core: NotaryAck interfaces. (#67)

10 files changed, 132 insertions, 67 deletions

diff --git a/core/application.go b/core/application.go
index 5bd325c..e39e238 100644
--- a/core/application.go
+++ b/core/application.go
@@ -21,6 +21,7 @@ import (
 	"time"
 
 	"github.com/dexon-foundation/dexon-consensus-core/common"
+	"github.com/dexon-foundation/dexon-consensus-core/core/types"
 )
 
 // Application describes the application interface that interacts with DEXON
@@ -34,4 +35,7 @@ type Application interface {
 
 	// DeliverBlock is called when a block is add to the compaction chain.
 	DeliverBlock(blockHash common.Hash, timestamp time.Time)
+
+	// NotaryAck is called when a notary ack is created.
+	NotaryAck(notaryAck types.NotaryAck)
 }
diff --git a/core/compaction-chain.go b/core/compaction-chain.go
index f2b4d1b..664b692 100644
--- a/core/compaction-chain.go
+++ b/core/compaction-chain.go
@@ -20,24 +20,37 @@
 package core
 
 import (
+	"fmt"
 	"sync"
 
-	//"github.com/dexon-foundation/dexon-consensus-core/common"
 	"github.com/dexon-foundation/dexon-consensus-core/core/types"
 	"github.com/dexon-foundation/dexon-consensus-core/crypto"
 )
 
+// Errors for compaction chain.
+var (
+	ErrIncorrectNotaryAck = fmt.Errorf(
+		"compaction chain notary of block is incorrect")
+)
+
 type compactionChain struct {
-	prevBlock *types.Block
-	lock      sync.RWMutex
+	prevBlock        *types.Block
+	lock             sync.RWMutex
+	latestNotaryAcks map[types.ValidatorID]types.NotaryAck
 }
 
 func newCompactionChain() *compactionChain {
 	return &compactionChain{}
 }
 
-func (cc *compactionChain) prepareBlock(
-	block *types.Block, prvKey crypto.PrivateKey) (err error) {
+func (cc *compactionChain) sanityCheck(notaryAck types.NotaryAck) bool {
+	return true
+}
+
+func (cc *compactionChain) processBlock(block *types.Block) (err error) {
+	cc.lock.Lock()
+	defer cc.lock.Unlock()
+	cc.prevBlock = block
 	/*
 		prevBlock := cc.lastBlock()
 		if prevBlock != nil {
@@ -51,8 +64,18 @@ func (cc *compactionChain) prepareBlock(
 	*/
 	return
 }
+func (cc *compactionChain) prepareNotaryAck(prvKey crypto.PrivateKey) (
+	notaryAck types.NotaryAck, err error) {
+	notaryAck.NotaryBlockHash = cc.lastBlock().Hash
+	return
+}
 
-func (cc *compactionChain) processBlock(block *types.Block) (err error) {
+func (cc *compactionChain) processNotaryAck(notaryAck types.NotaryAck) (
+	err error) {
+	if !cc.sanityCheck(notaryAck) {
+		err = ErrIncorrectNotaryAck
+		return
+	}
 	/*
 		prevBlock := cc.lastBlock()
 		if prevBlock == nil {
@@ -69,9 +92,14 @@ func (cc *compactionChain) processBlock(block *types.Block) (err error) {
 		defer cc.lock.Unlock()
 		cc.prevBlock = block
 	*/
+	cc.latestNotaryAcks[notaryAck.ProposerID] = notaryAck
 	return
 }
 
+func (cc *compactionChain) notaryAcks() map[types.ValidatorID]types.NotaryAck {
+	return cc.latestNotaryAcks
+}
+
 func (cc *compactionChain) lastBlock() *types.Block {
 	cc.lock.RLock()
 	defer cc.lock.RUnlock()
diff --git a/core/consensus.go b/core/consensus.go
index 3e8f87d..0b4ea62 100644
--- a/core/consensus.go
+++ b/core/consensus.go
@@ -48,8 +48,6 @@ var (
 		"hash of block is incorrect")
 	ErrIncorrectSignature = fmt.Errorf(
 		"signature of block is incorrect")
-	ErrIncorrectNotaryAck = fmt.Errorf(
-		"compaction chain notary of block is incorrect")
 	ErrGenesisBlockNotEmpty = fmt.Errorf(
 		"genesis block should be empty")
 )
@@ -204,6 +202,12 @@ func (con *Consensus) ProcessBlock(blockConv types.BlockConverter) (err error) {
 			}
 			con.app.DeliverBlock(b.Hash, b.Notary.Timestamp)
 		}
+		var notaryAck types.NotaryAck
+		notaryAck, err = con.ccModule.prepareNotaryAck(con.prvKey)
+		if err != nil {
+			return
+		}
+		con.app.NotaryAck(notaryAck)
 	}
 	return
 }
@@ -237,10 +241,6 @@ func (con *Consensus) PrepareBlock(blockConv types.BlockConverter,
 	if err != nil {
 		return
 	}
-	err = con.ccModule.prepareBlock(b, con.prvKey)
-	if err != nil {
-		return
-	}
 	blockConv.SetBlock(b)
 	return
 }
@@ -275,3 +275,19 @@ func (con *Consensus) PrepareGenesisBlock(blockConv types.BlockConverter,
 	blockConv.SetBlock(b)
 	return
 }
+
+// ProcessNotaryAck is the entry point to submit one notary ack.
+func (con *Consensus) ProcessNotaryAck(notaryAck types.NotaryAck) (err error) {
+	err = con.ccModule.processNotaryAck(notaryAck)
+	return
+}
+
+// NotaryAcks returns the latest NotaryAck received from all other validators.
+func (con *Consensus) NotaryAcks() (
+	notaryAcks map[types.ValidatorID]types.NotaryAck) {
+	notaryAcks = make(map[types.ValidatorID]types.NotaryAck)
+	for k, v := range con.ccModule.notaryAcks() {
+		notaryAcks[k] = v
+	}
+	return
+}
diff --git a/core/crypto.go b/core/crypto.go
index 664607b..0de73af 100644
--- a/core/crypto.go
+++ b/core/crypto.go
@@ -34,7 +34,7 @@ func hashNotary(block *types.Block) (common.Hash, error) {
 	binaryHeight := make([]byte, 8)
 	binary.LittleEndian.PutUint64(binaryHeight, block.Notary.Height)
 	hash := crypto.Keccak256Hash(
-		block.NotaryParentHash[:],
+		block.Notary.ParentHash[:],
 		binaryTime,
 		binaryHeight)
 	return hash, nil
diff --git a/core/crypto_test.go b/core/crypto_test.go
index 94b500e..3aa1674 100644
--- a/core/crypto_test.go
+++ b/core/crypto_test.go
@@ -69,19 +69,14 @@ func (s *CryptoTestSuite) prepareBlock(prevBlock *types.Block) *types.Block {
 	s.Require().NotEqual(prevBlock.Hash, common.Hash{})
 	acks[parentHash] = struct{}{}
 	return &types.Block{
-		ParentHash:       prevBlock.Hash,
-		Acks:             acks,
-		Timestamps:       timestamps,
-		NotaryParentHash: parentHash,
-		Height:           prevBlock.Height + 1,
-		/*
-			NotaryAck: types.NotaryAck{
-				NotaryBlockHash: prevBlock.Hash,
-			},
-		*/
+		ParentHash: prevBlock.Hash,
+		Acks:       acks,
+		Timestamps: timestamps,
+		Height:     prevBlock.Height + 1,
 		Notary: types.Notary{
-			Timestamp: time.Now(),
-			Height:    prevBlock.Notary.Height + 1,
+			ParentHash: parentHash,
+			Timestamp:  time.Now(),
+			Height:     prevBlock.Notary.Height + 1,
 		},
 	}
 }
@@ -104,7 +99,7 @@ func (s *CryptoTestSuite) generateCompactionChain(
 		blocks[idx] = block
 		var err error
 		if idx > 0 {
-			block.NotaryParentHash, err = hashNotary(blocks[idx-1])
+			block.Notary.ParentHash, err = hashNotary(blocks[idx-1])
 			s.Require().Nil(err)
 			/*
 				block.NotaryAck.NotarySignature, err =
diff --git a/core/nonblocking-application.go b/core/nonblocking-application.go
index 4c06ab9..a04d7d2 100644
--- a/core/nonblocking-application.go
+++ b/core/nonblocking-application.go
@@ -23,6 +23,7 @@ import (
 	"time"
 
 	"github.com/dexon-foundation/dexon-consensus-core/common"
+	"github.com/dexon-foundation/dexon-consensus-core/core/types"
 )
 
 type stronglyAckedEvent struct {
@@ -124,3 +125,7 @@ func (app *nonBlockingApplication) DeliverBlock(
 	blockHash common.Hash, timestamp time.Time) {
 	app.addEvent(deliverBlockEvent{blockHash, timestamp})
 }
+
+// NotaryAck is called when a notary ack is created.
+func (app *nonBlockingApplication) NotaryAck(notaryAck types.NotaryAck) {
+}
diff --git a/core/nonblocking-application_test.go b/core/nonblocking-application_test.go
index 070eae3..0f7d7f2 100644
--- a/core/nonblocking-application_test.go
+++ b/core/nonblocking-application_test.go
@@ -24,6 +24,7 @@ import (
 	"github.com/stretchr/testify/suite"
 
 	"github.com/dexon-foundation/dexon-consensus-core/common"
+	"github.com/dexon-foundation/dexon-consensus-core/core/types"
 )
 
 type slowApp struct {
@@ -31,6 +32,7 @@ type slowApp struct {
 	stronglyAcked        map[common.Hash]struct{}
 	totalOrderingDeliver map[common.Hash]struct{}
 	deliverBlock         map[common.Hash]struct{}
+	notaryAck            map[common.Hash]struct{}
 }
 
 func newSlowApp(sleep time.Duration) *slowApp {
@@ -39,6 +41,7 @@ func newSlowApp(sleep time.Duration) *slowApp {
 		stronglyAcked:        make(map[common.Hash]struct{}),
 		totalOrderingDeliver: make(map[common.Hash]struct{}),
 		deliverBlock:         make(map[common.Hash]struct{}),
+		notaryAck:            make(map[common.Hash]struct{}),
 	}
 }
 
@@ -59,6 +62,11 @@ func (app *slowApp) DeliverBlock(blockHash common.Hash, timestamp time.Time) {
 	app.deliverBlock[blockHash] = struct{}{}
 }
 
+func (app *slowApp) NotaryAck(notaryAck types.NotaryAck) {
+	time.Sleep(app.sleep)
+	app.notaryAck[notaryAck.Hash] = struct{}{}
+}
+
 type NonBlockingAppTestSuite struct {
 	suite.Suite
 }
diff --git a/core/test/app.go b/core/test/app.go
index 5c438a7..4a704a0 100644
--- a/core/test/app.go
+++ b/core/test/app.go
@@ -23,6 +23,7 @@ import (
 	"time"
 
 	"github.com/dexon-foundation/dexon-consensus-core/common"
+	"github.com/dexon-foundation/dexon-consensus-core/core/types"
 )
 
 var (
@@ -105,6 +106,10 @@ func (app *App) DeliverBlock(blockHash common.Hash, timestamp time.Time) {
 	app.DeliverSequence = append(app.DeliverSequence, blockHash)
 }
 
+// NotaryAck implements Application interface.
+func (app *App) NotaryAck(notaryAck types.NotaryAck) {
+}
+
 // Compare performs these checks against another App instance
 // and return erros if not passed:
 // - deliver sequence by comparing block hashes.
diff --git a/core/types/block.go b/core/types/block.go
index 0386ed7..557974f 100644
--- a/core/types/block.go
+++ b/core/types/block.go
@@ -28,28 +28,6 @@ import (
 	"github.com/dexon-foundation/dexon-consensus-core/crypto"
 )
 
-// NotaryAck represents the acking to the compaction chain.
-type NotaryAck struct {
-	NotaryBlockHash common.Hash `json:"notary_block_hash"`
-	// NotarySignature is the signature of the hash value of
-	// Block.NotaryParentHash and Block.Notary.
-	NotarySignature crypto.Signature `json:"notary_signature"`
-}
-
-// CompactionChainAck represents the acking to the compaction chain.
-type CompactionChainAck struct {
-	AckingBlockHash common.Hash `json:"acking_block_hash"`
-	// Signature is the signature of the hash value of
-	// Block.ConsensusInfoParentHash and Block.ConsensusInfo.
-	ConsensusSignature crypto.Signature `json:"consensus_signature"`
-}
-
-// Notary represents the consensus information on the compaction chain.
-type Notary struct {
-	Timestamp time.Time `json:"timestamp"`
-	Height    uint64    `json:"height"`
-}
-
 // Block represents a single event broadcasted on the network.
 type Block struct {
 	ProposerID ValidatorID               `json:"proposer_id"`
@@ -58,16 +36,9 @@ type Block struct {
 	Height     uint64                    `json:"height"`
 	Timestamps map[ValidatorID]time.Time `json:"timestamps"`
 	Acks       map[common.Hash]struct{}  `json:"acks"`
-	//NotaryAck  NotaryAck                 `json:"notary_ack"`
-	Signature crypto.Signature `json:"signature"`
+	Signature  crypto.Signature          `json:"signature"`
 
 	Notary Notary `json:"notary"`
-	// NotaryParentHash is the hash value of Block.NotaryParentHash
-	// and Block.Notary, where Block is the previous block on
-	// the compaction chain.
-	NotaryParentHash common.Hash `json:"notary_parent_hash"`
-
-	ConsensusInfoParentHash common.Hash `json:"consensus_info_parent_hash"`
 }
 
 // Block implements BlockConverter interface.
@@ -106,22 +77,12 @@ func (b *Block) Clone() *Block {
 		Height:     b.Height,
 		Timestamps: make(map[ValidatorID]time.Time),
 		Acks:       make(map[common.Hash]struct{}),
-		/*
-			NotaryAck: NotaryAck{
-				NotaryBlockHash: b.NotaryAck.NotaryBlockHash,
-			},
-		*/
-		Signature: b.Signature,
+		Signature:  b.Signature,
 		Notary: Notary{
 			Timestamp: b.Notary.Timestamp,
 			Height:    b.Notary.Height,
 		},
-		NotaryParentHash: b.NotaryParentHash,
 	}
-	/*
-		bcopy.NotaryAck.NotarySignature = append(
-			crypto.Signature(nil), b.NotaryAck.NotarySignature...)
-	*/
 	for k, v := range b.Timestamps {
 		bcopy.Timestamps[k] = v
 	}
diff --git a/core/types/notary.go b/core/types/notary.go
new file mode 100644
index 0000000..01237b4
--- /dev/null
+++ b/core/types/notary.go
@@ -0,0 +1,43 @@
+// Copyright 2018 The dexon-consensus-core Authors
+// This file is part of the dexon-consensus-core library.
+//
+// The dexon-consensus-core library is free software: you can redistribute it
+// and/or modify it under the terms of the GNU Lesser General Public License as
+// published by the Free Software Foundation, either version 3 of the License,
+// or (at your option) any later version.
+//
+// The dexon-consensus-core library is distributed in the hope that it will be
+// useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
+// General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the dexon-consensus-core library. If not, see
+// <http://www.gnu.org/licenses/>.
+
+// TODO(jimmy-dexon): remove comments of NotaryAck before open source.
+
+package types
+
+import (
+	"time"
+
+	"github.com/dexon-foundation/dexon-consensus-core/common"
+	"github.com/dexon-foundation/dexon-consensus-core/crypto"
+)
+
+// NotaryAck represents the acking to the compaction chain.
+type NotaryAck struct {
+	ProposerID      ValidatorID `json:"proposer_id"`
+	NotaryBlockHash common.Hash `json:"notary_block_hash"`
+	Hash            common.Hash `json:"hash"`
+	// NotarySignature is the signature of the hash value of BlockNotary.
+	Signature crypto.Signature `json:"signature"`
+}
+
+// Notary represents the consensus information on the compaction chain.
+type Notary struct {
+	ParentHash common.Hash `json:"parent_hash"`
+	Timestamp  time.Time   `json:"timestamp"`
+	Height     uint64      `json:"height"`
+}