DedupFileSystem is for demonstrating how to integrate external plugins with RocksDB. It depends on libcrypto to show how an external plugin can bring its dependencies into the RocksDB build. It provides a factory function in a header file to show integration with RocksDB header includes. It can also be enabled in text-based options to demonstrate use of the static registration framework.

The code first needs to be linked under RocksDB's "plugin/" directory. In your RocksDB directory, run:

$ pushd ./plugin/
$ git clone https://github.com/ajkr/dedupfs.git

Next, we can build and install RocksDB with this plugin as follows:

$ popd
$ make clean && DEBUG_LEVEL=0 ROCKSDB_PLUGINS="dedupfs" make -j48 db_bench install

For RocksDB binaries (such as the db_bench we built above), the plugin can be enabled through configuration. db_bench in particular takes a --fs_uri where we can specify "dedupfs" , which is the name registered by this plugin. Example usage:

$ ./db_bench --benchmarks=fillrandom --fs_uri=dedupfs --compression_type=none

The plugin's interface is also exposed to applications, which can enable it either through configuration or through code. Here is an example instantiating the plugin in code.

$ cat <<EOF >./tmp.cc
#include <rocksdb/plugin/dedupfs/dedupfs.h>

int main() {
  auto fs = ROCKSDB_NAMESPACE::NewDedupFileSystem();
  return 0;
}
EOF
$ g++ $(pkg-config --cflags rocksdb) -c ./tmp.cc -o ./tmp.o
$ g++ $(pkg-config --static --libs rocksdb) ./tmp.o -o ./tmp
$ ./tmp