Clone this repo:
  1. 52ea2dd Add file storage adapter for Fuchsia by Justin Mattson · 6 months ago master
  2. 3c5717c leveldb: DB.rotateMem: retry DB.newMem three times before panicking #167 by Suryandaru Triandana · 8 months ago upstream/master
  3. fec2aa7 leveldb: DB.memCompaction should raise errCompactionTransactExiting panic when canceled due to DB being closed #167 by Suryandaru Triandana · 8 months ago
  4. eade5ec Fix readRawBlock: a forgotten BufferPool Put (#168) by ByteInk · 8 months ago
  5. 23851d9 leveldb: version now locks individual files (fixes #161) by Suryandaru Triandana · 10 months ago

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.