1 files changed, 164 insertions, 0 deletions
diff --git a/vendor/github.com/dexon-foundation/dexon-consensus-core/core/nonblocking.go b/vendor/github.com/dexon-foundation/dexon-consensus-core/core/nonblocking.go
new file mode 100644
index 000000000..675675b2f
--- /dev/null
+++ b/vendor/github.com/dexon-foundation/dexon-consensus-core/core/nonblocking.go
@@ -0,0 +1,164 @@
+// 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/>.
+
+package core
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/dexon-foundation/dexon-consensus-core/common"
+	"github.com/dexon-foundation/dexon-consensus-core/core/types"
+)
+
+type blockConfirmedEvent struct {
+	block *types.Block
+}
+
+type stronglyAckedEvent struct {
+	blockHash common.Hash
+}
+
+type totalOrderingDeliveredEvent struct {
+	blockHashes common.Hashes
+	mode        uint32
+}
+
+type blockDeliveredEvent struct {
+	blockHash common.Hash
+	result    *types.FinalizationResult
+}
+
+// nonBlocking implements these interfaces and is a decorator for
+// them that makes the methods to be non-blocking.
+//  - Application
+//  - Debug
+//  - It also provides nonblockig for blockdb update.
+type nonBlocking struct {
+	app          Application
+	debug        Debug
+	eventChan    chan interface{}
+	events       []interface{}
+	eventsChange *sync.Cond
+	running      sync.WaitGroup
+}
+
+func newNonBlocking(app Application, debug Debug) *nonBlocking {
+	nonBlockingModule := &nonBlocking{
+		app:          app,
+		debug:        debug,
+		eventChan:    make(chan interface{}, 6),
+		events:       make([]interface{}, 0, 100),
+		eventsChange: sync.NewCond(&sync.Mutex{}),
+	}
+	go nonBlockingModule.run()
+	return nonBlockingModule
+}
+
+func (nb *nonBlocking) addEvent(event interface{}) {
+	nb.eventsChange.L.Lock()
+	defer nb.eventsChange.L.Unlock()
+	nb.events = append(nb.events, event)
+	nb.eventsChange.Broadcast()
+}
+
+func (nb *nonBlocking) run() {
+	// This go routine consume the first event from events and call the
+	// corresponding methods of Application/Debug/blockdb.
+	for {
+		var event interface{}
+		func() {
+			nb.eventsChange.L.Lock()
+			defer nb.eventsChange.L.Unlock()
+			for len(nb.events) == 0 {
+				nb.eventsChange.Wait()
+			}
+			event = nb.events[0]
+			nb.events = nb.events[1:]
+			nb.running.Add(1)
+		}()
+		switch e := event.(type) {
+		case stronglyAckedEvent:
+			nb.debug.StronglyAcked(e.blockHash)
+		case blockConfirmedEvent:
+			nb.app.BlockConfirmed(*e.block)
+		case totalOrderingDeliveredEvent:
+			nb.debug.TotalOrderingDelivered(e.blockHashes, e.mode)
+		case blockDeliveredEvent:
+			nb.app.BlockDelivered(e.blockHash, *e.result)
+		default:
+			fmt.Printf("Unknown event %v.", e)
+		}
+		nb.running.Done()
+		nb.eventsChange.Broadcast()
+	}
+}
+
+// wait will wait for all event in events finishes.
+func (nb *nonBlocking) wait() {
+	nb.eventsChange.L.Lock()
+	defer nb.eventsChange.L.Unlock()
+	for len(nb.events) > 0 {
+		nb.eventsChange.Wait()
+	}
+	nb.running.Wait()
+}
+
+// PreparePayload cannot be non-blocking.
+func (nb *nonBlocking) PreparePayload(position types.Position) ([]byte, error) {
+	return nb.app.PreparePayload(position)
+}
+
+// PrepareWitness cannot be non-blocking.
+func (nb *nonBlocking) PrepareWitness(height uint64) (types.Witness, error) {
+	return nb.app.PrepareWitness(height)
+}
+
+// VerifyBlock cannot be non-blocking.
+func (nb *nonBlocking) VerifyBlock(block *types.Block) bool {
+	return nb.app.VerifyBlock(block)
+}
+
+// BlockConfirmed is called when a block is confirmed and added to lattice.
+func (nb *nonBlocking) BlockConfirmed(block types.Block) {
+	nb.addEvent(blockConfirmedEvent{&block})
+}
+
+// StronglyAcked is called when a block is strongly acked.
+func (nb *nonBlocking) StronglyAcked(blockHash common.Hash) {
+	if nb.debug != nil {
+		nb.addEvent(stronglyAckedEvent{blockHash})
+	}
+}
+
+// TotalOrderingDelivered is called when the total ordering algorithm deliver
+// a set of block.
+func (nb *nonBlocking) TotalOrderingDelivered(
+	blockHashes common.Hashes, mode uint32) {
+	if nb.debug != nil {
+		nb.addEvent(totalOrderingDeliveredEvent{blockHashes, mode})
+	}
+}
+
+// BlockDelivered is called when a block is add to the compaction chain.
+func (nb *nonBlocking) BlockDelivered(
+	blockHash common.Hash, result types.FinalizationResult) {
+	nb.addEvent(blockDeliveredEvent{
+		blockHash: blockHash,
+		result:    &result,
+	})
+}