The DSI utilities are a mish mash of classes accumulated during the last ten years in projects developed at the former DSI (Dipartimento di Scienze dell'Informazione, i.e., Information Sciences Department), now DI (Dipartimento di Informatica, i.e., Informatics Department) of the Università degli Studi di Milano. They were originally distributed in several projects (mainly in MG4J) but we finally decided to gather all the material in a single place.

The DSI utilities are free software distributed under either the GNU Lesser General Public License 2.1+ or the Apache Software License 2.0.

Highlights

The implementations available are a bit eclectic due to the particular kind of applications we developed. Very broadly, we have:

• Implementations of pseudorandom number generators. See the package documentation for details.
• BitVector and its implementations—a high-performance but flexible set of bit vector classes.
• A it.unimi.dsi.compression package containing codecs for several types of encodings.
• ProgressLogger, a flexible logger with statistics marking the progress of the (many) classes we use that require hours of computation.
• ObjectParser, a class making it easy to specify complex objects on the command line.
• MutableString, our answer to the Java String class.
• The I/O package, containing fast version of several classes existing in java.io, many useful classes to read easily text data (e.g., FileLinesMutableStringIterable), bit streams, classes providing large-size memory mapping such as ByteBufferInputStream, and OfflineIterable—the easy & fast way to store large sequences of objects on disk and iterate on them.
• The it.unimi.dsi.util package, containing tries, immutable prefix maps, Bloom filters, a very comfortable Properties class and more.
• The it.unimi.dsi.stat package, containing a lightweight class for computing basic statistics and an arbitrary-precision implementation of the Jackknife method.
• Lots of utility methods in Util (have a look!)
• MappedFrontCodedStringBigList, which provides compact memory-mapped storage of strings, possibly with some compression.
• Big versions of I/O and utility classes in it.unimi.dsi.big.io and it.unimi.dsi.big.util.

Packages

Package	Description
it.unimi.dsi	General utilities
it.unimi.dsi.big.io	I/O big classes
it.unimi.dsi.big.util	Collections and similar big classes
it.unimi.dsi.bits	Main classes manipulating bits
it.unimi.dsi.compression	Word-based compression/decompression classes
it.unimi.dsi.io	I/O classes
it.unimi.dsi.lang	Basic classes
it.unimi.dsi.logging	Logging classes
it.unimi.dsi.parser	A fast, lightweight, on-demand (X)HTML parser
it.unimi.dsi.parser.callback	Callbacks for the BulletParser
it.unimi.dsi.stat	Statistics classes
it.unimi.dsi.util	Miscellaneous utility classes
it.unimi.dsi.util.concurrent	Concurrent data structures