Fuego Core XML Diff and Patch Tool

The Fuego Core XML Diff and Patch tool is a fast and memory-efficient general-purpose tool for diffing and patching XML files. The underlying algorithms have been described in T. Lindholm, J. Kangasharju, and S. Tarkoma: Fast and Simple XML Tree Differencing by Sequence Alignment, Proceedings of ACM DocEng 2006. acm.org hiit.fi.

The source code for the tool is released under the permissive MIT license News

• June 26, 2009: Project reincarnated at code.google.com after hoslab.cs.helsinki.fi was shut down

• March 25, 2009: Improved output of namespace prefixes by moving them to the root node. Also, the XAS parser now supports setting the text buffer size with the org.kxml2.io.textbuffer property. Try this if you are getting parse errors on documents with large attributes. Note: you'll need to build the fc-xas project and replace trunk/java/xmldiff/contrib/fc-xas-0.1.0.jar with the generated fc-xas.jar in order to pick up the text buffer size.

Installation from Source

At this point, we only provide source-based installation from the Subversion repository. Sorry. We're looking into providing more straightforward methods, such as a downloadable binary. Please request an alternate method if you find that you'll need one.

To install the tool using the subversion repository, proceed as follows.

1. Make sure you have Subversion, a Java Development Kit (>=version 1.6), and Apache Ant (>=1.7, older ones may work) installed. In Debian based-distributions, make sure the package ant-optional is installed.
2. Check out the sources using Subversion:

      svn checkout http://fc-xmldiff.googlecode.com/svn/trunk/ fc-xmldiff-read-only

3. Then in the checked out director (fc-xmldiff-read-only with the command above),

      cd java/xmldiff

4. Run ant to get instructions on how to proceed project setup. The project setup should download all dependencies automatically.

      ant

5. After project setup is completed, invoke (again)

      ant

to compile the sources.

Diffing XML

The easiest way to get the diff between the files old.xml and new.xml into diff.xml is to invoke the diff Ant task:

ant -Dbase=old.xml -Dnew=new.xml -Ddiff=diff.xml diff

Naturally, you may invoke the tool using java directly with the appropriate classpath. For instance,

java -Djava.ext.dirs=../contrib/jar:contrib -cp =build/lib/xmldiff.jar fc.xml.diff.Diff old.xml new.xml diff.xml

Patching XML

As for diffing, their is an Ant target for patching. To patch old.xml with diff.xml to get new.xml, you run

ant -Dbase=old.xml -Ddiff=diff.xml -Dnew=new.xml patch

As in the previous case, direct invocation can also be used. In this case the main class is fc.xml.diff.Patch