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Convert Narya (most of the way) over to a Maven Ant task based build. The

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ActionScript bits remain belligerent, but the Java stuff is mostly shipshape.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@6222 542714f4-19e9-0310-aa3c-eee0fc999fb1
This commit is contained in:
Michael Bayne
2010-10-22 21:12:29 +00:00
parent 555b865bbf
commit 9d2ca42eac
434 changed files with 163 additions and 208 deletions
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src/main/java/com/threerings/io/Streamer.java
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//
// $Id$
//
// Narya library - tools for developing networked games
// Copyright (C) 2002-2010 Three Rings Design, Inc., All Rights Reserved
// http://code.google.com/p/narya/
//
// This library is free software; you can redistribute it and/or modify it
// under the terms of the GNU Lesser General Public License as published
// by the Free Software Foundation; either version 2.1 of the License, or
// (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
package com.threerings.io;
import java.lang.reflect.Array;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.security.AccessController;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.List;
import java.util.Map;
import java.io.IOException;
import com.google.common.base.Predicate;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.samskivert.util.ByteEnum;
import com.samskivert.util.ByteEnumUtil;
import com.samskivert.util.ClassUtil;
import static com.threerings.NaryaLog.log;
/**
* Handles the streaming of {@link Streamable} instances as well as a set of basic object types
* (see {@link ObjectOutputStream}). An instance of {@link Streamer} is created for each distinct
* class that implements {@link Streamable}. The {@link Streamer} reflects on the streamed class
* and caches the information necessary to efficiently read and write objects of the class in
* question.
*/
public class Streamer
{
/**
* Returns true if the supplied target class can be streamed using a streamer.
*/
public synchronized static boolean isStreamable (Class<?> target)
{
while (true) {
// if we've got a streamer for it, it's good
if (_streamers.containsKey(target)) {
return true;
}
// enums can be streamed
if (target.isEnum()) {
return true;
}
// if it's not an array, it must be streamable
if (!target.isArray()) {
return Streamable.class.isAssignableFrom(target);
}
// otherwise extract the component type and loop back around for another check...
target = target.getComponentType();
}
}
/**
* Returns the class that should be used when streaming this object. In general that is the
* object's natural class, but for enum values, that might be its declaring class as enums use
* classes in a way that would otherwise pollute our id to class mapping space.
*/
public static Class<?> getStreamerClass (Object object)
{
return (object instanceof Enum<?>) ?
((Enum<?>)object).getDeclaringClass() : object.getClass();
}
/**
* Obtains a {@link Streamer} that can be used to read and write objects of the specified
* target class. {@link Streamer} instances are shared among all {@link ObjectInputStream}s and
* {@link ObjectOutputStream}s.
*
* @param target the class that is desired to be streamed. This should be the result of a call
* to {@link #getStreamerClass} if the caller has an instance they wish to stream.
*
* @throws IOException when a streamer is requested for an object that does not implement
* {@link Streamable} and is not one of the basic object types (@see {@link
* ObjectOutputStream}).
*/
public synchronized static Streamer getStreamer (final Class<?> target)
throws IOException
{
// if we have not yet initialized ourselves, do so now
if (_streamers == null) {
_streamers = Maps.newHashMap(BasicStreamers.BSTREAMERS);
}
Streamer stream = _streamers.get(target);
if (stream == null) {
// make sure this is a streamable class
if (!isStreamable(target)) {
throw new IOException(
"Requested to stream invalid class '" + target.getName() + "'");
}
// create a streamer for this class and cache it
if (ObjectInputStream.STREAM_DEBUG) {
log.info("Creating a streamer for '" + target.getName() + "'.");
}
// create our streamer in a privileged block so that it can introspect on the to be
// streamed class
try {
stream = AccessController.doPrivileged(new PrivilegedExceptionAction<Streamer>() {
public Streamer run () throws IOException {
return new Streamer(target);
}
});
} catch (PrivilegedActionException pae) {
throw (IOException) pae.getCause();
}
_streamers.put(target, stream);
}
return stream;
}
/**
* Writes the supplied object to the specified stream.
*
* @param object the instance to be written to the stream.
* @param out the stream to which to write the instance.
* @param useWriter whether or not to use the custom <code>writeObject</code> if one exists.
*/
public void writeObject (Object object, ObjectOutputStream out, boolean useWriter)
throws IOException
{
// if we're supposed to and one exists, use the writer method
if (useWriter && _writer != null) {
try {
if (ObjectInputStream.STREAM_DEBUG) {
log.info("Writing with writer", "class", _target.getName());
}
_writer.invoke(object, new Object[] { out });
} catch (Throwable t) {
if (t instanceof InvocationTargetException) {
t = ((InvocationTargetException)t).getTargetException();
}
if (t instanceof IOException) {
throw (IOException)t;
}
String errmsg = "Failure invoking streamable writer " +
"[class=" + _target.getName() + "]";
throw (IOException) new IOException(errmsg).initCause(t);
}
return;
}
// if we're writing an array, do some special business
if (_target.isArray()) {
int length = Array.getLength(object);
out.writeInt(length);
// if the component class is final, we can be sure that all instances in the array will
// be of the same class and thus can serialize things more efficiently
int cmods = _target.getComponentType().getModifiers();
if (Modifier.isFinal(cmods)) {
// compute a mask indicating which elements are null and which are populated
ArrayMask mask = new ArrayMask(length);
for (int ii = 0; ii < length; ii++) {
if (Array.get(object, ii) != null) {
mask.set(ii);
}
}
// write that mask out to the stream
mask.writeTo(out);
// now write out the populated elements
for (int ii = 0; ii < length; ii++) {
Object element = Array.get(object, ii);
if (element != null) {
out.writeBareObject(element, _delegate, useWriter);
}
}
} else {
// otherwise we've got to write each array element with its own class identifier
// because it could be any derived class of the array element type
for (int ii = 0; ii < length; ii++) {
out.writeObject(Array.get(object, ii));
}
}
return;
}
// if we're writing an enum; write its string value (to avoid future compatibility issues
// if someone serializes an enum to a file and then adds a value to the enum, changing the
// ordinal assignments)
if (_target.isEnum()) {
if (object instanceof ByteEnum) {
out.writeByte(((ByteEnum) object).toByte());
} else {
out.writeUTF(((Enum<?>)object).name());
}
return;
}
// otherwise simply write out the fields via our field marshallers
int fcount = _fields.length;
for (int ii = 0; ii < fcount; ii++) {
Field field = _fields[ii];
FieldMarshaller fm = _marshallers[ii];
if (fm == null) {
String errmsg = "Unable to marshall field [class=" + _target.getName() +
", field=" + field.getName() + ", type=" + field.getType().getName() + "]";
throw new IOException(errmsg);
}
try {
if (ObjectInputStream.STREAM_DEBUG) {
log.info("Writing field", "class", _target.getName(), "field", field.getName());
}
fm.writeField(field, object, out);
} catch (Exception e) {
String errmsg = "Failure writing streamable field [class=" + _target.getName() +
", field=" + field.getName() + "]";
throw (IOException) new IOException(errmsg).initCause(e);
}
}
}
/**
* Creates a blank object that can subsequently be read by this streamer. Data may be read
* from the input stream as a result of this method (in the case of arrays, the length of the
* array must be read before creating the array).
*/
public Object createObject (ObjectInputStream in)
throws IOException, ClassNotFoundException
{
try {
// if our target class is an array type, read in the element count and create an array
// instance of the appropriate type and size
if (_target.isArray()) {
int length = in.readInt();
if (ObjectInputStream.STREAM_DEBUG) {
log.info(in.hashCode() + ": Creating array '" +
_target.getComponentType().getName() + "[" + length + "]'.");
}
return Array.newInstance(_target.getComponentType(), length);
} else if (_target.isEnum()) {
if (ObjectInputStream.STREAM_DEBUG) {
log.info(in.hashCode() + ": Creating enum '" + _target.getName() + "'.");
}
@SuppressWarnings("unchecked") Class<EnumReader> eclass =
(Class<EnumReader>)_target;
if (ByteEnum.class.isAssignableFrom(_target)) {
return ByteEnumUtil.fromByte(eclass, in.readByte());
} else {
return Enum.valueOf(eclass, in.readUTF());
}
} else {
if (ObjectInputStream.STREAM_DEBUG) {
log.info(in.hashCode() + ": Creating object '" + _target.getName() + "'.");
}
return _target.newInstance();
}
} catch (InstantiationException ie) {
String errmsg = "Error instantiating object [type=" + _target.getName() + "]";
throw (IOException) new IOException(errmsg).initCause(ie);
} catch (IllegalAccessException iae) {
String errmsg = "Error instantiating object [type=" + _target.getName() + "]";
throw (IOException) new IOException(errmsg).initCause(iae);
}
}
/**
* Reads and populates the fields of the supplied object from the specified stream.
*
* @param object the instance to be read from the stream.
* @param in the stream from which to read the instance.
* @param useReader whether or not to use the custom <code>readObject</code> if one exists.
*/
public void readObject (Object object, ObjectInputStream in, boolean useReader)
throws IOException, ClassNotFoundException
{
// if we're supposed to and one exists, use the reader method
if (useReader && _reader != null) {
try {
if (ObjectInputStream.STREAM_DEBUG) {
log.info(in.hashCode() + ": Reading with reader '" + _target.getName() + "." +
_reader.getName() + "()'.");
}
_reader.invoke(object, new Object[] { in });
} catch (Throwable t) {
if (t instanceof InvocationTargetException) {
t = ((InvocationTargetException)t).getTargetException();
}
if (t instanceof IOException) {
throw (IOException)t;
}
String errmsg = "Failure invoking streamable reader " +
"[class=" + _target.getName() + "]";
throw (IOException) new IOException(errmsg).initCause(t);
}
return;
}
if (ObjectInputStream.STREAM_DEBUG) {
log.info(in.hashCode() + ": Reading '" + _target.getName() + "'.");
}
// if we're reading in an array, do some special business
if (_target.isArray()) {
int length = Array.getLength(object);
// if the component class is final, we can be sure that all instances in the array will
// be of the same class and thus have serialized things more efficiently
int cmods = _target.getComponentType().getModifiers();
if (Modifier.isFinal(cmods)) {
// read in the nullness mask
ArrayMask mask = new ArrayMask();
mask.readFrom(in);
// now read in the array elements given that we know which elements to read
for (int ii = 0; ii < length; ii++) {
if (mask.isSet(ii)) {
if (ObjectInputStream.STREAM_DEBUG) {
log.info(in.hashCode() + ": Reading fixed element '" + ii + "'.");
}
Object element = _delegate.createObject(in);
in.readBareObject(element, _delegate, useReader);
Array.set(object, ii, element);
} else if (ObjectInputStream.STREAM_DEBUG) {
log.info(in.hashCode() + ": Skipping null element '" + ii + "'.");
}
}
} else {
// otherwise we had to write each object out individually
for (int ii = 0; ii < length; ii++) {
if (ObjectInputStream.STREAM_DEBUG) {
log.info(in.hashCode() + ": Reading free element '" + ii + "'.");
}
Array.set(object, ii, in.readObject());
}
}
return;
}
// an enum has no additional state
if (_target.isEnum()) {
return;
}
// otherwise simply read the fields via our field marshallers
int fcount = _fields.length;
for (int ii = 0; ii < fcount; ii++) {
Field field = _fields[ii];
FieldMarshaller fm = _marshallers[ii];
if (fm == null) {
String errmsg = "Unable to marshall field [class=" + _target.getName() +
", field=" + field.getName() + ", type=" + field.getType().getName() + "]";
throw new IOException(errmsg);
}
try {
if (ObjectInputStream.STREAM_DEBUG) {
log.info(in.hashCode() + ": Reading field '" + field.getName() + "' " +
"with " + fm + ".");
}
// gracefully deal with objects that have had new fields added to their class
// definition
if (in.available() > 0) {
fm.readField(field, object, in);
} else {
log.info("Streamed instance missing field (probably newly added)",
"class", _target.getName(), "field", field.getName());
}
} catch (Exception e) {
String errmsg = "Failure reading streamable field [class=" + _target.getName() +
", field=" + field.getName() + ", error=" + e + "]";
throw (IOException) new IOException(errmsg).initCause(e);
}
}
if (ObjectInputStream.STREAM_DEBUG) {
log.info(in.hashCode() + ": Read object '" + object + "'.");
}
}
@Override
public String toString ()
{
return (_target == null) ? getClass().getName() :
"[target=" + _target.getName() + ", delegate=" + _delegate +
", fcount=" + (_fields == null ? 0 : _fields.length) +
", reader=" + _reader + ", writer=" + _writer + "]";
}
/**
* The constructor used by the basic streamers.
*/
protected Streamer ()
{
}
/**
* Constructs a streamer for the specified target class.
*/
protected Streamer (Class<?> target)
throws IOException
{
// keep a handle on the class
_target = target;
// if this is a non-static inner class, freak out because we cannot stream those
boolean isInner = false, isStatic = Modifier.isStatic(_target.getModifiers());
try {
isInner = (_target.getDeclaringClass() != null);
} catch (Throwable t) {
log.warning("Failure checking innerness of class", "class", _target.getName(),
"error", t);
}
if (isInner && !isStatic) {
throw new IllegalArgumentException(
"Cannot stream non-static inner class: " + _target.getName());
}
// if our target class is an array, we want to get a handle on a streamer delegate that
// we'll use to stream our elements
if (_target.isArray()) {
_delegate = Streamer.getStreamer(_target.getComponentType());
// sanity check
if (_delegate == null) {
String errmsg = "Aiya! Streamer created for array type but we have no registered " +
"streamer for the element type [type=" + _target.getName() + "]";
throw new RuntimeException(errmsg);
}
// and that's all we'll need
return;
}
// look up the reader and writer methods
try {
_reader = target.getMethod(READER_METHOD_NAME, READER_ARGS);
} catch (NoSuchMethodException nsme) {
// nothing to worry about, we just don't have one
}
try {
_writer = target.getMethod(WRITER_METHOD_NAME, WRITER_ARGS);
} catch (NoSuchMethodException nsme) {
// nothing to worry about, we just don't have one
}
// reflect on all the object's fields and remove all marked with NotStreamable
List<Field> fields = Lists.newArrayList();
ClassUtil.getFields(target, fields);
_fields = Iterables.toArray(Iterables.filter(fields, _isStreamableFieldPred), Field.class);
int fcount = _fields.length;
// obtain field marshallers for all of our fields
_marshallers = new FieldMarshaller[fcount];
for (int ii = 0; ii < fcount; ii++) {
_marshallers[ii] = FieldMarshaller.getFieldMarshaller(_fields[ii]);
if (ObjectInputStream.STREAM_DEBUG) {
log.info("Using " + _marshallers[ii] + " for " + _target.getName() + "." +
_fields[ii].getName() + ".");
}
}
}
/** Used to coerce the type system into quietude when reading enums from the wire. */
protected static enum EnumReader implements ByteEnum {
NOT_USED;
public byte toByte () { return 0; }
}
/** The class for which this streamer instance is configured. */
protected Class<?> _target;
/** If our target class is an array, this is a reference to a streamer that can stream our
* array elements, otherwise it is null. */
protected Streamer _delegate;
/** The non-transient, non-static public fields that we will stream when requested. */
protected Field[] _fields;
/** Field marshallers for each field that will be read or written in our objects. */
protected FieldMarshaller[] _marshallers;
/** A reference to the <code>readObject</code> method if one is defined by our target class. */
protected Method _reader;
/** A reference to the <code>writeObject</code> method if one is defined by our target
* class. */
protected Method _writer;
/** Contains the mapping from class names to configured streamer instances. */
protected static Map<Class<?>, Streamer> _streamers;
/** A simple predicate to filter "NotStreamable" members from a Streamable object's fields. */
protected static final Predicate<Field> _isStreamableFieldPred = new Predicate<Field>() {
public boolean apply (Field obj) {
return (obj.getAnnotation(NotStreamable.class) == null);
}
};
/** The name of the custom reader method. */
protected static final String READER_METHOD_NAME = "readObject";
/** The argument list for the custom reader method. */
protected static final Class<?>[] READER_ARGS = { ObjectInputStream.class };
/** The name of the custom writer method. */
protected static final String WRITER_METHOD_NAME = "writeObject";
/** The argument list for the custom writer method. */
protected static final Class<?>[] WRITER_ARGS = { ObjectOutputStream.class };
}