updated vendor

vendor/k8s.io/klog/v2/internal/serialize/keyvalues.go

@@ -20,7 +20,9 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
+	"slices"
 	"strconv"
+	"strings"
 
 	"github.com/go-logr/logr"
 )
@@ -51,139 +53,157 @@ func WithValues(oldKV, newKV []interface{}) []interface{} {
 	return kv
 }
 
-// MergeKVs deduplicates elements provided in two key/value slices.
-//
-// Keys in each slice are expected to be unique, so duplicates can only occur
-// when the first and second slice contain the same key. When that happens, the
-// key/value pair from the second slice is used. The first slice must be well-formed
-// (= even key/value pairs). The second one may have a missing value, in which
-// case the special "missing value" is added to the result.
-func MergeKVs(first, second []interface{}) []interface{} {
-	maxLength := len(first) + (len(second)+1)/2*2
-	if maxLength == 0 {
-		// Nothing to do at all.
-		return nil
-	}
-
-	if len(first) == 0 && len(second)%2 == 0 {
-		// Nothing to be overridden, second slice is well-formed
-		// and can be used directly.
-		return second
-	}
-
-	// Determine which keys are in the second slice so that we can skip
-	// them when iterating over the first one. The code intentionally
-	// favors performance over completeness: we assume that keys are string
-	// constants and thus compare equal when the string values are equal. A
-	// string constant being overridden by, for example, a fmt.Stringer is
-	// not handled.
-	overrides := map[interface{}]bool{}
-	for i := 0; i < len(second); i += 2 {
-		overrides[second[i]] = true
-	}
-	merged := make([]interface{}, 0, maxLength)
-	for i := 0; i+1 < len(first); i += 2 {
-		key := first[i]
-		if overrides[key] {
-			continue
-		}
-		merged = append(merged, key, first[i+1])
-	}
-	merged = append(merged, second...)
-	if len(merged)%2 != 0 {
-		merged = append(merged, missingValue)
-	}
-	return merged
-}
-
 type Formatter struct {
 	AnyToStringHook AnyToStringFunc
 }
 
 type AnyToStringFunc func(v interface{}) string
 
-// MergeKVsInto is a variant of MergeKVs which directly formats the key/value
-// pairs into a buffer.
-func (f Formatter) MergeAndFormatKVs(b *bytes.Buffer, first, second []interface{}) {
-	if len(first) == 0 && len(second) == 0 {
-		// Nothing to do at all.
-		return
-	}
-
-	if len(first) == 0 && len(second)%2 == 0 {
-		// Nothing to be overridden, second slice is well-formed
-		// and can be used directly.
-		for i := 0; i < len(second); i += 2 {
-			f.KVFormat(b, second[i], second[i+1])
-		}
-		return
-	}
-
-	// Determine which keys are in the second slice so that we can skip
-	// them when iterating over the first one. The code intentionally
-	// favors performance over completeness: we assume that keys are string
-	// constants and thus compare equal when the string values are equal. A
-	// string constant being overridden by, for example, a fmt.Stringer is
-	// not handled.
-	overrides := map[interface{}]bool{}
-	for i := 0; i < len(second); i += 2 {
-		overrides[second[i]] = true
-	}
-	for i := 0; i < len(first); i += 2 {
-		key := first[i]
-		if overrides[key] {
-			continue
-		}
-		f.KVFormat(b, key, first[i+1])
-	}
-	// Round down.
-	l := len(second)
-	l = l / 2 * 2
-	for i := 1; i < l; i += 2 {
-		f.KVFormat(b, second[i-1], second[i])
-	}
-	if len(second)%2 == 1 {
-		f.KVFormat(b, second[len(second)-1], missingValue)
-	}
-}
-
-func MergeAndFormatKVs(b *bytes.Buffer, first, second []interface{}) {
-	Formatter{}.MergeAndFormatKVs(b, first, second)
-}
-
 const missingValue = "(MISSING)"
 
-// KVListFormat serializes all key/value pairs into the provided buffer.
-// A space gets inserted before the first pair and between each pair.
-func (f Formatter) KVListFormat(b *bytes.Buffer, keysAndValues ...interface{}) {
-	for i := 0; i < len(keysAndValues); i += 2 {
-		var v interface{}
-		k := keysAndValues[i]
-		if i+1 < len(keysAndValues) {
-			v = keysAndValues[i+1]
-		} else {
-			v = missingValue
+func FormatKVs(b *bytes.Buffer, kvs ...[]interface{}) {
+	Formatter{}.FormatKVs(b, kvs...)
+}
+
+// FormatKVs formats all key/value pairs such that the output contains no
+// duplicates ("last one wins").
+func (f Formatter) FormatKVs(b *bytes.Buffer, kvs ...[]interface{}) {
+	// De-duplication is done by optimistically formatting all key value
+	// pairs and then cutting out the output of those key/value pairs which
+	// got overwritten later.
+	//
+	// In the common case of no duplicates, the only overhead is tracking
+	// previous keys. This uses a slice with a simple linear search because
+	// the number of entries is typically so low that allocating a map or
+	// keeping a sorted slice with binary search aren't justified.
+	//
+	// Using a fixed size here makes the Go compiler use the stack as
+	// initial backing store for the slice, which is crucial for
+	// performance.
+	existing := make([]obsoleteKV, 0, 32)
+	obsolete := make([]interval, 0, 32) // Sorted by start index.
+	for _, keysAndValues := range kvs {
+		for i := 0; i < len(keysAndValues); i += 2 {
+			var v interface{}
+			k := keysAndValues[i]
+			if i+1 < len(keysAndValues) {
+				v = keysAndValues[i+1]
+			} else {
+				v = missingValue
+			}
+			var e obsoleteKV
+			e.start = b.Len()
+			e.key = f.KVFormat(b, k, v)
+			e.end = b.Len()
+			i := findObsoleteEntry(existing, e.key)
+			if i >= 0 {
+				data := b.Bytes()
+				if bytes.Compare(data[existing[i].start:existing[i].end], data[e.start:e.end]) == 0 {
+					// The new entry gets obsoleted because it's identical.
+					// This has the advantage that key/value pairs from
+					// a WithValues call always come first, even if the same
+					// pair gets added again later. This makes different log
+					// entries more consistent.
+					//
+					// The new entry has a higher start index and thus can be appended.
+					obsolete = append(obsolete, e.interval)
+				} else {
+					// The old entry gets obsoleted because it's value is different.
+					//
+					// Sort order is not guaranteed, we have to insert at the right place.
+					index, _ := slices.BinarySearchFunc(obsolete, existing[i].interval, func(a, b interval) int { return a.start - b.start })
+					obsolete = slices.Insert(obsolete, index, existing[i].interval)
+					existing[i].interval = e.interval
+				}
+			} else {
+				// Instead of appending at the end and doing a
+				// linear search in findEntry, we could keep
+				// the slice sorted by key and do a binary search.
+				//
+				// Above:
+				//    i, ok := slices.BinarySearchFunc(existing, e, func(a, b entry) int { return strings.Compare(a.key, b.key) })
+				// Here:
+				//    existing = slices.Insert(existing, i, e)
+				//
+				// But that adds a dependency on the slices package
+				// and made performance slightly worse, presumably
+				// because the cost of shifting entries around
+				// did not pay of with faster lookups.
+				existing = append(existing, e)
+			}
 		}
-		f.KVFormat(b, k, v)
+	}
+
+	// If we need to remove some obsolete key/value pairs then move the memory.
+	if len(obsolete) > 0 {
+		// Potentially the next remaining output (might itself be obsolete).
+		from := obsolete[0].end
+		// Next obsolete entry.
+		nextObsolete := 1
+		// This is the source buffer, before truncation.
+		all := b.Bytes()
+		b.Truncate(obsolete[0].start)
+
+		for nextObsolete < len(obsolete) {
+			if from == obsolete[nextObsolete].start {
+				// Skip also the next obsolete key/value.
+				from = obsolete[nextObsolete].end
+				nextObsolete++
+				continue
+			}
+
+			// Preserve some output. Write uses copy, which
+			// explicitly allows source and destination to overlap.
+			// That could happen here.
+			valid := all[from:obsolete[nextObsolete].start]
+			b.Write(valid)
+			from = obsolete[nextObsolete].end
+			nextObsolete++
+		}
+		// Copy end of buffer.
+		valid := all[from:]
+		b.Write(valid)
 	}
 }
 
-func KVListFormat(b *bytes.Buffer, keysAndValues ...interface{}) {
-	Formatter{}.KVListFormat(b, keysAndValues...)
+type obsoleteKV struct {
+	key string
+	interval
 }
 
-func KVFormat(b *bytes.Buffer, k, v interface{}) {
-	Formatter{}.KVFormat(b, k, v)
+// interval includes the start and excludes the end.
+type interval struct {
+	start int
+	end   int
+}
+
+func findObsoleteEntry(entries []obsoleteKV, key string) int {
+	for i, entry := range entries {
+		if entry.key == key {
+			return i
+		}
+	}
+	return -1
 }
 
 // formatAny is the fallback formatter for a value. It supports a hook (for
 // example, for YAML encoding) and itself uses JSON encoding.
 func (f Formatter) formatAny(b *bytes.Buffer, v interface{}) {
-	b.WriteRune('=')
 	if f.AnyToStringHook != nil {
-		b.WriteString(f.AnyToStringHook(v))
+		str := f.AnyToStringHook(v)
+		if strings.Contains(str, "\n") {
+			// If it's multi-line, then pass it through writeStringValue to get start/end delimiters,
+			// which separates it better from any following key/value pair.
+			writeStringValue(b, str)
+			return
+		}
+		// Otherwise put it directly after the separator, on the same lime,
+		// The assumption is that the hook returns something where start/end are obvious.
+		b.WriteRune('=')
+		b.WriteString(str)
 		return
 	}
+	b.WriteRune('=')
 	formatAsJSON(b, v)
 }
 

vendor/k8s.io/klog/v2/internal/serialize/keyvalues_no_slog.go

@@ -28,7 +28,7 @@ import (
 
 // KVFormat serializes one key/value pair into the provided buffer.
 // A space gets inserted before the pair.
-func (f Formatter) KVFormat(b *bytes.Buffer, k, v interface{}) {
+func (f Formatter) KVFormat(b *bytes.Buffer, k, v interface{}) string {
 	// This is the version without slog support. Must be kept in sync with
 	// the version in keyvalues_slog.go.
 
@@ -37,13 +37,15 @@ func (f Formatter) KVFormat(b *bytes.Buffer, k, v interface{}) {
 	// https://github.com/kubernetes/community/blob/master/contributors/devel/sig-instrumentation/migration-to-structured-logging.md#name-arguments
 	// for the sake of performance. Keys with spaces,
 	// special characters, etc. will break parsing.
+	var key string
 	if sK, ok := k.(string); ok {
 		// Avoid one allocation when the key is a string, which
 		// normally it should be.
-		b.WriteString(sK)
+		key = sK
 	} else {
-		b.WriteString(fmt.Sprintf("%s", k))
+		key = fmt.Sprintf("%s", k)
 	}
+	b.WriteString(key)
 
 	// The type checks are sorted so that more frequently used ones
 	// come first because that is then faster in the common
@@ -94,4 +96,6 @@ func (f Formatter) KVFormat(b *bytes.Buffer, k, v interface{}) {
 	default:
 		f.formatAny(b, v)
 	}
+
+	return key
 }

vendor/k8s.io/klog/v2/internal/serialize/keyvalues_slog.go

@@ -29,8 +29,8 @@ import (
 )
 
 // KVFormat serializes one key/value pair into the provided buffer.
-// A space gets inserted before the pair.
-func (f Formatter) KVFormat(b *bytes.Buffer, k, v interface{}) {
+// A space gets inserted before the pair. It returns the key.
+func (f Formatter) KVFormat(b *bytes.Buffer, k, v interface{}) string {
 	// This is the version without slog support. Must be kept in sync with
 	// the version in keyvalues_slog.go.
 
@@ -39,13 +39,15 @@ func (f Formatter) KVFormat(b *bytes.Buffer, k, v interface{}) {
 	// https://github.com/kubernetes/community/blob/master/contributors/devel/sig-instrumentation/migration-to-structured-logging.md#name-arguments
 	// for the sake of performance. Keys with spaces,
 	// special characters, etc. will break parsing.
+	var key string
 	if sK, ok := k.(string); ok {
 		// Avoid one allocation when the key is a string, which
 		// normally it should be.
-		b.WriteString(sK)
+		key = sK
 	} else {
-		b.WriteString(fmt.Sprintf("%s", k))
+		key = fmt.Sprintf("%s", k)
 	}
+	b.WriteString(key)
 
 	// The type checks are sorted so that more frequently used ones
 	// come first because that is then faster in the common
@@ -112,6 +114,8 @@ func (f Formatter) KVFormat(b *bytes.Buffer, k, v interface{}) {
 	default:
 		f.formatAny(b, v)
 	}
+
+	return key
 }
 
 // generateJSON has the same preference for plain strings as KVFormat.