150 lines
3.5 KiB
Go
150 lines
3.5 KiB
Go
// Copyright (c) 2014 Couchbase, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package goleveldb
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import (
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"bytes"
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"fmt"
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"os"
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"github.com/blevesearch/bleve/index/store"
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"github.com/blevesearch/bleve/registry"
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"github.com/syndtr/goleveldb/leveldb"
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"github.com/syndtr/goleveldb/leveldb/opt"
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"github.com/syndtr/goleveldb/leveldb/util"
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)
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const (
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Name = "goleveldb"
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defaultCompactBatchSize = 250
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)
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type Store struct {
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path string
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opts *opt.Options
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db *leveldb.DB
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mo store.MergeOperator
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defaultWriteOptions *opt.WriteOptions
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defaultReadOptions *opt.ReadOptions
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}
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func New(mo store.MergeOperator, config map[string]interface{}) (store.KVStore, error) {
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path, ok := config["path"].(string)
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if !ok {
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return nil, fmt.Errorf("must specify path")
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}
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if path == "" {
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return nil, os.ErrInvalid
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}
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opts, err := applyConfig(&opt.Options{}, config)
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if err != nil {
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return nil, err
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}
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db, err := leveldb.OpenFile(path, opts)
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if err != nil {
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return nil, err
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}
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rv := Store{
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path: path,
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opts: opts,
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db: db,
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mo: mo,
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defaultReadOptions: &opt.ReadOptions{},
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defaultWriteOptions: &opt.WriteOptions{},
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}
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rv.defaultWriteOptions.Sync = true
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return &rv, nil
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}
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func (ldbs *Store) Close() error {
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return ldbs.db.Close()
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}
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func (ldbs *Store) Reader() (store.KVReader, error) {
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snapshot, _ := ldbs.db.GetSnapshot()
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return &Reader{
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store: ldbs,
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snapshot: snapshot,
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}, nil
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}
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func (ldbs *Store) Writer() (store.KVWriter, error) {
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return &Writer{
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store: ldbs,
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}, nil
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}
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// CompactWithBatchSize removes DictionaryTerm entries with a count of zero (in batchSize batches), then
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// compacts the underlying goleveldb store. Removing entries is a workaround for github issue #374.
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func (ldbs *Store) CompactWithBatchSize(batchSize int) error {
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// workaround for github issue #374 - remove DictionaryTerm keys with count=0
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batch := &leveldb.Batch{}
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for {
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t, err := ldbs.db.OpenTransaction()
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if err != nil {
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return err
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}
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iter := t.NewIterator(util.BytesPrefix([]byte("d")), ldbs.defaultReadOptions)
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for iter.Next() {
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if bytes.Equal(iter.Value(), []byte{0}) {
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k := append([]byte{}, iter.Key()...)
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batch.Delete(k)
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}
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if batch.Len() == batchSize {
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break
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}
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}
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iter.Release()
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if iter.Error() != nil {
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t.Discard()
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return iter.Error()
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}
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if batch.Len() > 0 {
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err := t.Write(batch, ldbs.defaultWriteOptions)
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if err != nil {
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t.Discard()
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return err
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}
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err = t.Commit()
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if err != nil {
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return err
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}
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} else {
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t.Discard()
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break
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}
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batch.Reset()
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}
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return ldbs.db.CompactRange(util.Range{Start: nil, Limit: nil})
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}
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// Compact compacts the underlying goleveldb store. The current implementation includes a workaround
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// for github issue #374 (see CompactWithBatchSize).
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func (ldbs *Store) Compact() error {
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return ldbs.CompactWithBatchSize(defaultCompactBatchSize)
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}
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func init() {
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registry.RegisterKVStore(Name, New)
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}
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