LevelDB

A Go wrapper for LevelDB, forked from jmhodges/levigo. This fork makes levigo go-gettable by including the C++ source for LevelDB and building it with the Go code. LevelDB and Snappy are both compiled and linked statically, so while you will not need them installed on your target machine, you should have a roughly compatible version of libstdc++.

This package currently includes LevelDB 1.19, and supports Linux and OS X. It should work on Go 1.5 or greater.

godoc documentation.

Building

This package supports Linux and OS X.

You'll need gcc and g++. Then:

go get github.com/DataDog/leveldb

This will take a long time as it compiles the LevelDB source code along with the Go library.

To avoid waiting for compilation every time you want to build your project, you can run:

go install github.com/DataDog/leveldb

Updating Vendored Snappy

1. Overwrite source in ./deps/snappy/
2. make link_snappy

If nothing significant in snappy has changed, things should JustWork™

Updating Vendored LevelDB

The embedded LevelDB source code is located in deps/leveldb. In order to get go build to compile LevelDB, we symlink the required LevelDB source files to the root directory of the project. These symlinks are prefixed with deps_.

To change the embedded version of LevelDB, do the following:

1. rm deps_*.cc
2. Replace deps/leveldb with the source code of the desired version of LevelDB
3. On Linux, run ./deps/leveldb/build_detect_platform linux.mk build_flags
4. On OS X, run ./deps/leveldb/build_detect_platform darwin.mk build_flags
5. cat build_flags/*, take a quick look at the new compiler and linker flags and see if there are any flags we're missing in cgo_flags_*.go. If so, add them.
6. make link_leveldb
7. On OS X and Linux, run go build and verify that everything compiles.

note I couldn't get build_detect_platform to run as advertised above -- j

Caveats

Comparators and WriteBatch iterators must be written in C in your own library. This seems like a pain in the ass, but remember that you'll have the LevelDB C API available to your in your client package when you import levigo.

An example of writing your own Comparator can be found in https://github.com/DataDog/leveldb/blob/master/examples.