sgsfak / http_msg

README

This is a C++ messaging library using channels as the underlying abstraction. There are two types of channels:

• An OutChannel is for output. It has a single put method for sending some data to the channel. This method returns immediately.

• An InChannel is for input. You can only "read" from these channels, using the get or the try_get methods. get is blocking i.e. if there's nothing to be read from this channle, the calling program waits indefinitely, until there's something to be retreived from the channel.

An output channel is usually connected to an input channel by using the same "communication identifier". Under the hood this id is used to identify the message queue in the message broker component that delivers messages.

How do I get set up?

The library requires QDB as the message broker receiving and dispatching the messages.

Examples

There are some examples in the examples folder...

Example: two "hypomodels" interacting in a master-worker fashion

Check the oncosim.cpp (producing the os executable) and the biomechanics.cpp (producing the bm executable). The os is a complex "model" that has some initial state, working in a time-driven loop (per hour iteration), that needs to communicate with the bm model. The bm model is the "worker" waiting for some request, computing some results that are sent back to "master" i.e. the os. The communication is implemented using the library with the qdb message broker behind the scenes. A typical execution script is the following:

• Start the qdb message broker and create a foo queue :

  curl http://127.0.0.1:9554/q/foo -d maxSize=10g

• Start the "master" providing the tumor radius, the simulation time in hours, the input and the output channel:

  ./os 100 96 bm-to-os os-to-bm

• Start the "worker" providing the input and the output channel in the reverse order so that the input of os is the output of bm and vice versa:

  ./bm os-to-bm bm-to-os