func keyToProto(k *Key) *pb.Key {
	if k == nil {
		return nil
	}

	// TODO(jbd): Eliminate unrequired allocations.
	path := []*pb.Key_PathElement(nil)
	for {
		el := &pb.Key_PathElement{
			Kind: proto.String(k.kind),
		}
		if k.id != 0 {
			el.Id = proto.Int64(k.id)
		}
		if k.name != "" {
			el.Name = proto.String(k.name)
		}
		path = append([]*pb.Key_PathElement{el}, path...)
		if k.parent == nil {
			break
		}
		k = k.parent
	}
	key := &pb.Key{
		PathElement: path,
	}
	if k.namespace != "" {
		key.PartitionId = &pb.PartitionId{
			Namespace: proto.String(k.namespace),
		}
	}
	return key
}

func ExampleLabelPairSorter() {
	labelPairs := []*dto.LabelPair{
		&dto.LabelPair{Name: proto.String("status"), Value: proto.String("404")},
		&dto.LabelPair{Name: proto.String("method"), Value: proto.String("get")},
	}

	sort.Sort(prometheus.LabelPairSorter(labelPairs))

	fmt.Println(labelPairs)
	// Output:
	// [name:"method" value:"get"  name:"status" value:"404" ]
}

func propertiesToProto(key *Key, props []Property) (*pb.Entity, error) {
	e := &pb.Entity{
		Key: keyToProto(key),
	}
	indexedProps := 0
	prevMultiple := make(map[string]*pb.Property)
	for _, p := range props {
		val, err := interfaceToProto(p.Value)
		if err != "" {
			return nil, fmt.Errorf("datastore: %s for a Property with Name %q", err, p.Name)
		}
		if !p.NoIndex {
			rVal := reflect.ValueOf(p.Value)
			if rVal.Kind() == reflect.Slice && rVal.Type().Elem().Kind() != reflect.Uint8 {
				indexedProps += rVal.Len()
			} else {
				indexedProps++
			}
		}
		if indexedProps > maxIndexedProperties {
			return nil, errors.New("datastore: too many indexed properties")
		}
		switch v := p.Value.(type) {
		case string:
		case []byte:
			if len(v) > 500 && !p.NoIndex {
				return nil, fmt.Errorf("datastore: cannot index a Property with Name %q", p.Name)
			}
		}
		val.Indexed = proto.Bool(!p.NoIndex)
		if p.Multiple {
			x, ok := prevMultiple[p.Name]
			if !ok {
				x = &pb.Property{
					Name:  proto.String(p.Name),
					Value: &pb.Value{},
				}
				prevMultiple[p.Name] = x
				e.Property = append(e.Property, x)
			}
			x.Value.ListValue = append(x.Value.ListValue, val)
		} else {
			e.Property = append(e.Property, &pb.Property{
				Name:  proto.String(p.Name),
				Value: val,
			})
		}
	}
	return e, nil
}

func init() {
	ext := &pb.Ext{
		Data: proto.String("extension"),
	}
	if err := proto.SetExtension(cloneTestMessage, pb.E_Ext_More, ext); err != nil {
		panic("SetExtension: " + err.Error())
	}
}

func TestStringEscaping(t *testing.T) {
	testCases := []struct {
		in  *pb.Strings
		out string
	}{
		{
			// Test data from C++ test (TextFormatTest.StringEscape).
			// Single divergence: we don't escape apostrophes.
			&pb.Strings{StringField: proto.String("\"A string with ' characters \n and \r newlines and \t tabs and \001 slashes \\ and  multiple   spaces")},
			"string_field: \"\\\"A string with ' characters \\n and \\r newlines and \\t tabs and \\001 slashes \\\\ and  multiple   spaces\"\n",
		},
		{
			// Test data from the same C++ test.
			&pb.Strings{StringField: proto.String("\350\260\267\346\255\214")},
			"string_field: \"\\350\\260\\267\\346\\255\\214\"\n",
		},
		{
			// Some UTF-8.
			&pb.Strings{StringField: proto.String("\x00\x01\xff\x81")},
			`string_field: "\000\001\377\201"` + "\n",
		},
	}

	for i, tc := range testCases {
		var buf bytes.Buffer
		if err := proto.MarshalText(&buf, tc.in); err != nil {
			t.Errorf("proto.MarsalText: %v", err)
			continue
		}
		s := buf.String()
		if s != tc.out {
			t.Errorf("#%d: Got:\n%s\nExpected:\n%s\n", i, s, tc.out)
			continue
		}

		// Check round-trip.
		pb := new(pb.Strings)
		if err := proto.UnmarshalText(s, pb); err != nil {
			t.Errorf("#%d: UnmarshalText: %v", i, err)
			continue
		}
		if !proto.Equal(pb, tc.in) {
			t.Errorf("#%d: Round-trip failed:\nstart: %v\n  end: %v", i, tc.in, pb)
		}
	}
}

// startLabelValue represents the state where the next byte read from p.buf is
// the start of a (quoted) label value (or whitespace leading up to it).
func (p *TextParser) startLabelValue() stateFn {
	if p.skipBlankTab(); p.err != nil {
		return nil // Unexpected end of input.
	}
	if p.currentByte != '"' {
		p.parseError(fmt.Sprintf("expected '\"' at start of label value, found %q", p.currentByte))
		return nil
	}
	if p.readTokenAsLabelValue(); p.err != nil {
		return nil
	}
	p.currentLabelPair.Value = proto.String(p.currentToken.String())
	// Special treatment of summaries:
	// - Quantile labels are special, will result in dto.Quantile later.
	// - Other labels have to be added to currentLabels for signature calculation.
	if p.currentMF.GetType() == dto.MetricType_SUMMARY {
		if p.currentLabelPair.GetName() == model.QuantileLabel {
			if p.currentQuantile, p.err = strconv.ParseFloat(p.currentLabelPair.GetValue(), 64); p.err != nil {
				// Create a more helpful error message.
				p.parseError(fmt.Sprintf("expected float as value for 'quantile' label, got %q", p.currentLabelPair.GetValue()))
				return nil
			}
		} else {
			p.currentLabels[p.currentLabelPair.GetName()] = p.currentLabelPair.GetValue()
		}
	}
	// Similar special treatment of histograms.
	if p.currentMF.GetType() == dto.MetricType_HISTOGRAM {
		if p.currentLabelPair.GetName() == model.BucketLabel {
			if p.currentBucket, p.err = strconv.ParseFloat(p.currentLabelPair.GetValue(), 64); p.err != nil {
				// Create a more helpful error message.
				p.parseError(fmt.Sprintf("expected float as value for 'le' label, got %q", p.currentLabelPair.GetValue()))
				return nil
			}
		} else {
			p.currentLabels[p.currentLabelPair.GetName()] = p.currentLabelPair.GetValue()
		}
	}
	if p.skipBlankTab(); p.err != nil {
		return nil // Unexpected end of input.
	}
	switch p.currentByte {
	case ',':
		return p.startLabelName

	case '}':
		if p.skipBlankTab(); p.err != nil {
			return nil // Unexpected end of input.
		}
		return p.readingValue
	default:
		p.parseError(fmt.Sprintf("unexpected end of label value %q", p.currentLabelPair.Value))
		return nil
	}
}

func TestExtensionsRoundTrip(t *testing.T) {
	msg := &pb.MyMessage{}
	ext1 := &pb.Ext{
		Data: proto.String("hi"),
	}
	ext2 := &pb.Ext{
		Data: proto.String("there"),
	}
	exists := proto.HasExtension(msg, pb.E_Ext_More)
	if exists {
		t.Error("Extension More present unexpectedly")
	}
	if err := proto.SetExtension(msg, pb.E_Ext_More, ext1); err != nil {
		t.Error(err)
	}
	if err := proto.SetExtension(msg, pb.E_Ext_More, ext2); err != nil {
		t.Error(err)
	}
	e, err := proto.GetExtension(msg, pb.E_Ext_More)
	if err != nil {
		t.Error(err)
	}
	x, ok := e.(*pb.Ext)
	if !ok {
		t.Errorf("e has type %T, expected testdata.Ext", e)
	} else if *x.Data != "there" {
		t.Errorf("SetExtension failed to overwrite, got %+v, not 'there'", x)
	}
	proto.ClearExtension(msg, pb.E_Ext_More)
	if _, err = proto.GetExtension(msg, pb.E_Ext_More); err != proto.ErrMissingExtension {
		t.Errorf("got %v, expected ErrMissingExtension", e)
	}
	if _, err := proto.GetExtension(msg, pb.E_X215); err == nil {
		t.Error("expected bad extension error, got nil")
	}
	if err := proto.SetExtension(msg, pb.E_X215, 12); err == nil {
		t.Error("expected extension err")
	}
	if err := proto.SetExtension(msg, pb.E_Ext_More, 12); err == nil {
		t.Error("expected some sort of type mismatch error, got nil")
	}
}

// readingHelp represents the state where the last byte read (now in
// p.currentByte) is the first byte of the docstring after 'HELP'.
func (p *TextParser) readingHelp() stateFn {
	if p.currentMF.Help != nil {
		p.parseError(fmt.Sprintf("second HELP line for metric name %q", p.currentMF.GetName()))
		return nil
	}
	// Rest of line is the docstring.
	if p.readTokenUntilNewline(true); p.err != nil {
		return nil // Unexpected end of input.
	}
	p.currentMF.Help = proto.String(p.currentToken.String())
	return p.startOfLine
}

func makeLabelPairs(desc *Desc, labelValues []string) []*dto.LabelPair {
	totalLen := len(desc.variableLabels) + len(desc.constLabelPairs)
	if totalLen == 0 {
		// Super fast path.
		return nil
	}
	if len(desc.variableLabels) == 0 {
		// Moderately fast path.
		return desc.constLabelPairs
	}
	labelPairs := make([]*dto.LabelPair, 0, totalLen)
	for i, n := range desc.variableLabels {
		labelPairs = append(labelPairs, &dto.LabelPair{
			Name:  proto.String(n),
			Value: proto.String(labelValues[i]),
		})
	}
	for _, lp := range desc.constLabelPairs {
		labelPairs = append(labelPairs, lp)
	}
	sort.Sort(LabelPairSorter(labelPairs))
	return labelPairs
}

func protoLabelSet(base, ext model.LabelSet) []*dto.LabelPair {
	labels := base.Clone().Merge(ext)
	delete(labels, model.MetricNameLabel)

	names := make([]string, 0, len(labels))
	for ln := range labels {
		names = append(names, string(ln))
	}
	sort.Strings(names)

	pairs := make([]*dto.LabelPair, 0, len(labels))

	for _, ln := range names {
		lv := labels[model.LabelName(ln)]

		pairs = append(pairs, &dto.LabelPair{
			Name:  proto.String(ln),
			Value: proto.String(string(lv)),
		})
	}

	return pairs
}

func newTestMessage() *pb.MyMessage {
	msg := &pb.MyMessage{
		Count: proto.Int32(42),
		Name:  proto.String("Dave"),
		Quote: proto.String(`"I didn't want to go."`),
		Pet:   []string{"bunny", "kitty", "horsey"},
		Inner: &pb.InnerMessage{
			Host:      proto.String("footrest.syd"),
			Port:      proto.Int32(7001),
			Connected: proto.Bool(true),
		},
		Others: []*pb.OtherMessage{
			{
				Key:   proto.Int64(0xdeadbeef),
				Value: []byte{1, 65, 7, 12},
			},
			{
				Weight: proto.Float32(6.022),
				Inner: &pb.InnerMessage{
					Host: proto.String("lesha.mtv"),
					Port: proto.Int32(8002),
				},
			},
		},
		Bikeshed: pb.MyMessage_BLUE.Enum(),
		Somegroup: &pb.MyMessage_SomeGroup{
			GroupField: proto.Int32(8),
		},
		// One normally wouldn't do this.
		// This is an undeclared tag 13, as a varint (wire type 0) with value 4.
		XXX_unrecognized: []byte{13<<3 | 0, 4},
	}
	ext := &pb.Ext{
		Data: proto.String("Big gobs for big rats"),
	}
	if err := proto.SetExtension(msg, pb.E_Ext_More, ext); err != nil {
		panic(err)
	}
	greetings := []string{"adg", "easy", "cow"}
	if err := proto.SetExtension(msg, pb.E_Greeting, greetings); err != nil {
		panic(err)
	}

	// Add an unknown extension. We marshal a pb.Ext, and fake the ID.
	b, err := proto.Marshal(&pb.Ext{Data: proto.String("3G skiing")})
	if err != nil {
		panic(err)
	}
	b = append(proto.EncodeVarint(201<<3|proto.WireBytes), b...)
	proto.SetRawExtension(msg, 201, b)

	// Extensions can be plain fields, too, so let's test that.
	b = append(proto.EncodeVarint(202<<3|proto.WireVarint), 19)
	proto.SetRawExtension(msg, 202, b)

	return msg
}

func TestNilExtension(t *testing.T) {
	msg := &pb.MyMessage{
		Count: proto.Int32(1),
	}
	if err := proto.SetExtension(msg, pb.E_Ext_Text, proto.String("hello")); err != nil {
		t.Fatal(err)
	}
	if err := proto.SetExtension(msg, pb.E_Ext_More, (*pb.Ext)(nil)); err == nil {
		t.Error("expected SetExtension to fail due to a nil extension")
	} else if want := "proto: SetExtension called with nil value of type *testdata.Ext"; err.Error() != want {
		t.Errorf("expected error %v, got %v", want, err)
	}
	// Note: if the behavior of Marshal is ever changed to ignore nil extensions, update
	// this test to verify that E_Ext_Text is properly propagated through marshal->unmarshal.
}

func TestRepeatedNilText(t *testing.T) {
	m := &pb.MessageList{
		Message: []*pb.MessageList_Message{
			nil,
			&pb.MessageList_Message{
				Name: proto.String("Horse"),
			},
			nil,
		},
	}
	want := `Message <nil>
Message {
  name: "Horse"
}
Message <nil>
`
	if s := proto.MarshalTextString(m); s != want {
		t.Errorf(" got: %s\nwant: %s", s, want)
	}
}

func fakeRunQuery(in *pb.RunQueryRequest, out *pb.RunQueryResponse) error {
	expectedIn := &pb.RunQueryRequest{
		Query: &pb.Query{
			Kind: []*pb.KindExpression{&pb.KindExpression{Name: proto.String("Gopher")}},
		},
	}
	if !proto.Equal(in, expectedIn) {
		return fmt.Errorf("unsupported argument: got %v want %v", in, expectedIn)
	}
	*out = pb.RunQueryResponse{
		Batch: &pb.QueryResultBatch{
			MoreResults:      pb.QueryResultBatch_NO_MORE_RESULTS.Enum(),
			EntityResultType: pb.EntityResult_FULL.Enum(),
			EntityResult: []*pb.EntityResult{
				&pb.EntityResult{
					Entity: &pb.Entity{
						Key: key1,
						Property: []*pb.Property{
							{
								Name:  proto.String("Name"),
								Value: &pb.Value{StringValue: proto.String("George")},
							},
							{
								Name: proto.String("Height"),
								Value: &pb.Value{
									IntegerValue: proto.Int64(32),
								},
							},
						},
					},
				},
				&pb.EntityResult{
					Entity: &pb.Entity{
						Key: key2,
						Property: []*pb.Property{
							{
								Name:  proto.String("Name"),
								Value: &pb.Value{StringValue: proto.String("Rufus")},
							},
							// No height for Rufus.
						},
					},
				},
			},
		},
	}
	return nil
}

func TestTextOneof(t *testing.T) {
	tests := []struct {
		m    proto.Message
		want string
	}{
		// zero message
		{&pb.Communique{}, ``},
		// scalar field
		{&pb.Communique{Union: &pb.Communique_Number{4}}, `number:4`},
		// message field
		{&pb.Communique{Union: &pb.Communique_Msg{
			&pb.Strings{StringField: proto.String("why hello!")},
		}}, `msg:<string_field:"why hello!" >`},
	}
	for _, test := range tests {
		got := strings.TrimSpace(test.m.String())
		if got != test.want {
			t.Errorf("\n got %s\nwant %s", got, test.want)
		}
	}
}

func interfaceToProto(iv interface{}) (p *pb.Value, errStr string) {
	val := new(pb.Value)
	switch v := iv.(type) {
	case int:
		val.IntegerValue = proto.Int64(int64(v))
	case int32:
		val.IntegerValue = proto.Int64(int64(v))
	case int64:
		val.IntegerValue = proto.Int64(v)
	case bool:
		val.BooleanValue = proto.Bool(v)
	case string:
		val.StringValue = proto.String(v)
	case float32:
		val.DoubleValue = proto.Float64(float64(v))
	case float64:
		val.DoubleValue = proto.Float64(v)
	case *Key:
		if v != nil {
			val.KeyValue = keyToProto(v)
		}
	case time.Time:
		if v.Before(minTime) || v.After(maxTime) {
			return nil, fmt.Sprintf("time value out of range")
		}
		val.TimestampMicrosecondsValue = proto.Int64(toUnixMicro(v))
	case []byte:
		val.BlobValue = v
	default:
		if iv != nil {
			return nil, fmt.Sprintf("invalid Value type %t", iv)
		}
	}
	// TODO(jbd): Support ListValue and EntityValue.
	// TODO(jbd): Support types whose underlying type is one of the types above.
	return val, ""
}

func (p *TextParser) setOrCreateCurrentMF() {
	p.currentIsSummaryCount = false
	p.currentIsSummarySum = false
	p.currentIsHistogramCount = false
	p.currentIsHistogramSum = false
	name := p.currentToken.String()
	if p.currentMF = p.metricFamiliesByName[name]; p.currentMF != nil {
		return
	}
	// Try out if this is a _sum or _count for a summary/histogram.
	summaryName := summaryMetricName(name)
	if p.currentMF = p.metricFamiliesByName[summaryName]; p.currentMF != nil {
		if p.currentMF.GetType() == dto.MetricType_SUMMARY {
			if isCount(name) {
				p.currentIsSummaryCount = true
			}
			if isSum(name) {
				p.currentIsSummarySum = true
			}
			return
		}
	}
	histogramName := histogramMetricName(name)
	if p.currentMF = p.metricFamiliesByName[histogramName]; p.currentMF != nil {
		if p.currentMF.GetType() == dto.MetricType_HISTOGRAM {
			if isCount(name) {
				p.currentIsHistogramCount = true
			}
			if isSum(name) {
				p.currentIsHistogramSum = true
			}
			return
		}
	}
	p.currentMF = &dto.MetricFamily{Name: proto.String(name)}
	p.metricFamiliesByName[name] = p.currentMF
}

// startLabelName represents the state where the next byte read from p.buf is
// the start of a label name (or whitespace leading up to it).
func (p *TextParser) startLabelName() stateFn {
	if p.skipBlankTab(); p.err != nil {
		return nil // Unexpected end of input.
	}
	if p.currentByte == '}' {
		if p.skipBlankTab(); p.err != nil {
			return nil // Unexpected end of input.
		}
		return p.readingValue
	}
	if p.readTokenAsLabelName(); p.err != nil {
		return nil // Unexpected end of input.
	}
	if p.currentToken.Len() == 0 {
		p.parseError(fmt.Sprintf("invalid label name for metric %q", p.currentMF.GetName()))
		return nil
	}
	p.currentLabelPair = &dto.LabelPair{Name: proto.String(p.currentToken.String())}
	if p.currentLabelPair.GetName() == string(model.MetricNameLabel) {
		p.parseError(fmt.Sprintf("label name %q is reserved", model.MetricNameLabel))
		return nil
	}
	// Special summary/histogram treatment. Don't add 'quantile' and 'le'
	// labels to 'real' labels.
	if !(p.currentMF.GetType() == dto.MetricType_SUMMARY && p.currentLabelPair.GetName() == model.QuantileLabel) &&
		!(p.currentMF.GetType() == dto.MetricType_HISTOGRAM && p.currentLabelPair.GetName() == model.BucketLabel) {
		p.currentMetric.Label = append(p.currentMetric.Label, p.currentLabelPair)
	}
	if p.skipBlankTabIfCurrentBlankTab(); p.err != nil {
		return nil // Unexpected end of input.
	}
	if p.currentByte != '=' {
		p.parseError(fmt.Sprintf("expected '=' after label name, found %q", p.currentByte))
		return nil
	}
	return p.startLabelValue
}

func testHandler(t testing.TB) {

	metricVec := NewCounterVec(
		CounterOpts{
			Name:        "name",
			Help:        "docstring",
			ConstLabels: Labels{"constname": "constvalue"},
		},
		[]string{"labelname"},
	)

	metricVec.WithLabelValues("val1").Inc()
	metricVec.WithLabelValues("val2").Inc()

	varintBuf := make([]byte, binary.MaxVarintLen32)

	externalMetricFamily := &dto.MetricFamily{
		Name: proto.String("externalname"),
		Help: proto.String("externaldocstring"),
		Type: dto.MetricType_COUNTER.Enum(),
		Metric: []*dto.Metric{
			{
				Label: []*dto.LabelPair{
					{
						Name:  proto.String("externalconstname"),
						Value: proto.String("externalconstvalue"),
					},
					{
						Name:  proto.String("externallabelname"),
						Value: proto.String("externalval1"),
					},
				},
				Counter: &dto.Counter{
					Value: proto.Float64(1),
				},
			},
		},
	}
	marshaledExternalMetricFamily, err := proto.Marshal(externalMetricFamily)
	if err != nil {
		t.Fatal(err)
	}
	var externalBuf bytes.Buffer
	l := binary.PutUvarint(varintBuf, uint64(len(marshaledExternalMetricFamily)))
	_, err = externalBuf.Write(varintBuf[:l])
	if err != nil {
		t.Fatal(err)
	}
	_, err = externalBuf.Write(marshaledExternalMetricFamily)
	if err != nil {
		t.Fatal(err)
	}
	externalMetricFamilyAsBytes := externalBuf.Bytes()
	externalMetricFamilyAsText := []byte(`# HELP externalname externaldocstring
# TYPE externalname counter
externalname{externalconstname="externalconstvalue",externallabelname="externalval1"} 1
`)
	externalMetricFamilyAsProtoText := []byte(`name: "externalname"
help: "externaldocstring"
type: COUNTER
metric: <
  label: <
    name: "externalconstname"
    value: "externalconstvalue"
  >
  label: <
    name: "externallabelname"
    value: "externalval1"
  >
  counter: <
    value: 1
  >
>

`)
	externalMetricFamilyAsProtoCompactText := []byte(`name:"externalname" help:"externaldocstring" type:COUNTER metric:<label:<name:"externalconstname" value:"externalconstvalue" > label:<name:"externallabelname" value:"externalval1" > counter:<value:1 > > 
`)

	expectedMetricFamily := &dto.MetricFamily{
		Name: proto.String("name"),
		Help: proto.String("docstring"),
		Type: dto.MetricType_COUNTER.Enum(),
		Metric: []*dto.Metric{
			{
				Label: []*dto.LabelPair{
					{
						Name:  proto.String("constname"),
						Value: proto.String("constvalue"),
					},
					{
						Name:  proto.String("labelname"),
						Value: proto.String("val1"),
					},
				},
				Counter: &dto.Counter{
					Value: proto.Float64(1),
				},
			},
			{
				Label: []*dto.LabelPair{
//.........这里部分代码省略.........

// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

package proto_test

import (
	"testing"

	"github.com/coreos/mantle/Godeps/_workspace/src/github.com/golang/protobuf/proto"

	proto3pb "github.com/coreos/mantle/Godeps/_workspace/src/github.com/golang/protobuf/proto/proto3_proto"
	pb "github.com/coreos/mantle/Godeps/_workspace/src/github.com/golang/protobuf/proto/testdata"
)

var cloneTestMessage = &pb.MyMessage{
	Count: proto.Int32(42),
	Name:  proto.String("Dave"),
	Pet:   []string{"bunny", "kitty", "horsey"},
	Inner: &pb.InnerMessage{
		Host:      proto.String("niles"),
		Port:      proto.Int32(9099),
		Connected: proto.Bool(true),
	},
	Others: []*pb.OtherMessage{
		{
			Value: []byte("some bytes"),
		},
	},
	Somegroup: &pb.MyMessage_SomeGroup{
		GroupField: proto.Int32(6),
	},
	RepBytes: [][]byte{[]byte("sham"), []byte("wow")},