// 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
}
