initial commit

vendor/github.com/ant0ine/go-json-rest/rest/recover.go

@@ -0,0 +1,74 @@
+package rest
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"runtime/debug"
+)
+
+// RecoverMiddleware catches the panic errors that occur in the wrapped HandleFunc,
+// and convert them to 500 responses.
+type RecoverMiddleware struct {
+
+	// Custom logger used for logging the panic errors,
+	// optional, defaults to log.New(os.Stderr, "", 0)
+	Logger *log.Logger
+
+	// If true, the log records will be printed as JSON. Convenient for log parsing.
+	EnableLogAsJson bool
+
+	// If true, when a "panic" happens, the error string and the stack trace will be
+	// printed in the 500 response body.
+	EnableResponseStackTrace bool
+}
+
+// MiddlewareFunc makes RecoverMiddleware implement the Middleware interface.
+func (mw *RecoverMiddleware) MiddlewareFunc(h HandlerFunc) HandlerFunc {
+
+	// set the default Logger
+	if mw.Logger == nil {
+		mw.Logger = log.New(os.Stderr, "", 0)
+	}
+
+	return func(w ResponseWriter, r *Request) {
+
+		// catch user code's panic, and convert to http response
+		defer func() {
+			if reco := recover(); reco != nil {
+				trace := debug.Stack()
+
+				// log the trace
+				message := fmt.Sprintf("%s\n%s", reco, trace)
+				mw.logError(message)
+
+				// write error response
+				if mw.EnableResponseStackTrace {
+					Error(w, message, http.StatusInternalServerError)
+				} else {
+					Error(w, "Internal Server Error", http.StatusInternalServerError)
+				}
+			}
+		}()
+
+		// call the handler
+		h(w, r)
+	}
+}
+
+func (mw *RecoverMiddleware) logError(message string) {
+	if mw.EnableLogAsJson {
+		record := map[string]string{
+			"error": message,
+		}
+		b, err := json.Marshal(&record)
+		if err != nil {
+			panic(err)
+		}
+		mw.Logger.Printf("%s", b)
+	} else {
+		mw.Logger.Print(message)
+	}
+}