path: root/swarm/storage/chunkstore.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 (
    "context"
    "sync"
)

/*
ChunkStore interface is implemented by :

- MemStore: a memory cache
- DbStore: local disk/db store
- LocalStore: a combination (sequence of) memStore and dbStore
- NetStore: cloud storage abstraction layer
- FakeChunkStore: dummy store which doesn't store anything just implements the interface
*/
type ChunkStore interface {
    Put(context.Context, *Chunk) // effectively there is no error even if there is an error
    Get(context.Context, Address) (*Chunk, error)
    Close()
}

// MapChunkStore is a very simple ChunkStore implementation to store chunks in a map in memory.
type MapChunkStore struct {
    chunks map[string]*Chunk
    mu     sync.RWMutex
}

func NewMapChunkStore() *MapChunkStore {
    return &MapChunkStore{
        chunks: make(map[string]*Chunk),
    }
}

func (m *MapChunkStore) Put(ctx context.Context, chunk *Chunk) {
    m.mu.Lock()
    defer m.mu.Unlock()
    m.chunks[chunk.Addr.Hex()] = chunk
    chunk.markAsStored()
}

func (m *MapChunkStore) Get(ctx context.Context, addr Address) (*Chunk, error) {
    m.mu.RLock()
    defer m.mu.RUnlock()
    chunk := m.chunks[addr.Hex()]
    if chunk == nil {
        return nil, ErrChunkNotFound
    }
    return chunk, nil
}

func (m *MapChunkStore) Close() {
}