3 files changed, 104 insertions, 18 deletions
diff --git a/vendor/github.com/prometheus/common/expfmt/decode.go b/vendor/github.com/prometheus/common/expfmt/decode.go
index 487fdc6cc..a7a42d5ef 100644
--- a/vendor/github.com/prometheus/common/expfmt/decode.go
+++ b/vendor/github.com/prometheus/common/expfmt/decode.go
@@ -31,6 +31,7 @@ type Decoder interface {
 	Decode(*dto.MetricFamily) error
 }
 
+// DecodeOptions contains options used by the Decoder and in sample extraction.
 type DecodeOptions struct {
 	// Timestamp is added to each value from the stream that has no explicit timestamp set.
 	Timestamp model.Time
@@ -142,6 +143,8 @@ func (d *textDecoder) Decode(v *dto.MetricFamily) error {
 	return nil
 }
 
+// SampleDecoder wraps a Decoder to extract samples from the metric families
+// decoded by the wrapped Decoder.
 type SampleDecoder struct {
 	Dec  Decoder
 	Opts *DecodeOptions
@@ -149,37 +152,51 @@ type SampleDecoder struct {
 	f dto.MetricFamily
 }
 
+// Decode calls the Decode method of the wrapped Decoder and then extracts the
+// samples from the decoded MetricFamily into the provided model.Vector.
 func (sd *SampleDecoder) Decode(s *model.Vector) error {
-	if err := sd.Dec.Decode(&sd.f); err != nil {
+	err := sd.Dec.Decode(&sd.f)
+	if err != nil {
 		return err
 	}
-	*s = extractSamples(&sd.f, sd.Opts)
-	return nil
+	*s, err = extractSamples(&sd.f, sd.Opts)
+	return err
 }
 
-// Extract samples builds a slice of samples from the provided metric families.
-func ExtractSamples(o *DecodeOptions, fams ...*dto.MetricFamily) model.Vector {
-	var all model.Vector
+// ExtractSamples builds a slice of samples from the provided metric
+// families. If an error occurs during sample extraction, it continues to
+// extract from the remaining metric families. The returned error is the last
+// error that has occured.
+func ExtractSamples(o *DecodeOptions, fams ...*dto.MetricFamily) (model.Vector, error) {
+	var (
+		all     model.Vector
+		lastErr error
+	)
 	for _, f := range fams {
-		all = append(all, extractSamples(f, o)...)
+		some, err := extractSamples(f, o)
+		if err != nil {
+			lastErr = err
+			continue
+		}
+		all = append(all, some...)
 	}
-	return all
+	return all, lastErr
 }
 
-func extractSamples(f *dto.MetricFamily, o *DecodeOptions) model.Vector {
+func extractSamples(f *dto.MetricFamily, o *DecodeOptions) (model.Vector, error) {
 	switch f.GetType() {
 	case dto.MetricType_COUNTER:
-		return extractCounter(o, f)
+		return extractCounter(o, f), nil
 	case dto.MetricType_GAUGE:
-		return extractGauge(o, f)
+		return extractGauge(o, f), nil
 	case dto.MetricType_SUMMARY:
-		return extractSummary(o, f)
+		return extractSummary(o, f), nil
 	case dto.MetricType_UNTYPED:
-		return extractUntyped(o, f)
+		return extractUntyped(o, f), nil
 	case dto.MetricType_HISTOGRAM:
-		return extractHistogram(o, f)
+		return extractHistogram(o, f), nil
 	}
-	panic("expfmt.extractSamples: unknown metric family type")
+	return nil, fmt.Errorf("expfmt.extractSamples: unknown metric family type %v", f.GetType())
 }
 
 func extractCounter(o *DecodeOptions, f *dto.MetricFamily) model.Vector {
diff --git a/vendor/github.com/prometheus/common/expfmt/decode_test.go b/vendor/github.com/prometheus/common/expfmt/decode_test.go
index c27325a9d..82c1130c9 100644
--- a/vendor/github.com/prometheus/common/expfmt/decode_test.go
+++ b/vendor/github.com/prometheus/common/expfmt/decode_test.go
@@ -21,6 +21,9 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/golang/protobuf/proto"
+	dto "github.com/prometheus/client_model/go"
+
 	"github.com/prometheus/common/model"
 )
 
@@ -365,3 +368,68 @@ func BenchmarkDiscriminatorHTTPHeader(b *testing.B) {
 		testDiscriminatorHTTPHeader(b)
 	}
 }
+
+func TestExtractSamples(t *testing.T) {
+	var (
+		goodMetricFamily1 = &dto.MetricFamily{
+			Name: proto.String("foo"),
+			Help: proto.String("Help for foo."),
+			Type: dto.MetricType_COUNTER.Enum(),
+			Metric: []*dto.Metric{
+				&dto.Metric{
+					Counter: &dto.Counter{
+						Value: proto.Float64(4711),
+					},
+				},
+			},
+		}
+		goodMetricFamily2 = &dto.MetricFamily{
+			Name: proto.String("bar"),
+			Help: proto.String("Help for bar."),
+			Type: dto.MetricType_GAUGE.Enum(),
+			Metric: []*dto.Metric{
+				&dto.Metric{
+					Gauge: &dto.Gauge{
+						Value: proto.Float64(3.14),
+					},
+				},
+			},
+		}
+		badMetricFamily = &dto.MetricFamily{
+			Name: proto.String("bad"),
+			Help: proto.String("Help for bad."),
+			Type: dto.MetricType(42).Enum(),
+			Metric: []*dto.Metric{
+				&dto.Metric{
+					Gauge: &dto.Gauge{
+						Value: proto.Float64(2.7),
+					},
+				},
+			},
+		}
+
+		opts = &DecodeOptions{
+			Timestamp: 42,
+		}
+	)
+
+	got, err := ExtractSamples(opts, goodMetricFamily1, goodMetricFamily2)
+	if err != nil {
+		t.Error("Unexpected error from ExtractSamples:", err)
+	}
+	want := model.Vector{
+		&model.Sample{Metric: model.Metric{model.MetricNameLabel: "foo"}, Value: 4711, Timestamp: 42},
+		&model.Sample{Metric: model.Metric{model.MetricNameLabel: "bar"}, Value: 3.14, Timestamp: 42},
+	}
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("unexpected samples extracted, got: %v, want: %v", got, want)
+	}
+
+	got, err = ExtractSamples(opts, goodMetricFamily1, badMetricFamily, goodMetricFamily2)
+	if err == nil {
+		t.Error("Expected error from ExtractSamples")
+	}
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("unexpected samples extracted, got: %v, want: %v", got, want)
+	}
+}
diff --git a/vendor/github.com/prometheus/common/expfmt/expfmt.go b/vendor/github.com/prometheus/common/expfmt/expfmt.go
index fae10f6eb..371ac7503 100644
--- a/vendor/github.com/prometheus/common/expfmt/expfmt.go
+++ b/vendor/github.com/prometheus/common/expfmt/expfmt.go
@@ -11,14 +11,15 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// A package for reading and writing Prometheus metrics.
+// Package expfmt contains tools for reading and writing Prometheus metrics.
 package expfmt
 
+// Format specifies the HTTP content type of the different wire protocols.
 type Format string
 
+// Constants to assemble the Content-Type values for the different wire protocols.
 const (
-	TextVersion = "0.0.4"
-
+	TextVersion   = "0.0.4"
 	ProtoType     = `application/vnd.google.protobuf`
 	ProtoProtocol = `io.prometheus.client.MetricFamily`
 	ProtoFmt      = ProtoType + "; proto=" + ProtoProtocol + ";"