From ae0caedaac6d08e09ae740db4ee00a7fc0753a4e Mon Sep 17 00:00:00 2001
From: Minhan Xia <mixia@google.com>
Date: Thu, 25 Oct 2018 14:39:26 -0700
Subject: [PATCH] add util for transaction table

---
 pkg/neg/syncers/transaction_table.go      | 78 +++++++++++++++++++
 pkg/neg/syncers/transaction_table_test.go | 92 +++++++++++++++++++++++
 2 files changed, 170 insertions(+)
 create mode 100644 pkg/neg/syncers/transaction_table.go
 create mode 100644 pkg/neg/syncers/transaction_table_test.go

diff --git a/pkg/neg/syncers/transaction_table.go b/pkg/neg/syncers/transaction_table.go
new file mode 100644
index 0000000000..d330d49a6c
--- /dev/null
+++ b/pkg/neg/syncers/transaction_table.go
@@ -0,0 +1,78 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+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,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package syncers
+
+const (
+	attachOp = iota
+	detachOp
+)
+
+type transactionOp int
+
+func (op transactionOp) String() string {
+	switch op {
+	case attachOp:
+		return "Attach"
+	case detachOp:
+		return "Detach"
+	default:
+		return "UnknownOperation"
+	}
+}
+
+type transactionEntry struct {
+	// Operation represents the operation type associated with each transaction
+	Operation transactionOp
+	// NeedReconcile indicates whether the entry needs to be reconciled.
+	NeedReconcile bool
+	// Zone represents the zone of the transaction
+	Zone string
+}
+
+// transactionTable records ongoing NEG API operation per endpoint
+// It uses the encoded endpoint as key and associate attributes of an transaction as value
+// WARNING: transactionTable is not thread safe
+type transactionTable struct {
+	data map[string]transactionEntry
+}
+
+func NewTransactionTable() transactionTable {
+	return transactionTable{
+		data: make(map[string]transactionEntry),
+	}
+}
+
+func (tt transactionTable) Keys() []string {
+	res := []string{}
+	for key := range tt.data {
+		res = append(res, key)
+	}
+	return res
+}
+
+func (tt transactionTable) Get(key string) (transactionEntry, bool) {
+	ret, ok := tt.data[key]
+	return ret, ok
+}
+
+func (tt transactionTable) Delete(key string) {
+	delete(tt.data, key)
+}
+
+func (tt transactionTable) Put(key string, entry transactionEntry) {
+	tt.data[key] = entry
+}
diff --git a/pkg/neg/syncers/transaction_table_test.go b/pkg/neg/syncers/transaction_table_test.go
new file mode 100644
index 0000000000..7d4a15528b
--- /dev/null
+++ b/pkg/neg/syncers/transaction_table_test.go
@@ -0,0 +1,92 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+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,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package syncers
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestTransactionTable(t *testing.T) {
+	table := NewTransactionTable()
+
+	// Verify table are empty initially
+	ret := table.Keys()
+	if len(ret) != 0 {
+		t.Errorf("Expect no keys, but got %v", ret)
+	}
+
+	_, ok := table.Get("non exist")
+	if ok {
+		t.Errorf("Expect ok = false, but got %v", ok)
+	}
+
+	testNum := 10
+	keyPrefix := "key"
+	zonePrefix := "zone"
+	testKeyMap := map[string]transactionEntry{}
+
+	// Insert entries into transaction table
+	for i := 0; i < testNum; i++ {
+		key := fmt.Sprintf("%s%d", keyPrefix, i)
+		entry := transactionEntry{
+			attachOp,
+			false,
+			fmt.Sprintf("%s%d", zonePrefix, i),
+		}
+		table.Put(key, entry)
+		testKeyMap[key] = entry
+	}
+
+	verifyTable(t, table, testKeyMap)
+
+	// Update half of the entries in the transaction table
+	for i := 0; i < testNum/2; i++ {
+		key := fmt.Sprintf("%s%d", keyPrefix, i)
+		newEntry := transactionEntry{
+			detachOp,
+			true,
+			fmt.Sprintf("%s%d", zonePrefix, i),
+		}
+		table.Put(key, newEntry)
+		testKeyMap[key] = newEntry
+	}
+
+	verifyTable(t, table, testKeyMap)
+}
+
+func verifyTable(t *testing.T, table transactionTable, expectTransactionMap map[string]transactionEntry) {
+	keys := table.Keys()
+	if len(expectTransactionMap) != len(keys) {
+		t.Errorf("Expect keys length to be %v, but got %v", len(expectTransactionMap), len(keys))
+	}
+
+	for _, key := range keys {
+		entry, ok := table.Get(key)
+		if !ok {
+			t.Errorf("Expect key %q to exist in transaction table, but got %v", key, ok)
+		}
+		expectEntry, ok := expectTransactionMap[key]
+		if !ok {
+			t.Errorf("Expect key %q to exist in testKeyMap, but got %v", key, ok)
+		}
+
+		if entry != expectEntry {
+			t.Errorf("Expect entry to be %v, but got %v", expectEntry, entry)
+		}
+	}
+}