func (db *RocksDB) Get(hash data.Hash256) (data.Hashable, error) {
db.mu.Lock()
cached, ok := db.cache.Get(hash)
db.mu.Unlock()
if ok {
db.hits.Mark(1)
return cached.(data.Hashable), nil
}
value, err := db.db.Get(db.ro, hash[:])
if err != nil {
return nil, err
}
defer value.Free()
if value.Size() == 0 {
return nil, ErrNotFound
}
node, err := data.NewDecoder(bytes.NewReader(value.Data())).Prefix()
if err != nil {
return nil, err
}
db.misses.Mark(1)
db.mu.Lock()
db.cache.Add(hash, node)
db.mu.Unlock()
return node, nil
}
func NewMemoryDB(path string) (*MemoryDB, error) {
mem := &MemoryDB{
nodes: make(map[data.Hash256]data.Hashable),
}
f, err := os.Open(path)
if err != nil {
return nil, err
}
defer f.Close()
r, err := gzip.NewReader(f)
if err != nil {
return nil, err
}
defer r.Close()
scanner := bufio.NewScanner(r)
for scanner.Scan() {
parts := strings.Split(scanner.Text(), ":")
var key data.Hash256
if _, err := hex.Decode(key[:], []byte(parts[0])); err != nil {
return nil, err
}
value, err := hex.DecodeString(parts[1])
if err != nil {
return nil, err
}
node, err := data.NewDecoder(bytes.NewReader(value)).Prefix()
if err != nil {
return nil, err
}
mem.nodes[key] = node
}
if scanner.Err() != nil {
return nil, scanner.Err()
}
return mem, nil
}