Integrate public as bindata optionally (#293)

* Dropped unused codekit config

* Integrated dynamic and static bindata for public

* Ignore public bindata

* Add a general generate make task

* Integrated flexible public assets into web command

* Updated vendoring, added all missiong govendor deps

* Made the linter happy with the bindata and dynamic code

* Moved public bindata definition to modules directory

* Ignoring the new bindata path now

* Updated to the new public modules import path

* Updated public bindata command and drop the new prefix

vendor/github.com/pingcap/tidb/kv/txn.go

@@ -0,0 +1,78 @@
+// Copyright 2015 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package kv
+
+import (
+	"math"
+	"math/rand"
+	"time"
+
+	"github.com/juju/errors"
+	"github.com/ngaut/log"
+)
+
+// RunInNewTxn will run the f in a new transaction environment.
+func RunInNewTxn(store Storage, retryable bool, f func(txn Transaction) error) error {
+	for i := 0; i < maxRetryCnt; i++ {
+		txn, err := store.Begin()
+		if err != nil {
+			log.Errorf("[kv] RunInNewTxn error - %v", err)
+			return errors.Trace(err)
+		}
+
+		err = f(txn)
+		if retryable && IsRetryableError(err) {
+			log.Warnf("[kv] Retry txn %v", txn)
+			txn.Rollback()
+			continue
+		}
+		if err != nil {
+			txn.Rollback()
+			return errors.Trace(err)
+		}
+
+		err = txn.Commit()
+		if retryable && IsRetryableError(err) {
+			log.Warnf("[kv] Retry txn %v", txn)
+			txn.Rollback()
+			BackOff(i)
+			continue
+		}
+		if err != nil {
+			return errors.Trace(err)
+		}
+		break
+	}
+
+	return nil
+}
+
+var (
+	// Max retry count in RunInNewTxn
+	maxRetryCnt = 100
+	// retryBackOffBase is the initial duration, in microsecond, a failed transaction stays dormancy before it retries
+	retryBackOffBase = 1
+	// retryBackOffCap is the max amount of duration, in microsecond, a failed transaction stays dormancy before it retries
+	retryBackOffCap = 100
+)
+
+// BackOff Implements exponential backoff with full jitter.
+// Returns real back off time in microsecond.
+// See: http://www.awsarchitectureblog.com/2015/03/backoff.html.
+func BackOff(attempts int) int {
+	upper := int(math.Min(float64(retryBackOffCap), float64(retryBackOffBase)*math.Pow(2.0, float64(attempts))))
+	sleep := time.Duration(rand.Intn(upper)) * time.Millisecond
+	time.Sleep(sleep)
+	return int(sleep)
+}