add snapshot unit test

snapshot_test.go

@@ -0,0 +1,185 @@
+package raft
+
+import (
+	"sync"
+	"testing"
+	"time"
+	//"fmt"
+)
+
+// test take and send snapshot
+func TestTakeAndSendSnapshot(t *testing.T) {
+	// Initialize the servers.
+	var mutex sync.Mutex
+	//fmt.Println("---Snapshot Test---")
+	names := []string{"1", "2", "3"}
+	servers := map[string]*Server{}
+	for _, server := range servers {
+		defer server.Stop()
+	}
+	transporter := &testTransporter{}
+	transporter.sendVoteRequestFunc = func(server *Server, peer *Peer, req *RequestVoteRequest) (*RequestVoteResponse, error) {
+		mutex.Lock()
+		s := servers[peer.name]
+		mutex.Unlock()
+		resp, err := s.RequestVote(req)
+		return resp, err
+	}
+	transporter.sendAppendEntriesRequestFunc = func(server *Server, peer *Peer, req *AppendEntriesRequest) (*AppendEntriesResponse, error) {
+		mutex.Lock()
+		s := servers[peer.name]
+		mutex.Unlock()
+		resp, err := s.AppendEntries(req)
+		return resp, err
+	}
+
+	transporter.sendSnapshotRequestFunc = func(server *Server, peer *Peer, req *SnapshotRequest) (*SnapshotResponse, error) {
+		mutex.Lock()
+		s := servers[peer.name]
+		mutex.Unlock()
+		resp, err := s.SnapshotRecovery(req)
+		return resp, err
+	}
+
+	var leader *Server
+	for _, name := range names {
+		server := newTestServer(name, transporter)
+		server.SetElectionTimeout(testElectionTimeout)
+		server.SetHeartbeatTimeout(testHeartbeatTimeout)
+		if err := server.Start(); err != nil {
+			t.Fatalf("Unable to start server[%s]: %v", name, err)
+		}
+		if name == "1" {
+			leader = server
+			if err := server.Initialize(); err != nil {
+				t.Fatalf("Unable to initialize server[%s]: %v", name, err)
+			}
+		}
+		if err := leader.Do(&joinCommand{Name:name}); err != nil {
+			t.Fatalf("Unable to join server[%s]: %v", name, err)
+		}
+
+		mutex.Lock()
+		servers[name] = server
+		mutex.Unlock()
+	}
+	time.Sleep(100 * time.Millisecond)
+
+	// Check that two peers exist on leader.
+	mutex.Lock()
+	if leader.MemberCount() != 3 {
+		t.Fatalf("Expected member count to be 3, got %v", leader.MemberCount())
+	}
+	mutex.Unlock()
+
+	// commit single entry.
+	err := leader.Do(&TestCommand1{"foo", 10})
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	index, term := leader.log.CommitInfo()
+
+	// three join and one test Command
+	if !(index == 4 && term == 1) {
+		t.Fatalf("Invalid commit info [IDX=%v, TERM=%v]", index, term)
+	}
+
+	leader.takeSnapshot()
+
+	logLen := len(leader.log.entries)
+
+	if logLen != 0 {
+		t.Fatalf("Invalid logLen [Len=%v]", logLen)
+	}
+
+	if leader.log.startIndex != 4 || leader.log.startTerm != 1 {
+		t.Fatalf("Invalid log info [StartIndex=%v, StartTERM=%v]", 
+			leader.log.startIndex, leader.log.startTerm)
+	}
+
+	// test send snapshot to a new node
+	// send from heartbeat
+	newServer := newTestServer("4", transporter)
+	if err := newServer.Start(); err != nil {
+		t.Fatalf("Unable to start server[4]: %v", err)
+	}
+
+	if err := leader.Do(&joinCommand{Name:"4"}); err != nil {
+		t.Fatalf("Unable to join server[4]: %v", err)
+	}
+
+	mutex.Lock()
+	servers["4"] = newServer
+	mutex.Unlock()
+
+	// wait for heartbeat :P
+	time.Sleep(100 * time.Millisecond)
+
+	if leader.log.startIndex != 4 || leader.log.startTerm != 1 {
+		t.Fatalf("Invalid log info [StartIndex=%v, StartTERM=%v]", 
+			leader.log.startIndex, leader.log.startTerm)
+	}
+	time.Sleep(100 * time.Millisecond)
+
+}
+
+
+func TestStartFormSnapshot(t *testing.T) {
+	server := newTestServer("1", &testTransporter{})
+	oldPath := server.path
+	server.Start()
+	
+	server.Initialize()
+
+	// commit single entry.
+	err := server.Do(&TestCommand1{"foo", 10})
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	server.takeSnapshot()
+
+	logLen := len(server.log.entries)
+
+	if logLen != 0 {
+		t.Fatalf("Invalid logLen [Len=%v]", logLen)
+	}
+
+	if server.log.startIndex != 1 || server.log.startTerm != 1 {
+		t.Fatalf("Invalid log info [StartIndex=%v, StartTERM=%v]", 
+			server.log.startIndex, server.log.startTerm)
+	}
+
+	server.Stop()
+
+	server = newTestServer("1", &testTransporter{})
+	// reset the oldPath
+	server.path = oldPath
+
+	server.Start()
+
+	logLen = len(server.log.entries)
+
+	if logLen != 0 {
+		t.Fatalf("Invalid logLen [Len=%v]", logLen)
+	}
+
+	if index, term := server.log.CommitInfo(); !(index == 0 && term == 0) {
+		t.Fatalf("Invalid commit info [IDX=%v, TERM=%v]", index, term)
+	}
+
+	if server.log.startIndex != 0 || server.log.startTerm != 0 {
+		t.Fatalf("Invalid log info [StartIndex=%v, StartTERM=%v]", 
+			server.log.startIndex, server.log.startTerm)
+	}
+
+	server.LoadSnapshot()
+	if server.log.startIndex != 1 || server.log.startTerm != 1 {
+		t.Fatalf("Invalid log info [StartIndex=%v, StartTERM=%v]", 
+			server.log.startIndex, server.log.startTerm)
+	}
+
+}