[stdlib] Set, Dictionary: Review _SwiftDeferredNS*

Author: lorentey

stdlib/public/core/Dictionary.swift

@@ -2826,7 +2826,7 @@ final internal class _SwiftDeferredNSDictionary<Key: Hashable, Value>
   //
   // Do not access this property directly.
   @nonobjc
-  internal var _heapStorageBridged_DoNotUse: AnyObject?
+  private var _bridgedStorage_DoNotUse: AnyObject?
 
   /// The unbridged elements.
   internal var native: _NativeDictionary<Key, Value>
@@ -2836,11 +2836,63 @@ final internal class _SwiftDeferredNSDictionary<Key: Hashable, Value>
     super.init()
   }
 
-  @objc(copyWithZone:)
-  internal func copy(with zone: _SwiftNSZone?) -> AnyObject {
-    // Instances of this class should be visible outside of standard library as
-    // having `NSDictionary` type, which is immutable.
-    return self
+  /// Returns the pointer to the stored property, which contains bridged
+  /// Dictionary elements.
+  @nonobjc
+  private var _bridgedStoragePtr: UnsafeMutablePointer<AnyObject?> {
+    return _getUnsafePointerToStoredProperties(self).assumingMemoryBound(
+      to: Optional<AnyObject>.self)
+  }
+
+  /// The buffer for bridged Dictionary elements, if present.
+  @nonobjc
+  private var _bridgedStorage: _RawNativeDictionaryStorage? {
+    get {
+      if let ref = _stdlib_atomicLoadARCRef(object: _bridgedStoragePtr) {
+        return unsafeDowncast(ref, to: _RawNativeDictionaryStorage.self)
+      }
+      return nil
+    }
+  }
+
+  /// Attach a buffer for bridged Dictionary elements.
+  @nonobjc
+  private func _initializeBridgedStorage(_ storage: AnyObject) {
+    _stdlib_atomicInitializeARCRef(object: _bridgedStoragePtr, desired: storage)
+  }
+
+  /// Returns the bridged Dictionary values.
+  internal var bridged: _NativeDictionary<AnyObject, AnyObject> {
+    return _NativeDictionary(_storage: _bridgedStorage!)
+  }
+
+  @nonobjc
+  internal func bridgeEverything() {
+    if _fastPath(_bridgedStorage != nil) {
+      return
+    }
+
+    // FIXME: rdar://problem/19486139 (split bridged buffers for keys and values)
+    // We bridge keys and values unconditionally here, even if one of them
+    // actually is verbatim bridgeable (e.g. Dictionary<Int, AnyObject>).
+    // Investigate only allocating the buffer for a Set in this case.
+
+    // Create buffer for bridged data.
+    let bridged = _NativeDictionary<AnyObject, AnyObject>(
+      _exactBucketCount: native.bucketCount,
+      unhashable: ())
+
+    // Bridge everything.
+    for i in 0..<native.bucketCount {
+      if native.isInitializedEntry(at: i) {
+        let key = _bridgeAnythingToObjectiveC(native.key(at: i))
+        let val = _bridgeAnythingToObjectiveC(native.value(at: i))
+        bridged.initializeKey(key, value: val, at: i)
+      }
+    }
+
+    // Atomically put the bridged elements in place.
+    _initializeBridgedStorage(bridged._storage)
   }
 
   //
@@ -2859,9 +2911,24 @@ final internal class _SwiftDeferredNSDictionary<Key: Hashable, Value>
     _sanityCheckFailure("don't call this designated initializer")
   }
 
+  @objc(copyWithZone:)
+  internal func copy(with zone: _SwiftNSZone?) -> AnyObject {
+    // Instances of this class should be visible outside of standard library as
+    // having `NSDictionary` type, which is immutable.
+    return self
+  }
+
   @objc(objectForKey:)
   internal func objectFor(_ aKey: AnyObject) -> AnyObject? {
-    return bridgingObjectForKey(aKey)
+    guard let nativeKey = _conditionallyBridgeFromObjectiveC(aKey, Key.self)
+    else { return nil }
+
+    let (i, found) = native._find(nativeKey)
+    if found {
+      bridgeEverything()
+      return bridged.value(at: i.bucket)
+    }
+    return nil
   }
 
   @objc
@@ -2885,18 +2952,18 @@ final internal class _SwiftDeferredNSDictionary<Key: Hashable, Value>
       if let unmanagedObjects = _UnmanagedAnyObjectArray(objects) {
         // keys nonnull, objects nonnull
         for position in 0..<bucketCount {
-          if bridgedDictionary.isInitializedEntry(at: position) {
-            unmanagedObjects[i] = bridgedDictionary.value(at: position)
-            unmanagedKeys[i] = bridgedDictionary.key(at: position)
+          if bridged.isInitializedEntry(at: position) {
+            unmanagedObjects[i] = bridged.value(at: position)
+            unmanagedKeys[i] = bridged.key(at: position)
             i += 1
             guard i < count else { break }
           }
         }
       } else {
         // keys nonnull, objects null
         for position in 0..<bucketCount {
-          if bridgedDictionary.isInitializedEntry(at: position) {
-            unmanagedKeys[i] = bridgedDictionary.key(at: position)
+          if bridged.isInitializedEntry(at: position) {
+            unmanagedKeys[i] = bridged.key(at: position)
             i += 1
             guard i < count else { break }
           }
@@ -2906,8 +2973,8 @@ final internal class _SwiftDeferredNSDictionary<Key: Hashable, Value>
       if let unmanagedObjects = _UnmanagedAnyObjectArray(objects) {
         // keys null, objects nonnull
         for position in 0..<bucketCount {
-          if bridgedDictionary.isInitializedEntry(at: position) {
-            unmanagedObjects[i] = bridgedDictionary.value(at: position)
+          if bridged.isInitializedEntry(at: position) {
+            unmanagedObjects[i] = bridged.value(at: position)
             i += 1
             guard i < count else { break }
           }
@@ -2926,99 +2993,24 @@ final internal class _SwiftDeferredNSDictionary<Key: Hashable, Value>
     let bucketCount = native.bucketCount
     var stop: UInt8 = 0
     for position in 0..<bucketCount {
-      if bridgedDictionary.isInitializedEntry(at: position) {
-        block(Unmanaged.passUnretained(bridgedDictionary.key(at: position)),
-          Unmanaged.passUnretained(bridgedDictionary.value(at: position)),
+      if bridged.isInitializedEntry(at: position) {
+        block(Unmanaged.passUnretained(bridged.key(at: position)),
+          Unmanaged.passUnretained(bridged.value(at: position)),
           &stop)
       }
       if stop != 0 { return }
     }
   }
 
-  /// Returns the pointer to the stored property, which contains bridged
-  /// Dictionary elements.
-  @nonobjc
-  internal var _heapStorageBridgedPtr: UnsafeMutablePointer<AnyObject?> {
-    return _getUnsafePointerToStoredProperties(self).assumingMemoryBound(
-      to: Optional<AnyObject>.self)
-  }
-
-  /// The buffer for bridged Dictionary elements, if present.
-  @nonobjc
-  internal var _bridgedStorage: _RawNativeDictionaryStorage? {
-    get {
-      if let ref = _stdlib_atomicLoadARCRef(object: _heapStorageBridgedPtr) {
-        return unsafeDowncast(ref, to: _RawNativeDictionaryStorage.self)
-      }
-      return nil
-    }
-  }
-
-  /// Attach a buffer for bridged Dictionary elements.
-  @nonobjc
-  internal func _initializeHeapStorageBridged(_ newStorage: AnyObject) {
-    _stdlib_atomicInitializeARCRef(
-      object: _heapStorageBridgedPtr, desired: newStorage)
-  }
-
-  /// Returns the bridged Dictionary values.
-  internal var bridgedDictionary: _NativeDictionary<AnyObject, AnyObject> {
-    return _NativeDictionary(_storage: _bridgedStorage!)
-  }
-
-  @nonobjc
-  internal func bridgeEverything() {
-    if _fastPath(_bridgedStorage != nil) {
-      return
-    }
-
-    // FIXME: rdar://problem/19486139 (split bridged buffers for keys and values)
-    // We bridge keys and values unconditionally here, even if one of them
-    // actually is verbatim bridgeable (e.g. Dictionary<Int, AnyObject>).
-    // Investigate only allocating the buffer for a Set in this case.
-
-    // Create buffer for bridged data.
-    let bridged = _NativeDictionary<AnyObject, AnyObject>(
-      _exactBucketCount: native.bucketCount,
-      unhashable: ())
-
-    // Bridge everything.
-    for i in 0..<native.bucketCount {
-      if native.isInitializedEntry(at: i) {
-        let key = _bridgeAnythingToObjectiveC(native.key(at: i))
-        let val = _bridgeAnythingToObjectiveC(native.value(at: i))
-        bridged.initializeKey(key, value: val, at: i)
-      }
-    }
-
-    // Atomically put the bridged elements in place.
-    _initializeHeapStorageBridged(bridged._storage)
-  }
-
   @objc
   internal var count: Int {
     return native.count
   }
 
-  @nonobjc
-  internal func bridgingObjectForKey(_ aKey: AnyObject)
-    -> AnyObject? {
-    guard let nativeKey = _conditionallyBridgeFromObjectiveC(aKey, Key.self)
-    else { return nil }
-
-    let (i, found) = native._find(
-      nativeKey, startBucket: native._bucket(nativeKey))
-    if found {
-      bridgeEverything()
-      return bridgedDictionary.value(at: i.bucket)
-    }
-    return nil
-  }
-
   @objc
   internal func enumerator() -> _NSEnumerator {
     bridgeEverything()
-    return _SwiftDictionaryNSEnumerator<AnyObject, AnyObject>(bridgedDictionary)
+    return _SwiftDictionaryNSEnumerator<AnyObject, AnyObject>(bridged)
   }
 
   @objc(countByEnumeratingWithState:objects:count:)
@@ -3058,7 +3050,7 @@ final internal class _SwiftDeferredNSDictionary<Key: Hashable, Value>
         break
       }
 
-      let bridgedKey = bridgedDictionary.key(at: currIndex.bucket)
+      let bridgedKey = bridged.key(at: currIndex.bucket)
       unmanagedObjects[i] = bridgedKey
       stored += 1
       native.formIndex(after: &currIndex)