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:

go
// 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)
...
defer db.Close()
...

go
// 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:

go
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()
...

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

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

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

go
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)
...

go
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.