CircularBuffer: use vendored swift-collections/Deque instead

NOTICE.txt

@@ -78,3 +78,12 @@ This product contains a derivation of Fabian Fett's 'Base64.swift'.
     * https://github.com/fabianfett/swift-base64-kit/blob/master/LICENSE
   * HOMEPAGE:
     * https://github.com/fabianfett/swift-base64-kit
+
+---
+
+This product contains the `DequeModule` from Swift Collections.
+
+  * LICENSE (Apache License 2.0):
+    * https://github.com/apple/swift-collections/blob/main/LICENSE.txt
+  * HOMEPAGE:
+    * https://github.com/apple/swift-collections

Sources/NIO/Codec.swift

@@ -287,7 +287,7 @@ extension B2MDBuffer {
         case .ready where self.buffers.count > 0:
             var buffer = self.buffers.removeFirst()
             buffer.writeBuffers(self.buffers)
-            self.buffers.removeAll(keepingCapacity: self.buffers.capacity < 16) // don't grow too much
+            self.buffers.removeAll(keepingCapacity: self.buffers.count < 16) // don't grow too much
             if buffer.readableBytes > 0 || allowEmptyBuffer {
                 self.state = .processingInProgress
                 return .available(buffer)
@@ -316,7 +316,7 @@ extension B2MDBuffer {
         } else {
             buffer.discardReadBytes()
             buffer.writeBuffers(self.buffers)
-            self.buffers.removeAll(keepingCapacity: self.buffers.capacity < 16) // don't grow too much
+            self.buffers.removeAll(keepingCapacity: self.buffers.count < 16) // don't grow too much
             self.buffers.append(buffer)
         }
     }

Sources/NIO/VendoredDeque/Deque+Codable.swift

@@ -0,0 +1,55 @@
+/* Changes for SwiftNIO
+   - renamed NIODeque to NIONIODeque (to prevent future clashes)
+   - made (NIO)NIODeque internal (not public)
+
+  DO NOT CHANGE THESE FILES, THEY ARE VENDORED FROM Swift Collections.
+*/
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift Collections open source project
+//
+// Copyright (c) 2021 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
+//
+//===----------------------------------------------------------------------===//
+
+extension NIODeque: Encodable where Element: Encodable {
+  /// Encodes the elements of this deque into the given encoder in an unkeyed
+  /// container.
+  ///
+  /// This function throws an error if any values are invalid for the given
+  /// encoder's format.
+  ///
+  /// - Parameter encoder: The encoder to write data to.
+  /* was @inlinable */
+  @usableFromInline internal /*was public */ func encode(to encoder: Encoder) throws {
+    var container = encoder.unkeyedContainer()
+    for element in self {
+      try container.encode(element)
+    }
+  }
+}
+
+extension NIODeque: Decodable where Element: Decodable {
+  /// Creates a new deque by decoding from the given decoder.
+  ///
+  /// This initializer throws an error if reading from the decoder fails, or
+  /// if the data read is corrupted or otherwise invalid.
+  ///
+  /// - Parameter decoder: The decoder to read data from.
+  /* was @inlinable */
+  @usableFromInline internal /*was public */ init(from decoder: Decoder) throws {
+    self.init()
+
+    var container = try decoder.unkeyedContainer()
+    if let count = container.count {
+      self.reserveCapacity(count)
+    }
+    while !container.isAtEnd {
+      let element = try container.decode(Element.self)
+      self.append(element)
+    }
+  }
+}

Sources/NIO/VendoredDeque/Deque+CustomDebugStringConvertible.swift

@@ -0,0 +1,34 @@
+/* Changes for SwiftNIO
+   - renamed NIODeque to NIONIODeque (to prevent future clashes)
+   - made (NIO)NIODeque internal (not public)
+
+  DO NOT CHANGE THESE FILES, THEY ARE VENDORED FROM Swift Collections.
+*/
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift Collections open source project
+//
+// Copyright (c) 2021 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
+//
+//===----------------------------------------------------------------------===//
+
+extension NIODeque: CustomDebugStringConvertible {
+  /// A textual representation of this instance, suitable for debugging.
+  @usableFromInline internal /*was public */ var debugDescription: String {
+    var result = "NIODeque<\(Element.self)>(["
+    var first = true
+    for item in self {
+      if first {
+        first = false
+      } else {
+        result += ", "
+      }
+      debugPrint(item, terminator: "", to: &result)
+    }
+    result += "])"
+    return result
+  }
+}

Sources/NIO/VendoredDeque/Deque+CustomReflectable.swift

@@ -0,0 +1,23 @@
+/* Changes for SwiftNIO
+   - renamed NIODeque to NIONIODeque (to prevent future clashes)
+   - made (NIO)NIODeque internal (not public)
+
+  DO NOT CHANGE THESE FILES, THEY ARE VENDORED FROM Swift Collections.
+*/
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift Collections open source project
+//
+// Copyright (c) 2021 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
+//
+//===----------------------------------------------------------------------===//
+
+extension NIODeque: CustomReflectable {
+  /// The custom mirror for this instance.
+  @usableFromInline internal /*was public */ var customMirror: Mirror {
+    Mirror(self, unlabeledChildren: self, displayStyle: .collection)
+  }
+}

Sources/NIO/VendoredDeque/Deque+CustomStringConvertible.swift

@@ -0,0 +1,34 @@
+/* Changes for SwiftNIO
+   - renamed NIODeque to NIONIODeque (to prevent future clashes)
+   - made (NIO)NIODeque internal (not public)
+
+  DO NOT CHANGE THESE FILES, THEY ARE VENDORED FROM Swift Collections.
+*/
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift Collections open source project
+//
+// Copyright (c) 2021 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
+//
+//===----------------------------------------------------------------------===//
+
+extension NIODeque: CustomStringConvertible {
+  /// A textual representation of this instance.
+  @usableFromInline internal /*was public */ var description: String {
+    var result = "["
+    var first = true
+    for item in self {
+      if first {
+        first = false
+      } else {
+        result += ", "
+      }
+      print(item, terminator: "", to: &result)
+    }
+    result += "]"
+    return result
+  }
+}

Sources/NIO/VendoredDeque/Deque+Equatable.swift

@@ -0,0 +1,28 @@
+/* Changes for SwiftNIO
+   - renamed NIODeque to NIONIODeque (to prevent future clashes)
+   - made (NIO)NIODeque internal (not public)
+
+  DO NOT CHANGE THESE FILES, THEY ARE VENDORED FROM Swift Collections.
+*/
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift Collections open source project
+//
+// Copyright (c) 2021 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
+//
+//===----------------------------------------------------------------------===//
+
+extension NIODeque: Equatable where Element: Equatable {
+  /// Returns a Boolean value indicating whether two values are equal. Two
+  /// deques are considered equal if they contain the same elements in the same
+  /// order.
+  ///
+  /// - Complexity: O(`min(left.count, right.count)`)
+  /* was @inlinable */
+  @usableFromInline internal /*was public */ static func ==(left: Self, right: Self) -> Bool {
+    return left.elementsEqual(right)
+  }
+}

Sources/NIO/VendoredDeque/Deque+ExpressibleByArrayLiteral.swift

@@ -0,0 +1,33 @@
+/* Changes for SwiftNIO
+   - renamed NIODeque to NIONIODeque (to prevent future clashes)
+   - made (NIO)NIODeque internal (not public)
+
+  DO NOT CHANGE THESE FILES, THEY ARE VENDORED FROM Swift Collections.
+*/
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift Collections open source project
+//
+// Copyright (c) 2021 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
+//
+//===----------------------------------------------------------------------===//
+
+extension NIODeque: ExpressibleByArrayLiteral {
+  /// Creates a new deque from the contents of an array literal.
+  ///
+  /// Do not call this initializer directly. It is used by the compiler when
+  /// you use an array literal. Instead, create a new set using an array
+  /// literal as its value by enclosing a comma-separated list of values in
+  /// square brackets. You can use an array literal anywhere a set is expected
+  /// by the type context.
+  ///
+  /// - Parameter elements: A variadic list of elements of the new set.
+  /* was @inlinable */
+  @inline(__always)
+  @usableFromInline internal /*was public */ init(arrayLiteral elements: Element...) {
+    self.init(elements)
+  }
+}