protected void buildEquals()

in drools-mvel/src/main/java/org/drools/mvel/asm/DefaultBeanClassBuilder.java [1368:1579]
171 lines of code
11 McCabe index (conditional complexity)

    protected void buildEquals(ClassVisitor cw,
                               ClassDefinition classDef) {
        MethodVisitor mv;
        // Building equals method
        {
            mv = cw.visitMethod( Opcodes.ACC_PUBLIC,
                                 "equals",
                                 "(Ljava/lang/Object;)Z",
                                 null,
                                 null );
            mv.visitCode();
            Label l0 = null;
            if ( this.debug ) {
                l0 = new Label();
                mv.visitLabel( l0 );
            }

            // if ( this == obj ) return true;
            mv.visitVarInsn( Opcodes.ALOAD,
                             0 );
            mv.visitVarInsn( Opcodes.ALOAD,
                             1 );
            Label l1 = new Label();
            mv.visitJumpInsn( Opcodes.IF_ACMPNE,
                              l1 );
            mv.visitInsn( Opcodes.ICONST_1 );
            mv.visitInsn( Opcodes.IRETURN );

            // if ( obj == null ) return false;
            mv.visitLabel( l1 );
            mv.visitVarInsn( Opcodes.ALOAD,
                             1 );
            Label l2 = new Label();
            mv.visitJumpInsn( Opcodes.IFNONNULL,
                              l2 );
            mv.visitInsn( Opcodes.ICONST_0 );
            mv.visitInsn( Opcodes.IRETURN );

            // if ( getClass() != obj.getClass() ) return false;
            mv.visitLabel( l2 );
            mv.visitVarInsn( Opcodes.ALOAD,
                             0 );
            mv.visitMethodInsn( Opcodes.INVOKEVIRTUAL,
                                Type.getInternalName( Object.class ),
                                "getClass",
                                Type.getMethodDescriptor( Type.getType( Class.class )
                                                        ) );
            mv.visitVarInsn( Opcodes.ALOAD,
                             1 );
            mv.visitMethodInsn( Opcodes.INVOKEVIRTUAL,
                                Type.getInternalName( Object.class ),
                                "getClass",
                                Type.getMethodDescriptor( Type.getType( Class.class )
                                                        ) );
            Label l3 = new Label();
            mv.visitJumpInsn( Opcodes.IF_ACMPEQ,
                              l3 );
            mv.visitInsn( Opcodes.ICONST_0 );
            mv.visitInsn( Opcodes.IRETURN );

            // final <classname> other = (<classname>) obj;
            mv.visitLabel( l3 );
            mv.visitVarInsn( Opcodes.ALOAD,
                             1 );
            mv.visitTypeInsn( Opcodes.CHECKCAST,
                              BuildUtils.getInternalType( classDef.getClassName() ) );
            mv.visitVarInsn( Opcodes.ASTORE,
                             2 );

            // for each key field
            int count = 0;
            for ( FieldDefinition field : classDef.getFieldsDefinitions() ) {
                if ( field.isKey() ) {
                    count++;

                    Label goNext = new Label();

                    if ( BuildUtils.isPrimitive(field.getTypeName()) ) {
                        // if attr is primitive

                        // if ( this.<attr> != other.<booleanAttr> ) return false;
                        mv.visitVarInsn( Opcodes.ALOAD,
                                         0 );


                        visitFieldOrGetter(mv, classDef, field);

                        mv.visitVarInsn(Opcodes.ALOAD,
                                        2);

                        visitFieldOrGetter(mv, classDef, field);

                        if ( field.getTypeName().equals( "long" ) ) {
                            mv.visitInsn( Opcodes.LCMP );
                            mv.visitJumpInsn( Opcodes.IFEQ,
                                              goNext );
                        } else if ( field.getTypeName().equals( "double" ) ) {
                            mv.visitInsn( Opcodes.DCMPL );
                            mv.visitJumpInsn( Opcodes.IFEQ,
                                              goNext );
                        } else if ( field.getTypeName().equals( "float" ) ) {
                            mv.visitInsn( Opcodes.FCMPL );
                            mv.visitJumpInsn( Opcodes.IFEQ,
                                              goNext );
                        } else {
                            // boolean, byte, char, short, int
                            mv.visitJumpInsn( Opcodes.IF_ICMPEQ,
                                              goNext );
                        }
                        mv.visitInsn( Opcodes.ICONST_0 );
                        mv.visitInsn( Opcodes.IRETURN );
                    } else {
                        // if attr is not a primitive

                        // if ( this.<attr> == null && other.<attr> != null ||
                        //      this.<attr> != null && ! this.<attr>.equals( other.<attr> ) ) return false;
                        mv.visitVarInsn( Opcodes.ALOAD,
                                         0 );

                        visitFieldOrGetter(mv, classDef, field);

                        Label secondIfPart = new Label();
                        mv.visitJumpInsn( Opcodes.IFNONNULL,
                                          secondIfPart );

                        // if ( other.objAttr != null ) return false;
                        mv.visitVarInsn( Opcodes.ALOAD,
                                         2 );

                        visitFieldOrGetter(mv, classDef, field);

                        Label returnFalse = new Label();
                        mv.visitJumpInsn( Opcodes.IFNONNULL,
                                          returnFalse );

                        mv.visitLabel( secondIfPart );
                        mv.visitVarInsn( Opcodes.ALOAD,
                                         0 );

                        visitFieldOrGetter(mv, classDef, field);

                        mv.visitJumpInsn( Opcodes.IFNULL,
                                          goNext );

                        mv.visitVarInsn( Opcodes.ALOAD,
                                         0 );

                        visitFieldOrGetter(mv, classDef, field);

                        mv.visitVarInsn( Opcodes.ALOAD,
                                         2 );

                        visitFieldOrGetter(mv, classDef, field);

                        if ( ! BuildUtils.isArray( field.getTypeName() ) ) {
                            mv.visitMethodInsn( Opcodes.INVOKEVIRTUAL,
                                                "java/lang/Object",
                                                "equals",
                                                "(Ljava/lang/Object;)Z" );
                        } else {
                            mv.visitMethodInsn( Opcodes.INVOKESTATIC,
                                                "java/util/Arrays",
                                                "equals",
                                                "(" +
                                                        BuildUtils.arrayType( field.getTypeName() ) +
                                                        BuildUtils.arrayType( field.getTypeName() ) +
                                                        ")Z" );
                        }
                        mv.visitJumpInsn( Opcodes.IFNE,
                                          goNext );

                        mv.visitLabel( returnFalse );
                        mv.visitInsn( Opcodes.ICONST_0 );
                        mv.visitInsn( Opcodes.IRETURN );
                    }
                    mv.visitLabel( goNext );
                }
            }
            if ( count > 0 ) {
                mv.visitInsn( Opcodes.ICONST_1 );
            } else {
                mv.visitInsn( Opcodes.ICONST_0 );
            }
            mv.visitInsn( Opcodes.IRETURN );
            Label lastLabel;
            if ( this.debug ) {
                lastLabel = new Label();
                mv.visitLabel( lastLabel );
                mv.visitLocalVariable( "this",
                                       BuildUtils.getTypeDescriptor( classDef.getClassName() ),
                                       null,
                                       l0,
                                       lastLabel,
                                       0 );
                mv.visitLocalVariable( "obj",
                                       Type.getDescriptor( Object.class ),
                                       null,
                                       l0,
                                       lastLabel,
                                       1 );
                mv.visitLocalVariable( "other",
                                       BuildUtils.getTypeDescriptor( classDef.getClassName() ),
                                       null,
                                       l0,
                                       lastLabel,
                                       2 );
            }
            mv.visitMaxs( 0,
                          0 );
            mv.visitEnd();
        }
    }