/*
* Copyright 2008 Google Inc.
*
* 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.gwt.user.rebind.rpc;
import com.google.gwt.core.client.UnsafeNativeLong;
import com.google.gwt.core.client.impl.WeakMapping;
import com.google.gwt.core.ext.GeneratorContext;
import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.core.ext.typeinfo.JArrayType;
import com.google.gwt.core.ext.typeinfo.JClassType;
import com.google.gwt.core.ext.typeinfo.JEnumType;
import com.google.gwt.core.ext.typeinfo.JField;
import com.google.gwt.core.ext.typeinfo.JPrimitiveType;
import com.google.gwt.core.ext.typeinfo.JType;
import com.google.gwt.core.ext.typeinfo.TypeOracle;
import com.google.gwt.dev.javac.TypeOracleMediator;
import com.google.gwt.user.client.rpc.SerializationException;
import com.google.gwt.user.client.rpc.SerializationStreamReader;
import com.google.gwt.user.client.rpc.SerializationStreamWriter;
import com.google.gwt.user.client.rpc.core.java.lang.Object_Array_CustomFieldSerializer;
import com.google.gwt.user.rebind.ClassSourceFileComposerFactory;
import com.google.gwt.user.rebind.SourceWriter;
import java.io.PrintWriter;
/**
* Creates a field serializer for a class that implements
* {@link com.google.gwt.user.client.rpc.IsSerializable IsSerializable} or
* {@link java.io.Serializable Serializable}. The field serializer is emitted
* into the same package as the class that it serializes.
*
* TODO(mmendez): Need to make the generated field serializers final
* TODO(mmendez): Would be nice to be able to have imports, rather than using
* fully qualified type names everywhere
*/
public class FieldSerializerCreator {
private static final String WEAK_MAPPING_CLASS_NAME = WeakMapping.class.getName();
private final JClassType serializableClass;
private final JField[] serializableFields;
private SourceWriter sourceWriter;
private final SerializableTypeOracle typesSentFromBrowser;
private final SerializableTypeOracle typesSentToBrowser;
private final TypeOracle typeOracle;
/**
* Constructs a field serializer for the class.
*/
public FieldSerializerCreator(TypeOracle typeOracle,
SerializableTypeOracle typesSentFromBrowser,
SerializableTypeOracle typesSentToBrowser, JClassType requestedClass) {
assert (requestedClass != null);
assert (requestedClass.isClass() != null || requestedClass.isArray() != null);
this.typeOracle = typeOracle;
this.typesSentFromBrowser = typesSentFromBrowser;
this.typesSentToBrowser = typesSentToBrowser;
serializableClass = requestedClass;
serializableFields = SerializationUtils.getSerializableFields(typeOracle,
requestedClass);
}
public String realize(TreeLogger logger, GeneratorContext ctx) {
assert (ctx != null);
assert (typesSentFromBrowser.isSerializable(serializableClass) || typesSentToBrowser.isSerializable(serializableClass));
logger = logger.branch(TreeLogger.DEBUG,
"Generating a field serializer for type '"
+ serializableClass.getQualifiedSourceName() + "'", null);
String fieldSerializerName = SerializationUtils.getFieldSerializerName(
typeOracle, serializableClass);
sourceWriter = getSourceWriter(logger, ctx);
if (sourceWriter == null) {
return fieldSerializerName;
}
assert sourceWriter != null;
writeFieldAccessors();
writeDeserializeMethod();
maybeWriteInstatiateMethod();
writeSerializeMethod();
sourceWriter.commit(logger);
return fieldSerializerName;
}
private String createArrayInstantiationExpression(JArrayType array) {
StringBuilder sb = new StringBuilder();
sb.append("new ");
sb.append(array.getLeafType().getQualifiedSourceName());
sb.append("[rank]");
for (int i = 0; i < array.getRank() - 1; ++i) {
sb.append("[]");
}
return sb.toString();
}
private SourceWriter getSourceWriter(TreeLogger logger, GeneratorContext ctx) {
String qualifiedSerializerName = SerializationUtils.getFieldSerializerName(
typeOracle, serializableClass);
int packageNameEnd = qualifiedSerializerName.lastIndexOf('.');
String className;
String packageName;
if (packageNameEnd != -1) {
className = qualifiedSerializerName.substring(packageNameEnd + 1);
packageName = qualifiedSerializerName.substring(0, packageNameEnd);
} else {
className = qualifiedSerializerName;
packageName = "";
}
PrintWriter printWriter = ctx.tryCreate(logger, packageName, className);
if (printWriter == null) {
return null;
}
ClassSourceFileComposerFactory composerFactory = new ClassSourceFileComposerFactory(
packageName, className);
return composerFactory.createSourceWriter(ctx, printWriter);
}
private void maybeSuppressLongWarnings(JType fieldType) {
if (fieldType == JPrimitiveType.LONG) {
/**
* Accessing long from JSNI causes a error, but field serializers need to
* be able to do just that in order to bypass java accessibility
* restrictions.
*/
sourceWriter.println("@" + UnsafeNativeLong.class.getName());
}
}
private void maybeWriteInstatiateMethod() {
if (serializableClass.isEnum() == null
&& (serializableClass.isAbstract() || !serializableClass.isDefaultInstantiable())) {
/*
* Field serializers are shared by all of the RemoteService proxies in a
* compilation. Therefore, we have to generate an instantiate method even
* if the type is not instantiable relative to the RemoteService which
* caused this field serializer to be created. If the type is not
* instantiable relative to any of the RemoteService proxies, dead code
* optimizations will cause the method to be removed from the compiled
* output.
*
* Enumerated types require an instantiate method even if they are
* abstract. You will have an abstract enum in cases where the enum type
* is sub-classed. Non-default instantiable classes cannot have
* instantiate methods.
*/
return;
}
JArrayType isArray = serializableClass.isArray();
JEnumType isEnum = serializableClass.isEnum();
boolean isNative = (isArray == null) && (isEnum == null);
sourceWriter.print("public static" + (isNative ? " native " : " "));
String qualifiedSourceName = serializableClass.getQualifiedSourceName();
sourceWriter.print(qualifiedSourceName);
sourceWriter.print(" instantiate(");
sourceWriter.print(SerializationStreamReader.class.getName());
sourceWriter.println(" streamReader) throws "
+ SerializationException.class.getName() + (isNative ? "/*-{" : "{"));
sourceWriter.indent();
if (isArray != null) {
sourceWriter.println("int rank = streamReader.readInt();");
sourceWriter.println("return "
+ createArrayInstantiationExpression(isArray) + ";");
} else if (isEnum != null) {
sourceWriter.println("int ordinal = streamReader.readInt();");
sourceWriter.println(qualifiedSourceName + "[] values = "
+ qualifiedSourceName + ".values();");
sourceWriter.println("assert (ordinal >= 0 && ordinal < values.length);");
sourceWriter.println("return values[ordinal];");
} else {
sourceWriter.println("return @" + qualifiedSourceName + "::new()();");
}
sourceWriter.outdent();
sourceWriter.println(isNative ? "}-*/;" : "}");
sourceWriter.println();
}
/**
* Returns true if we will need a get/set method pair for a field.
*
* @return true if the the field requires accessor methods
*/
private boolean needsAccessorMethods(JField field) {
/*
* Field serializers are always emitted into the the same package as the
* class that they serialize. This enables the serializer class to access
* all fields except those that are private.
*
* Java Access Levels: default - package private - class only protected -
* package and all subclasses public - all
*/
return field.isPrivate();
}
private void writeArrayDeserializationStatements(JArrayType isArray) {
JType componentType = isArray.getComponentType();
String readMethodName = Shared.getStreamReadMethodNameFor(componentType);
if ("readObject".equals(readMethodName)) {
// Optimize and use the default object custom serializer...
sourceWriter.println(Object_Array_CustomFieldSerializer.class.getName()
+ ".deserialize(streamReader, instance);");
} else {
sourceWriter.println("for (int i = 0, n = instance.length; i < n; ++i) {");
sourceWriter.indent();
sourceWriter.print("instance[i] = streamReader.");
sourceWriter.println(readMethodName + "();");
sourceWriter.outdent();
sourceWriter.println("}");
}
}
private void writeArraySerializationStatements(JArrayType isArray) {
JType componentType = isArray.getComponentType();
String writeMethodName = Shared.getStreamWriteMethodNameFor(componentType);
if ("writeObject".equals(writeMethodName)) {
// Optimize and use the default object custom serializer...
sourceWriter.println(Object_Array_CustomFieldSerializer.class.getName()
+ ".serialize(streamWriter, instance);");
} else {
sourceWriter.println("streamWriter.writeInt(instance.length);");
sourceWriter.println();
sourceWriter.println("for (int i = 0, n = instance.length; i < n; ++i) {");
sourceWriter.indent();
sourceWriter.print("streamWriter.");
sourceWriter.print(writeMethodName);
sourceWriter.println("(instance[i]);");
sourceWriter.outdent();
sourceWriter.println("}");
}
}
private void writeClassDeserializationStatements() {
/**
* If the type is capable of making a round trip between the client and
* server, store additional server-only field data using {@link WeakMapping}.
*/
if (typesSentToBrowser.maybeEnhanced(serializableClass)
&& typesSentFromBrowser.maybeEnhanced(serializableClass)) {
sourceWriter.println(WEAK_MAPPING_CLASS_NAME + ".set(instance, "
+ "\"server-enhanced-data\", streamReader.readString());");
}
for (JField serializableField : serializableFields) {
JType fieldType = serializableField.getType();
String readMethodName = Shared.getStreamReadMethodNameFor(fieldType);
String streamReadExpression = "streamReader." + readMethodName + "()";
if (Shared.typeNeedsCast(fieldType)) {
streamReadExpression = "(" + fieldType.getQualifiedSourceName() + ") "
+ streamReadExpression;
}
if (needsAccessorMethods(serializableField)) {
sourceWriter.print("set");
sourceWriter.print(Shared.capitalize(serializableField.getName()));
sourceWriter.print("(instance, ");
sourceWriter.print(streamReadExpression);
sourceWriter.println(");");
} else {
sourceWriter.print("instance.");
sourceWriter.print(serializableField.getName());
sourceWriter.print(" = ");
sourceWriter.print(streamReadExpression);
sourceWriter.println(";");
}
}
sourceWriter.println();
JClassType superClass = serializableClass.getSuperclass();
if (superClass != null
&& (typesSentFromBrowser.isSerializable(superClass) || typesSentToBrowser.isSerializable(superClass))) {
String fieldSerializerName = SerializationUtils.getFieldSerializerName(
typeOracle, superClass);
sourceWriter.print(fieldSerializerName);
sourceWriter.println(".deserialize(streamReader, instance);");
}
}
private void writeClassSerializationStatements() {
/**
* If the type is capable of making a round trip between the client and
* server, retrieve the additional server-only field data from {@link WeakMapping}.
*/
if (typesSentToBrowser.maybeEnhanced(serializableClass)
&& typesSentFromBrowser.maybeEnhanced(serializableClass)) {
sourceWriter.println("streamWriter.writeString((String) "
+ WEAK_MAPPING_CLASS_NAME + ".get(instance, \"server-enhanced-data\"));");
}
for (JField serializableField : serializableFields) {
JType fieldType = serializableField.getType();
String writeMethodName = Shared.getStreamWriteMethodNameFor(fieldType);
sourceWriter.print("streamWriter.");
sourceWriter.print(writeMethodName);
sourceWriter.print("(");
if (needsAccessorMethods(serializableField)) {
sourceWriter.print("get");
sourceWriter.print(Shared.capitalize(serializableField.getName()));
sourceWriter.println("(instance));");
} else {
sourceWriter.print("instance.");
sourceWriter.print(serializableField.getName());
sourceWriter.println(");");
}
}
sourceWriter.println();
JClassType superClass = serializableClass.getSuperclass();
if (superClass != null
&& (typesSentFromBrowser.isSerializable(superClass) || typesSentToBrowser.isSerializable(superClass))) {
String fieldSerializerName = SerializationUtils.getFieldSerializerName(
typeOracle, superClass);
sourceWriter.print(fieldSerializerName);
sourceWriter.println(".serialize(streamWriter, instance);");
}
}
private void writeDeserializeMethod() {
sourceWriter.print("public static void deserialize(");
sourceWriter.print(SerializationStreamReader.class.getName());
sourceWriter.print(" streamReader, ");
sourceWriter.print(serializableClass.getQualifiedSourceName());
sourceWriter.println(" instance) throws "
+ SerializationException.class.getName() + "{");
sourceWriter.indent();
JArrayType isArray = serializableClass.isArray();
if (isArray != null) {
writeArrayDeserializationStatements(isArray);
} else if (serializableClass.isEnum() != null) {
writeEnumDeserializationStatements();
} else {
writeClassDeserializationStatements();
}
sourceWriter.outdent();
sourceWriter.println("}");
sourceWriter.println();
}
private void writeEnumDeserializationStatements() {
sourceWriter.println("// Enum deserialization is handled via the instantiate method");
}
private void writeEnumSerializationStatements() {
sourceWriter.println("assert (instance != null);");
sourceWriter.println("streamWriter.writeInt(instance.ordinal());");
}
/**
* This method will generate a native JSNI accessor method for every field
* that is protected, private using the "Violator" pattern to allow an
* external class to access the field's value.
*/
private void writeFieldAccessors() {
for (JField serializableField : serializableFields) {
if (!needsAccessorMethods(serializableField)) {
continue;
}
writeFieldGet(serializableField);
writeFieldSet(serializableField);
}
}
/**
* Write a getter method for an instance field.
*/
private void writeFieldGet(JField serializableField) {
JType fieldType = serializableField.getType();
String fieldTypeQualifiedSourceName = fieldType.getQualifiedSourceName();
String fieldName = serializableField.getName();
maybeSuppressLongWarnings(fieldType);
sourceWriter.print("private static native ");
sourceWriter.print(fieldTypeQualifiedSourceName);
sourceWriter.print(" get");
sourceWriter.print(Shared.capitalize(fieldName));
sourceWriter.print("(");
sourceWriter.print(serializableClass.getQualifiedSourceName());
sourceWriter.println(" instance) /*-{");
sourceWriter.indent();
sourceWriter.print("return instance.@");
sourceWriter.print(TypeOracleMediator.computeBinaryClassName(serializableClass));
sourceWriter.print("::");
sourceWriter.print(fieldName);
sourceWriter.println(";");
sourceWriter.outdent();
sourceWriter.println("}-*/;");
sourceWriter.println();
}
/**
* Write a setter method for an instance field.
*/
private void writeFieldSet(JField serializableField) {
JType fieldType = serializableField.getType();
String fieldTypeQualifiedSourceName = fieldType.getQualifiedSourceName();
String serializableClassQualifedName = serializableClass.getQualifiedSourceName();
String fieldName = serializableField.getName();
maybeSuppressLongWarnings(fieldType);
sourceWriter.print("private static native void ");
sourceWriter.print(" set");
sourceWriter.print(Shared.capitalize(fieldName));
sourceWriter.print("(");
sourceWriter.print(serializableClassQualifedName);
sourceWriter.print(" instance, ");
sourceWriter.print(fieldTypeQualifiedSourceName);
sourceWriter.println(" value) /*-{");
sourceWriter.indent();
sourceWriter.print("instance.@");
sourceWriter.print(TypeOracleMediator.computeBinaryClassName(serializableClass));
sourceWriter.print("::");
sourceWriter.print(fieldName);
sourceWriter.println(" = value;");
sourceWriter.outdent();
sourceWriter.println("}-*/;");
sourceWriter.println();
}
private void writeSerializeMethod() {
sourceWriter.print("public static void serialize(");
sourceWriter.print(SerializationStreamWriter.class.getName());
sourceWriter.print(" streamWriter, ");
sourceWriter.print(serializableClass.getQualifiedSourceName());
sourceWriter.println(" instance) throws "
+ SerializationException.class.getName() + " {");
sourceWriter.indent();
JArrayType isArray = serializableClass.isArray();
if (isArray != null) {
writeArraySerializationStatements(isArray);
} else if (serializableClass.isEnum() != null) {
writeEnumSerializationStatements();
} else {
writeClassSerializationStatements();
}
sourceWriter.outdent();
sourceWriter.println("}");
sourceWriter.println();
}
}