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

Installation

go get github.com/syndtr/goleveldb/leveldb

Requirements

• Need at least go1.5 or newer.

Usage

Create or open a database:

// The returned DB instance is safe for concurrent use. Which mean that all// DB's methods may be called concurrently from multiple goroutine.db, err:=leveldb.OpenFile("path/to/db", nil)
...deferdb.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)
foriter.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)
forok:=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)
foriter.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)
foriter.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)
...deferdb.Close()
...

Documentation

You can read package documentation here.