storj.io/minio@v0.0.0-20230509071714-0cbc90f649b1/pkg/s3select/internal/parquet-go/encoding/common.go (about)

     1  /*
     2   * Minio Cloud Storage, (C) 2019 Minio, Inc.
     3   *
     4   * Licensed under the Apache License, Version 2.0 (the "License");
     5   * you may not use this file except in compliance with the License.
     6   * You may obtain a copy of the License at
     7   *
     8   *     http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  
    17  package encoding
    18  
    19  import (
    20  	"storj.io/minio/pkg/s3select/internal/parquet-go/common"
    21  )
    22  
    23  // Refer https://en.wikipedia.org/wiki/LEB128#Unsigned_LEB128
    24  func varIntEncode(ui64 uint64) []byte {
    25  	if ui64 == 0 {
    26  		return []byte{0}
    27  	}
    28  
    29  	length := int(common.BitWidth(ui64)+6) / 7
    30  	data := make([]byte, length)
    31  	for i := 0; i < length; i++ {
    32  		data[i] = byte(ui64&0x7F) | 0x80
    33  		ui64 >>= 7
    34  	}
    35  	data[length-1] &= 0x7F
    36  
    37  	return data
    38  }