init

vendor/k8s.io/apimachinery/pkg/util/naming/from_stack.go

@@ -0,0 +1,93 @@
+/*
+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 naming
+
+import (
+	"fmt"
+	"regexp"
+	goruntime "runtime"
+	"runtime/debug"
+	"strconv"
+	"strings"
+)
+
+// GetNameFromCallsite walks back through the call stack until we find a caller from outside of the ignoredPackages
+// it returns back a shortpath/filename:line to aid in identification of this reflector when it starts logging
+func GetNameFromCallsite(ignoredPackages ...string) string {
+	name := "????"
+	const maxStack = 10
+	for i := 1; i < maxStack; i++ {
+		_, file, line, ok := goruntime.Caller(i)
+		if !ok {
+			file, line, ok = extractStackCreator()
+			if !ok {
+				break
+			}
+			i += maxStack
+		}
+		if hasPackage(file, append(ignoredPackages, "/runtime/asm_")) {
+			continue
+		}
+
+		file = trimPackagePrefix(file)
+		name = fmt.Sprintf("%s:%d", file, line)
+		break
+	}
+	return name
+}
+
+// hasPackage returns true if the file is in one of the ignored packages.
+func hasPackage(file string, ignoredPackages []string) bool {
+	for _, ignoredPackage := range ignoredPackages {
+		if strings.Contains(file, ignoredPackage) {
+			return true
+		}
+	}
+	return false
+}
+
+// trimPackagePrefix reduces duplicate values off the front of a package name.
+func trimPackagePrefix(file string) string {
+	if l := strings.LastIndex(file, "/vendor/"); l >= 0 {
+		return file[l+len("/vendor/"):]
+	}
+	if l := strings.LastIndex(file, "/src/"); l >= 0 {
+		return file[l+5:]
+	}
+	if l := strings.LastIndex(file, "/pkg/"); l >= 0 {
+		return file[l+1:]
+	}
+	return file
+}
+
+var stackCreator = regexp.MustCompile(`(?m)^created by (.*)\n\s+(.*):(\d+) \+0x[[:xdigit:]]+$`)
+
+// extractStackCreator retrieves the goroutine file and line that launched this stack. Returns false
+// if the creator cannot be located.
+// TODO: Go does not expose this via runtime https://github.com/golang/go/issues/11440
+func extractStackCreator() (string, int, bool) {
+	stack := debug.Stack()
+	matches := stackCreator.FindStringSubmatch(string(stack))
+	if matches == nil || len(matches) != 4 {
+		return "", 0, false
+	}
+	line, err := strconv.Atoi(matches[3])
+	if err != nil {
+		return "", 0, false
+	}
+	return matches[2], line, true
+}