github.com/divan/go-ethereum@v1.8.14-0.20180820134928-1de9ada4016d/swarm/storage/chunkstore.go (about)

     1  // Copyright 2016 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package storage
    18  
    19  import (
    20  	"context"
    21  	"sync"
    22  )
    23  
    24  /*
    25  ChunkStore interface is implemented by :
    26  
    27  - MemStore: a memory cache
    28  - DbStore: local disk/db store
    29  - LocalStore: a combination (sequence of) memStore and dbStore
    30  - NetStore: cloud storage abstraction layer
    31  - FakeChunkStore: dummy store which doesn't store anything just implements the interface
    32  */
    33  type ChunkStore interface {
    34  	Put(context.Context, *Chunk) // effectively there is no error even if there is an error
    35  	Get(context.Context, Address) (*Chunk, error)
    36  	Close()
    37  }
    38  
    39  // MapChunkStore is a very simple ChunkStore implementation to store chunks in a map in memory.
    40  type MapChunkStore struct {
    41  	chunks map[string]*Chunk
    42  	mu     sync.RWMutex
    43  }
    44  
    45  func NewMapChunkStore() *MapChunkStore {
    46  	return &MapChunkStore{
    47  		chunks: make(map[string]*Chunk),
    48  	}
    49  }
    50  
    51  func (m *MapChunkStore) Put(ctx context.Context, chunk *Chunk) {
    52  	m.mu.Lock()
    53  	defer m.mu.Unlock()
    54  	m.chunks[chunk.Addr.Hex()] = chunk
    55  	chunk.markAsStored()
    56  }
    57  
    58  func (m *MapChunkStore) Get(ctx context.Context, addr Address) (*Chunk, error) {
    59  	m.mu.RLock()
    60  	defer m.mu.RUnlock()
    61  	chunk := m.chunks[addr.Hex()]
    62  	if chunk == nil {
    63  		return nil, ErrChunkNotFound
    64  	}
    65  	return chunk, nil
    66  }
    67  
    68  func (m *MapChunkStore) Close() {
    69  }