Examples with FieldDescriptor com.ibm.j9ddr.StructureReader.FieldDescriptor used on opensource projects

Example 11 with FieldDescriptor

use of com.ibm.j9ddr.StructureReader.FieldDescriptor in project openj9 by eclipse.

the class RuntimeTypeResolutionHelper method findRuntimeType.

// Design 42819
// Discover runtime type based on identifier field.
public static String findRuntimeType(String type, Pointer ptr, Context context) {
    StructureDescriptor fieldOwner = null;
    FieldDescriptor typeIdField = null;
    String classType = null;
    // not just as the top of the hierarchy, so we have to look at each level.
    try {
        if (ptr.notNull()) {
            // Skip the "!"
            classType = StructureCommandUtil.typeToCommand(type).substring(1);
            do {
                fieldOwner = StructureCommandUtil.getStructureDescriptor(classType, context);
                if (null != fieldOwner) {
                    for (FieldDescriptor aField : fieldOwner.getFields()) {
                        if (aField.getDeclaredName().equals("_typeId")) {
                            typeIdField = aField;
                            break;
                        }
                    }
                    if (null == typeIdField) {
                        classType = fieldOwner.getSuperName();
                    }
                }
            } while ((null == typeIdField) && (null != classType) && (null != fieldOwner) && (classType.length() > 0));
        }
        if (null != typeIdField) {
            VoidPointer untypedStrPtr = PointerPointer.cast(ptr).addOffset(typeIdField.getOffset()).at(0);
            if (untypedStrPtr.notNull()) {
                U8Pointer typeStrPtr = U8Pointer.cast(untypedStrPtr);
                type = typeStrPtr.getCStringAtOffset(0).toLowerCase();
            }
        }
    } catch (CorruptDataException e) {
    // Do nothing.
    }
    return RuntimeTypeResolutionUtils.cleanTypeStr(type);
}