Initial v1.0.0 commit

2026-07-13 00:22:42 +02:00 · 2021-01-28 17:37:47 +01:00
commit 1481d27782
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+
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+      To apply the Apache License to your work, attach the following
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+   Copyright [yyyy] [name of copyright owner]
+
+   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
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+   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.
@@ -0,0 +1,72 @@
+/*
+Copyright 2017 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 buffer
+
+// RingGrowing is a growing ring buffer.
+// Not thread safe.
+type RingGrowing struct {
+	data     []interface{}
+	n        int // Size of Data
+	beg      int // First available element
+	readable int // Number of data items available
+}
+
+// NewRingGrowing constructs a new RingGrowing instance with provided parameters.
+func NewRingGrowing(initialSize int) *RingGrowing {
+	return &RingGrowing{
+		data: make([]interface{}, initialSize),
+		n:    initialSize,
+	}
+}
+
+// ReadOne reads (consumes) first item from the buffer if it is available, otherwise returns false.
+func (r *RingGrowing) ReadOne() (data interface{}, ok bool) {
+	if r.readable == 0 {
+		return nil, false
+	}
+	r.readable--
+	element := r.data[r.beg]
+	r.data[r.beg] = nil // Remove reference to the object to help GC
+	if r.beg == r.n-1 {
+		// Was the last element
+		r.beg = 0
+	} else {
+		r.beg++
+	}
+	return element, true
+}
+
+// WriteOne adds an item to the end of the buffer, growing it if it is full.
+func (r *RingGrowing) WriteOne(data interface{}) {
+	if r.readable == r.n {
+		// Time to grow
+		newN := r.n * 2
+		newData := make([]interface{}, newN)
+		to := r.beg + r.readable
+		if to <= r.n {
+			copy(newData, r.data[r.beg:to])
+		} else {
+			copied := copy(newData, r.data[r.beg:])
+			copy(newData[copied:], r.data[:(to%r.n)])
+		}
+		r.beg = 0
+		r.data = newData
+		r.n = newN
+	}
+	r.data[(r.readable+r.beg)%r.n] = data
+	r.readable++
+}
@@ -0,0 +1,73 @@
+/*
+Copyright 2016 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 integer
+
+// IntMax returns the maximum of the params
+func IntMax(a, b int) int {
+	if b > a {
+		return b
+	}
+	return a
+}
+
+// IntMin returns the minimum of the params
+func IntMin(a, b int) int {
+	if b < a {
+		return b
+	}
+	return a
+}
+
+// Int32Max returns the maximum of the params
+func Int32Max(a, b int32) int32 {
+	if b > a {
+		return b
+	}
+	return a
+}
+
+// Int32Min returns the minimum of the params
+func Int32Min(a, b int32) int32 {
+	if b < a {
+		return b
+	}
+	return a
+}
+
+// Int64Max returns the maximum of the params
+func Int64Max(a, b int64) int64 {
+	if b > a {
+		return b
+	}
+	return a
+}
+
+// Int64Min returns the minimum of the params
+func Int64Min(a, b int64) int64 {
+	if b < a {
+		return b
+	}
+	return a
+}
+
+// RoundToInt32 rounds floats into integer numbers.
+func RoundToInt32(a float64) int32 {
+	if a < 0 {
+		return int32(a - 0.5)
+	}
+	return int32(a + 0.5)
+}
@@ -0,0 +1,10 @@
+# See the OWNERS docs at https://go.k8s.io/owners
+
+approvers:
+- apelisse
+- stewart-yu
+- thockin
+reviewers:
+- apelisse
+- stewart-yu
+- thockin
@@ -0,0 +1,3 @@
+# Pointer
+
+This package provides some functions for pointer-based operations.
@@ -0,0 +1,131 @@
+/*
+Copyright 2018 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 pointer
+
+import (
+	"fmt"
+	"reflect"
+)
+
+// AllPtrFieldsNil tests whether all pointer fields in a struct are nil.  This is useful when,
+// for example, an API struct is handled by plugins which need to distinguish
+// "no plugin accepted this spec" from "this spec is empty".
+//
+// This function is only valid for structs and pointers to structs.  Any other
+// type will cause a panic.  Passing a typed nil pointer will return true.
+func AllPtrFieldsNil(obj interface{}) bool {
+	v := reflect.ValueOf(obj)
+	if !v.IsValid() {
+		panic(fmt.Sprintf("reflect.ValueOf() produced a non-valid Value for %#v", obj))
+	}
+	if v.Kind() == reflect.Ptr {
+		if v.IsNil() {
+			return true
+		}
+		v = v.Elem()
+	}
+	for i := 0; i < v.NumField(); i++ {
+		if v.Field(i).Kind() == reflect.Ptr && !v.Field(i).IsNil() {
+			return false
+		}
+	}
+	return true
+}
+
+// Int32Ptr returns a pointer to an int32
+func Int32Ptr(i int32) *int32 {
+	return &i
+}
+
+// Int32PtrDerefOr dereference the int32 ptr and returns it if not nil,
+// else returns def.
+func Int32PtrDerefOr(ptr *int32, def int32) int32 {
+	if ptr != nil {
+		return *ptr
+	}
+	return def
+}
+
+// Int64Ptr returns a pointer to an int64
+func Int64Ptr(i int64) *int64 {
+	return &i
+}
+
+// Int64PtrDerefOr dereference the int64 ptr and returns it if not nil,
+// else returns def.
+func Int64PtrDerefOr(ptr *int64, def int64) int64 {
+	if ptr != nil {
+		return *ptr
+	}
+	return def
+}
+
+// BoolPtr returns a pointer to a bool
+func BoolPtr(b bool) *bool {
+	return &b
+}
+
+// BoolPtrDerefOr dereference the bool ptr and returns it if not nil,
+// else returns def.
+func BoolPtrDerefOr(ptr *bool, def bool) bool {
+	if ptr != nil {
+		return *ptr
+	}
+	return def
+}
+
+// StringPtr returns a pointer to the passed string.
+func StringPtr(s string) *string {
+	return &s
+}
+
+// StringPtrDerefOr dereference the string ptr and returns it if not nil,
+// else returns def.
+func StringPtrDerefOr(ptr *string, def string) string {
+	if ptr != nil {
+		return *ptr
+	}
+	return def
+}
+
+// Float32Ptr returns a pointer to the passed float32.
+func Float32Ptr(i float32) *float32 {
+	return &i
+}
+
+// Float32PtrDerefOr dereference the float32 ptr and returns it if not nil,
+// else returns def.
+func Float32PtrDerefOr(ptr *float32, def float32) float32 {
+	if ptr != nil {
+		return *ptr
+	}
+	return def
+}
+
+// Float64Ptr returns a pointer to the passed float64.
+func Float64Ptr(i float64) *float64 {
+	return &i
+}
+
+// Float64PtrDerefOr dereference the float64 ptr and returns it if not nil,
+// else returns def.
+func Float64PtrDerefOr(ptr *float64, def float64) float64 {
+	if ptr != nil {
+		return *ptr
+	}
+	return def
+}
@@ -0,0 +1,67 @@
+# Trace
+
+This package provides an interface for recording the latency of operations and logging details
+about all operations where the latency exceeds a limit.
+
+## Usage
+
+To create a trace:
+
+```go
+func doSomething() {
+    opTrace := trace.New("operation", Field{Key: "fieldKey1", Value: "fieldValue1"})
+    defer opTrace.LogIfLong(100 * time.Millisecond)
+    // do something
+}
+```
+
+To split an trace into multiple steps:
+
+```go
+func doSomething() {
+    opTrace := trace.New("operation")
+    defer opTrace.LogIfLong(100 * time.Millisecond)
+    // do step 1
+    opTrace.Step("step1", Field{Key: "stepFieldKey1", Value: "stepFieldValue1"})
+    // do step 2
+    opTrace.Step("step2")
+}
+```
+
+To nest traces:
+
+```go
+func doSomething() {
+    rootTrace := trace.New("rootOperation")
+    defer rootTrace.LogIfLong(100 * time.Millisecond)
+    
+    func() {
+        nestedTrace := rootTrace.Nest("nested", Field{Key: "nestedFieldKey1", Value: "nestedFieldValue1"})
+        defer nestedTrace.LogIfLong(50 * time.Millisecond)
+        // do nested operation
+    }()
+}
+```
+
+Traces can also be logged unconditionally or introspected:
+
+```go
+opTrace.TotalTime() // Duration since the Trace was created
+opTrace.Log() // unconditionally log the trace
+```
+
+### Using context.Context to nest traces
+
+`context.Context` can be used to manage nested traces. Create traces by calling `trace.GetTraceFromContext(ctx).Nest`. 
+This is safe even if there is no parent trace already in the context because `(*(Trace)nil).Nest()` returns
+a top level trace.
+
+```go
+func doSomething(ctx context.Context) {
+    opTrace := trace.FromContext(ctx).Nest("operation") // create a trace, possibly nested
+    ctx = trace.ContextWithTrace(ctx, opTrace) // make this trace the parent trace of the context
+    defer opTrace.LogIfLong(50 * time.Millisecond)
+    
+    doSomethingElse(ctx)
+}
+```
@@ -0,0 +1,282 @@
+/*
+Copyright 2015 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 trace
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"math/rand"
+	"time"
+
+	"k8s.io/klog/v2"
+)
+
+var klogV = func(lvl klog.Level) bool {
+	return klog.V(lvl).Enabled()
+}
+
+// Field is a key value pair that provides additional details about the trace.
+type Field struct {
+	Key   string
+	Value interface{}
+}
+
+func (f Field) format() string {
+	return fmt.Sprintf("%s:%v", f.Key, f.Value)
+}
+
+func writeFields(b *bytes.Buffer, l []Field) {
+	for i, f := range l {
+		b.WriteString(f.format())
+		if i < len(l)-1 {
+			b.WriteString(",")
+		}
+	}
+}
+
+func writeTraceItemSummary(b *bytes.Buffer, msg string, totalTime time.Duration, startTime time.Time, fields []Field) {
+	b.WriteString(fmt.Sprintf("%q ", msg))
+	if len(fields) > 0 {
+		writeFields(b, fields)
+		b.WriteString(" ")
+	}
+
+	b.WriteString(fmt.Sprintf("%vms (%v)", durationToMilliseconds(totalTime), startTime.Format("15:04:00.000")))
+}
+
+func durationToMilliseconds(timeDuration time.Duration) int64 {
+	return timeDuration.Nanoseconds() / 1e6
+}
+
+type traceItem interface {
+	// time returns when the trace was recorded as completed.
+	time() time.Time
+	// writeItem outputs the traceItem to the buffer. If stepThreshold is non-nil, only output the
+	// traceItem if its the duration exceeds the stepThreshold.
+	// Each line of output is prefixed by formatter to visually indent nested items.
+	writeItem(b *bytes.Buffer, formatter string, startTime time.Time, stepThreshold *time.Duration)
+}
+
+type traceStep struct {
+	stepTime time.Time
+	msg      string
+	fields   []Field
+}
+
+func (s traceStep) time() time.Time {
+	return s.stepTime
+}
+
+func (s traceStep) writeItem(b *bytes.Buffer, formatter string, startTime time.Time, stepThreshold *time.Duration) {
+	stepDuration := s.stepTime.Sub(startTime)
+	if stepThreshold == nil || *stepThreshold == 0 || stepDuration >= *stepThreshold || klogV(4) {
+		b.WriteString(fmt.Sprintf("%s---", formatter))
+		writeTraceItemSummary(b, s.msg, stepDuration, s.stepTime, s.fields)
+	}
+}
+
+// Trace keeps track of a set of "steps" and allows us to log a specific
+// step if it took longer than its share of the total allowed time
+type Trace struct {
+	name        string
+	fields      []Field
+	threshold   *time.Duration
+	startTime   time.Time
+	endTime     *time.Time
+	traceItems  []traceItem
+	parentTrace *Trace
+}
+
+func (t *Trace) time() time.Time {
+	if t.endTime != nil {
+		return *t.endTime
+	}
+	return t.startTime // if the trace is incomplete, don't assume an end time
+}
+
+func (t *Trace) writeItem(b *bytes.Buffer, formatter string, startTime time.Time, stepThreshold *time.Duration) {
+	if t.durationIsWithinThreshold() || klogV(4) {
+		b.WriteString(fmt.Sprintf("%v[", formatter))
+		writeTraceItemSummary(b, t.name, t.TotalTime(), t.startTime, t.fields)
+		if st := t.calculateStepThreshold(); st != nil {
+			stepThreshold = st
+		}
+		t.writeTraceSteps(b, formatter+" ", stepThreshold)
+		b.WriteString("]")
+		return
+	}
+	// If the trace should not be written, still check for nested traces that should be written
+	for _, s := range t.traceItems {
+		if nestedTrace, ok := s.(*Trace); ok {
+			nestedTrace.writeItem(b, formatter, startTime, stepThreshold)
+		}
+	}
+}
+
+// New creates a Trace with the specified name. The name identifies the operation to be traced. The
+// Fields add key value pairs to provide additional details about the trace, such as operation inputs.
+func New(name string, fields ...Field) *Trace {
+	return &Trace{name: name, startTime: time.Now(), fields: fields}
+}
+
+// Step adds a new step with a specific message. Call this at the end of an execution step to record
+// how long it took. The Fields add key value pairs to provide additional details about the trace
+// step.
+func (t *Trace) Step(msg string, fields ...Field) {
+	if t.traceItems == nil {
+		// traces almost always have less than 6 steps, do this to avoid more than a single allocation
+		t.traceItems = make([]traceItem, 0, 6)
+	}
+	t.traceItems = append(t.traceItems, traceStep{stepTime: time.Now(), msg: msg, fields: fields})
+}
+
+// Nest adds a nested trace with the given message and fields and returns it.
+// As a convenience, if the receiver is nil, returns a top level trace. This allows
+// one to call FromContext(ctx).Nest without having to check if the trace
+// in the context is nil.
+func (t *Trace) Nest(msg string, fields ...Field) *Trace {
+	newTrace := New(msg, fields...)
+	if t != nil {
+		newTrace.parentTrace = t
+		t.traceItems = append(t.traceItems, newTrace)
+	}
+	return newTrace
+}
+
+// Log is used to dump all the steps in the Trace. It also logs the nested trace messages using indentation.
+// If the Trace is nested it is not immediately logged. Instead, it is logged when the trace it is nested within
+// is logged.
+func (t *Trace) Log() {
+	endTime := time.Now()
+	t.endTime = &endTime
+	// an explicit logging request should dump all the steps out at the higher level
+	if t.parentTrace == nil { // We don't start logging until Log or LogIfLong is called on the root trace
+		t.logTrace()
+	}
+}
+
+// LogIfLong only logs the trace if the duration of the trace exceeds the threshold.
+// Only steps that took longer than their share or the given threshold are logged.
+// If klog is at verbosity level 4 or higher and the trace took longer than the threshold,
+// all substeps and subtraces are logged. Otherwise, only those which took longer than
+// their own threshold.
+// If the Trace is nested it is not immediately logged. Instead, it is logged when the trace it
+// is nested within is logged.
+func (t *Trace) LogIfLong(threshold time.Duration) {
+	t.threshold = &threshold
+	t.Log()
+}
+
+// logTopLevelTraces finds all traces in a hierarchy of nested traces that should be logged but do not have any
+// parents that will be logged, due to threshold limits, and logs them as top level traces.
+func (t *Trace) logTrace() {
+	if t.durationIsWithinThreshold() {
+		var buffer bytes.Buffer
+		traceNum := rand.Int31()
+
+		totalTime := t.endTime.Sub(t.startTime)
+		buffer.WriteString(fmt.Sprintf("Trace[%d]: %q ", traceNum, t.name))
+		if len(t.fields) > 0 {
+			writeFields(&buffer, t.fields)
+			buffer.WriteString(" ")
+		}
+
+		// if any step took more than it's share of the total allowed time, it deserves a higher log level
+		buffer.WriteString(fmt.Sprintf("(%v) (total time: %vms):", t.startTime.Format("02-Jan-2006 15:04:05.000"), totalTime.Milliseconds()))
+		stepThreshold := t.calculateStepThreshold()
+		t.writeTraceSteps(&buffer, fmt.Sprintf("\nTrace[%d]: ", traceNum), stepThreshold)
+		buffer.WriteString(fmt.Sprintf("\nTrace[%d]: [%v] [%v] END\n", traceNum, t.endTime.Sub(t.startTime), totalTime))
+
+		klog.Info(buffer.String())
+		return
+	}
+
+	// If the trace should not be logged, still check if nested traces should be logged
+	for _, s := range t.traceItems {
+		if nestedTrace, ok := s.(*Trace); ok {
+			nestedTrace.logTrace()
+		}
+	}
+}
+
+func (t *Trace) writeTraceSteps(b *bytes.Buffer, formatter string, stepThreshold *time.Duration) {
+	lastStepTime := t.startTime
+	for _, stepOrTrace := range t.traceItems {
+		stepOrTrace.writeItem(b, formatter, lastStepTime, stepThreshold)
+		lastStepTime = stepOrTrace.time()
+	}
+}
+
+func (t *Trace) durationIsWithinThreshold() bool {
+	if t.endTime == nil { // we don't assume incomplete traces meet the threshold
+		return false
+	}
+	return t.threshold == nil || *t.threshold == 0 || t.endTime.Sub(t.startTime) >= *t.threshold
+}
+
+// TotalTime can be used to figure out how long it took since the Trace was created
+func (t *Trace) TotalTime() time.Duration {
+	return time.Since(t.startTime)
+}
+
+// calculateStepThreshold returns a threshold for the individual steps of a trace, or nil if there is no threshold and
+// all steps should be written.
+func (t *Trace) calculateStepThreshold() *time.Duration {
+	if t.threshold == nil {
+		return nil
+	}
+	lenTrace := len(t.traceItems) + 1
+	traceThreshold := *t.threshold
+	for _, s := range t.traceItems {
+		nestedTrace, ok := s.(*Trace)
+		if ok && nestedTrace.threshold != nil {
+			traceThreshold = traceThreshold - *nestedTrace.threshold
+			lenTrace--
+		}
+	}
+
+	// the limit threshold is used when the threshold(
+	//remaining after subtracting that of the child trace) is getting very close to zero to prevent unnecessary logging
+	limitThreshold := *t.threshold / 4
+	if traceThreshold < limitThreshold {
+		traceThreshold = limitThreshold
+		lenTrace = len(t.traceItems) + 1
+	}
+
+	stepThreshold := traceThreshold / time.Duration(lenTrace)
+	return &stepThreshold
+}
+
+// ContextTraceKey provides a common key for traces in context.Context values.
+type ContextTraceKey struct{}
+
+// FromContext returns the trace keyed by ContextTraceKey in the context values, if one
+// is present, or nil If there is no trace in the Context.
+// It is safe to call Nest() on the returned value even if it is nil because ((*Trace)nil).Nest returns a top level
+// trace.
+func FromContext(ctx context.Context) *Trace {
+	if v, ok := ctx.Value(ContextTraceKey{}).(*Trace); ok {
+		return v
+	}
+	return nil
+}
+
+// ContextWithTrace returns a context with trace included in the context values, keyed by ContextTraceKey.
+func ContextWithTrace(ctx context.Context, trace *Trace) context.Context {
+	return context.WithValue(ctx, ContextTraceKey{}, trace)
+}