109 lines
3.2 KiB
Swift
109 lines
3.2 KiB
Swift
//
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// IntExtension.swift
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// CryptoSwift
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//
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// Created by Marcin Krzyzanowski on 12/08/14.
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// Copyright (C) 2014 Marcin Krzyżanowski <marcin.krzyzanowski@gmail.com>
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// This software is provided 'as-is', without any express or implied warranty.
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//
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// In no event will the authors be held liable for any damages arising from the use of this software.
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//
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// Permission is granted to anyone to use this software for any purpose,including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions:
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//
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// - The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation is required.
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// - Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
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// - This notice may not be removed or altered from any source or binary distribution.
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import Darwin
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/* array of bits */
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extension Int {
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init(bits: [Bit]) {
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self.init(bitPattern: integerFromBitsArray(bits) as UInt)
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}
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}
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/* array of bytes */
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extension Int {
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/** Array of bytes with optional padding (little-endian) */
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public func bytes(totalBytes: Int = sizeof(Int)) -> [UInt8] {
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return arrayOfBytes(self, length: totalBytes)
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}
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public static func withBytes(bytes: ArraySlice<UInt8>) -> Int {
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return Int.withBytes(Array(bytes))
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}
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/** Int with array bytes (little-endian) */
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public static func withBytes(bytes: [UInt8]) -> Int {
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return integerWithBytes(bytes)
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}
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}
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/** Shift bits */
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extension Int {
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/** Shift bits to the left. All bits are shifted (including sign bit) */
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private mutating func shiftLeft(count: Int) -> Int {
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self = CryptoSwift.shiftLeft(self, count: count) //FIXME: count:
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return self
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}
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/** Shift bits to the right. All bits are shifted (including sign bit) */
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private mutating func shiftRight(count: Int) -> Int {
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if (self == 0) {
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return self;
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}
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let bitsCount = sizeofValue(self) * 8
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if (count >= bitsCount) {
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return 0
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}
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let maxBitsForValue = Int(floor(log2(Double(self)) + 1))
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let shiftCount = Swift.min(count, maxBitsForValue - 1)
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var shiftedValue:Int = 0;
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for bitIdx in 0..<bitsCount {
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// if bit is set then copy to result and shift left 1
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let bit = 1 << bitIdx
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if ((self & bit) == bit) {
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shiftedValue = shiftedValue | (bit >> shiftCount)
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}
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}
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self = Int(shiftedValue)
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return self
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}
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}
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// Left operator
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/** shift left and assign with bits truncation */
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public func &<<= (inout lhs: Int, rhs: Int) {
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lhs.shiftLeft(rhs)
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}
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/** shift left with bits truncation */
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public func &<< (lhs: Int, rhs: Int) -> Int {
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var l = lhs;
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l.shiftLeft(rhs)
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return l
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}
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// Right operator
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/** shift right and assign with bits truncation */
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func &>>= (inout lhs: Int, rhs: Int) {
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lhs.shiftRight(rhs)
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}
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/** shift right and assign with bits truncation */
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func &>> (lhs: Int, rhs: Int) -> Int {
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var l = lhs;
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l.shiftRight(rhs)
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return l
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}
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