* CircularBuffer is now save to use even if the buffer allocation failed. This

fixes bug #3985.
* This happened as ViewHistory::Update() can obviously be called before the
  view is really layouted. Therefore it now restricts the view size to 16384.
* Since the Update() happens in Draw(), it looks like this is actually a problem
  of our layout engine (as the size is computed via BView::Frame()).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30967 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/apps/activitymonitor/ActivityView.cpp

@@ -225,6 +225,11 @@ void
 ViewHistory::Update(DataHistory* history, int32 width, int32 resolution,
 	bigtime_t toTime, bigtime_t step, bigtime_t refresh)
 {
+	if (width > 16384) {
+		// ignore this - it seems the view hasn't been layouted yet
+		return;
+	}
+
 	// Check if we need to invalidate the existing values
 	if ((int32)fValues.Size() != width
 		|| fResolution != resolution

src/apps/activitymonitor/CircularBuffer.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008, Axel Dörfler, [email protected]. All rights reserved.
+ * Copyright 2008-2009, Axel Dörfler, [email protected].
  * Distributed under the terms of the MIT License.
  */
 #ifndef CIRCULAR_BUFFER_H
@@ -40,7 +40,12 @@ public:
 
 		fSize = size;
 		fBuffer = (Type*)malloc(fSize * sizeof(Type));
-		return fBuffer != NULL ? B_OK : B_NO_MEMORY;
+		if (fBuffer == NULL) {
+			fSize = 0;
+			return B_NO_MEMORY;
+		}
+
+		return B_OK;
 	}
 
 	void MakeEmpty()
@@ -61,7 +66,7 @@ public:
 
 	Type* ItemAt(int32 index) const
 	{
-		if (index >= (int32)fIn || index < 0)
+		if (index >= (int32)fIn || index < 0 || fBuffer == NULL)
 			return NULL;
 
 		return &fBuffer[(fFirst + index) % fSize];
@@ -75,7 +80,8 @@ public:
 		else
 			index = fFirst++;
 
-		fBuffer[index % fSize] = item;
+		if (fBuffer != NULL)
+			fBuffer[index % fSize] = item;
 	}
 
 	size_t Size() const