RequestDispatchEndPointAnalyzer.java

/**
 * Copyright (c) 2009-2011 VMware, Inc. All Rights Reserved.
 *
 * 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.springsource.insight.plugin.servlet;

import com.springsource.insight.intercept.endpoint.AbstractSingleTypeEndpointAnalyzer;
import com.springsource.insight.intercept.endpoint.EndPointAnalysis;
import com.springsource.insight.intercept.endpoint.EndPointName;
import com.springsource.insight.intercept.operation.Operation;
import com.springsource.insight.intercept.operation.OperationType;
import com.springsource.insight.intercept.trace.Frame;
import com.springsource.insight.intercept.trace.Trace;

public class RequestDispatchEndPointAnalyzer extends AbstractSingleTypeEndpointAnalyzer {
    /**
     * The <U>static</U> score value assigned to endpoints - <B>Note:</B>
     * we return a score of {@link EndPointAnalysis#TOP_LAYER_SCORE} so as
     * to let other endpoints "beat" this one
     */
    public static final int DEFAULT_SCORE = EndPointAnalysis.TOP_LAYER_SCORE;
    private static final RequestDispatchEndPointAnalyzer INSTANCE = new RequestDispatchEndPointAnalyzer();

    private RequestDispatchEndPointAnalyzer() {
        super(OperationType.REQUEST_DISPATCH);
    }

    public static final RequestDispatchEndPointAnalyzer getInstance() {
        return INSTANCE;
    }

    @Override
    public Frame getScoringFrame(Trace trace) {
        Frame frame = super.getScoringFrame(trace);
        if (frame == null) {
            return frame;
        }

        if (validateScoringFrame(frame) == null) {
            return null;
        } else {
            return frame;
        }
    }

    @Override
    protected int getDefaultScore(int depth) {
        return DEFAULT_SCORE;
    }

    @Override
    protected OperationType validateScoringFrame(Frame frame) {
        OperationType type = super.validateScoringFrame(frame);
        if (type == null) {
            return null;
        }

        Operation op = frame.getOperation();
        Boolean fromValue = op.get("from", Boolean.class);
        if ((fromValue == null) || (!fromValue.booleanValue())) {
            return null;
        }

        return type;
    }

    @Override
    protected EndPointAnalysis makeEndPoint(Frame dispatchFrame, int depth) {
        Operation op = dispatchFrame.getOperation();
        String label = op.getLabel();
        EndPointName name = EndPointName.valueOf(label.replace('/', '_'));
        return new EndPointAnalysis(name, label, label, getOperationScore(op, depth), op);
    }
}