go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/common/data/recordio/size.go (about)

     1  // Copyright 2015 The LUCI Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package recordio
    16  
    17  // FrameHeaderSize calculates the size of the RecordIO frame header for a given
    18  // amount of data.
    19  //
    20  // A RecordIO frame header is a Uvarint containing the length. Uvarint values
    21  // contain 7 bits of size data and 1 continuation bit (see encoding/binary).
    22  func FrameHeaderSize(s int64) int {
    23  	size := 1
    24  	for s >>= 7; s > 0; s >>= 7 {
    25  		size++
    26  	}
    27  	return size
    28  }