ahat: limit default number of results shown.
Previously, ahat had performance issues rendering large pages. This
change causes ahat to limit the number results shown in large pages by
default, requiring the user to explicitly request more information if
they care about it.
Bug: 25114227
Change-Id: Ief67396be254be4c84e6971f5b903a701206e17b
diff --git a/tools/ahat/src/DominatedList.java b/tools/ahat/src/DominatedList.java
index 123d8be..34a5665 100644
--- a/tools/ahat/src/DominatedList.java
+++ b/tools/ahat/src/DominatedList.java
@@ -21,71 +21,35 @@
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
-import java.util.HashMap;
import java.util.List;
-import java.util.Map;
/**
* Class for rendering a list of instances dominated by a single instance in a
* pretty way.
*/
class DominatedList {
- private static final int kIncrAmount = 100;
- private static final int kDefaultShown = 100;
-
/**
* Render a table to the given HtmlWriter showing a pretty list of
* instances.
*
- * Rather than show all of the instances (which may be very many), we use
- * the query parameter "dominated" to specify a limited number of
- * instances to show. The 'uri' parameter should be the current page URI, so
- * that we can add links to "show more" and "show less" objects that go to
- * the same page with only the number of objects adjusted.
+ * @param snapshot the snapshot where the instances reside
+ * @param doc the document to render the dominated list to
+ * @param query the current page query
+ * @param id a unique identifier to use for the dominated list in the current page
+ * @param instances the collection of instances to generate a list for
*/
- public static void render(final AhatSnapshot snapshot, Doc doc,
- Collection<Instance> instances, Query query) {
+ public static void render(final AhatSnapshot snapshot,
+ Doc doc, Query query, String id, Collection<Instance> instances) {
List<Instance> insts = new ArrayList<Instance>(instances);
Collections.sort(insts, Sort.defaultInstanceCompare(snapshot));
-
- int numInstancesToShow = getNumInstancesToShow(query, insts.size());
- List<Instance> shown = new ArrayList<Instance>(insts.subList(0, numInstancesToShow));
- List<Instance> hidden = insts.subList(numInstancesToShow, insts.size());
-
- // Add 'null' as a marker for "all the rest of the objects".
- if (!hidden.isEmpty()) {
- shown.add(null);
- }
- HeapTable.render(doc, new TableConfig(snapshot, hidden), snapshot, shown);
-
- if (insts.size() > kDefaultShown) {
- printMenu(doc, query, numInstancesToShow, insts.size());
- }
+ HeapTable.render(doc, query, id, new TableConfig(snapshot), snapshot, insts);
}
private static class TableConfig implements HeapTable.TableConfig<Instance> {
AhatSnapshot mSnapshot;
- // Map from heap name to the total size of the instances not shown in the
- // table.
- Map<Heap, Long> mHiddenSizes;
-
- public TableConfig(AhatSnapshot snapshot, List<Instance> hidden) {
+ public TableConfig(AhatSnapshot snapshot) {
mSnapshot = snapshot;
- mHiddenSizes = new HashMap<Heap, Long>();
- for (Heap heap : snapshot.getHeaps()) {
- mHiddenSizes.put(heap, 0L);
- }
-
- if (!hidden.isEmpty()) {
- for (Instance inst : hidden) {
- for (Heap heap : snapshot.getHeaps()) {
- int index = snapshot.getHeapIndex(heap);
- long size = inst.getRetainedSize(index);
- mHiddenSizes.put(heap, mHiddenSizes.get(heap) + size);
- }
- }
- }
}
@Override
@@ -95,9 +59,6 @@
@Override
public long getSize(Instance element, Heap heap) {
- if (element == null) {
- return mHiddenSizes.get(heap);
- }
int index = mSnapshot.getHeapIndex(heap);
return element.getRetainedSize(index);
}
@@ -110,56 +71,10 @@
}
public DocString render(Instance element) {
- if (element == null) {
- return DocString.text("...");
- } else {
- return Value.render(element);
- }
+ return Value.render(element);
}
};
return Collections.singletonList(value);
}
}
-
- // Figure out how many objects to show based on the query parameter.
- // The resulting value is guaranteed to be at least zero, and no greater
- // than the number of total objects.
- private static int getNumInstancesToShow(Query query, int totalNumInstances) {
- String value = query.get("dominated", null);
- try {
- int count = Math.min(totalNumInstances, Integer.parseInt(value));
- return Math.max(0, count);
- } catch (NumberFormatException e) {
- // We can't parse the value as a number. Ignore it.
- }
- return Math.min(kDefaultShown, totalNumInstances);
- }
-
- // Print a menu line after the table to control how many objects are shown.
- // It has the form:
- // (showing X of Y objects - show none - show less - show more - show all)
- private static void printMenu(Doc doc, Query query, int shown, int all) {
- DocString menu = new DocString();
- menu.appendFormat("(%d of %d objects shown - ", shown, all);
- if (shown > 0) {
- int less = Math.max(0, shown - kIncrAmount);
- menu.appendLink(query.with("dominated", 0), DocString.text("show none"));
- menu.append(" - ");
- menu.appendLink(query.with("dominated", less), DocString.text("show less"));
- menu.append(" - ");
- } else {
- menu.append("show none - show less - ");
- }
- if (shown < all) {
- int more = Math.min(shown + kIncrAmount, all);
- menu.appendLink(query.with("dominated", more), DocString.text("show more"));
- menu.append(" - ");
- menu.appendLink(query.with("dominated", all), DocString.text("show all"));
- menu.append(")");
- } else {
- menu.append("show more - show all)");
- }
- doc.println(menu);
- }
}
-