LevelDB key/value database in Go.
Go
Latest commit 23851d9 Dec 27, 2016 @syndtr leveldb: version now locks individual files (fixes #161)
This way version doesn't need to locks successive versions.
So that intermediate files generated during compaction can
be released right away, even if old versions still being used.

README.md

This is an implementation of the LevelDB key/value database in the Go programming language.

Build Status

Installation

go get github.com/syndtr/goleveldb/leveldb

Requirements

  • Need at least go1.4 or newer.

Usage

Create or open a database:

db, err := leveldb.OpenFile("path/to/db", nil)
...
defer db.Close()
...

Read or modify the database content:

// Remember that the contents of the returned slice should not be modified.
data, err := db.Get([]byte("key"), nil)
...
err = db.Put([]byte("key"), []byte("value"), nil)
...
err = db.Delete([]byte("key"), nil)
...

Iterate over database content:

iter := db.NewIterator(nil, nil)
for iter.Next() {
    // Remember that the contents of the returned slice should not be modified, and
    // only valid until the next call to Next.
    key := iter.Key()
    value := iter.Value()
    ...
}
iter.Release()
err = iter.Error()
...

Seek-then-Iterate:

iter := db.NewIterator(nil, nil)
for ok := iter.Seek(key); ok; ok = iter.Next() {
    // Use key/value.
    ...
}
iter.Release()
err = iter.Error()
...

Iterate over subset of database content:

iter := db.NewIterator(&util.Range{Start: []byte("foo"), Limit: []byte("xoo")}, nil)
for iter.Next() {
    // Use key/value.
    ...
}
iter.Release()
err = iter.Error()
...

Iterate over subset of database content with a particular prefix:

iter := db.NewIterator(util.BytesPrefix([]byte("foo-")), nil)
for iter.Next() {
    // Use key/value.
    ...
}
iter.Release()
err = iter.Error()
...

Batch writes:

batch := new(leveldb.Batch)
batch.Put([]byte("foo"), []byte("value"))
batch.Put([]byte("bar"), []byte("another value"))
batch.Delete([]byte("baz"))
err = db.Write(batch, nil)
...

Use bloom filter:

o := &opt.Options{
    Filter: filter.NewBloomFilter(10),
}
db, err := leveldb.OpenFile("path/to/db", o)
...
defer db.Close()
...

Documentation

You can read package documentation here.