Welcome to fastutil
fastutil is a collection of type-specific Java classes that extend the Java Collections Framework by providing several containers, such as maps, sets, lists and prority queues, implementing the interfaces of the java.util package; it also provides big (64-bit) arrays, sets, lists, and fast, practical I/O classes for binary and text files.
fastutil provides a huge collection of specialized classes generated starting from a parameterized version; the classes are much more compact and much faster than the general ones. Please read the package documentation for more information.
Since version 8.5.5, fastutil is split into two jars for convenience:
fastutil-core.jarcontains data structures based on integers, longs, doubles, and objects;
fastutil.jaris the classic distribution, containing all classes.
Note that core classes are duplicated in the standard jar, so if you are depending on both (for example, because of transitive dependencies) you should exclude the core jar.
Previous split versions would provide different classes in different jars, but managing sensibly dependencies turned out to be impossible.
You can also create a small, customized fastutil jar (which you can put in
your repo, local maven repo, etc.) using the
find-deps.sh shell script.
It has mild prerequisites, as only the
jdeps tool is required (bundled
with JDK 8). It can be used to identify all fastutil classes your project
uses and build a minimized jar only containing the necessary classes.
First, you have to
make sources to get the actual Java sources.
ant jar will generate a single jar file;
ant javadoc will
generate the API documentation;
ant junit will run the unit tests.
If you want to obtain the three jars above, you have to run the script
split.sh, and then
The Java sources are generated using a C preprocessor. The
script reads in a driver file, that is, a Java source that uses some
preprocessor-defined symbols and some conditional compilation, and produces a
(fake) C source, which includes the driver code and some definitions that
customize the environment.