implemented String() methods for internalStats (#133)

* implemented String() methods for internalStats

* rename type

* cleanup

gojmx/gojmx.go

@@ -146,13 +146,13 @@ func (c *Client) QueryMBeanAttributes(mBeanNamePattern string, mBeanAttrName ...
 // Internal statistics must be enabled using JMXConfig.EnableInternalStats flag.
 // Additionally you can set a maximum size for the collected stats using JMXConfig.MaxInternalStatsSize. (default: 100000)
 // Each time you retrieve GetInternalStats, the internal stats will be cleaned.
-func (c *Client) GetInternalStats() ([]*InternalStat, error) {
+func (c *Client) GetInternalStats() (InternalStatsList, error) {
 	if err := c.checkNRJMXProccessError(); err != nil {
 		return nil, err
 	}
 	result, err := c.jmxService.GetInternalStats(c.ctx)
 
-	return toInternalStatList(result), c.handleError(err)
+	return toInternalStatsList(result), c.handleError(err)
 }
 
 // connect will pass the JMXConfig to nrjmx subprocess and establish the

gojmx/gojmx_test.go

@@ -905,33 +905,46 @@ func TestGetInternalStats(t *testing.T) {
 	internalStats, err := client.GetInternalStats()
 	assert.NoError(t, err)
 
-	totalCalls := 0
-	totalObjects := 0
-	totalTimeMs := 0
-	totalAttrs := 0
-	totalSucessful := 0
-
-	for _, stat := range internalStats {
-		totalCalls++
-		totalObjects += int(stat.ResponseCount)
-		totalTimeMs += int(stat.Milliseconds)
-		totalAttrs += len(stat.Attrs)
-
-		if stat.Successful {
-			totalSucessful++
-		}
-	}
-
-	assert.Equal(t, 3000, totalCalls)
-	assert.Equal(t, 18000, totalObjects)
-	assert.True(t, totalTimeMs > 0)
-	assert.Equal(t, 9000, totalAttrs)
-	assert.Equal(t, 3000, totalSucessful)
+	assert.Len(t, internalStats, 3000)
+	assert.Regexp(t, "StatType: 'getMBeanInfo', MBean: 'test:type=Cat,name=(.+?)', Attributes: '[]', TotalObjCount: 6, StartTimeMs: [0-9]+,  Duration: [0-9]+\\.[0-9]+ms, Successful: true", internalStats[0].String())
+	assert.Regexp(t, "TotalMs: '[0-9]+\\.[0-9]{3}', TotalObjects: 18000, TotalAttr: 9000, TotalCalls: 3000, TotalSuccessful: 3000", internalStats.String())
 
 	// AND internal stats get cleaned
 	internalStats, err = client.GetInternalStats()
 	assert.NoError(t, err)
-	assert.True(t, len(internalStats) == 0)
+	assert.Equal(t, "TotalMs: '0.000', TotalObjects: 0, TotalAttr: 0, TotalCalls: 0, TotalSuccessful: 0", internalStats.String())
+}
+
+func TestGetEmptyInternalStats(t *testing.T) {
+	ctx := context.Background()
+
+	// GIVEN a JMX Server running inside a container
+	container, err := testutils.RunJMXServiceContainer(ctx)
+	require.NoError(t, err)
+	defer container.Terminate(ctx)
+
+	jmxHost, jmxPort, err := testutils.GetContainerMappedPort(ctx, container, testutils.TestServerJMXPort)
+	require.NoError(t, err)
+
+	// THEN JMX connection can be oppened
+	config := &JMXConfig{
+		Hostname:            jmxHost,
+		Port:                int32(jmxPort.Int()),
+		EnableInternalStats: false,
+	}
+
+	client, err := NewClient(ctx).Open(config)
+	assert.NoError(t, err)
+	defer assertCloseClientNoError(t, client)
+
+	_, err = client.QueryMBeanAttributes("test:type=Cat,*")
+	assert.NoError(t, err)
+
+	// AND query doesn't generate any internal stats.
+	internalStats, err := client.GetInternalStats()
+
+	assert.Error(t, err)
+	assert.Equal(t, "<nil>", internalStats.String())
 }
 
 func TestConnectionRecovers(t *testing.T) {

gojmx/types.go

@@ -176,10 +176,40 @@ func (is *InternalStat) String() string {
 	)
 }
 
-func toInternalStatList(in []*nrprotocol.InternalStat) []*InternalStat {
+func toInternalStatsList(in []*nrprotocol.InternalStat) InternalStatsList {
 	return *(*[]*InternalStat)(unsafe.Pointer(&in))
 }
 
+type InternalStatsList []*InternalStat
+
+func (is InternalStatsList) String() string {
+	if is == nil {
+		return "<nil>"
+	}
+
+	var totalCalls = len(is)
+	var totalObjects, totalAttrs, totalSuccessful int
+
+	var totalTimeMs float64
+
+	for _, stat := range is {
+		if stat.Successful {
+			totalSuccessful++
+		}
+
+		totalObjects += int(stat.ResponseCount)
+		totalTimeMs += stat.Milliseconds
+		totalAttrs += len(stat.Attrs)
+	}
+	return fmt.Sprintf("TotalMs: '%.3f', TotalObjects: %d, TotalAttr: %d, TotalCalls: %d, TotalSuccessful: %d",
+		totalTimeMs,
+		totalObjects,
+		totalAttrs,
+		totalCalls,
+		totalSuccessful,
+	)
+}
+
 // JMXClientError is returned when there is an nrjmx process error.
 // Those errors require opening a new client.
 type JMXClientError struct {