github.com/zuoyebang/bitalosdb@v1.1.1-0.20240516111551-79a8c4d8ce20/internal/utils/func.go (about)

     1  // Copyright 2021 The Bitalosdb author(hustxrb@163.com) and other contributors.
     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 utils
    16  
    17  import (
    18  	"math/bits"
    19  	"math/rand"
    20  )
    21  
    22  func FuncRandBytes(n int) []byte {
    23  	randStr := "1qaz2wsx3edc4rfv5tgb6yhn7ujm8ik9ol0pabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
    24  	randStrLen := len(randStr)
    25  	b := make([]byte, n)
    26  	for i := range b {
    27  		b[i] = randStr[rand.Int63()%int64(randStrLen)]
    28  	}
    29  	return b
    30  }
    31  
    32  func FirstError(err0, err1 error) error {
    33  	if err0 != nil {
    34  		return err0
    35  	}
    36  	return err1
    37  }
    38  
    39  func CalcBitsSize(sz int) int {
    40  	return 1 << bits.Len(uint(sz))
    41  }