249 lines
8.3 KiB
Go
249 lines
8.3 KiB
Go
|
/*
|
||
|
|
Copyright 2014 Alexander Okoli
|
||
|
|
|
||
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
||
|
|
you may not use this file except in compliance with the License.
|
||
|
|
You may obtain a copy of the License at
|
||
|
|
|
||
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
||
|
|
|
||
|
|
Unless required by applicable law or agreed to in writing, software
|
||
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
||
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
|
|
See the License for the specific language governing permissions and
|
||
|
|
limitations under the License.
|
||
|
|
*/
|
||
|
|
|
||
|
|
package goutils
|
||
|
|
|
||
|
|
import (
|
||
|
|
"fmt"
|
||
|
|
"math"
|
||
|
|
"math/rand"
|
||
|
|
"time"
|
||
|
|
"unicode"
|
||
|
|
)
|
||
|
|
|
||
|
|
// RANDOM provides the time-based seed used to generate random numbers
|
||
|
|
var RANDOM = rand.New(rand.NewSource(time.Now().UnixNano()))
|
||
|
|
|
||
|
|
/*
|
||
|
|
RandomNonAlphaNumeric creates a random string whose length is the number of characters specified.
|
||
|
|
Characters will be chosen from the set of all characters (ASCII/Unicode values between 0 to 2,147,483,647 (math.MaxInt32)).
|
||
|
|
|
||
|
|
Parameter:
|
||
|
|
count - the length of random string to create
|
||
|
|
|
||
|
|
Returns:
|
||
|
|
string - the random string
|
||
|
|
error - an error stemming from an invalid parameter within underlying function, RandomSeed(...)
|
||
|
|
*/
|
||
|
|
func RandomNonAlphaNumeric(count int) (string, error) {
|
||
|
|
return RandomAlphaNumericCustom(count, false, false)
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
RandomAscii creates a random string whose length is the number of characters specified.
|
||
|
|
Characters will be chosen from the set of characters whose ASCII value is between 32 and 126 (inclusive).
|
||
|
|
|
||
|
|
Parameter:
|
||
|
|
count - the length of random string to create
|
||
|
|
|
||
|
|
Returns:
|
||
|
|
string - the random string
|
||
|
|
error - an error stemming from an invalid parameter within underlying function, RandomSeed(...)
|
||
|
|
*/
|
||
|
|
func RandomAscii(count int) (string, error) {
|
||
|
|
return Random(count, 32, 127, false, false)
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
RandomNumeric creates a random string whose length is the number of characters specified.
|
||
|
|
Characters will be chosen from the set of numeric characters.
|
||
|
|
|
||
|
|
Parameter:
|
||
|
|
count - the length of random string to create
|
||
|
|
|
||
|
|
Returns:
|
||
|
|
string - the random string
|
||
|
|
error - an error stemming from an invalid parameter within underlying function, RandomSeed(...)
|
||
|
|
*/
|
||
|
|
func RandomNumeric(count int) (string, error) {
|
||
|
|
return Random(count, 0, 0, false, true)
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
RandomAlphabetic creates a random string whose length is the number of characters specified.
|
||
|
|
Characters will be chosen from the set of alphabetic characters.
|
||
|
|
|
||
|
|
Parameters:
|
||
|
|
count - the length of random string to create
|
||
|
|
|
||
|
|
Returns:
|
||
|
|
string - the random string
|
||
|
|
error - an error stemming from an invalid parameter within underlying function, RandomSeed(...)
|
||
|
|
*/
|
||
|
|
func RandomAlphabetic(count int) (string, error) {
|
||
|
|
return Random(count, 0, 0, true, false)
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
RandomAlphaNumeric creates a random string whose length is the number of characters specified.
|
||
|
|
Characters will be chosen from the set of alpha-numeric characters.
|
||
|
|
|
||
|
|
Parameter:
|
||
|
|
count - the length of random string to create
|
||
|
|
|
||
|
|
Returns:
|
||
|
|
string - the random string
|
||
|
|
error - an error stemming from an invalid parameter within underlying function, RandomSeed(...)
|
||
|
|
*/
|
||
|
|
func RandomAlphaNumeric(count int) (string, error) {
|
||
|
|
return Random(count, 0, 0, true, true)
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
RandomAlphaNumericCustom creates a random string whose length is the number of characters specified.
|
||
|
|
Characters will be chosen from the set of alpha-numeric characters as indicated by the arguments.
|
||
|
|
|
||
|
|
Parameters:
|
||
|
|
count - the length of random string to create
|
||
|
|
letters - if true, generated string may include alphabetic characters
|
||
|
|
numbers - if true, generated string may include numeric characters
|
||
|
|
|
||
|
|
Returns:
|
||
|
|
string - the random string
|
||
|
|
error - an error stemming from an invalid parameter within underlying function, RandomSeed(...)
|
||
|
|
*/
|
||
|
|
func RandomAlphaNumericCustom(count int, letters bool, numbers bool) (string, error) {
|
||
|
|
return Random(count, 0, 0, letters, numbers)
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
Random creates a random string based on a variety of options, using default source of randomness.
|
||
|
|
This method has exactly the same semantics as RandomSeed(int, int, int, bool, bool, []char, *rand.Rand), but
|
||
|
|
instead of using an externally supplied source of randomness, it uses the internal *rand.Rand instance.
|
||
|
|
|
||
|
|
Parameters:
|
||
|
|
count - the length of random string to create
|
||
|
|
start - the position in set of chars (ASCII/Unicode int) to start at
|
||
|
|
end - the position in set of chars (ASCII/Unicode int) to end before
|
||
|
|
letters - if true, generated string may include alphabetic characters
|
||
|
|
numbers - if true, generated string may include numeric characters
|
||
|
|
chars - the set of chars to choose randoms from. If nil, then it will use the set of all chars.
|
||
|
|
|
||
|
|
Returns:
|
||
|
|
string - the random string
|
||
|
|
error - an error stemming from an invalid parameter within underlying function, RandomSeed(...)
|
||
|
|
*/
|
||
|
|
func Random(count int, start int, end int, letters bool, numbers bool, chars ...rune) (string, error) {
|
||
|
|
return RandomSeed(count, start, end, letters, numbers, chars, RANDOM)
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
RandomSeed creates a random string based on a variety of options, using supplied source of randomness.
|
||
|
|
If the parameters start and end are both 0, start and end are set to ' ' and 'z', the ASCII printable characters, will be used,
|
||
|
|
unless letters and numbers are both false, in which case, start and end are set to 0 and math.MaxInt32, respectively.
|
||
|
|
If chars is not nil, characters stored in chars that are between start and end are chosen.
|
||
|
|
This method accepts a user-supplied *rand.Rand instance to use as a source of randomness. By seeding a single *rand.Rand instance
|
||
|
|
with a fixed seed and using it for each call, the same random sequence of strings can be generated repeatedly and predictably.
|
||
|
|
|
||
|
|
Parameters:
|
||
|
|
count - the length of random string to create
|
||
|
|
start - the position in set of chars (ASCII/Unicode decimals) to start at
|
||
|
|
end - the position in set of chars (ASCII/Unicode decimals) to end before
|
||
|
|
letters - if true, generated string may include alphabetic characters
|
||
|
|
numbers - if true, generated string may include numeric characters
|
||
|
|
chars - the set of chars to choose randoms from. If nil, then it will use the set of all chars.
|
||
|
|
random - a source of randomness.
|
||
|
|
|
||
|
|
Returns:
|
||
|
|
string - the random string
|
||
|
|
error - an error stemming from invalid parameters: if count < 0; or the provided chars array is empty; or end <= start; or end > len(chars)
|
||
|
|
*/
|
||
|
|
func RandomSeed(count int, start int, end int, letters bool, numbers bool, chars []rune, random *rand.Rand) (string, error) {
|
||
|
|
|
||
|
|
if count == 0 {
|
||
|
|
return "", nil
|
||
|
|
} else if count < 0 {
|
||
|
|
err := fmt.Errorf("randomstringutils illegal argument: Requested random string length %v is less than 0.", count) // equiv to err := errors.New("...")
|
||
|
|
return "", err
|
||
|
|
}
|
||
|
|
if chars != nil && len(chars) == 0 {
|
||
|
|
err := fmt.Errorf("randomstringutils illegal argument: The chars array must not be empty")
|
||
|
|
return "", err
|
||
|
|
}
|
||
|
|
|
||
|
|
if start == 0 && end == 0 {
|
||
|
|
if chars != nil {
|
||
|
|
end = len(chars)
|
||
|
|
} else {
|
||
|
|
if !letters && !numbers {
|
||
|
|
end = math.MaxInt32
|
||
|
|
} else {
|
||
|
|
end = 'z' + 1
|
||
|
|
start = ' '
|
||
|
|
}
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
if end <= start {
|
||
|
|
err := fmt.Errorf("randomstringutils illegal argument: Parameter end (%v) must be greater than start (%v)", end, start)
|
||
|
|
return "", err
|
||
|
|
}
|
||
|
|
|
||
|
|
if chars != nil && end > len(chars) {
|
||
|
|
err := fmt.Errorf("randomstringutils illegal argument: Parameter end (%v) cannot be greater than len(chars) (%v)", end, len(chars))
|
||
|
|
return "", err
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
buffer := make([]rune, count)
|
||
|
|
gap := end - start
|
||
|
|
|
||
|
|
// high-surrogates range, (\uD800-\uDBFF) = 55296 - 56319
|
||
|
|
// low-surrogates range, (\uDC00-\uDFFF) = 56320 - 57343
|
||
|
|
|
||
|
|
for count != 0 {
|
||
|
|
count--
|
||
|
|
var ch rune
|
||
|
|
if chars == nil {
|
||
|
|
ch = rune(random.Intn(gap) + start)
|
||
|
|
} else {
|
||
|
|
ch = chars[random.Intn(gap)+start]
|
||
|
|
}
|
||
|
|
|
||
|
|
if letters && unicode.IsLetter(ch) || numbers && unicode.IsDigit(ch) || !letters && !numbers {
|
||
|
|
if ch >= 56320 && ch <= 57343 { // low surrogate range
|
||
|
|
if count == 0 {
|
||
|
|
count++
|
||
|
|
} else {
|
||
|
|
// Insert low surrogate
|
||
|
|
buffer[count] = ch
|
||
|
|
count--
|
||
|
|
// Insert high surrogate
|
||
|
|
buffer[count] = rune(55296 + random.Intn(128))
|
||
|
|
}
|
||
|
|
} else if ch >= 55296 && ch <= 56191 { // High surrogates range (Partial)
|
||
|
|
if count == 0 {
|
||
|
|
count++
|
||
|
|
} else {
|
||
|
|
// Insert low surrogate
|
||
|
|
buffer[count] = rune(56320 + random.Intn(128))
|
||
|
|
count--
|
||
|
|
// Insert high surrogate
|
||
|
|
buffer[count] = ch
|
||
|
|
}
|
||
|
|
} else if ch >= 56192 && ch <= 56319 {
|
||
|
|
// private high surrogate, skip it
|
||
|
|
count++
|
||
|
|
} else {
|
||
|
|
// not one of the surrogates*
|
||
|
|
buffer[count] = ch
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
count++
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return string(buffer), nil
|
||
|
|
}
|