[FAB-1944] Part 3: Remove duplicate code

https://jira.hyperledger.org/browse/FAB-1944

Some of the OrPanic methods were copy-pasted versions of the original
method, replacing error returns with panics.  This is code duplication
and should be removed.

Change-Id: Ib73914aa5392103ec698f1ced3bdf8dc11f3e6b5
Signed-off-by: Jason Yellick <[email protected]>

Author: Jason Yellick

protos/utils/blockutils.go

@@ -57,8 +57,7 @@ func GetMetadataFromBlock(block *cb.Block, index cb.BlockMetadataIndex) (*cb.Met
 
 // GetMetadataFromBlockOrPanic retrieves metadata at the specified index, or panics on error.
 func GetMetadataFromBlockOrPanic(block *cb.Block, index cb.BlockMetadataIndex) *cb.Metadata {
-	md := &cb.Metadata{}
-	err := proto.Unmarshal(block.Metadata.Metadata[index], md)
+	md, err := GetMetadataFromBlock(block, index)
 	if err != nil {
 		panic(err)
 	}
@@ -81,16 +80,11 @@ func GetLastConfigurationIndexFromBlock(block *cb.Block) (uint64, error) {
 
 // GetLastConfigurationIndexFromBlockOrPanic retrieves the index of the last configuration block as encoded in the block metadata, or panics on error.
 func GetLastConfigurationIndexFromBlockOrPanic(block *cb.Block) uint64 {
-	md, err := GetMetadataFromBlock(block, cb.BlockMetadataIndex_LAST_CONFIGURATION)
-	if err != nil {
-		panic(err)
-	}
-	lc := &cb.LastConfiguration{}
-	err = proto.Unmarshal(md.Value, lc)
+	index, err := GetLastConfigurationIndexFromBlock(block)
 	if err != nil {
 		panic(err)
 	}
-	return lc.Index
+	return index
 }
 
 // GetBlockFromBlockBytes marshals the bytes into Block

protos/utils/commonutils.go

@@ -103,14 +103,9 @@ func UnmarshalEnvelope(encoded []byte) (*cb.Envelope, error) {
 
 // ExtractEnvelopeOrPanic retrieves the requested envelope from a given block and unmarshals it -- it panics if either of these operation fail.
 func ExtractEnvelopeOrPanic(block *cb.Block, index int) *cb.Envelope {
-	envelopeCount := len(block.Data.Data)
-	if index < 0 || index >= envelopeCount {
-		panic("Envelope index out of bounds")
-	}
-	marshaledEnvelope := block.Data.Data[index]
-	envelope := &cb.Envelope{}
-	if err := proto.Unmarshal(marshaledEnvelope, envelope); err != nil {
-		panic(fmt.Errorf("Block data does not carry an envelope at index %d: %s", index, err))
+	envelope, err := ExtractEnvelope(block, index)
+	if err != nil {
+		panic(err)
 	}
 	return envelope
 }
@@ -131,9 +126,9 @@ func ExtractEnvelope(block *cb.Block, index int) (*cb.Envelope, error) {
 
 // ExtractPayloadOrPanic retrieves the payload of a given envelope and unmarshals it -- it panics if either of these operations fail.
 func ExtractPayloadOrPanic(envelope *cb.Envelope) *cb.Payload {
-	payload := &cb.Payload{}
-	if err := proto.Unmarshal(envelope.Payload, payload); err != nil {
-		panic(fmt.Errorf("Envelope does not carry a Payload: %s", err))
+	payload, err := ExtractPayload(envelope)
+	if err != nil {
+		panic(err)
 	}
 	return payload
 }