Assorted minor data updates (#1564)

* Replace inline buffer with withUnsafeTemporaryAllocation

* Fix Darwin build

* Move deprecated APIs off of internal implementations

* Move copyBytes(to:) implementation to DataProtocol file

* Don't calculate buffer length twice

* Align Data mirror children size with Array

Author: jmschonfeld

Sources/FoundationEssentials/Data/Data+Deprecated.swift

@@ -33,7 +33,7 @@ extension Data {
     /// - warning: The byte pointer argument should not be stored and used outside of the lifetime of the call to the closure.
     @available(swift, deprecated: 5, message: "use `withUnsafeBytes<R>(_: (UnsafeRawBufferPointer) throws -> R) rethrows -> R` instead")
     public func withUnsafeBytes<ResultType, ContentType>(_ body: (UnsafePointer<ContentType>) throws -> ResultType) rethrows -> ResultType {
-        return try _representation.withUnsafeBytes {
+        return try self.withUnsafeBytes {
             return try body($0.baseAddress?.assumingMemoryBound(to: ContentType.self) ?? UnsafePointer<ContentType>(bitPattern: 0xBAD0)!)
         }
     }
@@ -44,7 +44,7 @@ extension Data {
     /// - warning: The byte pointer argument should not be stored and used outside of the lifetime of the call to the closure.
     @available(swift, deprecated: 5, message: "use `withUnsafeMutableBytes<R>(_: (UnsafeMutableRawBufferPointer) throws -> R) rethrows -> R` instead")
     public mutating func withUnsafeMutableBytes<ResultType, ContentType>(_ body: (UnsafeMutablePointer<ContentType>) throws -> ResultType) rethrows -> ResultType {
-        return try _representation.withUnsafeMutableBytes {
+        return try self.withUnsafeMutableBytes {
             return try body($0.baseAddress?.assumingMemoryBound(to: ContentType.self) ?? UnsafeMutablePointer<ContentType>(bitPattern: 0xBAD0)!)
         }
     }
@@ -55,6 +55,9 @@ extension Data {
     /// - parameter block: The closure to invoke for each region of data. You may stop the enumeration by setting the `stop` parameter to `true`.
     @available(swift, deprecated: 5, message: "use `regions` or `for-in` instead")
     public func enumerateBytes(_ block: (_ buffer: UnsafeBufferPointer<UInt8>, _ byteIndex: Index, _ stop: inout Bool) -> Void) {
-        _representation.enumerateBytes(block)
+        self.withUnsafeBytes {
+            var stop = false
+            block($0.assumingMemoryBound(to: UInt8.self), 0, &stop)
+        }
     }
 }

Sources/FoundationEssentials/Data/Data.swift

@@ -106,25 +106,10 @@ internal func _withStackOrHeapBuffer(capacity: Int, _ body: (UnsafeMutableBuffer
         body(UnsafeMutableBufferPointer(start: nil, count: 0))
         return
     }
-    typealias InlineBuffer = ( // 32 bytes
-        UInt8, UInt8, UInt8, UInt8, UInt8, UInt8, UInt8, UInt8,
-        UInt8, UInt8, UInt8, UInt8, UInt8, UInt8, UInt8, UInt8,
-        UInt8, UInt8, UInt8, UInt8, UInt8, UInt8, UInt8, UInt8,
-        UInt8, UInt8, UInt8, UInt8, UInt8, UInt8, UInt8, UInt8
-    )
-    let inlineCount = MemoryLayout<InlineBuffer>.size
-    if capacity <= inlineCount {
-        var buffer: InlineBuffer = (
-            0, 0, 0, 0, 0, 0, 0, 0,
-            0, 0, 0, 0, 0, 0, 0, 0,
-            0, 0, 0, 0, 0, 0, 0, 0,
-            0, 0, 0, 0, 0, 0, 0, 0
-        )
-        withUnsafeMutableBytes(of: &buffer) { buffer in
-            assert(buffer.count == inlineCount)
-            buffer.withMemoryRebound(to: UInt8.self) {
-                body(UnsafeMutableBufferPointer(start: $0.baseAddress, count: capacity))
-            }
+    // Use an inline allocation for 32 bytes or fewer
+    if capacity <= 32 {
+        withUnsafeTemporaryAllocation(of: UInt8.self, capacity: capacity) { buffer in
+            body(buffer)
         }
         return
     }
@@ -493,63 +478,6 @@ public struct Data : RandomAccessCollection, MutableCollection, RangeReplaceable
         return try _representation.withUnsafeMutableBytes(body)
     }
 
-    // MARK: -
-    // MARK: Copy Bytes
-
-    /// Copy the contents of the data to a pointer.
-    ///
-    /// - parameter pointer: A pointer to the buffer you wish to copy the bytes into.
-    /// - parameter count: The number of bytes to copy.
-    /// - warning: This method does not verify that the contents at pointer have enough space to hold `count` bytes.
-    @inlinable // This is @inlinable as trivially forwarding.
-    public func copyBytes(to pointer: UnsafeMutablePointer<UInt8>, count: Int) {
-        precondition(count >= 0, "count of bytes to copy must not be negative")
-        if count == 0 { return }
-        _copyBytesHelper(to: UnsafeMutableRawPointer(pointer), from: startIndex..<(startIndex + count))
-    }
-
-    @inlinable // This is @inlinable as trivially forwarding.
-    internal func _copyBytesHelper(to pointer: UnsafeMutableRawPointer, from range: Range<Int>) {
-        if range.isEmpty { return }
-        _representation.copyBytes(to: pointer, from: range)
-    }
-
-    /// Copy a subset of the contents of the data to a pointer.
-    ///
-    /// - parameter pointer: A pointer to the buffer you wish to copy the bytes into.
-    /// - parameter range: The range in the `Data` to copy.
-    /// - warning: This method does not verify that the contents at pointer have enough space to hold the required number of bytes.
-    @inlinable // This is @inlinable as trivially forwarding.
-    public func copyBytes(to pointer: UnsafeMutablePointer<UInt8>, from range: Range<Index>) {
-        _copyBytesHelper(to: pointer, from: range)
-    }
-
-    // Copy the contents of the data into a buffer.
-    ///
-    /// This function copies the bytes in `range` from the data into the buffer. If the count of the `range` is greater than `MemoryLayout<DestinationType>.stride * buffer.count` then the first N bytes will be copied into the buffer.
-    /// - precondition: The range must be within the bounds of the data. Otherwise `fatalError` is called.
-    /// - parameter buffer: A buffer to copy the data into.
-    /// - parameter range: A range in the data to copy into the buffer. If the range is empty, this function will return 0 without copying anything. If the range is nil, as much data as will fit into `buffer` is copied.
-    /// - returns: Number of bytes copied into the destination buffer.
-    @inlinable // This is @inlinable as generic and reasonably small.
-    public func copyBytes<DestinationType>(to buffer: UnsafeMutableBufferPointer<DestinationType>, from range: Range<Index>? = nil) -> Int {
-        let cnt = count
-        guard cnt > 0 else { return 0 }
-
-        let copyRange : Range<Index>
-        if let r = range {
-            guard !r.isEmpty else { return 0 }
-            copyRange = r.lowerBound..<(r.lowerBound + Swift.min(buffer.count * MemoryLayout<DestinationType>.stride, r.upperBound - r.lowerBound))
-        } else {
-            copyRange = startIndex..<(startIndex + Swift.min(buffer.count * MemoryLayout<DestinationType>.stride, cnt))
-        }
-
-        guard !copyRange.isEmpty else { return 0 }
-
-        _copyBytesHelper(to: buffer.baseAddress!, from: copyRange)
-        return copyRange.upperBound - copyRange.lowerBound
-    }
-
     // MARK: -
 
     @inlinable // This is @inlinable as a generic, trivially forwarding function.
@@ -887,7 +815,8 @@ extension Data : Equatable {
                     }
 
                     // Compare the contents
-                    return memcmp(b1Address, b2Address, b2.count) == 0
+                    assert(length1 == b2.count)
+                    return memcmp(b1Address, b2Address, length1) == 0
                 }
             }
         }
@@ -917,8 +846,8 @@ extension Data : CustomStringConvertible, CustomDebugStringConvertible, CustomRe
         }
 
         // Minimal size data is output as an array
-        if nBytes < 64 {
-            children.append((label: "bytes", value: Array(self[startIndex..<Swift.min(nBytes + startIndex, endIndex)])))
+        if nBytes < 256 {
+            children.append((label: "bytes", value: Array(self)))
         }
 
         let m = Mirror(self, children:children, displayStyle: Mirror.DisplayStyle.struct)

Sources/FoundationEssentials/Data/DataProtocol.swift

@@ -239,6 +239,60 @@ extension Data : MutableDataProtocol {
     public var regions: CollectionOfOne<Data> {
         return CollectionOfOne(self)
     }
+    
+    /// Copy the contents of the data to a pointer.
+    ///
+    /// - parameter pointer: A pointer to the buffer you wish to copy the bytes into.
+    /// - parameter count: The number of bytes to copy.
+    /// - warning: This method does not verify that the contents at pointer have enough space to hold `count` bytes.
+    @inlinable // This is @inlinable as trivially forwarding.
+    public func copyBytes(to pointer: UnsafeMutablePointer<UInt8>, count: Int) {
+        precondition(count >= 0, "count of bytes to copy must not be negative")
+        if count == 0 { return }
+        _copyBytesHelper(to: UnsafeMutableRawPointer(pointer), from: startIndex..<(startIndex + count))
+    }
+    
+    @inlinable // This is @inlinable as trivially forwarding.
+    internal func _copyBytesHelper(to pointer: UnsafeMutableRawPointer, from range: Range<Int>) {
+        if range.isEmpty { return }
+        _representation.copyBytes(to: pointer, from: range)
+    }
+    
+    /// Copy a subset of the contents of the data to a pointer.
+    ///
+    /// - parameter pointer: A pointer to the buffer you wish to copy the bytes into.
+    /// - parameter range: The range in the `Data` to copy.
+    /// - warning: This method does not verify that the contents at pointer have enough space to hold the required number of bytes.
+    @inlinable // This is @inlinable as trivially forwarding.
+    public func copyBytes(to pointer: UnsafeMutablePointer<UInt8>, from range: Range<Index>) {
+        _copyBytesHelper(to: pointer, from: range)
+    }
+    
+    // Copy the contents of the data into a buffer.
+    ///
+    /// This function copies the bytes in `range` from the data into the buffer. If the count of the `range` is greater than `MemoryLayout<DestinationType>.stride * buffer.count` then the first N bytes will be copied into the buffer.
+    /// - precondition: The range must be within the bounds of the data. Otherwise `fatalError` is called.
+    /// - parameter buffer: A buffer to copy the data into.
+    /// - parameter range: A range in the data to copy into the buffer. If the range is empty, this function will return 0 without copying anything. If the range is nil, as much data as will fit into `buffer` is copied.
+    /// - returns: Number of bytes copied into the destination buffer.
+    @inlinable // This is @inlinable as generic and reasonably small.
+    public func copyBytes<DestinationType>(to buffer: UnsafeMutableBufferPointer<DestinationType>, from range: Range<Index>? = nil) -> Int {
+        let cnt = count
+        guard cnt > 0 else { return 0 }
+        
+        let copyRange : Range<Index>
+        if let r = range {
+            guard !r.isEmpty else { return 0 }
+            copyRange = r.lowerBound..<(r.lowerBound + Swift.min(buffer.count * MemoryLayout<DestinationType>.stride, r.upperBound - r.lowerBound))
+        } else {
+            copyRange = startIndex..<(startIndex + Swift.min(buffer.count * MemoryLayout<DestinationType>.stride, cnt))
+        }
+        
+        guard !copyRange.isEmpty else { return 0 }
+        
+        _copyBytesHelper(to: buffer.baseAddress!, from: copyRange)
+        return copyRange.upperBound - copyRange.lowerBound
+    }
 }
 
 //===--- DataProtocol Conditional Conformances ----------------------------===//

Sources/FoundationEssentials/Data/Representations/Data+Inline.swift

@@ -10,7 +10,9 @@
 //
 //===----------------------------------------------------------------------===//
 
-#if canImport(Glibc)
+#if canImport(Darwin)
+import Darwin
+#elseif canImport(Glibc)
 @preconcurrency import Glibc
 #elseif canImport(Musl)
 @preconcurrency import Musl

Sources/FoundationEssentials/Data/Representations/DataStorage.swift

@@ -10,7 +10,9 @@
 //
 //===----------------------------------------------------------------------===//
 
-#if canImport(Glibc)
+#if canImport(Darwin)
+import Darwin
+#elseif canImport(Glibc)
 @preconcurrency import Glibc
 #elseif canImport(Musl)
 @preconcurrency import Musl