tag
Hashmaps
- #58 13 min
Fast Topic Matching
A common problem in messaging middleware is that of efficiently matching message topics with interested subscribers. For example, assume we have a set of subscribers, numbered 1 to 3: Subscriber Match Request 1 forex.usd 2 forex.* 3 stock.nasdaq.msft And we have a stream of messages, numbered 1 to N: Message Topic 1 forex.gbp 2 stock.nyse.ibm 3 stock.nyse.ge 4 forex.eur 5 forex.usd … … N stock.nasdaq.msft We are then tasked with routing messages whose topics match the respective subscriber requests, where a “*” wildcard matches any word. This is frequently a bottleneck for message-oriented middleware like ZeroMQ, RabbitMQ, ActiveMQ, TIBCO EMS, et al. Because of this, there are a number of well-known solutions to the problem. In this post, I’ll describe some of these solutions, as well as a novel one, and attempt to quantify them through benchmarking. As usual, the code is available on GitHub.
- #1 8 min
Solving the Referential Integrity Problem
“A man with a watch knows what time it is. A man with two watches is never sure.” I’ve been developing my open source Android framework, Infinitum, for the better part of 10 months now. It has brought about some really interesting problems that I’ve had to tackle, which is one of the many reasons I enjoy working on it so much. Chicken or the Egg Although it’s much more now, Infinitum began as an object-relational mapper which was loosely modeled after Hibernate. One of the first major issues I faced while developing the ORM component was loading object graphs. To illustrate what I mean by this, suppose we’re developing some software for a department store. The domain model for this software might look something like this: