client: initial mmvdump backed tests for testing singleton metric wri…

…ting

client_test.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"os"
 	"testing"
+
+	"github.com/performancecopilot/speed/mmvdump"
 )
 
 func TestMmvFileLocation(t *testing.T) {
@@ -117,3 +119,122 @@ func TestMapping(t *testing.T) {
 
 	EraseFileOnStop = false
 }
+
+func TestWritingSingletonMetric(t *testing.T) {
+	c, err := NewPCPClient("test", ProcessFlag)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+
+	met, err := NewPCPSingletonMetric(10, "test.1", Int32Type, CounterSemantics, OneUnit, "test", "")
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	c.MustRegister(met)
+
+	c.MustStart()
+	defer c.MustStop()
+
+	h, toc, m, v, i, ind, s, err := mmvdump.Dump(c.buffer.Bytes())
+
+	if int(h.Toc) != len(toc) {
+		t.Errorf("expected the number of tocs specified in the header and the number of tocs in the toc array to be the same, h.Toc = %d, len(tocs) = %d", h.Toc, len(toc))
+	}
+
+	if h.Toc != 3 {
+		t.Errorf("expected client to write %d tocs, written %d", 3, h.Toc)
+	}
+
+	if h.Flag != int32(ProcessFlag) {
+		t.Errorf("expected client to write a ProcessFlag, writing %v", MMVFlag(h.Flag))
+	}
+
+	if len(m) != 1 {
+		t.Errorf("expected to write %d metrics, writing %d", 1, len(m))
+	}
+
+	// metrics
+
+	off := c.r.metricsoffset
+	metric, ok := m[uint64(off)]
+	if !ok {
+		t.Errorf("expected the metric to exist at offset %v", off)
+	}
+
+	if metric.Indom != mmvdump.NoIndom {
+		t.Error("expected indom to be null")
+	}
+
+	if int32(metric.Sem) != int32(CounterSemantics) {
+		t.Errorf("expected semantics to be %v, got %v", CounterSemantics, MetricSemantics(metric.Sem))
+	}
+
+	if int32(metric.Typ) != int32(Int32Type) {
+		t.Errorf("expected type to be %v, got %v", Int32Type, MetricType(metric.Typ))
+	}
+
+	if int32(metric.Unit) != int32(OneUnit) {
+		t.Errorf("expected unit to be %v, got %v", OneUnit, metric.Unit)
+	}
+
+	if metric.Shorttext == 0 {
+		t.Error("expected shorttext offset to not be 0")
+	}
+
+	if metric.Shorttext != uint64(c.r.stringsoffset) {
+		t.Errorf("expected shorttext offset to be %v", c.r.stringsoffset)
+	}
+
+	if metric.Longtext != 0 {
+		t.Errorf("expected longtext offset to be 0")
+	}
+
+	// values
+
+	mv, ok := v[uint64(c.r.valuesoffset)]
+	if !ok {
+		t.Errorf("expected a value to be written at offset %v", c.r.valuesoffset)
+	}
+
+	if mv.Metric != uint64(off) {
+		t.Errorf("expected value's metric to be at %v", off)
+	}
+
+	if av, err := mmvdump.FixedVal(mv.Val, mmvdump.Int32Type); err != nil || av.(int32) != 10 {
+		t.Errorf("expected the value to be %v, got %v", 10, av)
+	}
+
+	if mv.Instance != 0 {
+		t.Errorf("expected value instance to be 0")
+	}
+
+	// strings
+
+	if len(s) != 1 {
+		t.Error("expected one string")
+	}
+
+	str, ok := s[uint64(c.r.stringsoffset)]
+	if !ok {
+		t.Errorf("expected a string to be written at offset %v", c.r.stringsoffset)
+	}
+
+	sv := string(str.Payload[:4])
+	if sv != "test" {
+		t.Errorf("expected payload to be %v, got %v", "test", sv)
+	}
+
+	// instances
+
+	if len(i) != 0 {
+		t.Error("expected no instances when writing a singleton metric")
+	}
+
+	// indoms
+
+	if len(ind) != 0 {
+		t.Error("expected no indoms when writing a singleton metric")
+	}
+}