swarm: network rewrite merge

swarm/storage/filestore.go

@@ -0,0 +1,97 @@
+// 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 (
+	"io"
+)
+
+/*
+FileStore provides the client API entrypoints Store and Retrieve to store and retrieve
+It can store anything that has a byte slice representation, so files or serialised objects etc.
+
+Storage: FileStore calls the Chunker to segment the input datastream of any size to a merkle hashed tree of chunks. The key of the root block is returned to the client.
+
+Retrieval: given the key of the root block, the FileStore retrieves the block chunks and reconstructs the original data and passes it back as a lazy reader. A lazy reader is a reader with on-demand delayed processing, i.e. the chunks needed to reconstruct a large file are only fetched and processed if that particular part of the document is actually read.
+
+As the chunker produces chunks, FileStore dispatches them to its own chunk store
+implementation for storage or retrieval.
+*/
+
+const (
+	defaultLDBCapacity                = 5000000 // capacity for LevelDB, by default 5*10^6*4096 bytes == 20GB
+	defaultCacheCapacity              = 10000   // capacity for in-memory chunks' cache
+	defaultChunkRequestsCacheCapacity = 5000000 // capacity for container holding outgoing requests for chunks. should be set to LevelDB capacity
+)
+
+type FileStore struct {
+	ChunkStore
+	hashFunc SwarmHasher
+}
+
+type FileStoreParams struct {
+	Hash string
+}
+
+func NewFileStoreParams() *FileStoreParams {
+	return &FileStoreParams{
+		Hash: DefaultHash,
+	}
+}
+
+// for testing locally
+func NewLocalFileStore(datadir string, basekey []byte) (*FileStore, error) {
+	params := NewDefaultLocalStoreParams()
+	params.Init(datadir)
+	localStore, err := NewLocalStore(params, nil)
+	if err != nil {
+		return nil, err
+	}
+	localStore.Validators = append(localStore.Validators, NewContentAddressValidator(MakeHashFunc(DefaultHash)))
+	return NewFileStore(localStore, NewFileStoreParams()), nil
+}
+
+func NewFileStore(store ChunkStore, params *FileStoreParams) *FileStore {
+	hashFunc := MakeHashFunc(params.Hash)
+	return &FileStore{
+		ChunkStore: store,
+		hashFunc:   hashFunc,
+	}
+}
+
+// Public API. Main entry point for document retrieval directly. Used by the
+// FS-aware API and httpaccess
+// Chunk retrieval blocks on netStore requests with a timeout so reader will
+// report error if retrieval of chunks within requested range time out.
+// It returns a reader with the chunk data and whether the content was encrypted
+func (f *FileStore) Retrieve(addr Address) (reader *LazyChunkReader, isEncrypted bool) {
+	isEncrypted = len(addr) > f.hashFunc().Size()
+	getter := NewHasherStore(f.ChunkStore, f.hashFunc, isEncrypted)
+	reader = TreeJoin(addr, getter, 0)
+	return
+}
+
+// Public API. Main entry point for document storage directly. Used by the
+// FS-aware API and httpaccess
+func (f *FileStore) Store(data io.Reader, size int64, toEncrypt bool) (addr Address, wait func(), err error) {
+	putter := NewHasherStore(f.ChunkStore, f.hashFunc, toEncrypt)
+	return PyramidSplit(data, putter, putter)
+}
+
+func (f *FileStore) HashSize() int {
+	return f.hashFunc().Size()
+}