feat: initial tracing support (#1623)

1 files changed, 63 insertions, 0 deletions

diff --git a/vendor/google.golang.org/grpc/internal/grpcutil/encode_duration.go b/vendor/google.golang.org/grpc/internal/grpcutil/encode_duration.go
new file mode 100644
index 000000000..b25b0baec
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/grpcutil/encode_duration.go
@@ -0,0 +1,63 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpcutil
+
+import (
+	"strconv"
+	"time"
+)
+
+const maxTimeoutValue int64 = 100000000 - 1
+
+// div does integer division and round-up the result. Note that this is
+// equivalent to (d+r-1)/r but has less chance to overflow.
+func div(d, r time.Duration) int64 {
+	if d%r > 0 {
+		return int64(d/r + 1)
+	}
+	return int64(d / r)
+}
+
+// EncodeDuration encodes the duration to the format grpc-timeout header
+// accepts.
+//
+// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests
+func EncodeDuration(t time.Duration) string {
+	// TODO: This is simplistic and not bandwidth efficient. Improve it.
+	if t <= 0 {
+		return "0n"
+	}
+	if d := div(t, time.Nanosecond); d <= maxTimeoutValue {
+		return strconv.FormatInt(d, 10) + "n"
+	}
+	if d := div(t, time.Microsecond); d <= maxTimeoutValue {
+		return strconv.FormatInt(d, 10) + "u"
+	}
+	if d := div(t, time.Millisecond); d <= maxTimeoutValue {
+		return strconv.FormatInt(d, 10) + "m"
+	}
+	if d := div(t, time.Second); d <= maxTimeoutValue {
+		return strconv.FormatInt(d, 10) + "S"
+	}
+	if d := div(t, time.Minute); d <= maxTimeoutValue {
+		return strconv.FormatInt(d, 10) + "M"
+	}
+	// Note that maxTimeoutValue * time.Hour > MaxInt64.
+	return strconv.FormatInt(div(t, time.Hour), 10) + "H"
+}