level: fixes table compaction that may generate tables with overlapped ukey

This become a problem when new compaction picked-up and table key range search
doesn't expanded in the asumption that ukey never hop across tables (true in level > 0),
when this happen newer ukey might pushed into lower level, and since version.get
assume that this never happen, version.get will incorectly return older ukey instead.

This commit also fixes compaction retry, and will always expand key range search
when pick-up new compaction.

Fixes #83.
6 files changed
tree: 23e06599e051ccb9e692275554fe877c616ba372
  1. .travis.yml
  2. LICENSE
  3. README.md
  4. leveldb/
  5. manualtest/
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 go1.2 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.