GLCallGroups.java

/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.ide.eclipse.gltrace.editors;

import com.android.ide.eclipse.gltrace.GLProtoBuf.GLMessage.Function;
import com.android.ide.eclipse.gltrace.model.GLCall;
import com.android.ide.eclipse.gltrace.model.GLTrace;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Stack;

public class GLCallGroups {
    /**
     * A {@link GLCallNode} is a simple wrapper around a {@link GLCall} that
     * adds the notion of hierarchy.
     */
    public interface GLCallNode {
        /** Does this call have child nodes? */
        boolean hasChildren();

        /** Returns a list of child nodes of this call. */
        List<GLCallNode> getChildren();

        /** Returns the {@link GLCall} that is wrapped by this node. */
        GLCall getCall();

        /** Returns the parent of this node, the parent is null if this is a top level node */
        GLCallNode getParent();

        /** Set the parent node. */
        void setParent(GLCallNode parent);
    }

    private static class GLTreeNode implements GLCallNode {
        private final GLCall mCall;
        private GLCallNode mParent;
        private List<GLCallNode> mGLCallNodes;

        public GLTreeNode(GLCall call) {
            mCall = call;
            mGLCallNodes = new ArrayList<GLCallNode>();
        }

        @Override
        public boolean hasChildren() {
            return true;
        }

        @Override
        public GLCallNode getParent() {
            return mParent;
        }

        @Override
        public void setParent(GLCallNode parent) {
            mParent = parent;
        }

        @Override
        public List<GLCallNode> getChildren() {
            return mGLCallNodes;
        }

        public void addChild(GLCallNode n) {
            mGLCallNodes.add(n);
            n.setParent(this);
        }

        @Override
        public GLCall getCall() {
            return mCall;
        }
    }

    private static class GLLeafNode implements GLCallNode {
        private final GLCall mCall;
        private GLCallNode mParent;

        public GLLeafNode(GLCall call) {
            mCall = call;
        }

        @Override
        public boolean hasChildren() {
            return false;
        }

        @Override
        public List<GLCallNode> getChildren() {
            return null;
        }

        @Override
        public GLCallNode getParent() {
            return mParent;
        }

        @Override
        public void setParent(GLCallNode parent) {
            mParent = parent;
        }

        @Override
        public GLCall getCall() {
            return mCall;
        }
    }

    /**
     * Impose a hierarchy on a list of {@link GLCall}'s based on the presence of
     * {@link Function#glPushGroupMarkerEXT} and {@link Function#glPopGroupMarkerEXT} calls.
     * Such a hierarchy is possible only if calls from a single context are considered.
     * @param trace trace to look at
     * @param start starting call index
     * @param end ending call index
     * @param contextToGroup context from which calls should be grouped. If no such context
     *        is present, then all calls in the given range will be returned back as a flat
     *        list.
     * @return a tree structured list of {@link GLCallNode} objects
     */
    public static List<GLCallNode> constructCallHierarchy(GLTrace trace, int start, int end,
            int contextToGroup) {
        if (trace == null) {
            return Collections.emptyList();
        }

        if (contextToGroup < 0 || contextToGroup > trace.getContexts().size()) {
            return flatHierarchy(trace, start, end);
        }

        List<GLCall> calls = trace.getGLCalls();

        Stack<GLTreeNode> hierarchyStack = new Stack<GLTreeNode>();
        List<GLCallNode> items = new ArrayList<GLCallNode>();

        for (int i = start; i < end; i++) {
            GLCall c = calls.get(i);
            if (c.getContextId() != contextToGroup) {
                // skip this call if it is not part of the context we need to display
                continue;
            }

            if (c.getFunction() == Function.glPushGroupMarkerEXT) {
                GLTreeNode group = new GLTreeNode(c);
                if (hierarchyStack.size() > 0) {
                    hierarchyStack.peek().addChild(group);
                } else {
                    items.add(group);
                }
                hierarchyStack.push(group);
            } else if (c.getFunction() == Function.glPopGroupMarkerEXT) {
                if (hierarchyStack.size() > 0) {
                    hierarchyStack.pop();
                } else {
                    // FIXME: If we are attempting to pop from an empty stack,
                    // that implies that a push marker was seen in a prior frame
                    // (in a call before @start). In such a case, we simply continue
                    // adding further calls to the root of the hierarchy rather than
                    // searching backwards in the call list for the corresponding
                    // push markers.
                    items.add(new GLLeafNode(c));
                }
            } else {
              GLLeafNode leaf = new GLLeafNode(c);
              if (hierarchyStack.size() > 0) {
                  hierarchyStack.peek().addChild(leaf);
              } else {
                  items.add(leaf);
              }
            }
        }

        return items;
    }

    private static List<GLCallNode> flatHierarchy(GLTrace trace, int start, int end) {
        List<GLCallNode> items = new ArrayList<GLCallNode>();

        List<GLCall> calls = trace.getGLCalls();
        for (int i = start; i < end; i++) {
            items.add(new GLLeafNode(calls.get(i)));
        }

        return items;
    }
}