textproc/libxdiff 0.23_2 DragonFly

The LibXDiff library implements basic and yet complete functionalities to create file differences/patches to both binary and text files. The library uses memory files as file abstraction to achieve both performance and portability. For binary files, LibXDiff implements (with some modification) the algorithm described in File System Support for Delta Compression by Joshua P. MacDonald, while for text files it follows directives described in An O(ND) Difference Algorithm and Its Variations by Eugene W. Myers. Memory files used by the library are basically a collection of buffers that store the file content. There are two different requirements for memory files when passed to diff/patch functions. Text files for diff/patch functions require that a single line do not have to spawn across two different memory file blocks. Binary diff/patch functions require memory files to be compact. A compact memory files is a file whose content is stored inside a single block.