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 * Copyright (c) 2010, 2013, 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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

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package jdk.nashorn.internal.codegen;

import static jdk.nashorn.internal.codegen.CompilerConstants.ARGUMENTS;

import static jdk.nashorn.internal.codegen.CompilerConstants.constructorNoLookup;

import static jdk.nashorn.internal.codegen.CompilerConstants.typeDescriptor;

import static jdk.nashorn.internal.codegen.ObjectClassGenerator.PRIMITIVE_FIELD_TYPE;

import static jdk.nashorn.internal.codegen.ObjectClassGenerator.getFieldName;

import static jdk.nashorn.internal.codegen.ObjectClassGenerator.getPaddedFieldCount;

import static jdk.nashorn.internal.runtime.arrays.ArrayIndex.getArrayIndex;

import static jdk.nashorn.internal.runtime.arrays.ArrayIndex.isValidArrayIndex;

import java.util.List;

import jdk.nashorn.internal.codegen.types.Type;

import jdk.nashorn.internal.ir.Symbol;

import jdk.nashorn.internal.runtime.Context;

import jdk.nashorn.internal.runtime.JSType;

import jdk.nashorn.internal.runtime.PropertyMap;

import jdk.nashorn.internal.runtime.ScriptObject;

import jdk.nashorn.internal.runtime.arrays.ArrayIndex;

/**

 * Analyze an object's characteristics for appropriate code generation. This

 * is used for functions and for objects. A field object take a set of values which

 * to assign to the various fields in the object. This is done by the generated code

 *

 * @param <T> the value type for the fields being written on object creation, e.g. Node

 * @see jdk.nashorn.internal.ir.Node

 */

public abstract class FieldObjectCreator<T> extends ObjectCreator<T> {

    private String                        fieldObjectClassName;

    private Class<? extends ScriptObject> fieldObjectClass;

    private int                           fieldCount;

    private int                           paddedFieldCount;

    private int                           paramCount;

    /** call site flags to be used for invocations */

    private final int callSiteFlags;

    /** are we creating this field object from 'eval' code? */

    private final boolean evalCode;

    /**

     * Constructor

     *

     * @param codegen  code generator

     * @param tuples   tuples for fields in object

     */

    FieldObjectCreator(final CodeGenerator codegen, final List<MapTuple<T>> tuples) {

        this(codegen, tuples, false, false);

    }

    /**

     * Constructor

     *

     * @param codegen      code generator

     * @param tuples       tuples for fields in object

     * @param isScope      is this a scope object

     * @param hasArguments does the created object have an "arguments" property

     */

    FieldObjectCreator(final CodeGenerator codegen, final List<MapTuple<T>> tuples, final boolean isScope, final boolean hasArguments) {

        super(codegen, tuples, isScope, hasArguments);

        this.callSiteFlags = codegen.getCallSiteFlags();

        this.evalCode = codegen.isEvalCode();

        countFields();

        findClass();

    }

    @Override

        makeMap();

        final String className = getClassName();

        loadMap(method); //load the map

        if (isScope()) {

            loadScope(method);

            if (hasArguments()) {

                method.loadCompilerConstant(ARGUMENTS);

                method.invoke(constructorNoLookup(className, PropertyMap.class, ScriptObject.class, ARGUMENTS.type()));

            } else {

                method.invoke(constructorNoLookup(className, PropertyMap.class, ScriptObject.class));

            }

        } else {

            method.invoke(constructorNoLookup(className, PropertyMap.class));

        }

        // Set values.

            //we only load when we have both symbols and values (which can be == the symbol)

            //if we didn't load, we need an array property

            if (tuple.symbol != null && tuple.value != null) {

                final int index = getArrayIndex(tuple.key);

                method.dup();

                if (!isValidArrayIndex(index)) {

                    putField(method, tuple.key, tuple.symbol.getFieldIndex(), tuple);

                } else {

                    putSlot(method, ArrayIndex.toLongIndex(index), tuple);

                }

                //this is a nop of tuple.key isn't e.g. "apply" or another special name

                method.invalidateSpecialName(tuple.key);

            }

        }

    }

    @Override

    protected PropertyMap makeMap() {

        assert propertyMap == null : "property map already initialized";

        propertyMap = newMapCreator(fieldObjectClass).makeFieldMap(hasArguments(), codegen.useDualFields(), fieldCount, paddedFieldCount, evalCode);

        return propertyMap;

    }

    /**

     * Store a value in a field of the generated class object.

     *

     * @param method      Script method.

     * @param key         Property key.

     * @param fieldIndex  Field number.

     * @param tuple       Tuple to store.

     */

    private void putField(final MethodEmitter method, final String key, final int fieldIndex, final MapTuple<T> tuple) {

        final Type    fieldType   = codegen.useDualFields() && tuple.isPrimitive() ? PRIMITIVE_FIELD_TYPE : Type.OBJECT;

        final String  fieldClass  = getClassName();

        final String  fieldName   = getFieldName(fieldIndex, fieldType);

        final String  fieldDesc   = typeDescriptor(fieldType.getTypeClass());

        assert fieldName.equals(getFieldName(fieldIndex, PRIMITIVE_FIELD_TYPE)) || fieldType.isObject() :    key + " object keys must store to L*-fields";

        assert fieldName.equals(getFieldName(fieldIndex, Type.OBJECT))          || fieldType.isPrimitive() : key + " primitive keys must store to J*-fields";

        loadTuple(method, tuple);

        method.putField(fieldClass, fieldName, fieldDesc);

    }

    /**

     * Store a value in an indexed slot of a generated class object.

     *

     * @param method Script method.

     * @param index  Slot index.

     * @param tuple  Tuple to store.

     */

    private void putSlot(final MethodEmitter method, final long index, final MapTuple<T> tuple) {

        if (JSType.isRepresentableAsInt(index)) {

            method.load((int)index);

        } else {

            method.load(index);

        }

        loadTuple(method, tuple, false); //we don't pack array like objects

        method.dynamicSetIndex(callSiteFlags);

    }

    /**

     * Locate (or indirectly create) the object container class.

     */

    private void findClass() {

        fieldObjectClassName = isScope() ?

                ObjectClassGenerator.getClassName(fieldCount, paramCount, codegen.useDualFields()) :

                ObjectClassGenerator.getClassName(paddedFieldCount, codegen.useDualFields());

        try {

            this.fieldObjectClass = Context.forStructureClass(Compiler.binaryName(fieldObjectClassName));

        } catch (final ClassNotFoundException e) {

            throw new AssertionError("Nashorn has encountered an internal error.  Structure can not be created.");

        }

    }

    /**

     * Get the class name for the object class,

     * e.g. {@code com.nashorn.oracle.scripts.JO2P0}

     *

     * @return script class name

     */

    String getClassName() {

        return fieldObjectClassName;

    }

    /**

     * Tally the number of fields and parameters.

     */

    private void countFields() {

        for (final MapTuple<T> tuple : tuples) {

            final Symbol symbol = tuple.symbol;

            if (symbol != null) {

                if (hasArguments() && symbol.isParam()) {

                    symbol.setFieldIndex(paramCount++);

                } else if (!isValidArrayIndex(getArrayIndex(tuple.key))) {

                    symbol.setFieldIndex(fieldCount++);

                }

            }

        }

        paddedFieldCount = getPaddedFieldCount(fieldCount);

    }

}