Merge pull request #6098 from phausler/additional_data_refinements

Merge the swift-corelibs-foundation version of Data

Author: phausler

stdlib/public/SDK/Foundation/Data.swift

@@ -10,6 +10,26 @@
 //
 //===----------------------------------------------------------------------===//
 
+#if DEPLOYMENT_RUNTIME_SWIFT
+
+#if os(OSX) || os(iOS)
+import Darwin
+#elseif os(Linux)
+import Glibc
+#endif
+    
+import CoreFoundation
+
+internal func __NSDataInvokeDeallocatorUnmap(_ mem: UnsafeMutableRawPointer, _ length: Int) -> Void {
+    munmap(mem, length)
+}
+
+internal func __NSDataInvokeDeallocatorFree(_ mem: UnsafeMutableRawPointer, _ length: Int) -> Void {
+    free(mem)
+}
+
+#else
+
 @_exported import Foundation // Clang module
 
 @_silgen_name("__NSDataInvokeDeallocatorVM")
@@ -24,6 +44,8 @@ internal func __NSDataInvokeDeallocatorFree(_ mem: UnsafeMutableRawPointer, _ le
 @_silgen_name("_NSWriteDataToFile_Swift")
 internal func _NSWriteDataToFile_Swift(url: NSURL, data: NSData, options: UInt, error: NSErrorPointer) -> Bool
 
+#endif
+
 public final class _DataStorage {
     public enum Backing {
         // A mirror of the objective-c implementation that is suitable to inline in swift
@@ -583,6 +605,31 @@ public final class _DataStorage {
         _needToZero = true
     }
 
+    public init(bytes: UnsafeRawPointer?, length: Int) {
+        precondition(length < _DataStorage.maxSize)
+        if length == 0 {
+            _capacity = 0
+            _length = 0
+            _needToZero = false
+            _bytes = nil
+        } else if _DataStorage.vmOpsThreshold <= length {
+            _capacity = length
+            _length = length
+            _needToZero = true
+            _bytes = _DataStorage.allocate(length, false)!
+            _DataStorage.move(_bytes!, bytes, length)
+        } else {
+            var capacity = length
+            if (_DataStorage.vmOpsThreshold <= capacity) {
+                capacity = NSRoundUpToMultipleOfPageSize(capacity)
+            }
+            _length = length
+            _bytes = _DataStorage.allocate(capacity, false)!
+            _capacity = capacity
+            _needToZero = true
+            _DataStorage.move(_bytes!, bytes, length)
+        }
+    }
 
     public init(bytes: UnsafeMutableRawPointer?, length: Int, copy: Bool, deallocator: ((UnsafeMutableRawPointer, Int) -> Void)?) {
         precondition(length < _DataStorage.maxSize)
@@ -687,7 +734,8 @@ public final class _DataStorage {
     public func withInteriorPointerReference<T>(_ work: (NSData) throws -> T) rethrows -> T {
         switch _backing {
         case .swift:
-            return try work(NSData(bytesNoCopy: _bytes!, length: _length, freeWhenDone: false))
+            let d = _bytes == nil ? NSData() : NSData(bytesNoCopy: _bytes!, length: _length, freeWhenDone: false)
+            return try work(d)
         case .immutable(let d):
             return try work(d)
         case .mutable(let d):
@@ -829,15 +877,23 @@ internal class _NSSwiftData : NSData {
         return NSData(bytes: _backing.bytes, length: _backing.length)
     }
 
+#if !DEPLOYMENT_RUNTIME_SWIFT
     @objc
     func _isCompact() -> Bool {
         return true
     }
+#endif
 
+#if DEPLOYMENT_RUNTIME_SWIFT
+    override func _providesConcreteBacking() -> Bool {
+        return true
+    }
+#else
     @objc(_providesConcreteBacking)
     func _providesConcreteBacking() -> Bool {
         return true
     }
+#endif
 }
 
 public struct Data : ReferenceConvertible, Equatable, Hashable, RandomAccessCollection, MutableCollection, RangeReplaceableCollection {
@@ -859,7 +915,9 @@ public struct Data : ReferenceConvertible, Equatable, Hashable, RandomAccessColl
     /// When creating a `Data` with the no-copy initializer, you may specify a `Data.Deallocator` to customize the behavior of how the backing store is deallocated.
     public enum Deallocator {
         /// Use a virtual memory deallocator.
+#if !DEPLOYMENT_RUNTIME_SWIFT
         case virtualMemory
+#endif
 
         /// Use `munmap`.
         case unmap
@@ -874,6 +932,20 @@ public struct Data : ReferenceConvertible, Equatable, Hashable, RandomAccessColl
         case custom((UnsafeMutableRawPointer, Int) -> Void)
 
         fileprivate var _deallocator : ((UnsafeMutableRawPointer, Int) -> Void)? {
+#if DEPLOYMENT_RUNTIME_SWIFT
+            switch self {
+            case .unmap:
+                return { __NSDataInvokeDeallocatorUnmap($0, $1) }
+            case .free:
+                return { __NSDataInvokeDeallocatorFree($0, $1) }
+            case .none:
+                return nil
+            case .custom(let b):
+                return { (ptr, len) in
+                    b(ptr, len)
+                }
+            }
+#else
             switch self {
             case .virtualMemory:
                 return { __NSDataInvokeDeallocatorVM($0, $1) }
@@ -888,6 +960,7 @@ public struct Data : ReferenceConvertible, Equatable, Hashable, RandomAccessColl
                     b(ptr, len)
                 }
             }
+#endif
         }
     }
 
@@ -899,29 +972,29 @@ public struct Data : ReferenceConvertible, Equatable, Hashable, RandomAccessColl
     /// - parameter bytes: A pointer to the memory. It will be copied.
     /// - parameter count: The number of bytes to copy.
     public init(bytes: UnsafeRawPointer, count: Int) {
-        _backing = _DataStorage(bytes: UnsafeMutableRawPointer(mutating: bytes), length: count, copy: true, deallocator: nil)
+        _backing = _DataStorage(bytes: bytes, length: count)
     }
 
     /// Initialize a `Data` with copied memory content.
     ///
     /// - parameter buffer: A buffer pointer to copy. The size is calculated from `SourceType` and `buffer.count`.
     public init<SourceType>(buffer: UnsafeBufferPointer<SourceType>) {
-        _backing = _DataStorage(bytes: UnsafeMutableRawPointer(mutating: buffer.baseAddress), length: MemoryLayout<SourceType>.stride * buffer.count, copy: true, deallocator: nil)
+        _backing = _DataStorage(bytes: buffer.baseAddress, length: MemoryLayout<SourceType>.stride * buffer.count)
     }
 
     /// Initialize a `Data` with copied memory content.
     ///
     /// - parameter buffer: A buffer pointer to copy. The size is calculated from `SourceType` and `buffer.count`.
     public init<SourceType>(buffer: UnsafeMutableBufferPointer<SourceType>) {
-        _backing = _DataStorage(bytes: buffer.baseAddress, length: MemoryLayout<SourceType>.stride * buffer.count, copy: true, deallocator: nil)
+        _backing = _DataStorage(bytes: buffer.baseAddress, length: MemoryLayout<SourceType>.stride * buffer.count)
     }
 
     /// Initialize a `Data` with the contents of an Array.
     ///
     /// - parameter bytes: An array of bytes to copy.
     public init(bytes: Array<UInt8>) {
         _backing = bytes.withUnsafeBufferPointer {
-            return _DataStorage(bytes: UnsafeMutableRawPointer(mutating: $0.baseAddress), length: $0.count, copy: true, deallocator: nil)
+            return _DataStorage(bytes: $0.baseAddress, length: $0.count)
         }
     }
 
@@ -930,7 +1003,7 @@ public struct Data : ReferenceConvertible, Equatable, Hashable, RandomAccessColl
     /// - parameter bytes: An array of bytes to copy.
     public init(bytes: ArraySlice<UInt8>) {
         _backing = bytes.withUnsafeBufferPointer {
-            return _DataStorage(bytes: UnsafeMutableRawPointer(mutating: $0.baseAddress), length: $0.count, copy: true, deallocator: nil)
+            return _DataStorage(bytes: $0.baseAddress, length: $0.count)
         }
     }
 
@@ -968,7 +1041,7 @@ public struct Data : ReferenceConvertible, Equatable, Hashable, RandomAccessColl
     /// - parameter deallocator: Specifies the mechanism to free the indicated buffer, or `.none`.
     public init(bytesNoCopy bytes: UnsafeMutableRawPointer, count: Int, deallocator: Deallocator) {
         let whichDeallocator = deallocator._deallocator
-        _backing = _DataStorage(immutableReference: NSData(bytesNoCopy: bytes, length: count, deallocator: whichDeallocator))
+        _backing = _DataStorage(bytes: bytes, length: count, copy: false, deallocator: whichDeallocator)
     }
 
     /// Initialize a `Data` with the contents of a `URL`.
@@ -1015,12 +1088,17 @@ public struct Data : ReferenceConvertible, Equatable, Hashable, RandomAccessColl
     ///
     /// - parameter reference: The instance of `NSData` that you wish to wrap. This instance will be copied by `struct Data`.
     public init(referencing reference: NSData) {
+#if DEPLOYMENT_RUNTIME_SWIFT
+        let providesConcreteBacking = reference._providesConcreteBacking()
+#else
         let providesConcreteBacking = (reference as AnyObject)._providesConcreteBacking?() ?? false
+#endif
         if providesConcreteBacking {
             _backing = _DataStorage(immutableReference: reference.copy() as! NSData)
         } else {
             _backing = _DataStorage(customReference: reference.copy() as! NSData)
         }
+
     }
 
     // -----------------------------------
@@ -1047,8 +1125,7 @@ public struct Data : ReferenceConvertible, Equatable, Hashable, RandomAccessColl
     /// - warning: The byte pointer argument should not be stored and used outside of the lifetime of the call to the closure.
     @inline(__always)
     public func withUnsafeBytes<ResultType, ContentType>(_ body: (UnsafePointer<ContentType>) throws -> ResultType) rethrows -> ResultType {
-        let bytes =  _backing.bytes!
-        defer { _fixLifetime(self)}
+        let bytes =  _backing.bytes ?? UnsafeRawPointer(bitPattern: 0xBAD0)!
         let contentPtr = bytes.bindMemory(to: ContentType.self, capacity: count / MemoryLayout<ContentType>.stride)
         return try body(contentPtr)
     }
@@ -1063,8 +1140,7 @@ public struct Data : ReferenceConvertible, Equatable, Hashable, RandomAccessColl
         if !isKnownUniquelyReferenced(&_backing) {
             _backing = _backing.mutableCopy()
         }
-        let mutableBytes = _backing.mutableBytes!
-        defer { _fixLifetime(self)}
+        let mutableBytes = _backing.mutableBytes ?? UnsafeMutableRawPointer(bitPattern: 0xBAD0)!
         let contentPtr = mutableBytes.bindMemory(to: ContentType.self, capacity: count / MemoryLayout<ContentType>.stride)
         return try body(UnsafeMutablePointer(contentPtr))
     }
@@ -1079,11 +1155,13 @@ public struct Data : ReferenceConvertible, Equatable, Hashable, RandomAccessColl
     /// - warning: This method does not verify that the contents at pointer have enough space to hold `count` bytes.
     @inline(__always)
     public func copyBytes(to pointer: UnsafeMutablePointer<UInt8>, count: Int) {
+        if count == 0 { return }
         memcpy(UnsafeMutableRawPointer(pointer), _backing.bytes!, count)
     }
 
     @inline(__always)
     private func _copyBytesHelper(to pointer: UnsafeMutableRawPointer, from range: NSRange) {
+        if range.length == 0 { return }
         memcpy(UnsafeMutableRawPointer(pointer), _backing.bytes!.advanced(by: range.location), range.length)
     }
 
@@ -1129,7 +1207,7 @@ public struct Data : ReferenceConvertible, Equatable, Hashable, RandomAccessColl
     }
 
     // MARK: -
-    
+#if !DEPLOYMENT_RUNTIME_SWIFT
     @inline(__always)
     private func _shouldUseNonAtomicWriteReimplementation(options: Data.WritingOptions = []) -> Bool {
 
@@ -1144,6 +1222,7 @@ public struct Data : ReferenceConvertible, Equatable, Hashable, RandomAccessColl
             return false
         }
     }
+#endif
 
     /// Write the contents of the `Data` to a location.
     ///
@@ -1152,6 +1231,9 @@ public struct Data : ReferenceConvertible, Equatable, Hashable, RandomAccessColl
     /// - throws: An error in the Cocoa domain, if there is an error writing to the `URL`.
     public func write(to url: URL, options: Data.WritingOptions = []) throws {
         try _backing.withInteriorPointerReference {
+#if DEPLOYMENT_RUNTIME_SWIFT
+            try $0.write(to: url, options: WritingOptions(rawValue: options.rawValue))
+#else
             if _shouldUseNonAtomicWriteReimplementation(options: options) {
                 var error : NSError?
                 if !_NSWriteDataToFile_Swift(url: url._bridgeToObjectiveC(), data: $0, options: options.rawValue, error: &error) {
@@ -1160,6 +1242,7 @@ public struct Data : ReferenceConvertible, Equatable, Hashable, RandomAccessColl
             } else {
                 try $0.write(to: url, options: WritingOptions(rawValue: options.rawValue))
             }
+#endif
         }
     }
 
@@ -1599,7 +1682,14 @@ extension Data {
 }
 
 /// Provides bridging functionality for struct Data to class NSData and vice-versa.
-extension Data : _ObjectiveCBridgeable {
+
+#if DEPLOYMENT_RUNTIME_SWIFT
+internal typealias DataBridgeType = _ObjectTypeBridgeable
+#else
+internal typealias DataBridgeType = _ObjectiveCBridgeable
+#endif
+
+extension Data : DataBridgeType {
     @_semantics("convertToObjectiveC")
     public func _bridgeToObjectiveC() -> NSData {
         return _backing.bridgedReference()