/*
 * Copyright (c) 2015, 2015, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package com.oracle.graal.replacements;

import java.util.*;

import com.oracle.graal.api.code.*;
import com.oracle.graal.api.meta.*;
import com.oracle.graal.graphbuilderconf.*;
import com.oracle.graal.java.*;
import com.oracle.graal.nodes.*;
import com.oracle.graal.nodes.StructuredGraph.AllowAssumptions;
import com.oracle.graal.phases.*;
import com.oracle.graal.phases.common.*;
import com.oracle.graal.phases.tiers.*;
import com.oracle.graal.phases.util.*;
import com.oracle.jvmci.debug.*;

/**
 * A graph decoder that provides all necessary encoded graphs on-the-fly (by parsing the methods and
 * encoding the graphs).
 */
public class CachingPEGraphDecoder extends PEGraphDecoder {

    private final Providers providers;
    private final GraphBuilderConfiguration graphBuilderConfig;
    private final OptimisticOptimizations optimisticOpts;
    private final AllowAssumptions allowAssumptions;
    private final Map<ResolvedJavaMethod, EncodedGraph> graphCache;

    public CachingPEGraphDecoder(Providers providers, GraphBuilderConfiguration graphBuilderConfig, OptimisticOptimizations optimisticOpts, AllowAssumptions allowAssumptions, Architecture architecture) {
        super(providers.getMetaAccess(), providers.getConstantReflection(), providers.getStampProvider(), architecture);

        this.providers = providers;
        this.graphBuilderConfig = graphBuilderConfig;
        this.optimisticOpts = optimisticOpts;
        this.allowAssumptions = allowAssumptions;
        this.graphCache = new HashMap<>();
    }

    private EncodedGraph createGraph(ResolvedJavaMethod method) {
        StructuredGraph graph = new StructuredGraph(method, allowAssumptions);
        try (Debug.Scope scope = Debug.scope("createGraph", graph)) {

            new GraphBuilderPhase.Instance(providers.getMetaAccess(), providers.getStampProvider(), providers.getConstantReflection(), graphBuilderConfig, optimisticOpts, null).apply(graph);

            PhaseContext context = new PhaseContext(providers);
            new CanonicalizerPhase().apply(graph, context);

            EncodedGraph encodedGraph = GraphEncoder.encodeSingleGraph(graph, architecture);
            graphCache.put(method, encodedGraph);
            return encodedGraph;

        } catch (Throwable ex) {
            throw Debug.handle(ex);
        }
    }

    @Override
    protected EncodedGraph lookupEncodedGraph(ResolvedJavaMethod method) {
        EncodedGraph result = graphCache.get(method);
        if (result == null && method.hasBytecodes()) {
            result = createGraph(method);
        }
        return result;
    }
}