open-vcdiff is an encoder and decoder for the VCDIFF format, as described in RFC 3284: The VCDIFF Generic Differencing and Compression Data Format.
You will need to first synchronize gflags and gtest by running ./fetch_prereq.bat
on Windows or ./fetch_prereq.sh
on other platforms.
A library with a simple API is included, as well as a command-line executable that can apply the encoder and decoder to source, target, and delta files. For further details, please refer to this link.
See INSTALL for (generic) installation instructions for C++: basically
./configure && make && make install
This should compile the unit tests as well as vcdiff
, a simple command-line utility to run the encoder and decoder. Typical usage of vcdiff is as follows (the <
and >
are file redirect operations, not optional arguments):
vcdiff encode -dictionary file.dict < target_file > delta_file vcdiff decode -dictionary file.dict < delta_file > target_file
To see the command-line syntax of vcdiff, use vcdiff --help
or just vcdiff
.
To call the encoder from C++ code, assuming that dictionary, target, and delta are all std::string
objects:
#include <google/vcencoder.h> // Read this file for interface details // [...] open_vcdiff::VCDiffEncoder encoder(dictionary.data(), dictionary.size()); encoder.SetFormatFlags(open_vcdiff::VCD_FORMAT_INTERLEAVED); encoder.Encode(target.data(), target.size(), &delta);
Calling the decoder is just as simple:
#include <google/vcdecoder.h> // Read this file for interface details // [...] open_vcdiff::VCDiffDecoder decoder; decoder.Decode(dictionary.data(), dictionary.size(), delta, &target);
When using the encoder, the C++ application must be linked with the library options -lvcdcom
and -lvcdenc
; when using the decoder, it must be linked with -lvcdcom
and -lvcddec
.
To verify that the package works on your system, especially after making modifications to the source code, please run the unit tests using make check
.
For further details, please refer to this link.