Publisher API

The Publisher API builds and processes messages that allow users to publish data in a standard format.

The Publisher API is provided as a dynamically linked shared library. The shared library allows developers to compile a feed handler using any C or C++ compiler supported for their environment.

Market data feed handlers invoke the Publisher API.

Subscribers must be running before the publisher is started so that the subscribers are ready to receive messages when the publisher sends them.

If multiple publishers are running, each instance must use a unique UDP broadcast address.

Note: The term function is sometimes used in this document to refer to the Publisher API methods.

Reentrant Code and the Shared Library

The shared library (libpublisher.so) supports one thread per message context. It is thread-safe in the context of a program running multiple messages with one thread per message context. However, you cannot have one message context with multiple threads.

Initialization
The initialization method performs various operations to start the publication mechanism.
Functions to Send Messages
Sending messages requires a pub_beginMessage function, which signals the start of a new message, and a pub_sendMessage function, which places messages into the network buffer.
Error Codes
The Error codes table defines error codes.
Publisher API Data Structures
Publisher API data structures hold information for callbacks, initialization, and market data messages.
Methods
Feed handlers invoke the publisher API to build and process messages.
Logging
RAP uses log4cxx version 0.10.0, an open source logging API, to log events in publishers and subscribers.