github.com/whtcorpsinc/milevadb-prod@v0.0.0-20211104133533-f57f4be3b597/dbs/cmd/benchdb/ddltest/random.go (about)

     1  // Copyright 2020 WHTCORPS INC, Inc.
     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  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package dbstest
    15  
    16  import (
    17  	"math/rand"
    18  )
    19  
    20  func randomInt() int {
    21  	return rand.Int()
    22  }
    23  
    24  func randomIntn(n int) int {
    25  	return rand.Intn(n)
    26  }
    27  
    28  func randomFloat() float64 {
    29  	return rand.Float64()
    30  }
    31  
    32  func randomString(n int) string {
    33  	const alphanum = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
    34  	var bytes = make([]byte, n)
    35  	for i := range bytes {
    36  		bytes[i] = alphanum[randomIntn(len(alphanum))]
    37  	}
    38  	return string(bytes)
    39  }
    40  
    41  // Args
    42  // 0 -> min
    43  // 1 -> max
    44  // randomNum(1,10) -> [1,10)
    45  // randomNum(-1) -> random
    46  // randomNum() -> random
    47  func randomNum(args ...int) int {
    48  	if len(args) > 1 {
    49  		return args[0] + randomIntn(args[1]-args[0])
    50  	} else if len(args) == 1 {
    51  		return randomIntn(args[0])
    52  	} else {
    53  		return randomInt()
    54  	}
    55  }