go-ethereum/swarm/storage/localstore.go
ΞTHΞЯSPHΞЯΞ 4d300e4dec swarm: plan bee for content storage and distribution on web3
This change imports the Swarm protocol codebase. Compared to the 'swarm'
branch, a few mostly cosmetic changes had to be made:

* The various redundant log message prefixes are gone.
* All files now have LGPLv3 license headers.
* Minor code changes were needed to please go vet and make the tests
  pass on Windows.
* Further changes were required to adapt to the go-ethereum develop
  branch and its new Go APIs.

Some code has not (yet) been brought over:

* swarm/cmd/bzzhash: will reappear as cmd/bzzhash later
* swarm/cmd/bzzup.sh: will be reimplemented in cmd/bzzup
* swarm/cmd/makegenesis: will reappear somehow
* swarm/examples/album: will move to a separate repository
* swarm/examples/filemanager: ditto
* swarm/examples/files: will not be merged
* swarm/test/*: will not be merged
* swarm/services/swear: will reappear as contracts/swear when needed
2016-08-31 16:19:40 +02:00

75 lines
2.2 KiB
Go

// Copyright 2016 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 storage
import (
"encoding/binary"
)
// LocalStore is a combination of inmemory db over a disk persisted db
// implements a Get/Put with fallback (caching) logic using any 2 ChunkStores
type LocalStore struct {
memStore ChunkStore
DbStore ChunkStore
}
// This constructor uses MemStore and DbStore as components
func NewLocalStore(hash Hasher, params *StoreParams) (*LocalStore, error) {
dbStore, err := NewDbStore(params.ChunkDbPath, hash, params.DbCapacity, params.Radius)
if err != nil {
return nil, err
}
return &LocalStore{
memStore: NewMemStore(dbStore, params.CacheCapacity),
DbStore: dbStore,
}, nil
}
// LocalStore is itself a chunk store
// unsafe, in that the data is not integrity checked
func (self *LocalStore) Put(chunk *Chunk) {
chunk.dbStored = make(chan bool)
self.memStore.Put(chunk)
if chunk.wg != nil {
chunk.wg.Add(1)
}
go func() {
self.DbStore.Put(chunk)
if chunk.wg != nil {
chunk.wg.Done()
}
}()
}
// Get(chunk *Chunk) looks up a chunk in the local stores
// This method is blocking until the chunk is retrieved
// so additional timeout may be needed to wrap this call if
// ChunkStores are remote and can have long latency
func (self *LocalStore) Get(key Key) (chunk *Chunk, err error) {
chunk, err = self.memStore.Get(key)
if err == nil {
return
}
chunk, err = self.DbStore.Get(key)
if err != nil {
return
}
chunk.Size = int64(binary.LittleEndian.Uint64(chunk.SData[0:8]))
self.memStore.Put(chunk)
return
}