whatcanGOwrong

go/pkg/mod/golang.org/x/telemetry@v0.0.0-20240829154258-f29ab539cc98/counter/countertest/countertest.go

@@ -0,0 +1,63 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// countertest provides testing utilities for counters.
+// This package cannot be used except for testing.
+package countertest
+
+import (
+	"sync"
+
+	"golang.org/x/telemetry/counter"
+	ic "golang.org/x/telemetry/internal/counter"
+	"golang.org/x/telemetry/internal/telemetry"
+)
+
+var (
+	openedMu sync.Mutex
+	opened   bool
+)
+
+// SupportedPlatform reports if this platform supports Open()
+const SupportedPlatform = !telemetry.DisabledOnPlatform
+
+func isOpen() bool {
+	openedMu.Lock()
+	defer openedMu.Unlock()
+	return opened
+}
+
+// Open enables telemetry data writing to disk.
+// This is supposed to be called once during the program execution
+// (i.e. typically in TestMain), and must not be used with
+// golang.org/x/telemetry/counter.Open.
+func Open(telemetryDir string) {
+	openedMu.Lock()
+	defer openedMu.Unlock()
+	if opened {
+		panic("Open was called more than once")
+	}
+	telemetry.Default = telemetry.NewDir(telemetryDir)
+
+	// TODO(rfindley): reinstate test coverage with counter rotation enabled.
+	// Before the [counter.Open] and [counter.OpenAndRotate] APIs were split,
+	// this called counter.Open (which rotated!).
+	counter.Open()
+	opened = true
+}
+
+// ReadCounter reads the given counter.
+func ReadCounter(c *counter.Counter) (count uint64, _ error) {
+	return ic.Read(c)
+}
+
+// ReadStackCounter reads the given StackCounter.
+func ReadStackCounter(c *counter.StackCounter) (stackCounts map[string]uint64, _ error) {
+	return ic.ReadStack(c)
+}
+
+// ReadFile reads the counters and stack counters from the given file.
+func ReadFile(name string) (counters, stackCounters map[string]uint64, _ error) {
+	return ic.ReadFile(name)
+}

go/pkg/mod/golang.org/x/telemetry@v0.0.0-20240829154258-f29ab539cc98/counter/countertest/countertest_go121.go

@@ -0,0 +1,16 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build go1.21
+
+package countertest
+
+import "testing"
+
+func init() {
+	// Extra safety check for go1.21+.
+	if !testing.Testing() {
+		panic("use of this package is disallowed in non-testing code")
+	}
+}

go/pkg/mod/golang.org/x/telemetry@v0.0.0-20240829154258-f29ab539cc98/counter/countertest/countertest_test.go

@@ -0,0 +1,90 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build go1.21
+
+package countertest
+
+import (
+	"fmt"
+	"slices"
+	"strings"
+	"sync"
+	"testing"
+
+	"golang.org/x/telemetry/counter"
+	"golang.org/x/telemetry/internal/telemetry"
+	"golang.org/x/telemetry/internal/testenv"
+)
+
+func TestReadCounter(t *testing.T) {
+	testenv.SkipIfUnsupportedPlatform(t)
+	c := counter.New("foobar")
+
+	got, err := ReadCounter(c)
+	if err != nil {
+		t.Errorf("ReadCounter = (%d, %v), want (0,nil)", got, err)
+	}
+	if got != 0 {
+		t.Fatalf("ReadCounter = %d, want 0", got)
+	}
+
+	var wg sync.WaitGroup
+	wg.Add(100)
+	for i := 0; i < 100; i++ {
+		go func() {
+			c.Inc()
+			wg.Done()
+		}()
+	}
+	wg.Wait()
+	if got, err := ReadCounter(c); err != nil || got != 100 {
+		t.Errorf("ReadCounter = (%v, %v), want (%v, nil)", got, err, 100)
+	}
+}
+
+func TestReadStackCounter(t *testing.T) {
+	testenv.SkipIfUnsupportedPlatform(t)
+	c := counter.NewStack("foobar", 8)
+
+	if got, err := ReadStackCounter(c); err != nil || len(got) != 0 {
+		t.Errorf("ReadStackCounter = (%q, %v), want (%v, nil)", got, err, 0)
+	}
+
+	var wg sync.WaitGroup
+	wg.Add(100)
+	for i := 0; i < 100; i++ {
+		go func() {
+			c.Inc() // one stack!
+			wg.Done()
+		}()
+	}
+	wg.Wait()
+
+	got, err := ReadStackCounter(c)
+	if err != nil || len(got) != 1 {
+		t.Fatalf("ReadStackCounter = (%v, %v), want to read one entry", stringify(got), err)
+	}
+	for k, v := range got {
+		if !strings.Contains(k, t.Name()) || v != 100 {
+			t.Fatalf("ReadStackCounter = %v, want a stack counter with value 100", got)
+		}
+	}
+}
+
+func TestSupport(t *testing.T) {
+	if SupportedPlatform == telemetry.DisabledOnPlatform {
+		t.Errorf("supported mismatch: us %v, telemetry.internal.Disabled %v",
+			SupportedPlatform, telemetry.DisabledOnPlatform)
+	}
+}
+
+func stringify(m map[string]uint64) string {
+	kv := make([]string, 0, len(m))
+	for k, v := range m {
+		kv = append(kv, fmt.Sprintf("%q:%v", k, v))
+	}
+	slices.Sort(kv)
+	return "{" + strings.Join(kv, " ") + "}"
+}