| open-vcdiff is an encoder and decoder for the VCDIFF format, as described in |
| RFC 3284 : The VCDIFF Generic Differencing and Compression Data Format |
| (http://www.ietf.org/rfc/rfc3284.txt) |
| |
| 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: |
| https://github.com/google/open-vcdiff/wiki/How-to-use-openvcdiff |
| |
| open-vcdiff comes with a CMake build script CMakeLists.txt that can be used on |
| a wide range of platforms ("C" stands for cross-platform.). If you don't have |
| CMake installed already, you can download it for free from |
| <http://www.cmake.org/>. |
| |
| CMake works by generating native makefiles or build projects that can |
| be used in the compiler environment of your choice. The typical |
| workflow starts with: |
| |
| mkdir mybuild # Create a directory to hold the build output. |
| cd mybuild |
| cmake ${OPEN_VCDIFF_DIR} # Generate native build scripts. |
| |
| If you want to disable build of build tests and/or executable and build |
| libraries only replace last command with |
| |
| cmake -Dvcdiff_build_test=OFF -Dvcdiff_build_exec=OFF ${OPEN_VCDIFF_DIR} |
| |
| If you are on a \*nix system, you should now see a Makefile in the |
| current directory. Just type 'make' to build gtest. |
| |
| If you use Windows and have Visual Studio installed, a `gtest.sln` file |
| and several `.vcproj` files will be created. You can then build them |
| using Visual Studio. |
| |
| On Mac OS X with Xcode installed, a `.xcodeproj` file will be generated. |
| |
| After compilation you should have 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 run tests just use `make test` inside build directory. |
| |
| 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: |
| https://github.com/google/open-vcdiff/wiki/How-to-use-openvcdiff |