func (bs *blockstore) Get(k *cid.Cid) (blocks.Block, error) {
if k == nil {
log.Error("nil cid in blockstore")
return nil, ErrNotFound
}
maybeData, err := bs.datastore.Get(dshelp.CidToDsKey(k))
if err == ds.ErrNotFound {
return nil, ErrNotFound
}
if err != nil {
return nil, err
}
bdata, ok := maybeData.([]byte)
if !ok {
return nil, ValueTypeMismatch
}
if bs.rehash {
rbcid, err := k.Prefix().Sum(bdata)
if err != nil {
return nil, err
}
if !rbcid.Equals(k) {
return nil, ErrHashMismatch
}
return blocks.NewBlockWithCid(bdata, rbcid)
} else {
return blocks.NewBlockWithCid(bdata, k)
}
}
// NewBlockWithHash creates a new block when the hash of the data
// is already known, this is used to save time in situations where
// we are able to be confident that the data is correct
func NewBlockWithCid(data []byte, c *cid.Cid) (*BasicBlock, error) {
if u.Debug {
chkc, err := c.Prefix().Sum(data)
if err != nil {
return nil, err
}
if !chkc.Equals(c) {
return nil, ErrWrongHash
}
}
return &BasicBlock{data: data, cid: c}, nil
}