Define semantics for block metadata array positions

Created an enum to define human readable semantic for
block metadata array content.

Change-Id: I0b55340c3aa720d563d87d3e2ebc7cdb1b26c8f9
Signed-off-by: Artem Barger <[email protected]>

Author: C0rWin

protos/common/block.go

@@ -28,7 +28,9 @@ func NewBlock(seqNum uint64, previousHash []byte) *Block {
 	block.Header.Number = seqNum
 	block.Header.PreviousHash = previousHash
 	block.Data = &BlockData{}
-	block.Metadata = &BlockMetadata{}
+	block.Metadata = &BlockMetadata{
+		Metadata: [][]byte{[]byte{}, []byte{}, []byte{}},
+	}
 	return block
 }
 

protos/common/common.pb.go

@@ -41,6 +41,13 @@ enum HeaderType {
         ENDORSER_TRANSACTION = 3;      // Used by the SDK to submit endorser based transactions
 }
 
+// This enum enlist indexes of the block metadata array
+enum BlockMetadataIndex {
+    SIGNATURES = 0;             // Block metadata array position for block signatures
+    LAST_CONFIGURATION = 1;     // Block metadata array poistion to store last configuration block sequence number
+    TRANSACTIONS_FILTER = 2;    // Block metadata array poistion to store serialized bit array filter of invalid transactions
+}
+
 message Header {
     ChainHeader chainHeader = 1;
     SignatureHeader signatureHeader = 2;