package narco
import (
"fmt"
"io"
"log"
"net/http"
"os"
"runtime"
"github.com/codemodus/chain"
"golang.org/x/net/context"
)
type StackResponseFormatter func(w io.Writer, err interface{}, stack []byte)
func GoFormatStack(w io.Writer, err interface{}, stack []byte) {
fmt.Fprintf(w, "Server internal error: %s\n%s", err, stack)
}
func HtmlFormatStack(w io.Writer, err interface{}, stack []byte) {
fmt.Fprintf(w, `
Server internal error: %s
%s
`, err, stack)
}
type Recoverer struct {
Logger *log.Logger
ShowStackInResponse StackResponseFormatter
StackOtherGoroutine bool
}
func NewRecoverer() *Recoverer {
return &Recoverer{
Logger: log.New(os.Stdout, "[narco] ", log.LstdFlags),
ShowStackInResponse: nil,
StackOtherGoroutine: false,
}
}
func (rec *Recoverer) Wrap() func(chain.Handler) chain.Handler {
return func(other chain.Handler) chain.Handler {
return chain.HandlerFunc(func(ctx context.Context, h http.ResponseWriter, req *http.Request) {
defer func() {
err := recover()
if err == nil {
return
}
// h.Header()["Content-Type"] = []string{"text/html; charset=utf-8"}
h.WriteHeader(http.StatusInternalServerError)
stack := make([]byte, 8*1024)
stack = stack[:runtime.Stack(stack, rec.StackOtherGoroutine)]
rec.Logger.Printf("PANIC: %s\n%s", err, stack)
if rec.ShowStackInResponse != nil {
rec.ShowStackInResponse(h, err, stack)
} else {
fmt.Fprintf(h, "%s\n", http.StatusText(http.StatusInternalServerError))
}
}()
other.ServeHTTPContext(ctx, h, req)
})
}
}