Bug 1627765 - Remove mac heirarchy cache. r=morgan

Differential Revision: https://phabricator.services.mozilla.com/D69880

--HG--
extra : moz-landing-system : lando

accessible/mac/AccessibleWrap.h

@@ -47,9 +47,6 @@ class AccessibleWrap : public Accessible {
 
   virtual void Shutdown() override;
 
-  virtual bool InsertChildAt(uint32_t aIdx, Accessible* aChild) override;
-  virtual bool RemoveChild(Accessible* aAccessible) override;
-
   virtual nsresult HandleAccEvent(AccEvent* aEvent) override;
 
  protected:

accessible/mac/AccessibleWrap.mm

@@ -154,21 +154,6 @@ nsresult AccessibleWrap::HandleAccEvent(AccEvent* aEvent) {
   NS_OBJC_END_TRY_ABORT_BLOCK_NSRESULT;
 }
 
-bool AccessibleWrap::InsertChildAt(uint32_t aIdx, Accessible* aAccessible) {
-  bool inserted = Accessible::InsertChildAt(aIdx, aAccessible);
-  if (inserted && mNativeObject) [mNativeObject appendChild:aAccessible];
-
-  return inserted;
-}
-
-bool AccessibleWrap::RemoveChild(Accessible* aAccessible) {
-  bool removed = Accessible::RemoveChild(aAccessible);
-
-  if (removed && mNativeObject) [mNativeObject invalidateChildren];
-
-  return removed;
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 // AccessibleWrap protected
 

accessible/mac/Platform.mm

@@ -46,76 +46,16 @@ void ProxyCreated(ProxyAccessible* aProxy, uint32_t) {
   uintptr_t accWrap = reinterpret_cast<uintptr_t>(aProxy) | IS_PROXY;
   mozAccessible* mozWrapper = [[type alloc] initWithAccessible:accWrap];
   aProxy->SetWrapper(reinterpret_cast<uintptr_t>(mozWrapper));
-
-  mozAccessible* nativeParent = nullptr;
-  if (aProxy->IsDoc() && aProxy->AsDoc()->IsTopLevel()) {
-    // If proxy is top level, the parent we need to invalidate the children of
-    // will be a non-remote accessible.
-    Accessible* outerDoc = aProxy->OuterDocOfRemoteBrowser();
-    if (outerDoc) {
-      nativeParent = GetNativeFromGeckoAccessible(outerDoc);
-    }
-  } else {
-    // Non-top level proxies need proxy parents' children invalidated.
-    ProxyAccessible* parent = aProxy->Parent();
-    MOZ_ASSERT(parent ||
-                   // It's expected that an OOP iframe might not have a parent yet.
-                   (aProxy->IsDoc() && aProxy->AsDoc()->IsTopLevelInContentProcess()),
-               "a non-top-level proxy is missing a parent?");
-    nativeParent = parent ? GetNativeFromProxy(parent) : nullptr;
-  }
-
-  if (nativeParent) {
-    [nativeParent invalidateChildren];
-  }
 }
 
 void ProxyDestroyed(ProxyAccessible* aProxy) {
-  mozAccessible* nativeParent = nil;
-  if (aProxy->IsDoc() && aProxy->AsDoc()->IsTopLevel()) {
-    // Invalidate native parent in parent process's children on proxy destruction
-    Accessible* outerDoc = aProxy->OuterDocOfRemoteBrowser();
-    if (outerDoc) {
-      nativeParent = GetNativeFromGeckoAccessible(outerDoc);
-    }
-  } else {
-    if (!aProxy->Document()->IsShutdown()) {
-      // Only do if the document has not been shut down, else parent will return
-      // garbage since we don't shut down children from top down.
-      ProxyAccessible* parent = aProxy->Parent();
-      // Invalidate proxy parent's children.
-      if (parent) {
-        nativeParent = GetNativeFromProxy(parent);
-      }
-    }
-  }
-
   mozAccessible* wrapper = GetNativeFromProxy(aProxy);
   [wrapper expire];
   [wrapper release];
   aProxy->SetWrapper(0);
-
-  if (nativeParent) {
-    [nativeParent invalidateChildren];
-  }
 }
 
 void ProxyEvent(ProxyAccessible* aProxy, uint32_t aEventType) {
-  if (aEventType == nsIAccessibleEvent::EVENT_REORDER && aProxy->ChildrenCount() == 1 &&
-      aProxy->ChildAt(0)->IsDoc()) {
-    // This is a remote OuterDocAccessible. The reorder event indicates that Its
-    // embedded document has been added or changed. If the document itself is
-    // an existing Accessible, ProxyCreated won't have been called, so we won't
-    // have invalidated native children. This can happen for in-process iframes
-    // if the OuterDocAccessible is re-created (e.g. due to layout reflow).
-    // It always happens for out-of-process iframes, as we must always call
-    // ProxyCreated before DocAccessibleParent::AddChildDoc for those.
-    mozAccessible* wrapper = GetNativeFromProxy(aProxy);
-    if (wrapper) {
-      [wrapper invalidateChildren];
-    }
-  }
-
   // ignore everything but focus-changed, value-changed, caret and selection
   // events for now.
   if (aEventType != nsIAccessibleEvent::EVENT_FOCUS &&

accessible/mac/mozAccessible.h

@@ -48,16 +48,6 @@ static const uintptr_t IS_PROXY = 1;
    */
   uintptr_t mGeckoAccessible;
 
-  /**
-   * Strong ref to array of children
-   */
-  NSMutableArray* mChildren;
-
-  /**
-   * Weak reference to the parent
-   */
-  mozAccessible* mParent;
-
   /**
    * The role of our gecko accessible.
    */
@@ -148,14 +138,6 @@ static const uintptr_t IS_PROXY = 1;
 
 #pragma mark -
 
-// invalidates and removes all our children from our cached array.
-- (void)invalidateChildren;
-
-/**
- * Append a child if they are already cached.
- */
-- (void)appendChild:(mozilla::a11y::Accessible*)aAccessible;
-
 // makes ourselves "expired". after this point, we might be around if someone
 // has retained us (e.g., a third-party), but we really contain no information.
 - (void)expire;
@@ -188,6 +170,11 @@ static const uintptr_t IS_PROXY = 1;
 // value for the specified attribute
 - (id)accessibilityAttributeValue:(NSString*)attribute;
 
+// gets the array length of specified attribute values. Added
+// here to have a lighter way to get the child count instead
+// of constructing a full array.
+- (NSUInteger)accessibilityArrayAttributeCount:(NSString*)attribute;
+
 - (BOOL)accessibilityIsAttributeSettable:(NSString*)attribute;
 - (void)accessibilitySetValue:(id)value forAttribute:(NSString*)attribute;
 

accessible/mac/mozAccessible.mm

@@ -108,7 +108,6 @@ static inline NSMutableArray* ConvertToNSArray(nsTArray<ProxyAccessible*>& aArra
 - (void)dealloc {
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK;
 
-  [mChildren release];
   [super dealloc];
 
   NS_OBJC_END_TRY_ABORT_BLOCK;
@@ -297,6 +296,24 @@ static const uint64_t kCacheInitialized = ((uint64_t)0x1) << 63;
   mCachedState = 0;
 }
 
+- (NSUInteger)accessibilityArrayAttributeCount:(NSString*)attribute {
+  AccessibleWrap* accWrap = [self getGeckoAccessible];
+  ProxyAccessible* proxy = [self getProxyAccessible];
+  if (!accWrap && !proxy) return 0;
+
+  // By default this calls -[[mozAccessible children] count].
+  // Since we don't cache mChildren. This is faster.
+  if ([attribute isEqualToString:NSAccessibilityChildrenAttribute]) {
+    if (accWrap) return accWrap->ChildCount();
+
+    return proxy->ChildrenCount();
+  }
+
+  id array = [self accessibilityAttributeValue:attribute];
+
+  return [array isKindOfClass:[NSArray class]] ? [array count] : 0;
+}
+
 - (id)accessibilityAttributeValue:(NSString*)attribute {
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NIL;
 
@@ -745,21 +762,17 @@ static const uint64_t kCacheInitialized = ((uint64_t)0x1) << 63;
 }
 
 // gets our native children lazily.
-// returns nil when there are no children.
 - (NSArray*)children {
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NIL;
 
-  if (mChildren) return mChildren;
-
-  // get the array of children.
-  mChildren = [[NSMutableArray alloc] init];
+  NSMutableArray* children = [NSMutableArray new];
 
   AccessibleWrap* accWrap = [self getGeckoAccessible];
   if (accWrap) {
     uint32_t childCount = accWrap->ChildCount();
     for (uint32_t childIdx = 0; childIdx < childCount; childIdx++) {
       mozAccessible* nativeChild = GetNativeFromGeckoAccessible(accWrap->GetChildAt(childIdx));
-      if (nativeChild) [mChildren addObject:nativeChild];
+      if (nativeChild) [children addObject:nativeChild];
     }
 
     // children from child if this is an outerdoc
@@ -767,7 +780,7 @@ static const uint64_t kCacheInitialized = ((uint64_t)0x1) << 63;
     if (docOwner) {
       if (ProxyAccessible* proxyDoc = docOwner->RemoteChildDoc()) {
         mozAccessible* nativeRemoteChild = GetNativeFromProxy(proxyDoc);
-        [mChildren insertObject:nativeRemoteChild atIndex:0];
+        [children insertObject:nativeRemoteChild atIndex:0];
         NSAssert1(nativeRemoteChild, @"%@ found a child remote doc missing a native\n", self);
       }
     }
@@ -775,11 +788,11 @@ static const uint64_t kCacheInitialized = ((uint64_t)0x1) << 63;
     uint32_t childCount = proxy->ChildrenCount();
     for (uint32_t childIdx = 0; childIdx < childCount; childIdx++) {
       mozAccessible* nativeChild = GetNativeFromProxy(proxy->ChildAt(childIdx));
-      if (nativeChild) [mChildren addObject:nativeChild];
+      if (nativeChild) [children addObject:nativeChild];
     }
   }
 
-  return mChildren;
+  return children;
 
   NS_OBJC_END_TRY_ABORT_BLOCK_NIL;
 }
@@ -1267,26 +1280,6 @@ struct RoleDescrComparator {
   NS_OBJC_END_TRY_ABORT_BLOCK_NIL;
 }
 
-- (void)invalidateChildren {
-  NS_OBJC_BEGIN_TRY_ABORT_BLOCK;
-
-  // make room for new children
-  if (mChildren) {
-    [mChildren release];
-    mChildren = nil;
-  }
-
-  NS_OBJC_END_TRY_ABORT_BLOCK;
-}
-
-- (void)appendChild:(Accessible*)aAccessible {
-  // if mChildren is nil, then we don't even need to bother
-  if (!mChildren) return;
-
-  mozAccessible* curNative = GetNativeFromGeckoAccessible(aAccessible);
-  if (curNative) [mChildren addObject:curNative];
-}
-
 - (BOOL)accessibilityNotifiesWhenDestroyed {
   return YES;
 }
@@ -1294,8 +1287,6 @@ struct RoleDescrComparator {
 - (void)expire {
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK;
 
-  [self invalidateChildren];
-
   [self invalidateState];
 
   mGeckoAccessible = 0;