/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.crunch.scrunch;
import java.lang.reflect.Field;
import java.lang.reflect.GenericArrayType;
import java.lang.reflect.Modifier;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.Collection;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.avro.AvroRuntimeException;
import org.apache.avro.AvroTypeException;
import org.apache.avro.Schema;
import org.apache.avro.generic.GenericFixed;
import org.apache.avro.generic.IndexedRecord;
import org.apache.avro.reflect.ReflectData;
import org.apache.avro.reflect.Stringable;
import org.apache.avro.reflect.Union;
import org.apache.avro.specific.FixedSize;
import org.codehaus.jackson.JsonNode;
import org.codehaus.jackson.node.NullNode;
/**
* Scala-oriented support class for serialization via reflection.
*/
public class ScalaSafeReflectData extends ReflectData.AllowNull {
private static final ScalaSafeReflectData INSTANCE = new ScalaSafeReflectData();
public static ScalaSafeReflectData get() { return INSTANCE; }
static final String CLASS_PROP = "java-class";
static final String ELEMENT_PROP = "java-element-class";
static Class getClassProp(Schema schema, String prop) {
String name = schema.getProp(prop);
if (name == null) return null;
try {
return Class.forName(name);
} catch (ClassNotFoundException e) {
throw new AvroRuntimeException(e);
}
}
/**
* This method is the whole reason for this class to exist, so that I can
* hack around a problem where calling getSimpleName on a class that is
* defined inside of the Scala REPL can cause an internal language error,
* which I'm not a huge fan of.
*
* @param clazz
* @return
*/
private String getSimpleName(Class clazz) {
try {
return clean(clazz.getSimpleName());
} catch (InternalError ie) {
// This can happen in Scala when we're using the Console. Crazy, right?
String fullName = clazz.getName();
String[] pieces = fullName.split("\\.");
return clean(pieces[pieces.length - 1]);
}
}
@Override
@SuppressWarnings(value="unchecked")
protected Schema createSchema(Type type, Map<String,Schema> names) {
if (type instanceof GenericArrayType) { // generic array
Type component = ((GenericArrayType)type).getGenericComponentType();
if (component == Byte.TYPE) // byte array
return Schema.create(Schema.Type.BYTES);
Schema result = Schema.createArray(createSchema(component, names));
setElement(result, component);
return result;
} else if (type instanceof ParameterizedType) {
ParameterizedType ptype = (ParameterizedType)type;
Class raw = (Class)ptype.getRawType();
Type[] params = ptype.getActualTypeArguments();
if (java.util.Map.class.isAssignableFrom(raw) ||
scala.collection.Map.class.isAssignableFrom(raw)) {
Type key = params[0];
Type value = params[1];
if (!(key == String.class))
throw new AvroTypeException("Map key class not String: "+key);
Schema schema = Schema.createMap(createSchema(value, names));
schema.addProp(CLASS_PROP, raw.getName());
return schema;
} else if (Collection.class.isAssignableFrom(raw) ||
scala.collection.Iterable.class.isAssignableFrom(raw)) { // Collection
if (params.length != 1)
throw new AvroTypeException("No array type specified.");
Schema schema = Schema.createArray(createSchema(params[0], names));
schema.addProp(CLASS_PROP, raw.getName());
return schema;
} else {
throw new AvroTypeException("Could not convert type: " + type);
}
} else if ((type == Short.class) || (type == Short.TYPE)) {
Schema result = Schema.create(Schema.Type.INT);
result.addProp(CLASS_PROP, Short.class.getName());
return result;
} else if (type instanceof Class) { // Class
Class<?> c = (Class<?>)type;
if (c.isPrimitive() || Number.class.isAssignableFrom(c)
|| c == Void.class || c == Boolean.class) // primitive
return super.createSchema(type, names);
if (c.isArray()) { // array
Class component = c.getComponentType();
if (component == Byte.TYPE) // byte array
return Schema.create(Schema.Type.BYTES);
Schema result = Schema.createArray(createSchema(component, names));
setElement(result, component);
return result;
}
if (CharSequence.class.isAssignableFrom(c)) // String
return Schema.create(Schema.Type.STRING);
String fullName = c.getName();
Schema schema = names.get(fullName);
if (schema == null) {
String name = getSimpleName(c);
String space = c.getPackage() == null ? "" : c.getPackage().getName();
if (c.getEnclosingClass() != null) // nested class
space = c.getEnclosingClass().getName() + "$";
Union union = c.getAnnotation(Union.class);
if (union != null) { // union annotated
return getAnnotatedUnion(union, names);
} else if (c.isAnnotationPresent(Stringable.class)){ // Stringable
Schema result = Schema.create(Schema.Type.STRING);
result.addProp(CLASS_PROP, c.getName());
return result;
} else if (c.isEnum()) { // Enum
List<String> symbols = new ArrayList<String>();
Enum[] constants = (Enum[])c.getEnumConstants();
for (int i = 0; i < constants.length; i++)
symbols.add(constants[i].name());
schema = Schema.createEnum(name, null /* doc */, space, symbols);
} else if (GenericFixed.class.isAssignableFrom(c)) { // fixed
int size = c.getAnnotation(FixedSize.class).value();
schema = Schema.createFixed(name, null /* doc */, space, size);
} else if (IndexedRecord.class.isAssignableFrom(c)) { // specific
return super.createSchema(type, names);
} else { // record
List<Schema.Field> fields = new ArrayList<Schema.Field>();
boolean error = Throwable.class.isAssignableFrom(c);
schema = Schema.createRecord(name, null /* doc */, space, error);
names.put(c.getName(), schema);
for (Field field : getFields(c))
if ((field.getModifiers()&(Modifier.TRANSIENT|Modifier.STATIC))==0){
Schema fieldSchema = createFieldSchema(field, names);
JsonNode defaultValue = null;
if (fieldSchema.getType() == Schema.Type.UNION) {
Schema defaultType = fieldSchema.getTypes().get(0);
if (defaultType.getType() == Schema.Type.NULL) {
defaultValue = NullNode.getInstance();
}
}
fields.add(new Schema.Field(clean(field.getName()),
fieldSchema, null /* doc */, defaultValue));
}
if (error) // add Throwable message
fields.add(new Schema.Field("detailMessage", THROWABLE_MESSAGE,
null, null));
schema.setFields(fields);
}
names.put(fullName, schema);
}
return schema;
}
return super.createSchema(type, names);
}
private static final Schema THROWABLE_MESSAGE =
makeNullable(Schema.create(Schema.Type.STRING));
@Override
public Object getField(Object record, String name, int position) {
if (record instanceof IndexedRecord)
return super.getField(record, name, position);
try {
return getField(record.getClass(), name).get(record);
} catch (IllegalAccessException e) {
throw new AvroRuntimeException(e);
}
}
private static final Map<Class,Map<String,Field>> FIELD_CACHE =
new ConcurrentHashMap<Class,Map<String,Field>>();
private static Field getField(Class c, String name) {
Map<String,Field> fields = FIELD_CACHE.get(c);
if (fields == null) {
fields = new ConcurrentHashMap<String,Field>();
FIELD_CACHE.put(c, fields);
}
Field f = fields.get(name);
if (f == null) {
f = findField(c, name);
fields.put(name, f);
}
return f;
}
private static Field findField(Class original, String name) {
Class c = original;
do {
try {
Field f = c.getDeclaredField(dirty(name));
f.setAccessible(true);
return f;
} catch (NoSuchFieldException e) {}
c = c.getSuperclass();
} while (c != null);
throw new AvroRuntimeException("No field named "+name+" in: "+original);
}
private static String clean(String dirty) {
return dirty.replace('$', '_');
}
private static String dirty(String clean) {
return clean.replace('_', '$');
}
// Return of this class and its superclasses to serialize.
// Not cached, since this is only used to create schemas, which are cached.
private Collection<Field> getFields(Class recordClass) {
Map<String,Field> fields = new LinkedHashMap<String,Field>();
Class c = recordClass;
do {
if (c.getPackage() != null
&& c.getPackage().getName().startsWith("java."))
break; // skip java built-in classes
for (Field field : c.getDeclaredFields())
if ((field.getModifiers() & (Modifier.TRANSIENT|Modifier.STATIC)) == 0)
if (fields.put(field.getName(), field) != null)
throw new AvroTypeException(c+" contains two fields named: "+field);
c = c.getSuperclass();
} while (c != null);
return fields.values();
}
@SuppressWarnings(value="unchecked")
private void setElement(Schema schema, Type element) {
if (!(element instanceof Class)) return;
Class<?> c = (Class<?>)element;
Union union = c.getAnnotation(Union.class);
if (union != null) // element is annotated union
schema.addProp(ELEMENT_PROP, c.getName());
}
// construct a schema from a union annotation
private Schema getAnnotatedUnion(Union union, Map<String,Schema> names) {
List<Schema> branches = new ArrayList<Schema>();
for (Class branch : union.value())
branches.add(createSchema(branch, names));
return Schema.createUnion(branches);
}
@Override
protected boolean isArray(Object datum) {
if (datum == null) return false;
return (datum instanceof Collection) || datum.getClass().isArray() ||
(datum instanceof scala.collection.Iterable);
}
@Override
protected boolean isMap(Object datum) {
return (datum instanceof java.util.Map) || (datum instanceof scala.collection.Map);
}
}