core: remove ticker parameter from NewConsensus

- remove BlockProposingInterval, it's replaced
  by lambda.
- remove ticker parameter of NewConsensus,
  ticker would be derived from governance.
- leave a backdoor to hook the construction
  of ticker.
- move 'Lambda' config from to consensus.

1 files changed, 58 insertions, 0 deletions

diff --git a/core/ticker.go b/core/ticker.go
new file mode 100644
index 0000000..dffd676
--- /dev/null
+++ b/core/ticker.go
@@ -0,0 +1,58 @@
+// 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 "time"
+
+// defaultTicker is a wrapper to implement ticker interface based on
+// time.Ticker.
+type defaultTicker struct {
+	ticker *time.Ticker
+}
+
+// newDefaultTicker constructs an defaultTicker instance by giving an interval.
+func newDefaultTicker(lambda time.Duration) *defaultTicker {
+	return &defaultTicker{ticker: time.NewTicker(lambda)}
+}
+
+// Tick implements Tick method of ticker interface.
+func (t *defaultTicker) Tick() <-chan time.Time {
+	return t.ticker.C
+}
+
+// Stop implements Stop method of ticker interface.
+func (t *defaultTicker) Stop() {
+	t.ticker.Stop()
+}
+
+// newTicker is a helper to setup a ticker by giving an Governance. If
+// the governace object implements a ticker generator, a ticker from that
+// generator would be returned, else constructs a default one.
+func newTicker(gov Governance) (t Ticker) {
+	type tickerGenerator interface {
+		NewTicker() Ticker
+	}
+
+	if gen, ok := gov.(tickerGenerator); ok {
+		t = gen.NewTicker()
+	}
+	if t == nil {
+		t = newDefaultTicker(gov.GetLambda())
+	}
+	return
+}