Merge pull request #85 from jbenet/feat/blockstore

feat(blockstore): implement blockstore

blockstore/blockstore.go

+package blockstore
+
+import (
+	"errors"
+
+	ds "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/datastore.go"
+
+	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.Datastore) Blockstore {
+	return &blockstore{
+		datastore: d,
+	}
+}
+
+type blockstore struct {
+	datastore ds.Datastore
+}
+
+func (bs *blockstore) Get(k u.Key) (*blocks.Block, error) {
+	maybeData, err := bs.datastore.Get(toDatastoreKey(k))
+	if err != nil {
+		return nil, err
+	}
+	bdata, ok := maybeData.([]byte)
+	if !ok {
+		return nil, ValueTypeMismatch
+	}
+	return blocks.NewBlock(bdata)
+}
+
+func (bs *blockstore) Put(block blocks.Block) error {
+	return bs.datastore.Put(toDatastoreKey(block.Key()), block.Data)
+}
+
+func toDatastoreKey(k u.Key) ds.Key {
+	return ds.NewKey(string(k))
+}

blockstore/blockstore_test.go

+package blockstore
+
+import (
+	"bytes"
+	"testing"
+
+	ds "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/datastore.go"
+	u "github.com/jbenet/go-ipfs/util"
+	testutil "github.com/jbenet/go-ipfs/util/testutil"
+)
+
+// TODO(brian): TestGetReturnsNil
+
+func TestGetWhenKeyNotPresent(t *testing.T) {
+	bs := NewBlockstore(ds.NewMapDatastore())
+	_, err := bs.Get(u.Key("not present"))
+
+	if err != nil {
+		t.Log("As expected, block is not present")
+		return
+	}
+	t.Fail()
+}
+
+func TestPutThenGetBlock(t *testing.T) {
+	bs := NewBlockstore(ds.NewMapDatastore())
+	block := testutil.NewBlockOrFail(t, "some data")
+
+	err := bs.Put(block)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	blockFromBlockstore, err := bs.Get(block.Key())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(block.Data, blockFromBlockstore.Data) {
+		t.Fail()
+	}
+}
+
+func TestValueTypeMismatch(t *testing.T) {
+	block := testutil.NewBlockOrFail(t, "some data")
+
+	datastore := ds.NewMapDatastore()
+	datastore.Put(toDatastoreKey(block.Key()), "data that isn't a block!")
+
+	blockstore := NewBlockstore(datastore)
+
+	_, err := blockstore.Get(block.Key())
+	if err != ValueTypeMismatch {
+		t.Fatal(err)
+	}
+}

util/testutil/blocks.go

+package testutil
+
+import (
+	"testing"
+
+	blocks "github.com/jbenet/go-ipfs/blocks"
+)
+
+// NewBlockOrFail returns a block created from msgData. Signals test failure if
+// creation fails.
+//
+// NB: NewBlockOrFail accepts a msgData parameter to avoid non-determinism in
+// tests. Generating random block data could potentially result in unexpected
+// behavior in tests. Thus, it is left up to the caller to select the msgData
+// that will determine the blocks key.
+func NewBlockOrFail(t *testing.T, msgData string) blocks.Block {
+	block, blockCreationErr := blocks.NewBlock([]byte(msgData))
+	if blockCreationErr != nil {
+		t.Fatal(blockCreationErr)
+	}
+	return *block
+}