| // Copyright 2016 The LUCI 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 prpc |
| |
| import ( |
| "fmt" |
| "strconv" |
| "time" |
| ) |
| |
| // The rest of this file is adapted from |
| // https://github.com/grpc/grpc-go/blob/6a026b9f108b49838491178e5d9bf7a4dcf32cf2/transport/http_util.go#L295 |
| |
| type timeoutUnit uint8 |
| |
| const ( |
| hour timeoutUnit = 'H' |
| minute timeoutUnit = 'M' |
| second timeoutUnit = 'S' |
| millisecond timeoutUnit = 'm' |
| microsecond timeoutUnit = 'u' |
| nanosecond timeoutUnit = 'n' |
| ) |
| |
| func timeoutUnitToDuration(u timeoutUnit) (d time.Duration, ok bool) { |
| switch u { |
| case hour: |
| return time.Hour, true |
| case minute: |
| return time.Minute, true |
| case second: |
| return time.Second, true |
| case millisecond: |
| return time.Millisecond, true |
| case microsecond: |
| return time.Microsecond, true |
| case nanosecond: |
| return time.Nanosecond, true |
| default: |
| } |
| return |
| } |
| |
| // DecodeTimeout decodes a gRPC/pRPC timeout header string into a time.Duration. |
| func DecodeTimeout(s string) (time.Duration, error) { |
| size := len(s) |
| if size < 2 { |
| return 0, fmt.Errorf("too short: %q", s) |
| } |
| unit := timeoutUnit(s[size-1]) |
| d, ok := timeoutUnitToDuration(unit) |
| if !ok { |
| return 0, fmt.Errorf("unit is not recognized: %q", s) |
| } |
| t, err := strconv.ParseInt(s[:size-1], 10, 64) |
| if err != nil { |
| return 0, err |
| } |
| return d * time.Duration(t), nil |
| } |
| |
| 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 m := d % r; m > 0 { |
| return int64(d/r + 1) |
| } |
| return int64(d / r) |
| } |
| |
| // EncodeTimeout encodes a gRPC/pRPC timeout into a timeout header |
| // time.Duration. |
| // |
| // This rounds the time.Duration to the smallest time unit that can represent |
| // it. |
| func EncodeTimeout(t time.Duration) string { |
| 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" |
| } |