Files
swift-mirror/stdlib/core/NativeArrayBuffer.swift
Ted Kremenek fad874708e Adjust test cases.
Swift SVN r17964
2014-05-12 22:01:52 +00:00

357 lines
9.7 KiB
Swift

//===--- ArrayBridge.swift - Array<T> <=> NSArray bridging ----------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
import SwiftShims
// The empty array prototype. We use the same object for all empty
// [Native]Array<T>s.
let emptyNSSwiftArray : NSSwiftArray
= reinterpretCast(NativeArrayBuffer<Int>(count: 0, minimumCapacity: 0))
// The class that implements the storage for a NativeArray<T>
@final class NativeArrayStorage<T> : NSSwiftArray {
typealias Buffer = NativeArrayBuffer<T>
deinit {
let b = Buffer(self)
b.elementStorage.destroy(b.count)
b.base._value.destroy()
}
override var dynamicElementType: Any.Type {
return T.self
}
}
struct NativeArrayBuffer<T> : ArrayBufferType, LogicValue {
/// Make a buffer with uninitialized elements. After using this
/// method, you must either initialize the count elements at the
/// result's .elementStorage or set the result's .count to zero.
init(count: Int, minimumCapacity: Int)
{
base = HeapBuffer(
NativeArrayStorage<T>.self,
_ArrayBody(),
max(count, minimumCapacity))
var bridged = false
if _canBeClass(T.self) {
bridged = isBridgedVerbatimToObjectiveC(T.self)
}
base.value = _ArrayBody(count: count, capacity: base._capacity(),
elementTypeIsBridgedVerbatim: bridged)
}
init(_ storage: NativeArrayStorage<T>?) {
base = reinterpretCast(storage)
}
func getLogicValue() -> Bool {
return base.getLogicValue()
}
/// If the elements are stored contiguously, a pointer to the first
/// element. Otherwise, nil.
var elementStorage: UnsafePointer<T> {
return base ? base.elementStorage : nil
}
/// A pointer to the first element, assuming that the elements are stored
/// contiguously.
var _unsafeElementStorage: UnsafePointer<T> {
return base.elementStorage
}
func withUnsafePointerToElements<R>(body: (UnsafePointer<T>)->R) -> R {
let p = base.elementStorage
return withExtendedLifetime(base) { body(p) }
}
mutating func take() -> NativeArrayBuffer {
if !base {
return NativeArrayBuffer()
}
assert(base.isUniquelyReferenced(), "Can't \"take\" a shared array buffer")
let result = self
base = Base()
return result
}
//===--- ArrayBufferType conformance ------------------------------------===//
/// The type of elements stored in the buffer
typealias Element = T
/// create an empty buffer
init() {
base = HeapBuffer()
}
/// Adopt the storage of x
init(_ buffer: NativeArrayBuffer) {
self = buffer
}
mutating func requestUniqueMutableBuffer(minimumCapacity: Int)
-> NativeArrayBuffer<Element>?
{
return isUniquelyReferenced() && capacity >= minimumCapacity ? self : nil
}
/// If this buffer is backed by a NativeArrayBuffer, return it.
/// Otherwise, return nil. Note: the result's elementStorage may
/// not match ours, if we are a SliceBuffer.
func requestNativeBuffer() -> NativeArrayBuffer<Element>? {
return self
}
/// Get/set the value of the ith element
subscript(i: Int) -> T {
get {
assert(i >= 0 && i < count, "Array index out of range")
// If the index is in bounds, we can assume we have storage.
return _unsafeElementStorage[i]
}
nonmutating set {
assert(i >= 0 && i < count, "Array index out of range")
// If the index is in bounds, we can assume we have storage.
// FIXME: Manually swap because it makes the ARC optimizer happy. See
// <rdar://problem/16831852> check retain/release order
// _unsafeElementStorage[i] = newValue
var nv = newValue
let tmp = nv
nv = _unsafeElementStorage[i]
_unsafeElementStorage[i] = tmp
}
}
/// How many elements the buffer stores
var count: Int {
get {
return base ? base.value.count : 0
}
nonmutating set {
assert(newValue >= 0)
assert(
newValue <= capacity,
"Can't grow an array buffer past its capacity")
assert(base || newValue == 0)
if base {
base.value.count = newValue
}
}
}
/// How many elements the buffer can store without reallocation
var capacity: Int {
return base ? base.value.capacity : 0
}
/// Copy the given subRange of this buffer into uninitialized memory
/// starting at target. Return a pointer past-the-end of the
/// just-initialized memory.
func _uninitializedCopy(
subRange: Range<Int>, target: UnsafePointer<T>
) -> UnsafePointer<T> {
assert(subRange.startIndex >= 0)
assert(subRange.endIndex >= subRange.startIndex)
assert(subRange.endIndex <= count)
var dst = target
var src = elementStorage + subRange.startIndex
for i in subRange {
dst++.initialize(src++.get())
}
_fixLifetime(owner)
return dst
}
/// Return a SliceBuffer containing the given subRange of values
/// from this buffer.
subscript(subRange: Range<Int>) -> SliceBuffer<T>
{
return SliceBuffer(
owner: base.storage,
start: elementStorage + subRange.startIndex,
count: subRange.endIndex - subRange.startIndex,
hasNativeBuffer: true)
}
/// Return true iff this buffer's storage is uniquely-referenced.
/// NOTE: this does not mean the buffer is mutable. Other factors
/// may need to be considered, such as whether the buffer could be
/// some immutable Cocoa container.
mutating func isUniquelyReferenced() -> Bool {
return base.isUniquelyReferenced()
}
/// Returns true iff this buffer is mutable. NOTE: a true result
/// does not mean the buffer is uniquely-referenced.
func isMutable() -> Bool {
return true
}
/// Convert to an NSArray.
/// Precondition: T is bridged to Objective-C
/// O(1) if T is bridged verbatim, O(N) otherwise
func asCocoaArray() -> CocoaArray {
assert(
isBridgedToObjectiveC(T.self),
"Array element type is not bridged to ObjectiveC")
if count == 0 {
return emptyNSSwiftArray
}
if _fastPath(base.value.elementTypeIsBridgedVerbatim) {
return reinterpretCast(base.storage)
}
return NativeArray(self).map { bridgeToObjectiveC($0)! }.buffer.storage!
}
/// An object that keeps the elements stored in this buffer alive
var owner: AnyObject? {
return storage
}
/// A value that identifies first mutable element, if any. Two
/// arrays compare === iff they are both empty, or if their buffers
/// have the same identity and count.
var identity: Word {
return reinterpretCast(elementStorage)
}
var dynamicElementType: Any.Type {
return storage ? storage!.dynamicElementType : T.self
}
//===--- private --------------------------------------------------------===//
var storage: NativeArrayStorage<T>? {
return reinterpretCast(base.storage)
}
typealias Base = HeapBuffer<_ArrayBody, T>
var base: Base
}
/// Append the elements of rhs to lhs
func += <
T, C: Collection where C._Element == T
> (
inout lhs: NativeArrayBuffer<T>, rhs: C
) {
let oldCount = lhs.count
let newCount = oldCount + numericCast(countElements(rhs))
if _fastPath(newCount <= lhs.capacity) {
lhs.count = newCount
(lhs.elementStorage + oldCount).initializeFrom(rhs)
}
else {
let newLHS = NativeArrayBuffer<T>(count: newCount,
minimumCapacity: lhs.capacity * 2)
if lhs.base {
newLHS.elementStorage.moveInitializeFrom(lhs.elementStorage,
count: oldCount)
lhs.base.value.count = 0
}
lhs.base = newLHS.base
(lhs.base.elementStorage + oldCount).initializeFrom(rhs)
}
}
/// Append rhs to lhs
func += <T> (inout lhs: NativeArrayBuffer<T>, rhs: T) {
lhs += CollectionOfOne(rhs)
}
func === <T>(
lhs: NativeArrayBuffer<T>, rhs: NativeArrayBuffer<T>
) -> Bool {
return lhs.base == rhs.base
}
func !== <T>(
lhs: NativeArrayBuffer<T>, rhs: NativeArrayBuffer<T>
) -> Bool {
return lhs.base != rhs.base
}
extension NativeArrayBuffer : Collection {
var startIndex: Int {
return 0
}
var endIndex: Int {
return count
}
func generate() -> IndexingGenerator<NativeArrayBuffer> {
return IndexingGenerator(self)
}
}
func ~> <
S: _Sequence_
>(
source: S, _: (_CopyToNativeArrayBuffer,())
) -> NativeArrayBuffer<S.GeneratorType.Element>
{
var result = NativeArrayBuffer<S.GeneratorType.Element>()
// Using GeneratorSequence here essentially promotes the sequence to
// a Sequence from _Sequence_ so we can iterate the elements
for x in GeneratorSequence(source.generate()) {
result += x
}
return result.take()
}
func ~> <
C: Collection
>(
source: C, _:(_CopyToNativeArrayBuffer, ())
) -> NativeArrayBuffer<C.GeneratorType.Element>
{
return _copyCollectionToNativeArrayBuffer(source)
}
func _copyCollectionToNativeArrayBuffer<C: protocol<_Collection,_Sequence_>>(
source: C
) -> NativeArrayBuffer<C.GeneratorType.Element>
{
let count = countElements(source)
if count == 0 {
return NativeArrayBuffer()
}
var result = NativeArrayBuffer<C.GeneratorType.Element>(
count: numericCast(count),
minimumCapacity: 0
)
var p = result.elementStorage
for x in GeneratorSequence(source.generate()) {
(p++).initialize(x)
}
return result
}
protocol _ArrayType : Collection {
var count: Int {get}
typealias Buffer : ArrayBufferType
var buffer: Buffer {get}
}