Adding upstream version 2.5.1.

Signed-off-by: Daniel Baumann <daniel@debian.org>

index/upsidedown/store/boltdb/store.go

@@ -0,0 +1,184 @@
+//  Copyright (c) 2014 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package boltdb implements a store.KVStore on top of BoltDB. It supports the
+// following options:
+//
+// "bucket" (string): the name of BoltDB bucket to use, defaults to "bleve".
+//
+// "nosync" (bool): if true, set boltdb.DB.NoSync to true. It speeds up index
+// operations in exchange of losing integrity guarantees if indexation aborts
+// without closing the index. Use it when rebuilding indexes from zero.
+package boltdb
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"os"
+
+	"github.com/blevesearch/bleve/v2/registry"
+	store "github.com/blevesearch/upsidedown_store_api"
+	bolt "go.etcd.io/bbolt"
+)
+
+const (
+	Name                    = "boltdb"
+	defaultCompactBatchSize = 100
+)
+
+type Store struct {
+	path        string
+	bucket      string
+	db          *bolt.DB
+	noSync      bool
+	fillPercent float64
+	mo          store.MergeOperator
+}
+
+func New(mo store.MergeOperator, config map[string]interface{}) (store.KVStore, error) {
+	path, ok := config["path"].(string)
+	if !ok {
+		return nil, fmt.Errorf("must specify path")
+	}
+	if path == "" {
+		return nil, os.ErrInvalid
+	}
+
+	bucket, ok := config["bucket"].(string)
+	if !ok {
+		bucket = "bleve"
+	}
+
+	noSync, _ := config["nosync"].(bool)
+
+	fillPercent, ok := config["fillPercent"].(float64)
+	if !ok {
+		fillPercent = bolt.DefaultFillPercent
+	}
+
+	bo := &bolt.Options{}
+	ro, ok := config["read_only"].(bool)
+	if ok {
+		bo.ReadOnly = ro
+	}
+
+	if initialMmapSize, ok := config["initialMmapSize"].(int); ok {
+		bo.InitialMmapSize = initialMmapSize
+	} else if initialMmapSize, ok := config["initialMmapSize"].(float64); ok {
+		bo.InitialMmapSize = int(initialMmapSize)
+	}
+
+	db, err := bolt.Open(path, 0600, bo)
+	if err != nil {
+		return nil, err
+	}
+	db.NoSync = noSync
+
+	if !bo.ReadOnly {
+		err = db.Update(func(tx *bolt.Tx) error {
+			_, err := tx.CreateBucketIfNotExists([]byte(bucket))
+
+			return err
+		})
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	rv := Store{
+		path:        path,
+		bucket:      bucket,
+		db:          db,
+		mo:          mo,
+		noSync:      noSync,
+		fillPercent: fillPercent,
+	}
+	return &rv, nil
+}
+
+func (bs *Store) Close() error {
+	return bs.db.Close()
+}
+
+func (bs *Store) Reader() (store.KVReader, error) {
+	tx, err := bs.db.Begin(false)
+	if err != nil {
+		return nil, err
+	}
+	return &Reader{
+		store:  bs,
+		tx:     tx,
+		bucket: tx.Bucket([]byte(bs.bucket)),
+	}, nil
+}
+
+func (bs *Store) Writer() (store.KVWriter, error) {
+	return &Writer{
+		store: bs,
+	}, nil
+}
+
+func (bs *Store) Stats() json.Marshaler {
+	return &stats{
+		s: bs,
+	}
+}
+
+// CompactWithBatchSize removes DictionaryTerm entries with a count of zero (in batchSize batches)
+// Removing entries is a workaround for github issue #374.
+func (bs *Store) CompactWithBatchSize(batchSize int) error {
+	for {
+		cnt := 0
+		err := bs.db.Batch(func(tx *bolt.Tx) error {
+			c := tx.Bucket([]byte(bs.bucket)).Cursor()
+			prefix := []byte("d")
+
+			for k, v := c.Seek(prefix); bytes.HasPrefix(k, prefix); k, v = c.Next() {
+				if bytes.Equal(v, []byte{0}) {
+					cnt++
+					if err := c.Delete(); err != nil {
+						return err
+					}
+					if cnt == batchSize {
+						break
+					}
+				}
+
+			}
+			return nil
+		})
+		if err != nil {
+			return err
+		}
+
+		if cnt == 0 {
+			break
+		}
+	}
+	return nil
+}
+
+// Compact calls CompactWithBatchSize with a default batch size of 100.  This is a workaround
+// for github issue #374.
+func (bs *Store) Compact() error {
+	return bs.CompactWithBatchSize(defaultCompactBatchSize)
+}
+
+func init() {
+	err := registry.RegisterKVStore(Name, New)
+	if err != nil {
+		panic(err)
+	}
+}