Make BlockService an interface.

License: MIT
Signed-off-by: Kevin Atkinson <k@kevina.org>

blockservice.go

@@ -23,34 +23,52 @@ var ErrNotFound = errors.New("blockservice: key not found")
 // BlockService is a hybrid block datastore. It stores data in a local
 // datastore and may retrieve data from a remote Exchange.
 // It uses an internal `datastore.Datastore` instance to store values.
-type BlockService struct {
-	// TODO don't expose underlying impl details
-	Blockstore blockstore.Blockstore
-	Exchange   exchange.Interface
+type BlockService interface {
+	Blockstore() blockstore.Blockstore
+	Exchange() exchange.Interface
+	AddBlock(o blocks.Block) (*cid.Cid, error)
+	AddBlocks(bs []blocks.Block) ([]*cid.Cid, error)
+	GetBlock(ctx context.Context, c *cid.Cid) (blocks.Block, error)
+	GetBlocks(ctx context.Context, ks []*cid.Cid) <-chan blocks.Block
+	DeleteBlock(o blocks.Block) error
+	Close() error
+}
+
+type blockService struct {
+	blockstore blockstore.Blockstore
+	exchange   exchange.Interface
 }
 
 // NewBlockService creates a BlockService with given datastore instance.
-func New(bs blockstore.Blockstore, rem exchange.Interface) *BlockService {
+func New(bs blockstore.Blockstore, rem exchange.Interface) BlockService {
 	if rem == nil {
 		log.Warning("blockservice running in local (offline) mode.")
 	}
 
-	return &BlockService{
-		Blockstore: bs,
-		Exchange:   rem,
+	return &blockService{
+		blockstore: bs,
+		exchange:   rem,
 	}
 }
 
+func (bs *blockService) Blockstore() blockstore.Blockstore {
+	return bs.blockstore
+}
+
+func (bs *blockService) Exchange() exchange.Interface {
+	return bs.exchange
+}
+
 // AddBlock adds a particular block to the service, Putting it into the datastore.
 // TODO pass a context into this if the remote.HasBlock is going to remain here.
-func (s *BlockService) AddBlock(o blocks.Block) (*cid.Cid, error) {
+func (s *blockService) AddBlock(o blocks.Block) (*cid.Cid, error) {
 	// TODO: while this is a great optimization, we should think about the
 	// possibility of streaming writes directly to disk. If we can pass this object
 	// all the way down to the datastore without having to 'buffer' its data,
 	// we could implement a `WriteTo` method on it that could do a streaming write
 	// of the content, saving us (probably) considerable memory.
 	c := o.Cid()
-	has, err := s.Blockstore.Has(c)
+	has, err := s.blockstore.Has(c)
 	if err != nil {
 		return nil, err
 	}
@@ -59,22 +77,22 @@ func (s *BlockService) AddBlock(o blocks.Block) (*cid.Cid, error) {
 		return c, nil
 	}
 
-	err = s.Blockstore.Put(o)
+	err = s.blockstore.Put(o)
 	if err != nil {
 		return nil, err
 	}
 
-	if err := s.Exchange.HasBlock(o); err != nil {
+	if err := s.exchange.HasBlock(o); err != nil {
 		return nil, errors.New("blockservice is closed")
 	}
 
 	return c, nil
 }
 
-func (s *BlockService) AddBlocks(bs []blocks.Block) ([]*cid.Cid, error) {
+func (s *blockService) AddBlocks(bs []blocks.Block) ([]*cid.Cid, error) {
 	var toput []blocks.Block
 	for _, b := range bs {
-		has, err := s.Blockstore.Has(b.Cid())
+		has, err := s.blockstore.Has(b.Cid())
 		if err != nil {
 			return nil, err
 		}
@@ -86,14 +104,14 @@ func (s *BlockService) AddBlocks(bs []blocks.Block) ([]*cid.Cid, error) {
 		toput = append(toput, b)
 	}
 
-	err := s.Blockstore.PutMany(toput)
+	err := s.blockstore.PutMany(toput)
 	if err != nil {
 		return nil, err
 	}
 
 	var ks []*cid.Cid
 	for _, o := range toput {
-		if err := s.Exchange.HasBlock(o); err != nil {
+		if err := s.exchange.HasBlock(o); err != nil {
 			return nil, fmt.Errorf("blockservice is closed (%s)", err)
 		}
 
@@ -104,19 +122,19 @@ func (s *BlockService) AddBlocks(bs []blocks.Block) ([]*cid.Cid, error) {
 
 // GetBlock retrieves a particular block from the service,
 // Getting it from the datastore using the key (hash).
-func (s *BlockService) GetBlock(ctx context.Context, c *cid.Cid) (blocks.Block, error) {
+func (s *blockService) GetBlock(ctx context.Context, c *cid.Cid) (blocks.Block, error) {
 	log.Debugf("BlockService GetBlock: '%s'", c)
 
-	block, err := s.Blockstore.Get(c)
+	block, err := s.blockstore.Get(c)
 	if err == nil {
 		return block, nil
 	}
 
-	if err == blockstore.ErrNotFound && s.Exchange != nil {
+	if err == blockstore.ErrNotFound && s.exchange != nil {
 		// TODO be careful checking ErrNotFound. If the underlying
 		// implementation changes, this will break.
 		log.Debug("Blockservice: Searching bitswap")
-		blk, err := s.Exchange.GetBlock(ctx, c)
+		blk, err := s.exchange.GetBlock(ctx, c)
 		if err != nil {
 			if err == blockstore.ErrNotFound {
 				return nil, ErrNotFound
@@ -137,13 +155,13 @@ func (s *BlockService) GetBlock(ctx context.Context, c *cid.Cid) (blocks.Block,
 // GetBlocks gets a list of blocks asynchronously and returns through
 // the returned channel.
 // NB: No guarantees are made about order.
-func (s *BlockService) GetBlocks(ctx context.Context, ks []*cid.Cid) <-chan blocks.Block {
+func (s *blockService) GetBlocks(ctx context.Context, ks []*cid.Cid) <-chan blocks.Block {
 	out := make(chan blocks.Block, 0)
 	go func() {
 		defer close(out)
 		var misses []*cid.Cid
 		for _, c := range ks {
-			hit, err := s.Blockstore.Get(c)
+			hit, err := s.blockstore.Get(c)
 			if err != nil {
 				misses = append(misses, c)
 				continue
@@ -160,7 +178,7 @@ func (s *BlockService) GetBlocks(ctx context.Context, ks []*cid.Cid) <-chan bloc
 			return
 		}
 
-		rblocks, err := s.Exchange.GetBlocks(ctx, misses)
+		rblocks, err := s.exchange.GetBlocks(ctx, misses)
 		if err != nil {
 			log.Debugf("Error with GetBlocks: %s", err)
 			return
@@ -178,11 +196,11 @@ func (s *BlockService) GetBlocks(ctx context.Context, ks []*cid.Cid) <-chan bloc
 }
 
 // DeleteBlock deletes a block in the blockservice from the datastore
-func (s *BlockService) DeleteBlock(o blocks.Block) error {
-	return s.Blockstore.DeleteBlock(o.Cid())
+func (s *blockService) DeleteBlock(o blocks.Block) error {
+	return s.blockstore.DeleteBlock(o.Cid())
 }
 
-func (s *BlockService) Close() error {
+func (s *blockService) Close() error {
 	log.Debug("blockservice is shutting down...")
-	return s.Exchange.Close()
+	return s.exchange.Close()
 }

test/mock.go

@@ -9,13 +9,13 @@ import (
 )
 
 // Mocks returns |n| connected mock Blockservices
-func Mocks(n int) []*BlockService {
+func Mocks(n int) []BlockService {
 	net := tn.VirtualNetwork(mockrouting.NewServer(), delay.Fixed(0))
 	sg := bitswap.NewTestSessionGenerator(net)
 
 	instances := sg.Instances(n)
 
-	var servs []*BlockService
+	var servs []BlockService
 	for _, i := range instances {
 		servs = append(servs, New(i.Blockstore(), i.Exchange))
 	}