swarm/storage/localstore: new localstore package (#19015)

swarm/storage/localstore/mode_set.go

@@ -0,0 +1,205 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package localstore
+
+import (
+	"github.com/ethereum/go-ethereum/swarm/storage"
+	"github.com/syndtr/goleveldb/leveldb"
+)
+
+// ModeSet enumerates different Setter modes.
+type ModeSet int
+
+// Setter modes.
+const (
+	// ModeSetAccess: when an update request is received for a chunk or chunk is retrieved for delivery
+	ModeSetAccess ModeSet = iota
+	// ModeSetSync: when push sync receipt is received
+	ModeSetSync
+	// modeSetRemove: when GC-d
+	// unexported as no external packages should remove chunks from database
+	modeSetRemove
+)
+
+// Setter sets the state of a particular
+// Chunk in database by changing indexes.
+type Setter struct {
+	db   *DB
+	mode ModeSet
+}
+
+// NewSetter returns a new Setter on database
+// with a specific Mode.
+func (db *DB) NewSetter(mode ModeSet) *Setter {
+	return &Setter{
+		mode: mode,
+		db:   db,
+	}
+}
+
+// Set updates database indexes for a specific
+// chunk represented by the address.
+func (s *Setter) Set(addr storage.Address) (err error) {
+	return s.db.set(s.mode, addr)
+}
+
+// set updates database indexes for a specific
+// chunk represented by the address.
+// It acquires lockAddr to protect two calls
+// of this function for the same address in parallel.
+func (db *DB) set(mode ModeSet, addr storage.Address) (err error) {
+	// protect parallel updates
+	unlock, err := db.lockAddr(addr)
+	if err != nil {
+		return err
+	}
+	defer unlock()
+
+	batch := new(leveldb.Batch)
+
+	// variables that provide information for operations
+	// to be done after write batch function successfully executes
+	var gcSizeChange int64   // number to add or subtract from gcSize
+	var triggerPullFeed bool // signal pull feed subscriptions to iterate
+
+	item := addressToItem(addr)
+
+	switch mode {
+	case ModeSetAccess:
+		// add to pull, insert to gc
+
+		// need to get access timestamp here as it is not
+		// provided by the access function, and it is not
+		// a property of a chunk provided to Accessor.Put.
+
+		i, err := db.retrievalDataIndex.Get(item)
+		switch err {
+		case nil:
+			item.StoreTimestamp = i.StoreTimestamp
+		case leveldb.ErrNotFound:
+			db.pushIndex.DeleteInBatch(batch, item)
+			item.StoreTimestamp = now()
+		default:
+			return err
+		}
+
+		i, err = db.retrievalAccessIndex.Get(item)
+		switch err {
+		case nil:
+			item.AccessTimestamp = i.AccessTimestamp
+			db.gcIndex.DeleteInBatch(batch, item)
+			gcSizeChange--
+		case leveldb.ErrNotFound:
+			// the chunk is not accessed before
+		default:
+			return err
+		}
+		item.AccessTimestamp = now()
+		db.retrievalAccessIndex.PutInBatch(batch, item)
+		db.pullIndex.PutInBatch(batch, item)
+		triggerPullFeed = true
+		db.gcIndex.PutInBatch(batch, item)
+		db.gcUncountedHashesIndex.PutInBatch(batch, item)
+		gcSizeChange++
+
+	case ModeSetSync:
+		// delete from push, insert to gc
+
+		// need to get access timestamp here as it is not
+		// provided by the access function, and it is not
+		// a property of a chunk provided to Accessor.Put.
+		i, err := db.retrievalDataIndex.Get(item)
+		if err != nil {
+			if err == leveldb.ErrNotFound {
+				// chunk is not found,
+				// no need to update gc index
+				// just delete from the push index
+				// if it is there
+				db.pushIndex.DeleteInBatch(batch, item)
+				return nil
+			}
+			return err
+		}
+		item.StoreTimestamp = i.StoreTimestamp
+
+		i, err = db.retrievalAccessIndex.Get(item)
+		switch err {
+		case nil:
+			item.AccessTimestamp = i.AccessTimestamp
+			db.gcIndex.DeleteInBatch(batch, item)
+			gcSizeChange--
+		case leveldb.ErrNotFound:
+			// the chunk is not accessed before
+		default:
+			return err
+		}
+		item.AccessTimestamp = now()
+		db.retrievalAccessIndex.PutInBatch(batch, item)
+		db.pushIndex.DeleteInBatch(batch, item)
+		db.gcIndex.PutInBatch(batch, item)
+		db.gcUncountedHashesIndex.PutInBatch(batch, item)
+		gcSizeChange++
+
+	case modeSetRemove:
+		// delete from retrieve, pull, gc
+
+		// need to get access timestamp here as it is not
+		// provided by the access function, and it is not
+		// a property of a chunk provided to Accessor.Put.
+
+		i, err := db.retrievalAccessIndex.Get(item)
+		switch err {
+		case nil:
+			item.AccessTimestamp = i.AccessTimestamp
+		case leveldb.ErrNotFound:
+		default:
+			return err
+		}
+		i, err = db.retrievalDataIndex.Get(item)
+		if err != nil {
+			return err
+		}
+		item.StoreTimestamp = i.StoreTimestamp
+
+		db.retrievalDataIndex.DeleteInBatch(batch, item)
+		db.retrievalAccessIndex.DeleteInBatch(batch, item)
+		db.pullIndex.DeleteInBatch(batch, item)
+		db.gcIndex.DeleteInBatch(batch, item)
+		db.gcUncountedHashesIndex.DeleteInBatch(batch, item)
+		// a check is needed for decrementing gcSize
+		// as delete is not reporting if the key/value pair
+		// is deleted or not
+		if _, err := db.gcIndex.Get(item); err == nil {
+			gcSizeChange = -1
+		}
+
+	default:
+		return ErrInvalidMode
+	}
+
+	err = db.shed.WriteBatch(batch)
+	if err != nil {
+		return err
+	}
+	if gcSizeChange != 0 {
+		db.incGCSize(gcSizeChange)
+	}
+	if triggerPullFeed {
+		db.triggerPullSubscriptions(db.po(item.Address))
+	}
+	return nil
+}