refactor(blockstore) mv under blocks/

@jbenet @whyrusleeping

the pyramids were built one brick at a time

addresses: https://github.com/jbenet/go-ipfs/issues/370

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

blocks/blockstore/blockstore.go

@@ -0,0 +1,47 @@
+// package blockstore implements a thin wrapper over a datastore, giving a
+// clean interface for Getting and Putting block objects.
+package blockstore
+
+import (
+	"errors"
+
+	ds "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-datastore"
+
+	mh "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-multihash"
+	blocks "github.com/jbenet/go-ipfs/blocks"
+	u "github.com/jbenet/go-ipfs/util"
+)
+
+var ValueTypeMismatch = errors.New("The retrieved value is not a Block")
+
+type Blockstore interface {
+	Get(u.Key) (*blocks.Block, error)
+	Put(*blocks.Block) error
+}
+
+func NewBlockstore(d ds.ThreadSafeDatastore) Blockstore {
+	return &blockstore{
+		datastore: d,
+	}
+}
+
+type blockstore struct {
+	datastore ds.ThreadSafeDatastore
+}
+
+func (bs *blockstore) Get(k u.Key) (*blocks.Block, error) {
+	maybeData, err := bs.datastore.Get(k.DsKey())
+	if err != nil {
+		return nil, err
+	}
+	bdata, ok := maybeData.([]byte)
+	if !ok {
+		return nil, ValueTypeMismatch
+	}
+
+	return blocks.NewBlockWithHash(bdata, mh.Multihash(k))
+}
+
+func (bs *blockstore) Put(block *blocks.Block) error {
+	return bs.datastore.Put(block.Key().DsKey(), block.Data)
+}