StructFieldDeclaration.java

/*
 * BridJ - Dynamic and blazing-fast native interop for Java.
 * http://bridj.googlecode.com/
 *
 * Copyright (c) 2010-2015, Olivier Chafik (http://ochafik.com/)
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of Olivier Chafik nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY OLIVIER CHAFIK AND CONTRIBUTORS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.bridj;

import static org.bridj.util.AnnotationUtils.isAnnotationPresent;

import java.lang.reflect.AnnotatedElement;
import java.lang.reflect.Member;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.List;

import org.bridj.ann.Alignment;
import org.bridj.ann.Array;
import org.bridj.ann.Bits;
import org.bridj.ann.Field;
import org.bridj.ann.Static;
import org.bridj.ann.Union;

class StructFieldDeclaration {

    final StructFieldDescription desc = new StructFieldDescription();
    Method setter;
    long index = -1, unionWith = -1;//, byteOffset = -1;
    Class<?> valueClass;
    Class<?> declaringClass;

    @Override
    public String toString() {
        return desc.name + " (index = " + index + (unionWith < 0 ? "" : ", unionWith = " + unionWith) + ", desc = " + desc + ")";
    }

    protected static boolean acceptFieldGetter(Member member, boolean getter) {
        if ((member instanceof Method) && ((Method) member).getParameterTypes().length != (getter ? 0 : 1)) {
            return false;
        }

        if (((AnnotatedElement) member).getAnnotation(Field.class) == null) {
            return false;
        }

        int modifiers = member.getModifiers();

        return !(((AnnotatedElement) member).getAnnotation(Static.class) != null
            || Modifier.isStatic(modifiers));
    }

    /**
     * Creates a list of structure fields
     */
    protected static List<StructFieldDeclaration> listFields(Class<?> structClass) {
        List<StructFieldDeclaration> list = new ArrayList<StructFieldDeclaration>();
        for (Method method : structClass.getMethods()) {
            if (acceptFieldGetter(method, true)) {
                StructFieldDeclaration io = fromGetter(method);
                try {
                    Method setter = structClass.getMethod(method.getName(), io.valueClass);
                    if (acceptFieldGetter(setter, false)) {
                        io.setter = setter;
                    }
                } catch (Exception ex) {
                    //assert BridJ.info("No setter for getter " + method);
                }
                if (io != null) {
                    list.add(io);
                }
            }
        }

        int nFieldFields = 0;
        for (java.lang.reflect.Field field : structClass.getFields()) {
            if (acceptFieldGetter(field, true)) {
                StructFieldDeclaration io = StructFieldDeclaration.fromField(field);
                if (io != null) {
                    list.add(io);
                    nFieldFields++;
                }
            }
        }
        if (nFieldFields > 0 && BridJ.warnStructFields) {
            BridJ.warning("Struct " + structClass.getName() + " has " + nFieldFields + " struct fields implemented as Java fields, which won't give the best performance and might require counter-intuitive calls to BridJ.readFromNative / .writeToNative. Please consider using JNAerator to generate your struct instead, or use BRIDJ_WARN_STRUCT_FIELDS=0 or -Dbridj.warnStructFields=false to mute this warning.");
        }

        return list;
    }

    protected static StructFieldDeclaration fromField(java.lang.reflect.Field getter) {
        StructFieldDeclaration field = fromMember((Member) getter);
        field.desc.field = getter;
        field.desc.valueType = getter.getGenericType();
        field.valueClass = getter.getType();
        return field;
    }

    protected static StructFieldDeclaration fromGetter(Method getter) {
        StructFieldDeclaration field = fromMember((Member) getter);
        field.desc.getter = getter;
        field.desc.valueType = getter.getGenericReturnType();
        field.valueClass = getter.getReturnType();
        return field;
    }

    private static StructFieldDeclaration fromMember(Member member) {
        StructFieldDeclaration field = new StructFieldDeclaration();
        field.declaringClass = member.getDeclaringClass();

        String name = member.getName();
        if (name.matches("get[A-Z].*")) {
            name = Character.toLowerCase(name.charAt(3)) + name.substring(4);
        }

        field.desc.name = name;

        AnnotatedElement getter = (AnnotatedElement) member;
        Field fil = getter.getAnnotation(Field.class);
        Bits bits = getter.getAnnotation(Bits.class);
        Alignment alignment = getter.getAnnotation(Alignment.class);
        Array arr = getter.getAnnotation(Array.class);
        if (fil != null) {
            field.index = fil.value();
            //field.byteOffset = fil.offset();
            field.unionWith = fil.unionWith();
        }
        if (field.unionWith < 0 && field.declaringClass.getAnnotation(Union.class) != null) {
            field.unionWith = 0;
        }

        if (bits != null) {
            field.desc.bitLength = bits.value();
        }
        if (alignment != null) {
            field.desc.alignment = alignment.value();
        }
        if (arr != null) {
            long length = 1;
            for (long dim : arr.value()) {
                length *= dim;
            }
            field.desc.arrayLength = length;
            field.desc.isArray = true;
        }
        field.desc.isCLong = isAnnotationPresent(org.bridj.ann.CLong.class, getter);
        field.desc.isSizeT = isAnnotationPresent(org.bridj.ann.Ptr.class, getter);
        return field;
    }
}