[FAB-1278] Generalize Config Execution Path

For the impending chain creation work, a second type of transaction will
need to be 'executed' beyond a configuration transaction.  This
changeset generalizes the old configuration specific code paths into a
re-usable path.

In particular, the broadcast filters have been generalized to be a more
generic filtering mechanism.  Instead of replying with the matched rule
type, and then having the invoker make decisions based on the match, the
filters now return a Committer which can perform those actions with no
specific knowledge from the caller.

The configuration transaction was being treated specially in several
parts of the orderer code.  This created ugly case switching and
ultimately produced more code than with a more generic approach.  So
this changeset produces a net decrease in overall lines of code.

Change-Id: Ifaa769a0303f828de1d76e0a014e47d9044756ce
Signed-off-by: Jason Yellick <jyellick@us.ibm.com>

orderer/common/blockcutter/blockcutter.go

@@ -17,11 +17,9 @@ limitations under the License.
 package blockcutter
 
 import (
-	"github.com/hyperledger/fabric/orderer/common/broadcastfilter"
-	"github.com/hyperledger/fabric/orderer/common/configtx"
+	"github.com/hyperledger/fabric/orderer/common/filter"
 	cb "github.com/hyperledger/fabric/protos/common"
 
-	"github.com/golang/protobuf/proto"
 	"github.com/op/go-logging"
 )
 
@@ -34,98 +32,79 @@ func init() {
 // Receiver defines a sink for the ordered broadcast messages
 type Receiver interface {
 	// Ordered should be invoked sequentially as messages are ordered
-	// If the message is a valid normal message and does not fill the batch, nil, true is returned
-	// If the message is a valid normal message and fills a batch, the batch, true is returned
+	// If the message is a valid normal message and does not fill the batch, nil, nil, true is returned
+	// If the message is a valid normal message and fills a batch, the batch, committers, true is returned
 	// If the message is a valid special message (like a config message) it terminates the current batch
-	// and returns the current batch (if it is not empty), plus a second batch containing the special transaction and true
-	// If the ordered message is determined to be invalid, then nil, false is returned
-	Ordered(msg *cb.Envelope) ([][]*cb.Envelope, bool)
+	// and returns the current batch and committers (if it is not empty), plus a second batch containing the special transaction and commiter, and true
+	// If the ordered message is determined to be invalid, then nil, nil, false is returned
+	Ordered(msg *cb.Envelope) ([][]*cb.Envelope, [][]filter.Committer, bool)
 
 	// Cut returns the current batch and starts a new one
-	Cut() []*cb.Envelope
+	Cut() ([]*cb.Envelope, []filter.Committer)
 }
 
 type receiver struct {
-	batchSize     int
-	filters       *broadcastfilter.RuleSet
-	configManager configtx.Manager
-	curBatch      []*cb.Envelope
+	batchSize int
+	filters   *filter.RuleSet
+	curBatch  []*cb.Envelope
+	batchComs []filter.Committer
 }
 
 // NewReceiverImpl creates a Receiver implementation based on the given batchsize, filters, and configtx manager
-func NewReceiverImpl(batchSize int, filters *broadcastfilter.RuleSet, configManager configtx.Manager) Receiver {
+func NewReceiverImpl(batchSize int, filters *filter.RuleSet) Receiver {
 	return &receiver{
-		batchSize:     batchSize,
-		filters:       filters,
-		configManager: configManager,
+		batchSize: batchSize,
+		filters:   filters,
 	}
 }
 
 // Ordered should be invoked sequentially as messages are ordered
-// If the message is a valid normal message and does not fill the batch, nil, true is returned
-// If the message is a valid normal message and fills a batch, the batch, true is returned
+// If the message is a valid normal message and does not fill the batch, nil, nil, true is returned
+// If the message is a valid normal message and fills a batch, the batch, committers, true is returned
 // If the message is a valid special message (like a config message) it terminates the current batch
-// and returns the current batch (if it is not empty), plus a second batch containing the special transaction and true
-// If the ordered message is determined to be invalid, then nil, false is returned
-func (r *receiver) Ordered(msg *cb.Envelope) ([][]*cb.Envelope, bool) {
+// and returns the current batch and committers (if it is not empty), plus a second batch containing the special transaction and commiter, and true
+// If the ordered message is determined to be invalid, then nil, nil, false is returned
+func (r *receiver) Ordered(msg *cb.Envelope) ([][]*cb.Envelope, [][]filter.Committer, bool) {
 	// The messages must be filtered a second time in case configuration has changed since the message was received
-	action, _ := r.filters.Apply(msg)
-	switch action {
-	case broadcastfilter.Accept:
-		logger.Debugf("Enqueuing message into batch")
-		r.curBatch = append(r.curBatch, msg)
-
-		if len(r.curBatch) < r.batchSize {
-			return nil, true
-		}
-
-		logger.Debugf("Batch size met, creating block")
-		newBatch := r.curBatch
-		r.curBatch = nil
-		return [][]*cb.Envelope{newBatch}, true
-	case broadcastfilter.Reconfigure:
-		// TODO, this is unmarshaling for a second time, we need a cleaner interface, maybe Apply returns a second arg with thing to put in the batch
-		payload := &cb.Payload{}
-		if err := proto.Unmarshal(msg.Payload, payload); err != nil {
-			logger.Errorf("A change was flagged as configuration, but could not be unmarshaled: %v", err)
-			return nil, false
-		}
-		newConfig := &cb.ConfigurationEnvelope{}
-		if err := proto.Unmarshal(payload.Data, newConfig); err != nil {
-			logger.Errorf("A change was flagged as configuration, but could not be unmarshaled: %v", err)
-			return nil, false
-		}
-		err := r.configManager.Validate(newConfig)
-		if err != nil {
-			logger.Warningf("A configuration change made it through the ingress filter but could not be included in a batch: %v", err)
-			return nil, false
-		}
+	committer, err := r.filters.Apply(msg)
+	if err != nil {
+		logger.Debugf("Rejecting message: %s", err)
+		return nil, nil, false
+	}
 
-		logger.Debugf("Configuration change applied successfully, committing previous block and configuration block")
+	if committer.Isolated() {
+		logger.Debugf("Found message which requested to be isolated, cutting into its own block")
 		firstBatch := r.curBatch
 		r.curBatch = nil
+		firstComs := r.batchComs
+		r.batchComs = nil
 		secondBatch := []*cb.Envelope{msg}
 		if firstBatch == nil {
-			return [][]*cb.Envelope{secondBatch}, true
+			return [][]*cb.Envelope{secondBatch}, [][]filter.Committer{[]filter.Committer{committer}}, true
 		}
-		return [][]*cb.Envelope{firstBatch, secondBatch}, true
-	case broadcastfilter.Reject:
-		logger.Debugf("Rejecting message")
-		return nil, false
-	case broadcastfilter.Forward:
-		logger.Debugf("Ignoring message because it was not accepted by a filter")
-		return nil, false
-	default:
-		logger.Fatalf("Received an unknown rule response: %v", action)
+		return [][]*cb.Envelope{firstBatch, secondBatch}, [][]filter.Committer{firstComs, []filter.Committer{committer}}, true
 	}
 
-	return nil, false // Unreachable
+	logger.Debugf("Enqueuing message into batch")
+	r.curBatch = append(r.curBatch, msg)
+	r.batchComs = append(r.batchComs, committer)
 
+	if len(r.curBatch) < r.batchSize {
+		return nil, nil, true
+	}
+
+	logger.Debugf("Batch size met, creating block")
+	newBatch := r.curBatch
+	newComs := r.batchComs
+	r.curBatch = nil
+	return [][]*cb.Envelope{newBatch}, [][]filter.Committer{newComs}, true
 }
 
 // Cut returns the current batch and starts a new one
-func (r *receiver) Cut() []*cb.Envelope {
+func (r *receiver) Cut() ([]*cb.Envelope, []filter.Committer) {
 	batch := r.curBatch
 	r.curBatch = nil
-	return batch
+	committers := r.batchComs
+	r.batchComs = nil
+	return batch, committers
 }