src/main/java/com/google/devtools/build/lib/skyframe/serialization/DynamicCodec.java - bazel - Git at Google

 // Copyright 2018 The Bazel Authors. All rights reserved.
 //
 // Licensed 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 com.google.devtools.build.lib.skyframe.serialization;

 import com.google.devtools.build.lib.unsafe.UnsafeProvider;
 import com.google.protobuf.CodedInputStream;
 import com.google.protobuf.CodedOutputStream;
 import java.io.IOException;
 import java.lang.reflect.Array;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
 import java.nio.ByteBuffer;
 import java.util.Comparator;
 import java.util.Map;
 import java.util.TreeMap;
 import sun.reflect.ReflectionFactory;

 /**
  * A codec that serializes arbitrary types.
  *
  * <p>TODO(shahan): replace Unsafe with VarHandle once it's available.
  */
 public class DynamicCodec implements ObjectCodec<Object> {

   private final Class<?> type;
   private final Constructor<?> constructor;
   private final TypeAndOffset[] offsets;

   public DynamicCodec(Class<?> type) throws ReflectiveOperationException {
     this.type = type;
     this.constructor = getConstructor(type);
     this.offsets = getOffsets(type);
   }

   @Override
   public Class<?> getEncodedClass() {
     return type;
   }

   @Override
   public MemoizationStrategy getStrategy() {
     return ObjectCodec.MemoizationStrategy.MEMOIZE_BEFORE;
   }

   @Override
   public void serialize(SerializationContext context, Object obj, CodedOutputStream codedOut)
       throws SerializationException, IOException {
     for (int i = 0; i < offsets.length; ++i) {
       serializeField(context, codedOut, obj, offsets[i].type, offsets[i].offset);
     }
   }

   /**
    * Serializes a field.
    *
    * @param obj the object containing the field to serialize. Can be an array or plain object.
    * @param type class of the field to serialize
    * @param offset unsafe offset into obj where the field will be found
    */
   private void serializeField(
       SerializationContext context,
       CodedOutputStream codedOut,
       Object obj,
       Class<?> type,
       long offset)
       throws SerializationException, IOException {
     if (type.isPrimitive()) {
       if (type.equals(boolean.class)) {
         codedOut.writeBoolNoTag(UnsafeProvider.getInstance().getBoolean(obj, offset));
       } else if (type.equals(byte.class)) {
         codedOut.writeRawByte(UnsafeProvider.getInstance().getByte(obj, offset));
       } else if (type.equals(short.class)) {
         ByteBuffer buffer =
             ByteBuffer.allocate(2).putShort(UnsafeProvider.getInstance().getShort(obj, offset));
         codedOut.writeRawBytes(buffer);
       } else if (type.equals(char.class)) {
         ByteBuffer buffer =
             ByteBuffer.allocate(2).putChar(UnsafeProvider.getInstance().getChar(obj, offset));
         codedOut.writeRawBytes(buffer);
       } else if (type.equals(int.class)) {
         codedOut.writeInt32NoTag(UnsafeProvider.getInstance().getInt(obj, offset));
       } else if (type.equals(long.class)) {
         codedOut.writeInt64NoTag(UnsafeProvider.getInstance().getLong(obj, offset));
       } else if (type.equals(float.class)) {
         codedOut.writeFloatNoTag(UnsafeProvider.getInstance().getFloat(obj, offset));
       } else if (type.equals(double.class)) {
         codedOut.writeDoubleNoTag(UnsafeProvider.getInstance().getDouble(obj, offset));
       } else if (type.equals(void.class)) {
         // Does nothing for void type.
       } else {
         throw new UnsupportedOperationException("Unknown primitive type: " + type);
       }
     } else if (type.isArray()) {
       Object arr = UnsafeProvider.getInstance().getObject(obj, offset);
       if (type.getComponentType().equals(byte.class)) {
         if (arr == null) {
           codedOut.writeBoolNoTag(false);
         } else {
           codedOut.writeBoolNoTag(true);
           codedOut.writeByteArrayNoTag((byte[]) arr);
         }
         return;
       }
       if (arr == null) {
         codedOut.writeInt32NoTag(-1);
         return;
       }
       int length = Array.getLength(arr);
       codedOut.writeInt32NoTag(length);
       int base = UnsafeProvider.getInstance().arrayBaseOffset(type);
       int scale = UnsafeProvider.getInstance().arrayIndexScale(type);
       if (scale == 0) {
         throw new SerializationException("Failed to get index scale for type: " + type);
       }
       for (int i = 0; i < length; ++i) {
         // Serializes the ith array field directly from array memory.
         serializeField(context, codedOut, arr, type.getComponentType(), base + scale * i);
       }
     } else {
       try {
         context.serialize(UnsafeProvider.getInstance().getObject(obj, offset), codedOut);
       } catch (SerializationException e) {
         e.addTrail(this.type);
         throw e;
       }
     }
   }

   @Override
   public Object deserialize(DeserializationContext context, CodedInputStream codedIn)
       throws SerializationException, IOException {
     Object instance;
     try {
       instance = constructor.newInstance();
     } catch (ReflectiveOperationException e) {
       throw new SerializationException("Could not instantiate object of type: " + type, e);
     }
     context.registerInitialValue(instance);
     for (int i = 0; i < offsets.length; ++i) {
       deserializeField(context, codedIn, instance, offsets[i].type, offsets[i].offset);
     }
     return instance;
   }

   /**
    * Deserializes a field directly into the supplied object.
    *
    * @param obj the object containing the field to deserialize. Can be an array or a plain object.
    * @param type class of the field to deserialize
    * @param offset unsafe offset into obj where the field should be written
    */
   private void deserializeField(
       DeserializationContext context,
       CodedInputStream codedIn,
       Object obj,
       Class<?> type,
       long offset)
       throws SerializationException, IOException {
     if (type.isPrimitive()) {
       if (type.equals(boolean.class)) {
         UnsafeProvider.getInstance().putBoolean(obj, offset, codedIn.readBool());
       } else if (type.equals(byte.class)) {
         UnsafeProvider.getInstance().putByte(obj, offset, codedIn.readRawByte());
       } else if (type.equals(short.class)) {
         ByteBuffer buffer = ByteBuffer.allocate(2).put(codedIn.readRawBytes(2));
         UnsafeProvider.getInstance().putShort(obj, offset, buffer.getShort(0));
       } else if (type.equals(char.class)) {
         ByteBuffer buffer = ByteBuffer.allocate(2).put(codedIn.readRawBytes(2));
         UnsafeProvider.getInstance().putChar(obj, offset, buffer.getChar(0));
       } else if (type.equals(int.class)) {
         UnsafeProvider.getInstance().putInt(obj, offset, codedIn.readInt32());
       } else if (type.equals(long.class)) {
         UnsafeProvider.getInstance().putLong(obj, offset, codedIn.readInt64());
       } else if (type.equals(float.class)) {
         UnsafeProvider.getInstance().putFloat(obj, offset, codedIn.readFloat());
       } else if (type.equals(double.class)) {
         UnsafeProvider.getInstance().putDouble(obj, offset, codedIn.readDouble());
       } else if (type.equals(void.class)) {
         // Does nothing for void type.
       } else {
         throw new UnsupportedOperationException("Unknown primitive type: " + type);
       }
     } else if (type.isArray()) {
       if (type.getComponentType().equals(byte.class)) {
         boolean isNonNull = codedIn.readBool();
         UnsafeProvider.getInstance()
             .putObject(obj, offset, isNonNull ? codedIn.readByteArray() : null);
         return;
       }
       int length = codedIn.readInt32();
       if (length < 0) {
         UnsafeProvider.getInstance().putObject(obj, offset, null);
         return;
       }
       Object arr = Array.newInstance(type.getComponentType(), length);
       UnsafeProvider.getInstance().putObject(obj, offset, arr);
       int base = UnsafeProvider.getInstance().arrayBaseOffset(type);
       int scale = UnsafeProvider.getInstance().arrayIndexScale(type);
       if (scale == 0) {
         throw new SerializationException("Failed to get index scale for type: " + type);
       }
       for (int i = 0; i < length; ++i) {
         // Deserializes type directly into array memory.
         deserializeField(context, codedIn, arr, type.getComponentType(), base + scale * i);
       }
     } else {
       UnsafeProvider.getInstance().putObject(obj, offset, context.deserialize(codedIn));
     }
   }

   private static <T> TypeAndOffset[] getOffsets(Class<T> type) {
     TreeMap<Field, Long> offsets = new TreeMap<>(new FieldComparator());
     for (Class<? super T> next = type; next != null; next = next.getSuperclass()) {
       for (Field field : next.getDeclaredFields()) {
         if ((field.getModifiers() & (Modifier.STATIC | Modifier.TRANSIENT)) != 0) {
           continue; // Skips static or transient fields.
         }
         field.setAccessible(true);
         offsets.put(field, UnsafeProvider.getInstance().objectFieldOffset(field));
       }
     }
     // Converts to an array to make it easy to avoid the use of iterators.
     TypeAndOffset[] offsetsArr = new TypeAndOffset[offsets.size()];
     int i = 0;
     for (Map.Entry<Field, Long> entry : offsets.entrySet()) {
       offsetsArr[i] = new TypeAndOffset(entry.getKey().getType(), entry.getValue());
       ++i;
     }
     return offsetsArr;
   }

   private static class TypeAndOffset {
     public final Class<?> type;
     public final long offset;

     public TypeAndOffset(Class<?> type, long offset) {
       this.type = type;
       this.offset = offset;
     }
   }

   private static Constructor<?> getConstructor(Class<?> type) throws ReflectiveOperationException {
     Constructor<?> constructor =
         ReflectionFactory.getReflectionFactory()
             .newConstructorForSerialization(type, Object.class.getDeclaredConstructor());
     constructor.setAccessible(true);
     return constructor;
   }

   private static class FieldComparator implements Comparator<Field> {

     @Override
     public int compare(Field f1, Field f2) {
       int classCompare =
           f1.getDeclaringClass().getName().compareTo(f2.getDeclaringClass().getName());
       if (classCompare != 0) {
         return classCompare;
       }
       return f1.getName().compareTo(f2.getName());
     }
   }
 }
	// Copyright 2018 The Bazel Authors. All rights reserved.
	//
	// Licensed 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 com.google.devtools.build.lib.skyframe.serialization;

	import com.google.devtools.build.lib.unsafe.UnsafeProvider;
	import com.google.protobuf.CodedInputStream;
	import com.google.protobuf.CodedOutputStream;
	import java.io.IOException;
	import java.lang.reflect.Array;
	import java.lang.reflect.Constructor;
	import java.lang.reflect.Field;
	import java.lang.reflect.Modifier;
	import java.nio.ByteBuffer;
	import java.util.Comparator;
	import java.util.Map;
	import java.util.TreeMap;
	import sun.reflect.ReflectionFactory;

	/**
	* A codec that serializes arbitrary types.
	*
	* <p>TODO(shahan): replace Unsafe with VarHandle once it's available.
	*/
	public class DynamicCodec implements ObjectCodec<Object> {

	private final Class<?> type;
	private final Constructor<?> constructor;
	private final TypeAndOffset[] offsets;

	public DynamicCodec(Class<?> type) throws ReflectiveOperationException {
	this.type = type;
	this.constructor = getConstructor(type);
	this.offsets = getOffsets(type);
	}

	@Override
	public Class<?> getEncodedClass() {
	return type;
	}

	@Override
	public MemoizationStrategy getStrategy() {
	return ObjectCodec.MemoizationStrategy.MEMOIZE_BEFORE;
	}

	@Override
	public void serialize(SerializationContext context, Object obj, CodedOutputStream codedOut)
	throws SerializationException, IOException {
	for (int i = 0; i < offsets.length; ++i) {
	serializeField(context, codedOut, obj, offsets[i].type, offsets[i].offset);
	}
	}

	/**
	* Serializes a field.
	*
	* @param obj the object containing the field to serialize. Can be an array or plain object.
	* @param type class of the field to serialize
	* @param offset unsafe offset into obj where the field will be found
	*/
	private void serializeField(
	SerializationContext context,
	CodedOutputStream codedOut,
	Object obj,
	Class<?> type,
	long offset)
	throws SerializationException, IOException {
	if (type.isPrimitive()) {
	if (type.equals(boolean.class)) {
	codedOut.writeBoolNoTag(UnsafeProvider.getInstance().getBoolean(obj, offset));
	} else if (type.equals(byte.class)) {
	codedOut.writeRawByte(UnsafeProvider.getInstance().getByte(obj, offset));
	} else if (type.equals(short.class)) {
	ByteBuffer buffer =
	ByteBuffer.allocate(2).putShort(UnsafeProvider.getInstance().getShort(obj, offset));
	codedOut.writeRawBytes(buffer);
	} else if (type.equals(char.class)) {
	ByteBuffer buffer =
	ByteBuffer.allocate(2).putChar(UnsafeProvider.getInstance().getChar(obj, offset));
	codedOut.writeRawBytes(buffer);
	} else if (type.equals(int.class)) {
	codedOut.writeInt32NoTag(UnsafeProvider.getInstance().getInt(obj, offset));
	} else if (type.equals(long.class)) {
	codedOut.writeInt64NoTag(UnsafeProvider.getInstance().getLong(obj, offset));
	} else if (type.equals(float.class)) {
	codedOut.writeFloatNoTag(UnsafeProvider.getInstance().getFloat(obj, offset));
	} else if (type.equals(double.class)) {
	codedOut.writeDoubleNoTag(UnsafeProvider.getInstance().getDouble(obj, offset));
	} else if (type.equals(void.class)) {
	// Does nothing for void type.
	} else {
	throw new UnsupportedOperationException("Unknown primitive type: " + type);
	}
	} else if (type.isArray()) {
	Object arr = UnsafeProvider.getInstance().getObject(obj, offset);
	if (type.getComponentType().equals(byte.class)) {
	if (arr == null) {
	codedOut.writeBoolNoTag(false);
	} else {
	codedOut.writeBoolNoTag(true);
	codedOut.writeByteArrayNoTag((byte[]) arr);
	}
	return;
	}
	if (arr == null) {
	codedOut.writeInt32NoTag(-1);
	return;
	}
	int length = Array.getLength(arr);
	codedOut.writeInt32NoTag(length);
	int base = UnsafeProvider.getInstance().arrayBaseOffset(type);
	int scale = UnsafeProvider.getInstance().arrayIndexScale(type);
	if (scale == 0) {
	throw new SerializationException("Failed to get index scale for type: " + type);
	}
	for (int i = 0; i < length; ++i) {
	// Serializes the ith array field directly from array memory.
	serializeField(context, codedOut, arr, type.getComponentType(), base + scale * i);
	}
	} else {
	try {
	context.serialize(UnsafeProvider.getInstance().getObject(obj, offset), codedOut);
	} catch (SerializationException e) {
	e.addTrail(this.type);
	throw e;
	}
	}
	}

	@Override
	public Object deserialize(DeserializationContext context, CodedInputStream codedIn)
	throws SerializationException, IOException {
	Object instance;
	try {
	instance = constructor.newInstance();
	} catch (ReflectiveOperationException e) {
	throw new SerializationException("Could not instantiate object of type: " + type, e);
	}
	context.registerInitialValue(instance);
	for (int i = 0; i < offsets.length; ++i) {
	deserializeField(context, codedIn, instance, offsets[i].type, offsets[i].offset);
	}
	return instance;
	}

	/**
	* Deserializes a field directly into the supplied object.
	*
	* @param obj the object containing the field to deserialize. Can be an array or a plain object.
	* @param type class of the field to deserialize
	* @param offset unsafe offset into obj where the field should be written
	*/
	private void deserializeField(
	DeserializationContext context,
	CodedInputStream codedIn,
	Object obj,
	Class<?> type,
	long offset)
	throws SerializationException, IOException {
	if (type.isPrimitive()) {
	if (type.equals(boolean.class)) {
	UnsafeProvider.getInstance().putBoolean(obj, offset, codedIn.readBool());
	} else if (type.equals(byte.class)) {
	UnsafeProvider.getInstance().putByte(obj, offset, codedIn.readRawByte());
	} else if (type.equals(short.class)) {
	ByteBuffer buffer = ByteBuffer.allocate(2).put(codedIn.readRawBytes(2));
	UnsafeProvider.getInstance().putShort(obj, offset, buffer.getShort(0));
	} else if (type.equals(char.class)) {
	ByteBuffer buffer = ByteBuffer.allocate(2).put(codedIn.readRawBytes(2));
	UnsafeProvider.getInstance().putChar(obj, offset, buffer.getChar(0));
	} else if (type.equals(int.class)) {
	UnsafeProvider.getInstance().putInt(obj, offset, codedIn.readInt32());
	} else if (type.equals(long.class)) {
	UnsafeProvider.getInstance().putLong(obj, offset, codedIn.readInt64());
	} else if (type.equals(float.class)) {
	UnsafeProvider.getInstance().putFloat(obj, offset, codedIn.readFloat());
	} else if (type.equals(double.class)) {
	UnsafeProvider.getInstance().putDouble(obj, offset, codedIn.readDouble());
	} else if (type.equals(void.class)) {
	// Does nothing for void type.
	} else {
	throw new UnsupportedOperationException("Unknown primitive type: " + type);
	}
	} else if (type.isArray()) {
	if (type.getComponentType().equals(byte.class)) {
	boolean isNonNull = codedIn.readBool();
	UnsafeProvider.getInstance()
	.putObject(obj, offset, isNonNull ? codedIn.readByteArray() : null);
	return;
	}
	int length = codedIn.readInt32();
	if (length < 0) {
	UnsafeProvider.getInstance().putObject(obj, offset, null);
	return;
	}
	Object arr = Array.newInstance(type.getComponentType(), length);
	UnsafeProvider.getInstance().putObject(obj, offset, arr);
	int base = UnsafeProvider.getInstance().arrayBaseOffset(type);
	int scale = UnsafeProvider.getInstance().arrayIndexScale(type);
	if (scale == 0) {
	throw new SerializationException("Failed to get index scale for type: " + type);
	}
	for (int i = 0; i < length; ++i) {
	// Deserializes type directly into array memory.
	deserializeField(context, codedIn, arr, type.getComponentType(), base + scale * i);
	}
	} else {
	UnsafeProvider.getInstance().putObject(obj, offset, context.deserialize(codedIn));
	}
	}

	private static <T> TypeAndOffset[] getOffsets(Class<T> type) {
	TreeMap<Field, Long> offsets = new TreeMap<>(new FieldComparator());
	for (Class<? super T> next = type; next != null; next = next.getSuperclass()) {
	for (Field field : next.getDeclaredFields()) {
	if ((field.getModifiers() & (Modifier.STATIC \| Modifier.TRANSIENT)) != 0) {
	continue; // Skips static or transient fields.
	}
	field.setAccessible(true);
	offsets.put(field, UnsafeProvider.getInstance().objectFieldOffset(field));
	}
	}
	// Converts to an array to make it easy to avoid the use of iterators.
	TypeAndOffset[] offsetsArr = new TypeAndOffset[offsets.size()];
	int i = 0;
	for (Map.Entry<Field, Long> entry : offsets.entrySet()) {
	offsetsArr[i] = new TypeAndOffset(entry.getKey().getType(), entry.getValue());
	++i;
	}
	return offsetsArr;
	}

	private static class TypeAndOffset {
	public final Class<?> type;
	public final long offset;

	public TypeAndOffset(Class<?> type, long offset) {
	this.type = type;
	this.offset = offset;
	}
	}

	private static Constructor<?> getConstructor(Class<?> type) throws ReflectiveOperationException {
	Constructor<?> constructor =
	ReflectionFactory.getReflectionFactory()
	.newConstructorForSerialization(type, Object.class.getDeclaredConstructor());
	constructor.setAccessible(true);
	return constructor;
	}

	private static class FieldComparator implements Comparator<Field> {

	@Override
	public int compare(Field f1, Field f2) {
	int classCompare =
	f1.getDeclaringClass().getName().compareTo(f2.getDeclaringClass().getName());
	if (classCompare != 0) {
	return classCompare;
	}
	return f1.getName().compareTo(f2.getName());
	}
	}
	}