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Diffstat (limited to 'vendor/github.com/Masterminds/goutils/randomstringutils.go')
| -rw-r--r-- | vendor/github.com/Masterminds/goutils/randomstringutils.go | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/vendor/github.com/Masterminds/goutils/randomstringutils.go b/vendor/github.com/Masterminds/goutils/randomstringutils.go new file mode 100644 index 000000000..272670231 --- /dev/null +++ b/vendor/github.com/Masterminds/goutils/randomstringutils.go @@ -0,0 +1,248 @@ +/* +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 +} |