This is an implementation of the LevelDB key/value database in the Go programming language.
go get github.com/syndtr/goleveldb/leveldb - Need at least
go1.14or newer.
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) ... 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() ...You can read package documentation here.