Add example

Makefile

@@ -33,4 +33,5 @@ run-examples:
 	go run basic_example/graph_client_basic_example.go && \
 	go run basic_example/parameter_example.go && \
 	go run gorountines_example/graph_client_goroutines_example.go && \
-	go run json_example/parse_json_example.go
+	go run json_example/parse_json_example.go && \
+	go run session_pool_example/session_pool_example.go

client_test.go

@@ -1408,6 +1408,7 @@ func prepareSpace(t *testing.T, spaceName string) error {
 	}
 	checkConResp(t, query, resp)
 	time.Sleep(5 * time.Second)
+
 	return nil
 }
 

session_pool.go

@@ -32,6 +32,8 @@ import (
 //
 // Release:
 // sessionPool.close()
+//
+// Notice that all queries will be executed in the default space specified in the pool config.
 type SessionPool struct {
 	idleSessions   list.List
 	activeSessions list.List
@@ -76,9 +78,8 @@ func (pool *SessionPool) init() error {
 
 // Execute returns the result of the given query as a ResultSet
 // Notice there are some limitations:
-// 1. The query should not be a plain space switch statement, e.g. "USE space test_space",
+// 1. The query should not be a plain space switch statement, e.g. "USE test_space",
 // but queries like "use space xxx; match (v) return v" are accepted.
-
 func (pool *SessionPool) Execute(stmt string) (*ResultSet, error) {
 	return pool.ExecuteWithParameter(stmt, map[string]interface{}{})
 }
@@ -114,7 +115,7 @@ func (pool *SessionPool) ExecuteWithParameter(stmt string, params map[string]int
 	// if the space was changed in after the execution of the given query,
 	// change it back to the default space specified in the pool config
 	if resSet.GetSpaceName() != "" && resSet.GetSpaceName() != pool.conf.spaceName {
-		stmt = fmt.Sprintf("USE SPACE %s", pool.conf.spaceName)
+		stmt = fmt.Sprintf("USE %s", pool.conf.spaceName)
 		resp, err := session.connection.execute(session.sessionID, stmt)
 		if err != nil {
 			return nil, err
@@ -300,11 +301,15 @@ func (pool *SessionPool) newSession() (*Session, error) {
 		return nil, err
 	}
 
-	stmt := fmt.Sprintf("USE SPACE %s", pool.conf.spaceName)
-	_, err = newSession.connection.execute(newSession.sessionID, stmt)
+	stmt := fmt.Sprintf("USE %s", pool.conf.spaceName)
+	createSpaceResp, err := newSession.connection.execute(newSession.sessionID, stmt)
 	if err != nil {
 		return nil, err
 	}
+	if createSpaceResp.GetErrorCode() != nebula.ErrorCode_SUCCEEDED {
+		return nil, fmt.Errorf("failed to use space %s: %s",
+			pool.conf.spaceName, createSpaceResp.GetErrorMsg())
+	}
 	return &newSession, nil
 }
 

session_pool_example/session_pool_example.go

@@ -11,6 +11,7 @@ package main
 import (
 	"fmt"
 	"strings"
+	"sync"
 	"time"
 
 	nebula "github.com/vesoft-inc/nebula-go/v3"
@@ -87,13 +88,21 @@ func main() {
 	// Extract data from the resultSet
 	{
 		query := "GO FROM 'Bob' OVER like YIELD $^.person.name, $^.person.age, like.likeness"
-		// Send query
-		resultSet, err := sessionPool.Execute(query)
-		if err != nil {
-			fmt.Print(err.Error())
-			return
-		}
-		checkResultSet(query, resultSet)
+		// Send query in goroutine
+		wg := sync.WaitGroup{}
+		wg.Add(1)
+		var resultSet *nebula.ResultSet
+		go func(wg *sync.WaitGroup) {
+			defer wg.Done()
+
+			resultSet, err = sessionPool.Execute(query)
+			if err != nil {
+				fmt.Print(err.Error())
+				return
+			}
+			checkResultSet(query, resultSet)
+		}(&wg)
+		wg.Wait()
 
 		// Get all column names from the resultSet
 		colNames := resultSet.GetColNames()
@@ -137,7 +146,7 @@ func main() {
 		checkResultSet(query, resultSet)
 	}
 	fmt.Print("\n")
-	log.Info("Nebula Go Client Gorountines Example Finished")
+	log.Info("Nebula Go Client Session Pool Example Finished")
 }
 
 // Just a helper function to create a space for this example to run.
@@ -173,7 +182,7 @@ func prepareSpace() {
 	{
 		// Prepare the query
 		createSchema := "CREATE SPACE IF NOT EXISTS example_space(vid_type=FIXED_STRING(20)); " +
-			"USE basic_example_space;" +
+			"USE example_space;" +
 			"CREATE TAG IF NOT EXISTS person(name string, age int);" +
 			"CREATE EDGE IF NOT EXISTS like(likeness double)"
 

session_pool_test.go

@@ -142,5 +142,36 @@ func TestSessionPoolMultiThread(t *testing.T) {
 
 // TODO(Aiee): add more test cases
 func TestSessionPoolSpaceChange(t *testing.T) {
-	// query that changes space is not allowed in session pool. i.g. `USE space nba`
+	err := prepareSpace(t, "test_space_1")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dropSpace(t, "test_space_1")
+
+	err = prepareSpace(t, "test_space_2")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dropSpace(t, "test_space_2")
+
+	hostAddress := HostAddress{Host: address, Port: port}
+	config, err := NewSessionPoolConf("root", "nebula", []HostAddress{hostAddress}, "test_space_1")
+	if err != nil {
+		t.Errorf("failed to create session pool config, %s", err.Error())
+	}
+
+	// create session pool
+	sessionPool, err := NewSessionPool(*config, DefaultLogger{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer sessionPool.Close()
+
+	// execute query
+	resultSet, err := sessionPool.Execute("USE test_space_2; SHOW HOSTS;")
+	if err != nil {
+		t.Fatal(err)
+	}
+	assert.True(t, resultSet.IsSucceed(), fmt.Errorf("error code: %d, error msg: %s",
+		resultSet.GetErrorCode(), resultSet.GetErrorMsg()))
 }