Merge 6f28374 into 193de0d

xpanic/README.md

@@ -0,0 +1,20 @@
+# Usage
+
+It's a powerful panic handler to simplify reasoning of panics
+
+## Example 
+```go 
+package main 
+
+import (
+	"github.com/donutloop/toolkit/xpanic"
+	"log"
+)
+
+func main() {
+    logF := func(format string, args ...interface{}) { log.Println(fmt.Sprintf(format, args...)) }
+    panicHandler := BuildPanicHandler(logF, xpanic.CrashOnErrorDeactivated)
+    defer panicHandler
+    panic("hello world")
+}
+```

xpanic/handlepanic.go

@@ -0,0 +1,59 @@
+package xpanic
+
+import (
+	"bytes"
+	"fmt"
+	"os/signal"
+	"runtime/pprof"
+	"strings"
+	"syscall"
+)
+
+// If crashOnError is set a coredump will be produced and kill program else it continues.
+const (
+	CrashOnErrorActivated = true
+	CrashOnErrorDeactivated = false
+)
+
+// BuildPanicHandler builds a panic handler and verifies a none nil logger got passed
+func BuildPanicHandler(errorf func(format string, args ...interface{}), crashOnError bool) func() {
+	if errorf == nil {
+		panic("errorf is not set")
+	}
+	// handlePanic writes a message to the logger and causes a backtrace to be produced.
+	return func() {
+		r := recover()
+		if r != nil {
+			errorf("capture panic infos")
+
+			errorf(fmt.Sprintf("panic: %s", r))
+			Backtrace(errorf)
+
+			if crashOnError {
+				signal.Reset(syscall.SIGABRT)
+				errorf("finished capturing of panic infos")
+				syscall.Kill(0, syscall.SIGABRT)
+			} else {
+				errorf("finished capturing of panic infos")
+			}
+		}
+	}
+}
+
+// Backtrace writes a multi-line backtrace to the logger.
+func Backtrace(errorf func(format string, args ...interface{})) {
+	profiles := pprof.Profiles()
+	buf := new(bytes.Buffer)
+
+	for _, p := range profiles {
+		// https://golang.org/pkg/runtime/pprof/#Profile.WriteTo.
+		err := pprof.Lookup(p.Name()).WriteTo(buf, 2)
+		if err != nil {
+			errorf("could not write profile: %v", err)
+		}
+	}
+
+	for _, line := range strings.Split(buf.String(), "\n") {
+		errorf(line)
+	}
+}

xpanic/handlepanic_test.go

@@ -0,0 +1,29 @@
+package xpanic_test
+
+import (
+	"bytes"
+	"fmt"
+	"github.com/donutloop/toolkit/xpanic"
+	"sync"
+	"testing"
+)
+
+func TestHandlePanic(t *testing.T) {
+
+	var buff bytes.Buffer
+	panicHandler := xpanic.BuildPanicHandler(func(format string, args ...interface{}) { buff.WriteString(fmt.Sprintf(format, args...)) }, xpanic.CrashOnErrorDeactivated)
+
+	var wait sync.WaitGroup
+	wait.Add(1)
+	go func() {
+		defer panicHandler()
+		defer wait.Done()
+		panic("hello world")
+	}()
+
+	wait.Wait()
+
+	if buff.Len() == 0 {
+		t.Fatal("buff is empty")
+	}
+}