common/prpc, tools/cmd/cproto: prpc client

common/prpc/codes.go

Index: common/prpc/codes.go
diff --git a/common/prpc/codes.go b/common/prpc/codes.go
new file mode 100644
index 0000000000000000000000000000000000000000..98100e4800863a40fb9c42574b532c540e8d11a6
--- /dev/null
+++ b/common/prpc/codes.go
@@ -0,0 +1,84 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package prpc
+
+import (
+	"net/http"
+
+	"google.golang.org/grpc/codes"
+)
+
+// This file maps gRPC codes to HTTP statuses and vice-versa.
+
+// codeToStatus maps gRPC codes to HTTP statuses.
+// This map may need to be corrected when
+// https://github.com/grpc/grpc-common/issues/210
+// is closed.
+var codeToStatus = map[codes.Code]int{
+	codes.OK:                 http.StatusOK,
+	codes.Canceled:           http.StatusNoContent,
+	codes.Unknown:            http.StatusInternalServerError,
+	codes.InvalidArgument:    http.StatusBadRequest,
+	codes.DeadlineExceeded:   http.StatusServiceUnavailable,
+	codes.NotFound:           http.StatusNotFound,
+	codes.AlreadyExists:      http.StatusConflict,
+	codes.PermissionDenied:   http.StatusForbidden,
+	codes.Unauthenticated:    http.StatusUnauthorized,
+	codes.ResourceExhausted:  http.StatusServiceUnavailable,
+	codes.FailedPrecondition: http.StatusPreconditionFailed,
+	codes.Aborted:            http.StatusInternalServerError,
+	codes.OutOfRange:         http.StatusBadRequest,
+	codes.Unimplemented:      http.StatusNotImplemented,
+	codes.Internal:           http.StatusInternalServerError,
+	codes.Unavailable:        http.StatusServiceUnavailable,
+	codes.DataLoss:           http.StatusInternalServerError,
+}
+
+// CodeStatus maps gRPC codes to HTTP statuses.
+//
+// The behavior of this function may change when
+// https://github.com/grpc/grpc-common/issues/210
+// is closed.
+func CodeStatus(code codes.Code) (status int, ok bool) {
+	status, ok = codeToStatus[code]
+	return
+}
+
+// StatusCode maps HTTP statuses to gRPC codes.
+// Falls back to codes.Unknown.
+//
+// The behavior of this function may change when
+// https://github.com/grpc/grpc-common/issues/210
+// is closed.
+func StatusCode(status int) codes.Code {
+	switch {
+
+	case status >= 200 && status < 300:
+		return codes.OK
+
+	case status == http.StatusUnauthorized:
+		return codes.Unauthenticated
+	case status == http.StatusForbidden:
+		return codes.PermissionDenied
+	case status == http.StatusNotFound:
+		return codes.NotFound
+	case status == http.StatusGone:
+		return codes.NotFound
+	case status == http.StatusPreconditionFailed:
+		return codes.FailedPrecondition
+	case status >= 400 && status < 500:
+		return codes.InvalidArgument
+
+	case status == http.StatusNotImplemented:
+		return codes.Unimplemented
+	case status == http.StatusServiceUnavailable:
+		return codes.Unavailable
+	case status >= 500 && status < 600:
+		return codes.Internal
+
+	default:
+		return codes.Unknown
+	}
+}