add other session providers (#5963)

vendor/github.com/syndtr/goleveldb/leveldb/db_util.go

@@ -0,0 +1,102 @@
+// Copyright (c) 2012, Suryandaru Triandana <syndtr@gmail.com>
+// All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package leveldb
+
+import (
+	"github.com/syndtr/goleveldb/leveldb/errors"
+	"github.com/syndtr/goleveldb/leveldb/iterator"
+	"github.com/syndtr/goleveldb/leveldb/opt"
+	"github.com/syndtr/goleveldb/leveldb/storage"
+	"github.com/syndtr/goleveldb/leveldb/util"
+)
+
+// Reader is the interface that wraps basic Get and NewIterator methods.
+// This interface implemented by both DB and Snapshot.
+type Reader interface {
+	Get(key []byte, ro *opt.ReadOptions) (value []byte, err error)
+	NewIterator(slice *util.Range, ro *opt.ReadOptions) iterator.Iterator
+}
+
+// Sizes is list of size.
+type Sizes []int64
+
+// Sum returns sum of the sizes.
+func (sizes Sizes) Sum() int64 {
+	var sum int64
+	for _, size := range sizes {
+		sum += size
+	}
+	return sum
+}
+
+// Logging.
+func (db *DB) log(v ...interface{})                 { db.s.log(v...) }
+func (db *DB) logf(format string, v ...interface{}) { db.s.logf(format, v...) }
+
+// Check and clean files.
+func (db *DB) checkAndCleanFiles() error {
+	v := db.s.version()
+	defer v.release()
+
+	tmap := make(map[int64]bool)
+	for _, tables := range v.levels {
+		for _, t := range tables {
+			tmap[t.fd.Num] = false
+		}
+	}
+
+	fds, err := db.s.stor.List(storage.TypeAll)
+	if err != nil {
+		return err
+	}
+
+	var nt int
+	var rem []storage.FileDesc
+	for _, fd := range fds {
+		keep := true
+		switch fd.Type {
+		case storage.TypeManifest:
+			keep = fd.Num >= db.s.manifestFd.Num
+		case storage.TypeJournal:
+			if !db.frozenJournalFd.Zero() {
+				keep = fd.Num >= db.frozenJournalFd.Num
+			} else {
+				keep = fd.Num >= db.journalFd.Num
+			}
+		case storage.TypeTable:
+			_, keep = tmap[fd.Num]
+			if keep {
+				tmap[fd.Num] = true
+				nt++
+			}
+		}
+
+		if !keep {
+			rem = append(rem, fd)
+		}
+	}
+
+	if nt != len(tmap) {
+		var mfds []storage.FileDesc
+		for num, present := range tmap {
+			if !present {
+				mfds = append(mfds, storage.FileDesc{Type: storage.TypeTable, Num: num})
+				db.logf("db@janitor table missing @%d", num)
+			}
+		}
+		return errors.NewErrCorrupted(storage.FileDesc{}, &errors.ErrMissingFiles{Fds: mfds})
+	}
+
+	db.logf("db@janitor F·%d G·%d", len(fds), len(rem))
+	for _, fd := range rem {
+		db.logf("db@janitor removing %s-%d", fd.Type, fd.Num)
+		if err := db.s.stor.Remove(fd); err != nil {
+			return err
+		}
+	}
+	return nil
+}