LevelDBGoWrapper

LevelDBGoWrapper is a Go wrapper for LevelDB. It also demonstrates a way to bind C++ codes at Golang programs, which is leverage on cgo and swig.

Setup

• Install leveldb:

  leveldb is a submodule as this repo. You are able to install leveldb by following commands:

  > git submodule update --init
  > cd leveldb
  > make
  

• Install swig:

  swig is able to easily be installed by apt-get or brew install.

• How to bind leveldb to LevelDBGoWrapper

  • Firstly install leveldb which will generate include files and shared-lib. Put these to /usr/local/include and /usr/local/lib to make gcc/g++ to be able to find leveldb library easier.

  • Write wrapper file like leveldb_interface.* is c++ wrapper function which is going to expose to golang function. Swig compiles our c++ programs with leveldb library and generate its binding go-code leveldbwrapperlib.go and leveldbwrapper_wrap.cxx.

  • lib.go is to indicate package name of wrapper.

  • leveldbwrapperlib.i is swig file to indicate what functions is it going to expose to golang.

  • To generate binding codes, following command swig -go -cgo -c++ -intgosize 64 leveldbwrapperlib.i

  • Make our wrapper link leveldb at runtime. Add a line #cgo LDFLAGS: -lleveldb just right ahead of import "C"

• Test and Benchmark

  • simple test:

    run go run cmd/main.go, it works when it shows elsa