304
P0100000000000000000000000000003
Foo
P0200000000000000000000000000011
Hello World
P0300000000000000000000000000032
d7e7f68761d34838494b233148b5486c
P0500000000000000000000000000004
3300

Note: TTL was reduced to 3300 seconds.

Acknowledge a message

Client acknowledges the consumed message with ID d7e7f68761d34838494b233148b5486c.

H0100402
P0100000000000000000000000000003
Foo
P0300000000000000000000000000032
d7e7f68761d34838494b233148b5486c

Re-queue a message

Client wants the message to be re-queued at the end of the queue, with a new TTL of 3600 seconds.

H0100503
P0100000000000000000000000000003
Foo
P0300000000000000000000000000032
d7e7f68761d34838494b233148b5486c
P0500000000000000000000000000004
3600

Send a dead letter

Client wants the message to be removed from queue, regardless its TTL

H0100602
P0100000000000000000000000000003
Foo
P0300000000000000000000000000032
d7e7f68761d34838494b233148b5486c

Contributing

Contributions are welcome and will be fully credited. Please see the contribution guide for details.

php-mq / protocol

Maintainers

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