split AssembledBlock/ProposableBlock

agreement/abstractions.go

@@ -77,19 +77,24 @@ type BlockFactory interface {
 	// produce a AssembledBlock for the given round. If an insufficient number of
 	// nodes on the network can assemble entries, the agreement protocol may
 	// lose liveness.
-	AssembleBlock(basics.Round) (AssembledBlock, error)
+	AssembleBlock(rnd basics.Round, partAddresses []basics.Address) (AssembledBlock, error)
 }
 
 // An AssembledBlock represents a Block produced by a BlockFactory
-// and can now be proposed by agreement.
+// and must be finalized before being proposed by agreement.
 type AssembledBlock interface {
 	// WithSeed creates a copy of this AssembledBlock with its
 	// cryptographically random seed set to the given value.
 	//
 	// Calls to Seed() or to Digest() on the copy's Block must
 	// reflect the value of the new seed.
-	WithSeed(committee.Seed) AssembledBlock
+	FinalizeBlock(seed committee.Seed, proposer basics.Address) ProposableBlock
+}
 
+// An ProposableBlock represents a Block produced by a BlockFactory,
+// that was later finalized by providing the seed and the proposer,
+// and can now be proposed by agreement.
+type ProposableBlock interface {
 	// Block returns the underlying block that has been assembled.
 	Block() bookkeeping.Block
 }

agreement/proposal.go

@@ -103,7 +103,7 @@ type proposal struct {
 
 // makeProposalFromAssembledBlock is called when making a new proposal message,
 // using the output of AssembleBlock (from makeProposals -> proposalForBlock)
-func makeProposalFromAssembledBlock(blk AssembledBlock, pf crypto.VrfProof, origPer period, origProp basics.Address) proposal {
+func makeProposalFromAssembledBlock(blk ProposableBlock, pf crypto.VrfProof, origPer period, origProp basics.Address) proposal {
 	e := blk.Block()
 	var payload unauthenticatedProposal
 	payload.Block = e
@@ -265,8 +265,8 @@ func proposalForBlock(address basics.Address, vrf *crypto.VRFSecrets, blk Assemb
 		return proposal{}, proposalValue{}, fmt.Errorf("proposalForBlock: could not derive new seed: %v", err)
 	}
 
-	blk = blk.WithSeed(newSeed)
-	prop := makeProposalFromAssembledBlock(blk, seedProof, period, address)
+	proposableBlock := blk.FinalizeBlock(newSeed, address)
+	prop := makeProposalFromAssembledBlock(proposableBlock, seedProof, period, address)
 	value := proposalValue{
 		OriginalPeriod:   period,
 		OriginalProposer: address,

agreement/pseudonode.go

@@ -284,7 +284,7 @@ func (n asyncPseudonode) makePseudonodeVerifier(voteVerifier *AsyncVoteVerifier)
 
 // makeProposals creates a slice of block proposals for the given round and period.
 func (n asyncPseudonode) makeProposals(round basics.Round, period period, accounts []account.ParticipationRecordForRound) ([]proposal, []unauthenticatedVote) {
-	ve, err := n.factory.AssembleBlock(round)
+	ve, err := n.factory.AssembleBlock(round, accounts)
 	if err != nil {
 		if err != ErrAssembleBlockRoundStale {
 			n.log.Errorf("pseudonode.makeProposals: could not generate a proposal for round %d: %v", round, err)