forked from cerc-io/plugeth
98 lines
3.7 KiB
Go
98 lines
3.7 KiB
Go
// Copyright 2016 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// The go-ethereum library is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package storage
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import (
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"io"
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)
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/*
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FileStore provides the client API entrypoints Store and Retrieve to store and retrieve
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It can store anything that has a byte slice representation, so files or serialised objects etc.
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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.
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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.
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As the chunker produces chunks, FileStore dispatches them to its own chunk store
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implementation for storage or retrieval.
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*/
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const (
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defaultLDBCapacity = 5000000 // capacity for LevelDB, by default 5*10^6*4096 bytes == 20GB
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defaultCacheCapacity = 10000 // capacity for in-memory chunks' cache
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defaultChunkRequestsCacheCapacity = 5000000 // capacity for container holding outgoing requests for chunks. should be set to LevelDB capacity
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)
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type FileStore struct {
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ChunkStore
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hashFunc SwarmHasher
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}
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type FileStoreParams struct {
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Hash string
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}
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func NewFileStoreParams() *FileStoreParams {
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return &FileStoreParams{
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Hash: DefaultHash,
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}
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}
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// for testing locally
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func NewLocalFileStore(datadir string, basekey []byte) (*FileStore, error) {
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params := NewDefaultLocalStoreParams()
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params.Init(datadir)
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localStore, err := NewLocalStore(params, nil)
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if err != nil {
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return nil, err
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}
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localStore.Validators = append(localStore.Validators, NewContentAddressValidator(MakeHashFunc(DefaultHash)))
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return NewFileStore(localStore, NewFileStoreParams()), nil
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}
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func NewFileStore(store ChunkStore, params *FileStoreParams) *FileStore {
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hashFunc := MakeHashFunc(params.Hash)
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return &FileStore{
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ChunkStore: store,
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hashFunc: hashFunc,
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}
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}
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// Public API. Main entry point for document retrieval directly. Used by the
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// FS-aware API and httpaccess
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// Chunk retrieval blocks on netStore requests with a timeout so reader will
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// report error if retrieval of chunks within requested range time out.
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// It returns a reader with the chunk data and whether the content was encrypted
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func (f *FileStore) Retrieve(addr Address) (reader *LazyChunkReader, isEncrypted bool) {
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isEncrypted = len(addr) > f.hashFunc().Size()
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getter := NewHasherStore(f.ChunkStore, f.hashFunc, isEncrypted)
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reader = TreeJoin(addr, getter, 0)
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return
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}
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// Public API. Main entry point for document storage directly. Used by the
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// FS-aware API and httpaccess
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func (f *FileStore) Store(data io.Reader, size int64, toEncrypt bool) (addr Address, wait func(), err error) {
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putter := NewHasherStore(f.ChunkStore, f.hashFunc, toEncrypt)
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return PyramidSplit(data, putter, putter)
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}
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func (f *FileStore) HashSize() int {
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return f.hashFunc().Size()
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}
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