HK2BindTracingService.java

/*
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 *
 * Copyright (c) 2012 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
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 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
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 * GPL Classpath Exception:
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package org.glassfish.common.util.admin;

import java.util.StringTokenizer;

import javax.inject.Singleton;

import org.glassfish.hk2.api.ActiveDescriptor;
import org.glassfish.hk2.api.Descriptor;
import org.glassfish.hk2.api.Filter;
import org.glassfish.hk2.api.ValidationInformation;
import org.glassfish.hk2.api.ValidationService;
import org.glassfish.hk2.api.Validator;
import org.glassfish.hk2.utilities.BuilderHelper;
import org.jvnet.hk2.annotations.Service;

/**
 * This file is used to turn on HK2 bind and unbind tracing
 * 
 * @author jwells
 *
 */
@Service
@Singleton
public class HK2BindTracingService implements ValidationService {
    private final static Filter ALL_FILTER = BuilderHelper.allFilter();
    private final static Filter NONE_FILTER = new Filter() {

        @Override
        public boolean matches(Descriptor d) {
            return false;
        }
        
    };
    private final static boolean TRACE_BINDS = Boolean.parseBoolean(
            System.getProperty("org.glassfish.hk2.tracing.binds", "false"));
    private final static String TRACE_BINDS_PATTERN =
            System.getProperty("org.glassfish.hk2.tracing.bindsPattern");
    private final static boolean TRACE_LOOKUPS = Boolean.parseBoolean(
            System.getProperty("org.glassfish.hk2.tracing.lookups", "false"));
    private final static String TRACE_LOOKUPS_PATTERN =
            System.getProperty("org.glassfish.hk2.tracing.lookupsPattern");
    
    private final static String STACK_PATTERN =
            System.getProperty("org.glassfish.hk2.tracing.binds.stackPattern");
    
    private final static Validator VALIDATOR = new ValidatorImpl();

    /* (non-Javadoc)
     * @see org.glassfish.hk2.api.ValidationService#getLookupFilter()
     */
    @Override
    public Filter getLookupFilter() {
        if (TRACE_LOOKUPS == true) return ALL_FILTER;
        
        return NONE_FILTER;
    }

    /* (non-Javadoc)
     * @see org.glassfish.hk2.api.ValidationService#getValidator()
     */
    @Override
    public Validator getValidator() {
        return VALIDATOR;
    }
    
    private static boolean matchesPattern(String pattern, ActiveDescriptor<?> descriptor) {
        if (pattern == null) return true;
        
        StringTokenizer st = new StringTokenizer(pattern, "|");
        
        while (st.hasMoreTokens()) {
            String token = st.nextToken();
            
            if (descriptor.getImplementation().contains(token)) {
                return true;
            }
            
            for (String contract : descriptor.getAdvertisedContracts()) {
                if (contract.contains(token)) {
                    return true;
                }
            }
        }
        
        return false;        
    }
    
    private static class ValidatorImpl implements Validator {

        /* (non-Javadoc)
         * @see org.glassfish.hk2.api.Validator#validate(org.glassfish.hk2.api.ValidationInformation)
         */
        @Override
        public boolean validate(ValidationInformation info) {
            if (!TRACE_BINDS && !TRACE_LOOKUPS) return true;
            
            switch (info.getOperation()) {
            case BIND:
                if (TRACE_BINDS && matchesPattern(TRACE_BINDS_PATTERN, info.getCandidate())) {
                    System.out.println("HK2 Tracing (BIND): " + info.getCandidate());
                }
                break;
            case UNBIND:
                if (TRACE_BINDS && matchesPattern(TRACE_BINDS_PATTERN, info.getCandidate())) {
                    System.out.println("HK2 Tracing (UNBIND): " + info.getCandidate());
                }
                break;
            case LOOKUP:
                if (TRACE_LOOKUPS && matchesPattern(TRACE_LOOKUPS_PATTERN, info.getCandidate())) {
                    System.out.println("HK2 Tracing (LOOKUP) Candidate: " + info.getCandidate());
                    if (info.getInjectee() != null) {
                        System.out.println("HK2 Tracing (LOOKUP) Injectee: " + info.getInjectee());
                    }
                }
                break;
            default:
                // Do nothing
                    
            }
            
            if ((STACK_PATTERN != null) && matchesPattern(STACK_PATTERN, info.getCandidate())) {
                Thread.dumpStack();
            }
            
            return true;
        }
        
    }

}