/*
* 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.flink.api.java.tuple;
import org.apache.flink.util.FileUtils;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Scanner;
/**
* Source code generator for tuple classes and classes which depend on the arity of tuples.
*/
class TupleGenerator {
// Parameters for tuple classes
private static final String ROOT_DIRECTORY = "./flink-core/src/main/java";
private static final String PACKAGE = "org.apache.flink.api.java.tuple";
private static final String BUILDER_SUFFIX = "builder";
private static final String GEN_TYPE_PREFIX = "T";
// Parameters for tuple-dependent classes
private static final String BEGIN_INDICATOR = "BEGIN_OF_TUPLE_DEPENDENT_CODE";
private static final String END_INDICATOR = "END_OF_TUPLE_DEPENDENT_CODE";
// Parameters for TupleTypeInfo
private static final String TUPLE_PACKAGE = "org.apache.flink.api.java.tuple";
private static final String TUPLE_CLASSNAME = "Tuple";
// min. and max. tuple arity
private static final int FIRST = 1;
private static final int LAST = 25;
public static void main(String[] args) throws Exception {
System.err.println("Current directory "+System.getProperty("user.dir"));
String rootDir = ROOT_DIRECTORY;
if(args.length > 0) {
rootDir = args[0] + "/" + ROOT_DIRECTORY;
}
System.err.println("Using root directory: "+rootDir);
File root = new File(rootDir);
createTupleClasses(root);
createTupleBuilderClasses(root);
modifyTupleType(root);
}
private static File getPackage(File root, String packageString) {
File dir = new File(root, packageString.replace('.', '/'));
if (!dir.exists() && dir.isDirectory()) {
System.err.println("None existent directory: " + dir.getAbsolutePath());
System.exit(1);
}
return dir;
}
private static void insertCodeIntoFile(String code, File file) throws IOException {
String fileContent = FileUtils.readFileUtf8(file);
try (Scanner s = new Scanner(fileContent)) {
StringBuilder sb = new StringBuilder();
String line;
boolean indicatorFound = false;
// add file beginning
while (s.hasNextLine() && (line = s.nextLine()) != null) {
sb.append(line).append("\n");
if (line.contains(BEGIN_INDICATOR)) {
indicatorFound = true;
break;
}
}
if(!indicatorFound) {
System.out.println("No indicator found in '" + file + "'. Will skip code generation.");
s.close();
return;
}
// add generator signature
sb.append("\t// GENERATED FROM ").append(TupleGenerator.class.getName()).append(".\n");
// add tuple dependent code
sb.append(code).append("\n");
// skip generated code
while (s.hasNextLine() && (line = s.nextLine()) != null) {
if (line.contains(END_INDICATOR)) {
sb.append(line).append("\n");
break;
}
}
// add file ending
while (s.hasNextLine() && (line = s.nextLine()) != null) {
sb.append(line).append("\n");
}
FileUtils.writeFileUtf8(file, sb.toString());
}
}
private static void modifyTupleType(File root) throws IOException {
// generate code
StringBuilder sb = new StringBuilder();
sb.append("\tprivate static final Class<?>[] CLASSES = new Class<?>[] {\n\t\tTuple0.class");
for (int i = FIRST; i <= LAST; i++) {
sb.append(", Tuple").append(i).append(".class");
}
sb.append("\n\t};");
// insert code into file
File dir = getPackage(root, TUPLE_PACKAGE);
File tupleTypeInfoClass = new File(dir, TUPLE_CLASSNAME + ".java");
insertCodeIntoFile(sb.toString(), tupleTypeInfoClass);
}
private static void createTupleClasses(File root) throws FileNotFoundException {
File dir = getPackage(root, PACKAGE);
for (int i = FIRST; i <= LAST; i++) {
File tupleFile = new File(dir, "Tuple" + i + ".java");
PrintWriter writer = new PrintWriter(tupleFile);
writeTupleClass(writer, i);
writer.flush();
writer.close();
}
}
private static void writeTupleClass(PrintWriter w, int numFields) {
final String className = "Tuple" + numFields;
// head
w.print(HEADER);
// package and imports
w.println("package " + PACKAGE + ';');
w.println();
w.println("import org.apache.flink.annotation.Public;");
w.println("import org.apache.flink.util.StringUtils;");
w.println();
// class declaration and class comments
w.println("/**");
w.println(" * A tuple with " + numFields + " fields. Tuples are strongly typed; each field may be of a separate type.");
w.println(" * The fields of the tuple can be accessed directly as public fields (f0, f1, ...) or via their position");
w.println(" * through the {@link #getField(int)} method. The tuple field positions start at zero.");
w.println(" *");
w.println(" * <p>Tuples are mutable types, meaning that their fields can be re-assigned. This allows functions that work");
w.println(" * with Tuples to reuse objects in order to reduce pressure on the garbage collector.</p>");
w.println(" *");
w.println(" * <p>Warning: If you subclass " + className + ", then be sure to either <ul>");
w.println(" * <li> not add any new fields, or </li>");
w.println(" * <li> make it a POJO, and always declare the element type of your DataStreams/DataSets to your descendant");
w.println(" * type. (That is, if you have a \"class Foo extends " + className + "\", then don't use instances of");
w.println(" * Foo in a DataStream<" + className + "> / DataSet<" + className + ">, but declare it as");
w.println(" * DataStream<Foo> / DataSet<Foo>.) </li>");
w.println(" * </ul></p>");
w.println(" * @see Tuple");
w.println(" *");
for (int i = 0; i < numFields; i++) {
w.println(" * @param <" + GEN_TYPE_PREFIX + i + "> The type of field " + i);
}
w.println(" */");
w.println("@Public");
w.print("public class " + className + "<");
for (int i = 0; i < numFields; i++) {
if (i > 0) {
w.print(", ");
}
w.print(GEN_TYPE_PREFIX + i);
}
w.println("> extends Tuple {");
w.println();
w.println("\tprivate static final long serialVersionUID = 1L;");
w.println();
// fields
for (int i = 0; i < numFields; i++) {
w.println("\t/** Field " + i + " of the tuple. */");
w.println("\tpublic " + GEN_TYPE_PREFIX + i + " f" + i + ';');
}
w.println();
String paramList = "("; // This will be like "(T0 value0, T1 value1)"
for (int i = 0; i < numFields; i++) {
if (i > 0) {
paramList += ", ";
}
paramList += GEN_TYPE_PREFIX + i + " value" + i;
}
paramList += ")";
// constructors
w.println("\t/**");
w.println("\t * Creates a new tuple where all fields are null.");
w.println("\t */");
w.println("\tpublic " + className + "() {}");
w.println();
w.println("\t/**");
w.println("\t * Creates a new tuple and assigns the given values to the tuple's fields.");
w.println("\t *");
for (int i = 0; i < numFields; i++) {
w.println("\t * @param value" + i + " The value for field " + i);
}
w.println("\t */");
w.println("\tpublic " + className + paramList + " {");
for (int i = 0; i < numFields; i++) {
w.println("\t\tthis.f" + i + " = value" + i + ';');
}
w.println("\t}");
w.println();
// arity accessor
w.println("\t@Override");
w.println("\tpublic int getArity() { return " + numFields + "; }");
w.println();
// accessor getter method
w.println("\t@Override");
w.println("\t@SuppressWarnings(\"unchecked\")");
w.println("\tpublic <T> T getField(int pos) {");
w.println("\t\tswitch(pos) {");
for (int i = 0; i < numFields; i++) {
w.println("\t\t\tcase " + i + ": return (T) this.f" + i + ';');
}
w.println("\t\t\tdefault: throw new IndexOutOfBoundsException(String.valueOf(pos));");
w.println("\t\t}");
w.println("\t}");
w.println();
// accessor setter method
w.println("\t@Override");
w.println("\t@SuppressWarnings(\"unchecked\")");
w.println("\tpublic <T> void setField(T value, int pos) {");
w.println("\t\tswitch(pos) {");
for (int i = 0; i < numFields; i++) {
w.println("\t\t\tcase " + i + ':');
w.println("\t\t\t\tthis.f" + i + " = (" + GEN_TYPE_PREFIX + i + ") value;");
w.println("\t\t\t\tbreak;");
}
w.println("\t\t\tdefault: throw new IndexOutOfBoundsException(String.valueOf(pos));");
w.println("\t\t}");
w.println("\t}");
w.println();
// accessor setter method for all fields
w.println("\t/**");
w.println("\t * Sets new values to all fields of the tuple.");
w.println("\t *");
for (int i = 0; i < numFields; i++) {
w.println("\t * @param value" + i + " The value for field " + i);
}
w.println("\t */");
w.println("\tpublic void setFields" + paramList + " {");
for (int i = 0; i < numFields; i++) {
w.println("\t\tthis.f" + i + " = value" + i + ';');
}
w.println("\t}");
w.println();
// swap method only for Tuple2
if (numFields == 2) {
w.println("\t/**");
w.println("\t* Returns a shallow copy of the tuple with swapped values.");
w.println("\t*");
w.println("\t* @return shallow copy of the tuple with swapped values");
w.println("\t*/");
w.println("\tpublic Tuple2<T1, T0> swap() {");
w.println("\t\treturn new Tuple2<T1, T0>(f1, f0);");
w.println("\t}");
}
// standard utilities (toString, equals, hashCode, copy)
w.println();
w.println("\t// -------------------------------------------------------------------------------------------------");
w.println("\t// standard utilities");
w.println("\t// -------------------------------------------------------------------------------------------------");
w.println();
w.println("\t/**");
w.println("\t * Creates a string representation of the tuple in the form");
w.print("\t * (f0");
for (int i = 1; i < numFields; i++) {
w.print(", f" + i);
}
w.println("),");
w.println("\t * where the individual fields are the value returned by calling {@link Object#toString} on that field.");
w.println("\t * @return The string representation of the tuple.");
w.println("\t */");
w.println("\t@Override");
w.println("\tpublic String toString() {");
w.println("\t\treturn \"(\" + StringUtils.arrayAwareToString(this.f0)");
for (int i = 1; i < numFields; i++) {
w.println("\t\t\t+ \",\" + StringUtils.arrayAwareToString(this.f" + i + ")");
}
w.println("\t\t\t+ \")\";");
w.println("\t}");
w.println();
w.println("\t/**");
w.println("\t * Deep equality for tuples by calling equals() on the tuple members");
w.println("\t * @param o the object checked for equality");
w.println("\t * @return true if this is equal to o.");
w.println("\t */");
w.println("\t@Override");
w.println("\tpublic boolean equals(Object o) {");
w.println("\t\tif(this == o) { return true; }");
w.println("\t\tif (!(o instanceof " + className + ")) { return false; }");
w.println("\t\t@SuppressWarnings(\"rawtypes\")");
w.println("\t\t" + className + " tuple = (" + className + ") o;");
for (int i = 0; i < numFields; i++) {
String field = "f" + i;
w.println("\t\tif (" + field + " != null ? !" + field +".equals(tuple." +
field + ") : tuple." + field + " != null) { return false; }");
}
w.println("\t\treturn true;");
w.println("\t}");
w.println();
w.println("\t@Override");
w.println("\tpublic int hashCode() {");
w.println("\t\tint result = f0 != null ? f0.hashCode() : 0;");
for (int i = 1; i < numFields; i++) {
String field = "f" + i;
w.println("\t\tresult = 31 * result + (" + field + " != null ? " + field + ".hashCode() : 0);");
}
w.println("\t\treturn result;");
w.println("\t}");
String tupleTypes = "<";
for (int i = 0; i < numFields; i++) {
tupleTypes += "T" + i;
if (i < numFields - 1) {
tupleTypes += ",";
}
}
tupleTypes += ">";
w.println();
w.println("\t/**");
w.println("\t* Shallow tuple copy.");
w.println("\t* @return A new Tuple with the same fields as this.");
w.println("\t*/");
w.println("\t@Override");
w.println("\t@SuppressWarnings(\"unchecked\")");
w.println("\tpublic " + className + tupleTypes + " copy(){ ");
w.print("\t\treturn new " + className + tupleTypes + "(this.f0");
if (numFields > 1) {
w.println(",");
}
for (int i = 1; i < numFields; i++) {
String field = "f" + i;
w.print("\t\t\tthis." + field);
if (i < numFields - 1) {
w.println(",");
}
}
w.println(");");
w.println("\t}");
w.println();
w.println("\t/**");
w.println("\t * Creates a new tuple and assigns the given values to the tuple's fields.");
w.println("\t * This is more convenient than using the constructor, because the compiler can");
w.println("\t * infer the generic type arguments implicitly. For example:");
w.println("\t * {@code Tuple3.of(n, x, s)}");
w.println("\t * instead of");
w.println("\t * {@code new Tuple3<Integer, Double, String>(n, x, s)}");
w.println("\t */");
w.println("\tpublic static " + tupleTypes + " " + className + tupleTypes + " of" + paramList + " {");
w.print("\t\treturn new " + className + tupleTypes + "(");
for(int i = 0; i < numFields; i++) {
w.print("value" + i);
if(i < numFields - 1) {
w.print(", ");
}
}
w.println(");");
w.println("\t}");
// foot
w.println("}");
}
private static void createTupleBuilderClasses(File root) throws FileNotFoundException {
File dir = getPackage(root, PACKAGE+"."+BUILDER_SUFFIX);
for (int i = FIRST; i <= LAST; i++) {
File tupleFile = new File(dir, "Tuple" + i + "Builder.java");
PrintWriter writer = new PrintWriter(tupleFile);
writeTupleBuilderClass(writer, i);
writer.flush();
writer.close();
}
}
private static void printGenericsString(PrintWriter w, int numFields){
w.print("<");
for (int i = 0; i < numFields; i++) {
if (i > 0) {
w.print(", ");
}
w.print(GEN_TYPE_PREFIX + i);
}
w.print(">");
}
private static void writeTupleBuilderClass(PrintWriter w, int numFields) {
final String className = "Tuple" + numFields + "Builder";
// head
w.print(HEADER);
// package and imports
w.println("package " + PACKAGE + "." + BUILDER_SUFFIX + ';');
w.println();
w.println("import java.util.ArrayList;");
w.println("import java.util.List;");
w.println();
w.println("import org.apache.flink.annotation.Public;");
w.println("import " + PACKAGE + ".Tuple" + numFields + ";");
w.println();
// class declaration
w.println("@Public");
w.print("public class " + className);
printGenericsString(w, numFields);
w.println(" {");
w.println();
// Class-Attributes - a list of tuples
w.print("\tprivate List<Tuple" + numFields);
printGenericsString(w, numFields);
w.println("> tuples = new ArrayList<>();");
w.println();
// add(...) function for adding a single tuple
w.print("\tpublic " + className);
printGenericsString(w, numFields);
w.print(" add(");
for (int i = 0; i < numFields; i++) {
if (i > 0) {
w.print(", ");
}
w.print(GEN_TYPE_PREFIX + i + " value" + i);
}
w.println("){");
w.print("\t\ttuples.add(new Tuple" + numFields + "<>(");
for (int i = 0; i < numFields; i++) {
if (i > 0) {
w.print(", ");
}
w.print("value" + i);
}
w.println("));");
w.println("\t\treturn this;");
w.println("\t}");
w.println();
// build() function, returns an array of tuples
w.println("\t@SuppressWarnings(\"unchecked\")");
w.print("\tpublic Tuple" + numFields);
printGenericsString(w, numFields);
w.println("[] build(){");
w.println("\t\treturn tuples.toArray(new Tuple" + numFields + "[tuples.size()]);");
w.println("\t}");
// foot
w.println("}");
}
private static String HEADER =
"/*\n"
+ " * Licensed to the Apache Software Foundation (ASF) under one\n"
+ " * or more contributor license agreements. See the NOTICE file\n"
+ " * distributed with this work for additional information\n"
+ " * regarding copyright ownership. The ASF licenses this file\n"
+ " * to you under the Apache License, Version 2.0 (the\n"
+ " * \"License\"); you may not use this file except in compliance\n"
+ " * with the License. You may obtain a copy of the License at\n"
+ " *\n"
+ " * http://www.apache.org/licenses/LICENSE-2.0\n"
+ " *\n"
+ " * Unless required by applicable law or agreed to in writing, software\n"
+ " * distributed under the License is distributed on an \"AS IS\" BASIS,\n"
+ " * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n"
+ " * See the License for the specific language governing permissions and\n"
+ " * limitations under the License.\n"
+ " */" +
"\n" +
"\n" +
"\n" +
"// --------------------------------------------------------------\n" +
"// THIS IS A GENERATED SOURCE FILE. DO NOT EDIT!\n" +
"// GENERATED FROM " + TupleGenerator.class.getName() + ".\n" +
"// --------------------------------------------------------------\n\n\n";
}