fix issue in stack trace for package gdebug; improve package gsmtp

debug/gdebug/gdebug_caller.go

@@ -42,12 +42,14 @@ func init() {
 	}
 }
 
-// CallerPath returns the function name and the absolute file path along with its line number of the caller.
+// CallerPath returns the function name and the absolute file path along with its line
+// number of the caller.
 func Caller(skip ...int) (function string, path string, line int) {
 	return CallerWithFilter("", skip...)
 }
 
-// CallerPathWithFilter returns the function name and the absolute file path along with its line number of the caller.
+// CallerPathWithFilter returns the function name and the absolute file path along with
+// its line number of the caller.
 //
 // The parameter <filter> is used to filter the path of the caller.
 func CallerWithFilter(filter string, skip ...int) (function string, path string, line int) {
@@ -84,7 +86,10 @@ func CallerWithFilter(filter string, skip ...int) (function string, path string,
 	return "", "", -1
 }
 
-// callerFromIndex returns the caller position and according information exclusive of the debug package.
+// callerFromIndex returns the caller position and according information exclusive of the
+// debug package.
+//
+// VERY NOTE THAT, the returned index value should be <index - 1> as the caller's start point.
 func callerFromIndex(filters []string) (pc uintptr, file string, line int, index int) {
 	var filtered, ok bool
 	for index = 0; index < gMAX_DEPTH; index++ {
@@ -102,6 +107,9 @@ func callerFromIndex(filters []string) (pc uintptr, file string, line int, index
 			if strings.Contains(file, gFILTER_KEY) {
 				continue
 			}
+			if index > 0 {
+				index--
+			}
 			return
 		}
 	}

debug/gdebug/gdebug_stack.go

@@ -35,25 +35,33 @@ func StackWithFilter(filter string, skip ...int) string {
 // StackWithFilters returns a formatted stack trace of the goroutine that calls it.
 // It calls runtime.Stack with a large enough buffer to capture the entire trace.
 //
-// The parameter <filters> is a slice of strings, which are used to filter the path of the caller.
+// The parameter <filters> is a slice of strings, which are used to filter the path of the
+// caller.
+//
+// TODO Improve the performance using debug.Stack.
 func StackWithFilters(filters []string, skip ...int) string {
 	number := 0
 	if len(skip) > 0 {
 		number = skip[0]
 	}
-	name := ""
-	space := "  "
-	index := 1
-	buffer := bytes.NewBuffer(nil)
-	filtered := false
-	ok := true
-	pc, file, line, start := callerFromIndex(filters)
+	var (
+		name                  = ""
+		space                 = "  "
+		index                 = 1
+		buffer                = bytes.NewBuffer(nil)
+		filtered              = false
+		ok                    = true
+		pc, file, line, start = callerFromIndex(filters)
+	)
 	for i := start + number; i < gMAX_DEPTH; i++ {
 		if i != start {
 			pc, file, line, ok = runtime.Caller(i)
 		}
 		if ok {
-			if goRootForFilter != "" && len(file) >= len(goRootForFilter) && file[0:len(goRootForFilter)] == goRootForFilter {
+			// GOROOT filter.
+			if goRootForFilter != "" &&
+				len(file) >= len(goRootForFilter) &&
+				file[0:len(goRootForFilter)] == goRootForFilter {
 				continue
 			}
 			filtered = false

debug/gdebug/gdebug_z_bench_test.go

@@ -10,6 +10,7 @@ package gdebug
 
 import (
 	"runtime"
+	"runtime/debug"
 	"testing"
 )
 
@@ -49,6 +50,12 @@ func Benchmark_Stack(b *testing.B) {
 	}
 }
 
+func Benchmark_StackOfStdlib(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		debug.Stack()
+	}
+}
+
 func Benchmark_StackWithFilter(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		StackWithFilter("test")