Book Image

Clojure High Performance Programming

By : Shantanu Kumar
Book Image

Clojure High Performance Programming

By: Shantanu Kumar

Overview of this book

<p>Clojure is a young, dynamic, functional programming language that runs on the Java Virtual Machine. It is built with performance, pragmatism, and simplicity in mind. Like most general purpose languages, Clojure’s features have different performance characteristics that one should know in order to write high performance code.<br /><br />Clojure High Performance Programming is a practical, to-the-point guide that shows you how to evaluate the performance implications of different Clojure abstractions, learn about their underpinnings, and apply the right approach for optimum performance in real-world programs.<br /><br />This book discusses the Clojure language in the light of performance factors that you can exploit in your own code.</p> <p>You will also learn about hardware and JVM internals that also impact Clojure’s performance. Key features include performance vocabulary, performance analysis, optimization techniques, and how to apply these to your programs. You will also find detailed information on Clojure's concurrency, state-management, and parallelization primitives.</p> <p>This book is your key to writing high performance Clojure code using the right abstraction, in the right place, using the right technique.</p>
Table of Contents (15 chapters)
Clojure High Performance Programming
Credits
About the Author
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Index

Resorting to Java and native code


In a handful of cases, where the lack of imperative, stack-based, mutable variables in Clojure may make the code not perform as well as Java, we may need to evaluate alternatives to make it faster. I would advise that you consider writing such code directly in Java for better performance.

Another consideration is to use native OS capabilities, such as memory-mapped buffers (http://docs.oracle.com/javase/7/docs/api/java/nio/MappedByteBuffer.html) or files and unsafe operations (http://highlyscalable.wordpress.com/2012/02/02/direct-memory-access-in-java/). Note that unsafe operations are potentially hazardous and are not recommended in general. Such times are also an opportunity to consider writing performance-critical pieces of code in C or C++ and accessing them via Java Native Interface (JNI).

Proteus – mutable locals in Clojure

Proteus is an open source Clojure library that lets you treat a local like a local variable, thereby allowing its unsynchronized...