BEGIN LICENSE BLOCK *****
Version: EPL 2.0/GPL 2.0/LGPL 2.1
The contents of this file are subject to the Eclipse Public
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.eclipse.org/legal/epl-v20.html
Software distributed under the License is distributed on an "AS
IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
implied. See the License for the specific language governing
rights and limitations under the License.
Copyright (C) 2001-2004 Jan Arne Petersen 
Copyright (C) 2002 Benoit Cerrina 
Copyright (C) 2002-2004 Anders Bengtsson 
Copyright (C) 2004 Thomas E Enebo 
Copyright (C) 2004 Stefan Matthias Aust 
Copyright (C) 2005 Charles O Nutter 
Copyright (C) 2007 William N Dortch 
Alternatively, the contents of this file may be used under the terms of
either of the GNU General Public License Version 2 or later (the "GPL"),
or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
in which case the provisions of the GPL or the LGPL are applicable instead
of those above. If you wish to allow use of your version of this file only
under the terms of either the GPL or the LGPL, and not to allow others to
use your version of this file under the terms of the EPL, indicate your
decision by deleting the provisions above and replace them with the notice
and other provisions required by the GPL or the LGPL. If you do not delete
the provisions above, a recipient may use your version of this file under
the terms of any one of the EPL, the GPL or the LGPL.
END LICENSE BLOCK /***** BEGIN LICENSE BLOCK *****
 * Version: EPL 2.0/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Eclipse Public
 * 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.eclipse.org/legal/epl-v20.html
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * Copyright (C) 2001-2004 Jan Arne Petersen <jpetersen@uni-bonn.de>
 * Copyright (C) 2002 Benoit Cerrina <b.cerrina@wanadoo.fr>
 * Copyright (C) 2002-2004 Anders Bengtsson <ndrsbngtssn@yahoo.se>
 * Copyright (C) 2004 Thomas E Enebo <enebo@acm.org>
 * Copyright (C) 2004 Stefan Matthias Aust <sma@3plus4.de>
 * Copyright (C) 2005 Charles O Nutter <headius@headius.com>
 * Copyright (C) 2007 William N Dortch <bill.dortch@gmail.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the EPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the EPL, the GPL or the LGPL.
 ***** END LICENSE BLOCK *****/

package org.jruby.javasupport;

import java.lang.reflect.Member;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.locks.ReentrantLock;

import org.jruby.Ruby;
import org.jruby.RubyClass;
import org.jruby.RubyModule;
import org.jruby.exceptions.RaiseException;
import org.jruby.exceptions.Unrescuable;
import org.jruby.javasupport.ext.JavaExtensions;
import org.jruby.runtime.Helpers;
import org.jruby.util.ArraySupport;
import org.jruby.util.Loader;
import org.jruby.util.collections.ClassValue;
import org.jruby.javasupport.binding.AssignedName;
import org.jruby.javasupport.proxy.JavaProxyClass;
import org.jruby.javasupport.util.ObjectProxyCache;
import org.jruby.runtime.builtin.IRubyObject;
import org.jruby.util.WeakIdentityHashMap;
import org.jruby.util.collections.ClassValueCalculator;

public class JavaSupportImpl extends JavaSupport {
    private final Ruby runtime;

    private final ObjectProxyCache<IRubyObject,RubyClass> objectProxyCache =
            // TODO: specifying soft refs, may want to compare memory consumption,
            // behavior with weak refs (specify WEAK in place of SOFT below)
            new ObjectProxyCache<IRubyObject,RubyClass>(ObjectProxyCache.ReferenceType.WEAK) {

                public IRubyObject allocateProxy(Object javaObject, RubyClass clazz) {
                    return Java.allocateProxy(javaObject, clazz);
                }
            };

    private final ClassValue<JavaClass> javaClassCache;
    private final ClassValue<RubyModule> proxyClassCache;
    private static final class UnfinishedProxy extends ReentrantLock {
        volatile RubyModule proxy;
        UnfinishedProxy(RubyModule proxy) {
            this.proxy = proxy;
        }
    }
    private final Map<Class, UnfinishedProxy> unfinishedProxies;
    private final ClassValue<Map<String, AssignedName>> staticAssignedNames;
    private final ClassValue<Map<String, AssignedName>> instanceAssignedNames;

    private RubyModule javaModule;
    private RubyModule javaUtilitiesModule;
    private RubyModule javaArrayUtilitiesModule;
    private RubyClass javaObjectClass;
    private JavaClass objectJavaClass;
    private RubyClass javaClassClass;
    private RubyClass javaPackageClass;
    private RubyClass javaArrayClass;
    private RubyClass javaProxyClass;
    private RubyClass arrayJavaProxyCreatorClass;
    private RubyClass javaFieldClass;
    private RubyClass javaMethodClass;
    private RubyClass javaConstructorClass;
    private RubyModule javaInterfaceTemplate;
    private RubyClass arrayProxyClass;
    private RubyClass concreteProxyClass;
    private RubyClass mapJavaProxy;
    private RubyClass javaProxyConstructorClass;

    private final Map<String, JavaClass> nameClassMap = new HashMap<String, JavaClass>(64);

    public JavaSupportImpl(final Ruby runtime) {
        this.runtime = runtime;

        this.javaClassCache = ClassValue.newInstance(new ClassValueCalculator<JavaClass>() {
            @Override
            public JavaClass computeValue(Class<?> klass) {
                return new JavaClass(runtime, getJavaClassClass(), klass);
            }
        });

        this.proxyClassCache = ClassValue.newInstance(new ClassValueCalculator<RubyModule>() {
            
Because of the complexity of processing a given class and all its dependencies,
we opt to synchronize this logic. Creation of all proxies goes through here,
allowing us to skip some threading work downstream.
/**
             * Because of the complexity of processing a given class and all its dependencies,
             * we opt to synchronize this logic. Creation of all proxies goes through here,
             * allowing us to skip some threading work downstream.
             */
            @Override
            public synchronized RubyModule computeValue(Class<?> klass) {
                RubyModule proxyKlass = Java.createProxyClassForClass(runtime, klass);
                JavaExtensions.define(runtime, klass, proxyKlass); // (lazy) load extensions
                return proxyKlass;
            }
        });

        this.staticAssignedNames = ClassValue.newInstance(new ClassValueCalculator<Map<String, AssignedName>>() {
            @Override
            public Map<String, AssignedName> computeValue(Class<?> cls) { return new HashMap<>(); }
        });
        this.instanceAssignedNames = ClassValue.newInstance(new ClassValueCalculator<Map<String, AssignedName>>() {
            @Override
            public Map<String, AssignedName> computeValue(Class<?> cls) { return new HashMap<>(); }
        });

        // Proxy creation is synchronized (see above) so a HashMap is fine for recursion detection.
        this.unfinishedProxies = new ConcurrentHashMap<>(8, 0.75f, 1);
    }

    public Class loadJavaClass(String className) throws ClassNotFoundException {
        Class<?> primitiveClass;
        if ((primitiveClass = JavaUtil.getPrimitiveClass(className)) == null) {
            if (!Ruby.isSecurityRestricted()) {
                for(Loader loader : runtime.getInstanceConfig().getExtraLoaders()) {
                    try {
                        return loader.loadClass(className);
                    }
                    catch(ClassNotFoundException ignored) {
                    }
                }
                return Class.forName(className, true, runtime.getJRubyClassLoader());
            }
            return Class.forName(className);
        }
        return primitiveClass;
    }

    public Class loadJavaClassVerbose(String className) {
        try {
            return loadJavaClass(className);
        } catch (ClassNotFoundException ex) {
            throw initCause(runtime.newNameError("cannot load Java class " + className, className, ex), ex);
        } catch (ExceptionInInitializerError ex) {
            throw initCause(runtime.newNameError("cannot initialize Java class " + className, className, ex), ex);
        } catch (LinkageError ex) {
            throw initCause(runtime.newNameError("cannot link Java class " + className + ", probable missing dependency: " + ex.getLocalizedMessage(), className, ex), ex);
        } catch (SecurityException ex) {
            if (runtime.isVerbose()) ex.printStackTrace(runtime.getErrorStream());
            throw initCause(runtime.newSecurityError(ex.getLocalizedMessage()), ex);
        }
    }

    public Class loadJavaClassQuiet(String className) {
        try {
            return loadJavaClass(className);
        } catch (ClassNotFoundException ex) {
            throw initCause(runtime.newNameError("cannot load Java class " + className, className, ex, false), ex);
        } catch (ExceptionInInitializerError ex) {
            throw initCause(runtime.newNameError("cannot initialize Java class " + className, className, ex, false), ex);
        } catch (LinkageError ex) {
            throw initCause(runtime.newNameError("cannot link Java class " + className, className, ex, false), ex);
        } catch (SecurityException ex) {
            throw initCause(runtime.newSecurityError(ex.getLocalizedMessage()), ex);
        }
    }

    private static RaiseException initCause(final RaiseException ex, final Throwable cause) {
        ex.initCause(cause); return ex;
    }

    public JavaClass getJavaClassFromCache(Class clazz) {
        return javaClassCache.get(clazz);
    }

    public RubyModule getProxyClassFromCache(Class clazz) {
        return proxyClassCache.get(clazz);
    }

    public void handleNativeException(Throwable exception, Member target) {
        if ( exception instanceof RaiseException ) {
            // allow RaiseExceptions to propagate
            throw (RaiseException) exception;
        }
        if (exception instanceof Unrescuable) {
            // allow "unrescuable" flow-control exceptions to propagate
            if ( exception instanceof Error ) {
                throw (Error) exception;
            }
            if ( exception instanceof RuntimeException ) {
                throw (RuntimeException) exception;
            }
        }
        // rethrow original
        Helpers.throwException(exception);
    }

    public ObjectProxyCache<IRubyObject,RubyClass> getObjectProxyCache() {
        return objectProxyCache;
    }

    // not synchronizing these methods, no harm if these values get set more
    // than once.
    // (also note that there's no chance of getting a partially initialized
    // class/module, as happens-before is guaranteed by volatile write/read
    // of constants table.)

    public Map<String, JavaClass> getNameClassMap() {
        return nameClassMap;
    }

    public RubyModule getJavaModule() {
        RubyModule module;
        if ((module = javaModule) != null) return module;
        return javaModule = runtime.getModule("Java");
    }

    public RubyModule getJavaUtilitiesModule() {
        RubyModule module;
        if ((module = javaUtilitiesModule) != null) return module;
        return javaUtilitiesModule = runtime.getModule("JavaUtilities");
    }

    public RubyModule getJavaArrayUtilitiesModule() {
        RubyModule module;
        if ((module = javaArrayUtilitiesModule) != null) return module;
        return javaArrayUtilitiesModule = runtime.getModule("JavaArrayUtilities");
    }

    public RubyClass getJavaObjectClass() {
        RubyClass clazz;
        if ((clazz = javaObjectClass) != null) return clazz;
        return javaObjectClass = getJavaModule().getClass("JavaObject");
    }

    public RubyClass getJavaProxyConstructorClass() {
        RubyClass clazz;
        if ((clazz = javaProxyConstructorClass) != null) return clazz;
        return javaProxyConstructorClass = getJavaModule().getClass("JavaProxyConstructor");
    }

    public JavaClass getObjectJavaClass() {
        return objectJavaClass;
    }

    public void setObjectJavaClass(JavaClass objectJavaClass) {
        this.objectJavaClass = objectJavaClass;
    }

    public RubyClass getJavaArrayClass() {
        RubyClass clazz;
        if ((clazz = javaArrayClass) != null) return clazz;
        return javaArrayClass = getJavaModule().getClass("JavaArray");
    }

    public RubyClass getJavaClassClass() {
        RubyClass clazz;
        if ((clazz = javaClassClass) != null) return clazz;
        return javaClassClass = getJavaModule().getClass("JavaClass");
    }

    public RubyClass getJavaPackageClass() {
        RubyClass clazz;
        if ((clazz = javaPackageClass) != null) return clazz;
        return javaPackageClass = getJavaModule().getClass("JavaPackage");
    }

    public RubyModule getJavaInterfaceTemplate() {
        RubyModule module;
        if ((module = javaInterfaceTemplate) != null) return module;
        return javaInterfaceTemplate = runtime.getModule("JavaInterfaceTemplate");
    }

    @Deprecated
    public RubyModule getPackageModuleTemplate() {
        return null; // no longer used + has been deprecated since ~ 9.1
    }

    public RubyClass getJavaProxyClass() {
        RubyClass clazz;
        if ((clazz = javaProxyClass) != null) return clazz;
        return javaProxyClass = runtime.getClass("JavaProxy");
    }

    public RubyClass getArrayJavaProxyCreatorClass() {
        RubyClass clazz;
        if ((clazz = arrayJavaProxyCreatorClass) != null) return clazz;
        return arrayJavaProxyCreatorClass = runtime.getClass("ArrayJavaProxyCreator");
    }

    public RubyClass getConcreteProxyClass() {
        RubyClass clazz;
        if ((clazz = concreteProxyClass) != null) return clazz;
        return concreteProxyClass = runtime.getClass("ConcreteJavaProxy");
    }

    public RubyClass getMapJavaProxyClass() {
        RubyClass clazz;
        if ((clazz = mapJavaProxy) != null) return clazz;
        return mapJavaProxy = runtime.getClass("MapJavaProxy");
    }

    public RubyClass getArrayProxyClass() {
        RubyClass clazz;
        if ((clazz = arrayProxyClass) != null) return clazz;
        return arrayProxyClass = runtime.getClass("ArrayJavaProxy");
    }

    public RubyClass getJavaFieldClass() {
        RubyClass clazz;
        if ((clazz = javaFieldClass) != null) return clazz;
        return javaFieldClass = getJavaModule().getClass("JavaField");
    }

    public RubyClass getJavaMethodClass() {
        RubyClass clazz;
        if ((clazz = javaMethodClass) != null) return clazz;
        return javaMethodClass = getJavaModule().getClass("JavaMethod");
    }

    public RubyClass getJavaConstructorClass() {
        RubyClass clazz;
        if ((clazz = javaConstructorClass) != null) return clazz;
        return javaConstructorClass = getJavaModule().getClass("JavaConstructor");
    }

    public ClassValue<Map<String, AssignedName>> getStaticAssignedNames() {
        return staticAssignedNames;
    }

    public ClassValue<Map<String, AssignedName>> getInstanceAssignedNames() {
        return instanceAssignedNames;
    }

    @Deprecated
    @Override
    public final void beginProxy(Class cls, RubyModule proxy) {
        UnfinishedProxy up = new UnfinishedProxy(proxy);
        up.lock();
        unfinishedProxies.put(cls, up);
    }

    @Deprecated
    @Override
    public final void endProxy(Class cls) {
        UnfinishedProxy up = unfinishedProxies.remove(cls);
        up.unlock();
    }

    @Deprecated
    @Override
    public final RubyModule getUnfinishedProxy(Class cls) {
        UnfinishedProxy up = unfinishedProxies.get(cls);
        if (up != null && up.isHeldByCurrentThread()) return up.proxy;
        return null;
    }

    @Deprecated
    public Map<Set<?>, JavaProxyClass> getJavaProxyClassCache() {
        Map<Set<?>, JavaProxyClass> javaProxyClassCache = new HashMap<>(javaProxyClasses.size());
        synchronized (javaProxyClasses) {
            for ( Map.Entry<ProxyClassKey, JavaProxyClass> entry : javaProxyClasses.entrySet() ) {
                final ProxyClassKey key = entry.getKey();
                final Set<Object> cacheKey = new HashSet<>();
                cacheKey.add(key.superClass);
                for (int i = 0; i < key.interfaces.length; i++) {
                    cacheKey.add(key.interfaces[i]);
                }
                // add (potentially) overridden names to the key.
                if ( ! key.names.isEmpty() ) cacheKey.addAll(key.names);

                javaProxyClassCache.put(cacheKey, entry.getValue());
            }
        }

        return Collections.unmodifiableMap(javaProxyClassCache);
    }

    // cache of all JavaProxyClass objects created for this runtime
    private final Map<ProxyClassKey, JavaProxyClass> javaProxyClasses = new HashMap<>();

    @Override
    final protected JavaProxyClass fetchJavaProxyClass(ProxyClassKey classKey) {
        synchronized (javaProxyClasses) {
            return javaProxyClasses.get(classKey);
        }
    }

    @Override
    final protected JavaProxyClass saveJavaProxyClass(ProxyClassKey classKey, JavaProxyClass klass) {
        synchronized (javaProxyClasses) {
            JavaProxyClass existing = javaProxyClasses.get(classKey);
            if ( existing != null ) return existing;
            javaProxyClasses.put(classKey, klass);
        }
        return klass;
    }

    // internal helper to access non-public fetch method
    public static JavaProxyClass fetchJavaProxyClass(final Ruby runtime, ProxyClassKey classKey) {
        return runtime.getJavaSupport().fetchJavaProxyClass(classKey);
    }

    // internal helper to access non-public save method
    public static JavaProxyClass saveJavaProxyClass(final Ruby runtime, ProxyClassKey classKey, JavaProxyClass klass) {
        return runtime.getJavaSupport().saveJavaProxyClass(classKey, klass);
    }

    @Deprecated
    private volatile Map<Object, Object[]> javaObjectVariables;

    @Deprecated
    public Object getJavaObjectVariable(Object o, int i) {
        if (i == -1) return null;

        Map<Object, Object[]> variables = javaObjectVariables;
        if (variables == null) return null;

        synchronized (this) {
            Object[] vars = variables.get(o);
            if (vars == null || vars.length <= i) return null;
            return vars[i];
        }
    }

    @Deprecated
    public void setJavaObjectVariable(Object o, int i, Object v) {
        if (i == -1) return;

        synchronized (this) {
            Map<Object, Object[]> variables = javaObjectVariables;

            if (variables == null) {
                variables = javaObjectVariables = new WeakIdentityHashMap();
            }

            Object[] vars = variables.get(o);
            if (vars == null) {
                vars = new Object[i + 1];
                variables.put(o, vars);
            }
            else if (vars.length <= i) {
                vars = ArraySupport.newCopy(vars, i + 1);
                variables.put(o, vars);
            }
            vars[i] = v;
        }
    }

}