| //===----------------------------------------------------------------------===// |
| // |
| // This source file is part of the Swift.org open source project |
| // |
| // Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors |
| // Licensed under Apache License v2.0 with Runtime Library Exception |
| // |
| // See https://swift.org/LICENSE.txt for license information |
| // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors |
| // |
| //===----------------------------------------------------------------------===// |
| |
| import SwiftShims |
| |
| #if _runtime(_ObjC) |
| @_inlineable // FIXME(sil-serialize-all) |
| @_versioned // FIXME(sil-serialize-all) |
| @_silgen_name("swift_stdlib_NSStringHashValue") |
| internal func _stdlib_NSStringHashValue( |
| _ str: AnyObject, _ isASCII: Bool) -> Int |
| |
| @_inlineable // FIXME(sil-serialize-all) |
| @_versioned // FIXME(sil-serialize-all) |
| @_silgen_name("swift_stdlib_NSStringHashValuePointer") |
| internal func _stdlib_NSStringHashValuePointer( |
| _ str: OpaquePointer, _ isASCII: Bool) -> Int |
| |
| @_inlineable // FIXME(sil-serialize-all) |
| @_versioned // FIXME(sil-serialize-all) |
| @_silgen_name("swift_stdlib_CFStringHashCString") |
| internal func _stdlib_CFStringHashCString( |
| _ str: OpaquePointer, _ len: Int) -> Int |
| #endif |
| |
| extension Unicode { |
| // FIXME: cannot be marked @_versioned. See <rdar://problem/34438258> |
| // @_inlineable // FIXME(sil-serialize-all) |
| // @_versioned // FIXME(sil-serialize-all) |
| internal static func hashASCII( |
| _ string: UnsafeBufferPointer<UInt8> |
| ) -> Int { |
| let collationTable = _swift_stdlib_unicode_getASCIICollationTable() |
| var hasher = _SipHash13Context(key: _Hashing.secretKey) |
| for c in string { |
| _precondition(c <= 127) |
| let element = collationTable[Int(c)] |
| // Ignore zero valued collation elements. They don't participate in the |
| // ordering relation. |
| if element != 0 { |
| hasher.append(element) |
| } |
| } |
| return hasher._finalizeAndReturnIntHash() |
| } |
| |
| // FIXME: cannot be marked @_versioned. See <rdar://problem/34438258> |
| // @_inlineable // FIXME(sil-serialize-all) |
| // @_versioned // FIXME(sil-serialize-all) |
| internal static func hashUTF16( |
| _ string: UnsafeBufferPointer<UInt16> |
| ) -> Int { |
| let collationIterator = _swift_stdlib_unicodeCollationIterator_create( |
| string.baseAddress!, |
| UInt32(string.count)) |
| defer { _swift_stdlib_unicodeCollationIterator_delete(collationIterator) } |
| |
| var hasher = _SipHash13Context(key: _Hashing.secretKey) |
| while true { |
| var hitEnd = false |
| let element = |
| _swift_stdlib_unicodeCollationIterator_next(collationIterator, &hitEnd) |
| if hitEnd { |
| break |
| } |
| // Ignore zero valued collation elements. They don't participate in the |
| // ordering relation. |
| if element != 0 { |
| hasher.append(element) |
| } |
| } |
| return hasher._finalizeAndReturnIntHash() |
| } |
| } |
| |
| @_versioned // FIXME(sil-serialize-all) |
| @inline(never) // Hide the CF dependency |
| internal func _hashString(_ string: String) -> Int { |
| let core = string._core |
| #if _runtime(_ObjC) |
| // Mix random bits into NSString's hash so that clients don't rely on |
| // Swift.String.hashValue and NSString.hash being the same. |
| #if arch(i386) || arch(arm) |
| let hashOffset = Int(bitPattern: 0x88dd_cc21) |
| #else |
| let hashOffset = Int(bitPattern: 0x429b_1266_88dd_cc21) |
| #endif |
| // If we have a contiguous string then we can use the stack optimization. |
| let isASCII = core.isASCII |
| if core.hasContiguousStorage { |
| if isASCII { |
| return hashOffset ^ _stdlib_CFStringHashCString( |
| OpaquePointer(core.startASCII), core.count) |
| } else { |
| let stackAllocated = _NSContiguousString(core) |
| return hashOffset ^ stackAllocated._unsafeWithNotEscapedSelfPointer { |
| return _stdlib_NSStringHashValuePointer($0, false) |
| } |
| } |
| } else { |
| let cocoaString = unsafeBitCast( |
| string._bridgeToObjectiveCImpl(), to: _NSStringCore.self) |
| return hashOffset ^ _stdlib_NSStringHashValue(cocoaString, isASCII) |
| } |
| #else |
| if let asciiBuffer = core.asciiBuffer { |
| return Unicode.hashASCII(UnsafeBufferPointer( |
| start: asciiBuffer.baseAddress!, |
| count: asciiBuffer.count)) |
| } else { |
| return Unicode.hashUTF16( |
| UnsafeBufferPointer(start: core.startUTF16, count: core.count)) |
| } |
| #endif |
| } |
| |
| |
| extension String : Hashable { |
| /// The string's hash value. |
| /// |
| /// Hash values are not guaranteed to be equal across different executions of |
| /// your program. Do not save hash values to use during a future execution. |
| @_inlineable // FIXME(sil-serialize-all) |
| public var hashValue: Int { |
| return _hashString(self) |
| } |
| } |
| |