github.com/hxx258456/ccgo@v0.0.5-0.20230213014102-48b35f46f66f/grpc/internal/grpcutil/encode_duration.go (about)

     1  /*
     2   *
     3   * Copyright 2020 gRPC authors.
     4   *
     5   * Licensed under the Apache License, Version 2.0 (the "License");
     6   * you may not use this file except in compliance with the License.
     7   * You may obtain a copy of the License at
     8   *
     9   *     http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the License for the specific language governing permissions and
    15   * limitations under the License.
    16   *
    17   */
    18  
    19  package grpcutil
    20  
    21  import (
    22  	"strconv"
    23  	"time"
    24  )
    25  
    26  const maxTimeoutValue int64 = 100000000 - 1
    27  
    28  // div does integer division and round-up the result. Note that this is
    29  // equivalent to (d+r-1)/r but has less chance to overflow.
    30  func div(d, r time.Duration) int64 {
    31  	if d%r > 0 {
    32  		return int64(d/r + 1)
    33  	}
    34  	return int64(d / r)
    35  }
    36  
    37  // EncodeDuration encodes the duration to the format grpc-timeout header
    38  // accepts.
    39  //
    40  // https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests
    41  func EncodeDuration(t time.Duration) string {
    42  	// TODO: This is simplistic and not bandwidth efficient. Improve it.
    43  	if t <= 0 {
    44  		return "0n"
    45  	}
    46  	if d := div(t, time.Nanosecond); d <= maxTimeoutValue {
    47  		return strconv.FormatInt(d, 10) + "n"
    48  	}
    49  	if d := div(t, time.Microsecond); d <= maxTimeoutValue {
    50  		return strconv.FormatInt(d, 10) + "u"
    51  	}
    52  	if d := div(t, time.Millisecond); d <= maxTimeoutValue {
    53  		return strconv.FormatInt(d, 10) + "m"
    54  	}
    55  	if d := div(t, time.Second); d <= maxTimeoutValue {
    56  		return strconv.FormatInt(d, 10) + "S"
    57  	}
    58  	if d := div(t, time.Minute); d <= maxTimeoutValue {
    59  		return strconv.FormatInt(d, 10) + "M"
    60  	}
    61  	// Note that maxTimeoutValue * time.Hour > MaxInt64.
    62  	return strconv.FormatInt(div(t, time.Hour), 10) + "H"
    63  }