Update getLocalChain, update tests, add UpToDate for blockchain sync

app/app.go

@@ -53,7 +53,7 @@ func Run(cfg conf.Config) {
 	a := App{
 		PeerStore:        peer.NewPeerStore(addr),
 		CurrentUser:      user,
-		Chain:            getLocalChain(user),
+		Chain:            createBlockchain(user),
 		Pool:             getLocalPool(),
 		blockQueue:       make(chan *blockchain.Block, blockQueueSize),
 		transactionQueue: make(chan *blockchain.Transaction, transactionQueueSize),
@@ -171,6 +171,8 @@ func (a *App) RequestHandler(req *msg.Request) msg.Response {
 		"Resource not found.")
 	badRequestErr := msg.NewProtocolError(msg.BadRequest,
 		"Bad request")
+	upToDateErr := msg.NewProtocolError(msg.UpToDate,
+		"The requested block has not yet been mined")
 
 	switch req.ResourceType {
 	case msg.ResourcePeerInfo:
@@ -190,6 +192,9 @@ func (a *App) RequestHandler(req *msg.Request) msg.Response {
 		if err != nil {
 			res.Error = badRequestErr
 			break
+		} else if len(a.Chain.Blocks) > 0 && hash == blockchain.HashSum(a.Chain.LastBlock()) {
+			res.Error = upToDateErr
+			break
 		}
 
 		block, err := a.Chain.GetBlockByLastBlockHash(hash)
@@ -230,19 +235,19 @@ func (a *App) PushHandler(push *msg.Push) {
 	}
 }
 
-// getLocalChain returns an instance of the blockchain.
-func getLocalChain(user *User) *blockchain.BlockChain {
-	// TODO: Look for local chain on disk. If doesn't exist, go rummaging
+// createBlockchain returns a new instance of a blockchain with only a genesis
+// block.
+func createBlockchain(user *User) *blockchain.BlockChain {
 	// around on the internets for one.
 	bc := blockchain.BlockChain{
 		Blocks: make([]*blockchain.Block, 0),
 		Head:   blockchain.NilHash,
 	}
 
-	genisisBlock := blockchain.Genesis(user.Wallet.Public(),
+	genesisBlock := blockchain.Genesis(user.Wallet.Public(),
 		consensus.CurrentTarget(), consensus.StartingBlockReward, []byte{})
 
-	bc.AppendBlock(genisisBlock)
+	bc.AppendBlock(genesisBlock)
 	return &bc
 }
 
@@ -344,7 +349,6 @@ func (a *App) Mine() {
 // to any peers.
 func (a *App) SyncBlockChain() (bool, error) {
 	var currentHeadHash blockchain.Hash
-	prevHead := a.Chain.LastBlock()
 	newBlockChan := make(chan *blockchain.Block)
 	errChan := make(chan *msg.ProtocolError)
 	changed := false
@@ -364,7 +368,6 @@ func (a *App) SyncBlockChain() (bool, error) {
 
 		block, err := blockchain.DecodeBlockJSON(blockBytes)
 		if err != nil {
-			log.WithError(err).Error("Error decoding block")
 			newBlockChan <- nil
 			return
 		}
@@ -424,17 +427,14 @@ func (a *App) SyncBlockChain() (bool, error) {
 			a.Chain.AppendBlock(newBlock)
 			changed = true
 
-			if (&newBlock.BlockHeader).Equal(&prevHead.BlockHeader) {
-				// Our blockchain is up to date
-				return changed, nil
-			}
-
 		case err := <-errChan:
 			if err.Code == msg.ResourceNotFound {
 				// Our chain might be out of sync, roll it back by one block
 				// and request the next block
-				prevHead = a.Chain.RollBack()
+				a.Chain.RollBack()
 				changed = true
+			} else if err.Code == msg.UpToDate {
+				return changed, nil
 			}
 
 			// Some other protocol error occurred. Try again

app/app_test.go

@@ -48,18 +48,17 @@ func TestPushHandlerNewTestTransaction(t *testing.T) {
 	}
 }
 
-// TODO: Enable once block request by hash implemented.
-// func TestRequestHandlerNewBlockOK(t *testing.T) {
-// 	// Request a new block by hash and verify we get the right one.
-// 	a := createNewTestApp()
+func TestRequestHandlerNewBlockOK(t *testing.T) {
+	// Request a new block by hash and verify we get the right one.
+	a := createNewTestApp()
 
-// 	req := createNewTestBlockRequest(a.Chain.Blocks[1].LastBlock)
-// 	resp := a.RequestHandler(req)
-// 	block, ok := resp.Resource.(*blockchain.Block)
+	req := createNewTestBlockRequest(a.Chain.Blocks[1].LastBlock)
+	resp := a.RequestHandler(req)
+	block, ok := resp.Resource.(*blockchain.Block)
 
-// 	assert.True(t, ok, "resource should contain block")
-// 	assert.Equal(t, block, a.Chain.Blocks[1])
-// }
+	assert.True(t, ok, "resource should contain block")
+	assert.Equal(t, block, a.Chain.Blocks[1])
+}
 
 func TestRequestHandlerNewBlockBadParams(t *testing.T) {
 	a := createNewTestApp()
@@ -73,7 +72,7 @@ func TestRequestHandlerNewBlockBadParams(t *testing.T) {
 
 	// Make sure request failed.
 	assert.False(t, ok, "resource should not contain block")
-	assert.Equal(t, msg.ResourceNotFound, int(resp.Error.Code), resp.Error.Message)
+	assert.Equal(t, msg.BadRequest, int(resp.Error.Code), resp.Error.Message)
 }
 
 func TestRequestHandlerNewBlockBadType(t *testing.T) {
@@ -161,8 +160,8 @@ func TestGetLocalPool(t *testing.T) {
 	assert.NotNil(t, getLocalPool())
 }
 
-func TestGetLocalChain(t *testing.T) {
-	assert.NotNil(t, getLocalChain(NewUser()))
+func TestCreateBlockchain(t *testing.T) {
+	assert.NotNil(t, createBlockchain(NewUser()))
 }
 
 func TestHandleBlock(t *testing.T) {

app/test_utils.go

@@ -7,9 +7,9 @@ import (
 	"github.com/ubclaunchpad/cumulus/pool"
 )
 
-func createNewTestBlockRequest(lastBlock interface{}) *msg.Request {
+func createNewTestBlockRequest(lastBlockHash interface{}) *msg.Request {
 	params := make(map[string]interface{}, 1)
-	params["lastBlock"] = lastBlock
+	params["lastBlockHash"] = lastBlockHash
 	return &msg.Request{
 		ResourceType: msg.ResourceBlock,
 		Params:       params,

msg/message.go

@@ -33,16 +33,20 @@ const (
 )
 
 const (
-	// BadRequest occurs when a malformatted request is received
+	// BadRequest occurs when a malformatted request is received.
 	BadRequest = 400
 	// InvalidResourceType occurs when a request is received with an unknown
 	// ResourceType value.
 	InvalidResourceType = 401
+	// ResourceNotFound occurs when a node reports the requested resource missing.
+	ResourceNotFound = 404
 	// RequestTimeout occurs when a peer does not respond to a request within
 	// some predefined period of time (see peer.DefaultRequestTimeout)
 	RequestTimeout = 408
-	// ResourceNotFound occurs when a node reports the requested resource missing.
-	ResourceNotFound = 404
+	// UpToDate occurs when a block request is received for a block that has
+	// not yet been mined (i.e. the lastBlockHash param in the request is the
+	// hash of the latest block in the blockchain).
+	UpToDate = 416
 	// NotImplemented occurs when a message or request is received whos response
 	// requires functionality that does not yet exist.
 	NotImplemented = 501

peer/peer.go

@@ -142,7 +142,7 @@ func (p *Peer) Dispatch() {
 			res := message.(*msg.Response)
 			rh := p.getResponseHandler(res.ID)
 			if rh == nil {
-				log.Error("Dispatcher could not find response handler for response on peer",
+				log.Errorf("Dispatcher could not find response handler for response on peer %s",
 					p.ListenAddr)
 			} else {
 				rh(res)