simulation: add simulation with scheduler (#71)

- Add new field in test.Event: HistoryIndex
   HistoryIndex allow us to access them by their position in event history.
- Record local time in test.App when receiving events.
- Add statisitics module for slices of test.Event.
- add new command line utility *dexcon-simulation-with-scheduler
   to verify the execution time of core.Consensus.

1 files changed, 72 insertions, 0 deletions

diff --git a/integration_test/utils.go b/integration_test/utils.go
new file mode 100644
index 0000000..c1eafb7
--- /dev/null
+++ b/integration_test/utils.go
@@ -0,0 +1,72 @@
+package integration
+
+import (
+	"github.com/dexon-foundation/dexon-consensus-core/blockdb"
+	"github.com/dexon-foundation/dexon-consensus-core/core/test"
+	"github.com/dexon-foundation/dexon-consensus-core/core/types"
+	"github.com/dexon-foundation/dexon-consensus-core/crypto"
+)
+
+// PrepareValidators setups validators for testing.
+func PrepareValidators(
+	validatorCount int,
+	networkLatency, proposingLatency LatencyModel) (
+	apps map[types.ValidatorID]*test.App,
+	dbs map[types.ValidatorID]blockdb.BlockDatabase,
+	validators map[types.ValidatorID]*Validator,
+	err error) {
+
+	var (
+		db  blockdb.BlockDatabase
+		key crypto.PrivateKey
+	)
+
+	apps = make(map[types.ValidatorID]*test.App)
+	dbs = make(map[types.ValidatorID]blockdb.BlockDatabase)
+	validators = make(map[types.ValidatorID]*Validator)
+
+	gov, err := test.NewGovernance(validatorCount, 700)
+	if err != nil {
+		return
+	}
+	for vID := range gov.GetValidatorSet() {
+		apps[vID] = test.NewApp()
+
+		if db, err = blockdb.NewMemBackedBlockDB(); err != nil {
+			return
+		}
+		dbs[vID] = db
+	}
+	for vID := range gov.GetValidatorSet() {
+		if key, err = gov.GetPrivateKey(vID); err != nil {
+			return
+		}
+		validators[vID] = NewValidator(
+			apps[vID],
+			gov,
+			dbs[vID],
+			key,
+			vID,
+			networkLatency,
+			proposingLatency)
+	}
+	return
+}
+
+// VerifyApps is a helper to check delivery between test.Apps
+func VerifyApps(apps map[types.ValidatorID]*test.App) (err error) {
+	for vFrom, fromApp := range apps {
+		if err = fromApp.Verify(); err != nil {
+			return
+		}
+		for vTo, toApp := range apps {
+			if vFrom == vTo {
+				continue
+			}
+			if err = fromApp.Compare(toApp); err != nil {
+				return
+			}
+		}
+	}
+	return
+}