Merge pull request #310 from pohly/fork-clock

dependencies: avoid k8s.io/utils, fork clock code instead

go.mod

@@ -2,7 +2,4 @@ module k8s.io/klog/v2
 
 go 1.13
 
-require (
-	github.com/go-logr/logr v1.2.0
-	k8s.io/utils v0.0.0-20220210201930-3a6ce19ff2f9
-)
+require github.com/go-logr/logr v1.2.0

go.sum

@@ -1,13 +1,2 @@
-github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/go-logr/logr v0.1.0/go.mod h1:ixOQHD9gLJUVQQ2ZOR7zLEifBX6tGkNJF4QyIY7sIas=
 github.com/go-logr/logr v1.2.0 h1:QK40JKJyMdUDz+h+xvCsru/bJhvG0UxvePV0ufL/AcE=
 github.com/go-logr/logr v1.2.0/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
-github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/spf13/afero v1.2.2/go.mod h1:9ZxEEn6pIJ8Rxe320qSDBk6AsU0r9pR7Q4OcevTdifk=
-github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
-golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-k8s.io/klog/v2 v2.0.0/go.mod h1:PBfzABfn139FHAV07az/IF9Wp1bkk3vpT2XSJ76fSDE=
-k8s.io/utils v0.0.0-20220210201930-3a6ce19ff2f9 h1:HNSDgDCrr/6Ly3WEGKZftiE7IY19Vz2GdbOCyI4qqhc=
-k8s.io/utils v0.0.0-20220210201930-3a6ce19ff2f9/go.mod h1:jPW/WVKK9YHAvNhRxK0md/EJ228hCsBRufyofKtW8HA=

internal/clock/README.md

@@ -0,0 +1,7 @@
+# Clock
+
+This package provides an interface for time-based operations.  It allows
+mocking time for testing.
+
+This is a copy of k8s.io/utils/clock. We have to copy it to avoid a circular
+dependency (k8s.io/klog -> k8s.io/utils -> k8s.io/klog).

internal/clock/clock.go

@@ -0,0 +1,178 @@
+/*
+Copyright 2014 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package clock
+
+import "time"
+
+// PassiveClock allows for injecting fake or real clocks into code
+// that needs to read the current time but does not support scheduling
+// activity in the future.
+type PassiveClock interface {
+	Now() time.Time
+	Since(time.Time) time.Duration
+}
+
+// Clock allows for injecting fake or real clocks into code that
+// needs to do arbitrary things based on time.
+type Clock interface {
+	PassiveClock
+	// After returns the channel of a new Timer.
+	// This method does not allow to free/GC the backing timer before it fires. Use
+	// NewTimer instead.
+	After(d time.Duration) <-chan time.Time
+	// NewTimer returns a new Timer.
+	NewTimer(d time.Duration) Timer
+	// Sleep sleeps for the provided duration d.
+	// Consider making the sleep interruptible by using 'select' on a context channel and a timer channel.
+	Sleep(d time.Duration)
+	// Tick returns the channel of a new Ticker.
+	// This method does not allow to free/GC the backing ticker. Use
+	// NewTicker from WithTicker instead.
+	Tick(d time.Duration) <-chan time.Time
+}
+
+// WithTicker allows for injecting fake or real clocks into code that
+// needs to do arbitrary things based on time.
+type WithTicker interface {
+	Clock
+	// NewTicker returns a new Ticker.
+	NewTicker(time.Duration) Ticker
+}
+
+// WithDelayedExecution allows for injecting fake or real clocks into
+// code that needs to make use of AfterFunc functionality.
+type WithDelayedExecution interface {
+	Clock
+	// AfterFunc executes f in its own goroutine after waiting
+	// for d duration and returns a Timer whose channel can be
+	// closed by calling Stop() on the Timer.
+	AfterFunc(d time.Duration, f func()) Timer
+}
+
+// WithTickerAndDelayedExecution allows for injecting fake or real clocks
+// into code that needs Ticker and AfterFunc functionality
+type WithTickerAndDelayedExecution interface {
+	WithTicker
+	// AfterFunc executes f in its own goroutine after waiting
+	// for d duration and returns a Timer whose channel can be
+	// closed by calling Stop() on the Timer.
+	AfterFunc(d time.Duration, f func()) Timer
+}
+
+// Ticker defines the Ticker interface.
+type Ticker interface {
+	C() <-chan time.Time
+	Stop()
+}
+
+var _ = WithTicker(RealClock{})
+
+// RealClock really calls time.Now()
+type RealClock struct{}
+
+// Now returns the current time.
+func (RealClock) Now() time.Time {
+	return time.Now()
+}
+
+// Since returns time since the specified timestamp.
+func (RealClock) Since(ts time.Time) time.Duration {
+	return time.Since(ts)
+}
+
+// After is the same as time.After(d).
+// This method does not allow to free/GC the backing timer before it fires. Use
+// NewTimer instead.
+func (RealClock) After(d time.Duration) <-chan time.Time {
+	return time.After(d)
+}
+
+// NewTimer is the same as time.NewTimer(d)
+func (RealClock) NewTimer(d time.Duration) Timer {
+	return &realTimer{
+		timer: time.NewTimer(d),
+	}
+}
+
+// AfterFunc is the same as time.AfterFunc(d, f).
+func (RealClock) AfterFunc(d time.Duration, f func()) Timer {
+	return &realTimer{
+		timer: time.AfterFunc(d, f),
+	}
+}
+
+// Tick is the same as time.Tick(d)
+// This method does not allow to free/GC the backing ticker. Use
+// NewTicker instead.
+func (RealClock) Tick(d time.Duration) <-chan time.Time {
+	return time.Tick(d)
+}
+
+// NewTicker returns a new Ticker.
+func (RealClock) NewTicker(d time.Duration) Ticker {
+	return &realTicker{
+		ticker: time.NewTicker(d),
+	}
+}
+
+// Sleep is the same as time.Sleep(d)
+// Consider making the sleep interruptible by using 'select' on a context channel and a timer channel.
+func (RealClock) Sleep(d time.Duration) {
+	time.Sleep(d)
+}
+
+// Timer allows for injecting fake or real timers into code that
+// needs to do arbitrary things based on time.
+type Timer interface {
+	C() <-chan time.Time
+	Stop() bool
+	Reset(d time.Duration) bool
+}
+
+var _ = Timer(&realTimer{})
+
+// realTimer is backed by an actual time.Timer.
+type realTimer struct {
+	timer *time.Timer
+}
+
+// C returns the underlying timer's channel.
+func (r *realTimer) C() <-chan time.Time {
+	return r.timer.C
+}
+
+// Stop calls Stop() on the underlying timer.
+func (r *realTimer) Stop() bool {
+	return r.timer.Stop()
+}
+
+// Reset calls Reset() on the underlying timer.
+func (r *realTimer) Reset(d time.Duration) bool {
+	return r.timer.Reset(d)
+}
+
+type realTicker struct {
+	ticker *time.Ticker
+}
+
+func (r *realTicker) C() <-chan time.Time {
+	return r.ticker.C
+}
+
+func (r *realTicker) Stop() {
+	r.ticker.Stop()
+}