core: Add Consensus to replace core.Blocklattice (#35)

* Make Sequencer return slice of blocks.

* Fix naming issue

The function 'getHeightVecto' would return ackingStatusVector.

* Fix comment error.

* Add methods to collect info when proposing blocks.

* Add test.App

* Add test.Gov

* Move this type to core.types to avoid cyclic import.

* Add core.Consensus

* Move getMedianTime, interpoTime to util

These functions are not depending on members of core.consensusTimestamp and
is required when testing core.Consensus.

* Make sure types.Block.Clone would copy critical fields.

* Remove core.blocklattice

* Define 'infinity' in core/total-ordering

This definition is defined in core/blocklattice originally.

* Fix a bug when processing the same block twice.

* Integrate simulation with core.Consensus

core.Consensus is a replacement of core.Blocklattice

* Fix the comment to use sigular form.

* Move lock mechanism to sub modules.

* phi should be 2*fmax+1

* Fixup: should aborting when the validator is added

* Fix for new block fields

* Fix the bug that the total ordering sequence is wrong.

2 files changed, 135 insertions, 0 deletions

diff --git a/core/test/app.go b/core/test/app.go
new file mode 100644
index 0000000..f596afb
--- /dev/null
+++ b/core/test/app.go
@@ -0,0 +1,72 @@
+// 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 test
+
+import (
+	"time"
+
+	"github.com/dexon-foundation/dexon-consensus-core/common"
+	"github.com/dexon-foundation/dexon-consensus-core/core/types"
+)
+
+// App implements Application interface for testing purpose.
+type App struct {
+	Acked        map[common.Hash]struct{}
+	TotalOrdered []*struct {
+		BlockHashes common.Hashes
+		Early       bool
+	}
+	Delivered map[common.Hash]time.Time
+}
+
+// NewApp constructs a TestApp instance.
+func NewApp() *App {
+	return &App{
+		Acked: make(map[common.Hash]struct{}),
+		TotalOrdered: []*struct {
+			BlockHashes common.Hashes
+			Early       bool
+		}{},
+		Delivered: make(map[common.Hash]time.Time),
+	}
+}
+
+// StronglyAcked implements Application interface.
+func (app *App) StronglyAcked(blockHash common.Hash) {
+	app.Acked[blockHash] = struct{}{}
+}
+
+// TotalOrderingDeliver implements Application interface.
+func (app *App) TotalOrderingDeliver(blocks []*types.Block, early bool) {
+	var hashes common.Hashes
+	for _, b := range blocks {
+		hashes = append(hashes, b.Hash)
+	}
+	app.TotalOrdered = append(app.TotalOrdered, &struct {
+		BlockHashes common.Hashes
+		Early       bool
+	}{
+		BlockHashes: hashes,
+		Early:       early,
+	})
+}
+
+// DeliverBlock implements Application interface.
+func (app *App) DeliverBlock(blockHash common.Hash, timestamp time.Time) {
+	app.Delivered[blockHash] = timestamp
+}
diff --git a/core/test/gov.go b/core/test/gov.go
new file mode 100644
index 0000000..7a5bdfc
--- /dev/null
+++ b/core/test/gov.go
@@ -0,0 +1,63 @@
+// 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 test
+
+import (
+	"github.com/dexon-foundation/dexon-consensus-core/common"
+	"github.com/dexon-foundation/dexon-consensus-core/core/types"
+	"github.com/shopspring/decimal"
+)
+
+// Gov is an implementation of Goverance for testing purpose.
+type Gov struct {
+	BlockProposingInterval int
+	Validators             map[types.ValidatorID]decimal.Decimal
+}
+
+// NewGov constructs a Gov instance.
+func NewGov(
+	validatorCount, proposingInterval int) (gov *Gov) {
+
+	gov = &Gov{
+		BlockProposingInterval: proposingInterval,
+		Validators:             make(map[types.ValidatorID]decimal.Decimal),
+	}
+	for i := 0; i < validatorCount; i++ {
+		gov.Validators[types.ValidatorID{Hash: common.NewRandomHash()}] =
+			decimal.NewFromFloat(0)
+	}
+	return
+}
+
+// GetValidatorSet implements Governance interface to return current
+// validator set.
+func (gov *Gov) GetValidatorSet() map[types.ValidatorID]decimal.Decimal {
+	return gov.Validators
+}
+
+// GetBlockProposingInterval implements Governance interface to return maximum
+// allowed block proposing interval in millisecond.
+func (gov *Gov) GetBlockProposingInterval() int {
+	return gov.BlockProposingInterval
+}
+
+// GetMembershipEvents implements Governance interface to return membership
+// changed events.
+func (gov *Gov) GetMembershipEvents(epoch int) []types.MembershipEvent {
+	return nil
+}