/*
* Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code 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 General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.CharArrayReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.LineNumberReader;
import java.io.PipedReader;
import java.io.PipedWriter;
import java.io.PushbackReader;
import java.io.Reader;
import java.io.StringReader;
import java.io.UncheckedIOException;
import java.util.Arrays;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;
import java.util.function.Function;
import static java.lang.String.format;
/*
* @test
* @bug 8029689
* @summary checks the bounds part of the contract of java.io.Reader.read(char[], int, int):
*
* 0 <= off <= off+len <= cbuf.length
*
* for publicly exported subtypes of java.io.Reader
*/
public class ReaderBulkReadContract {
public static void main(String[] args) throws IOException {
ReaderBulkReadContract t = new ReaderBulkReadContract();
t.test();
}
private void test() throws IOException {
Iterator<Object[]> args = args();
while (args.hasNext()) {
Object[] a = args.next();
Reader r = (Reader) a[0];
int size = (int) a[1];
int off = (int) a[2];
int len = (int) a[3];
try {
read(r, size, off, len);
} finally {
r.close();
}
}
}
private Iterator<Object[]> args() {
Integer[] lens = {Integer.MIN_VALUE, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, Integer.MAX_VALUE};
Integer[] offs = {Integer.MIN_VALUE, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, Integer.MAX_VALUE};
Integer[] sizes = {0, 1, 2, 3, 4, 5};
String[] contents = {"", "a", "ab"};
List<Function<String, Reader>> fs = Arrays.asList(
(String s) -> new BufferedReader(new StringReader(s)),
(String s) -> new LineNumberReader(new StringReader(s)),
(String s) -> new CharArrayReader(s.toCharArray()),
(String s) -> new InputStreamReader(new ByteArrayInputStream(s.getBytes())),
(String s) -> newFileReader(s),
(String s) -> new PushbackReader(new StringReader(s)),
(String s) -> newPipedReader(s),
(String s) -> new StringReader(s)
);
// The easiest way to produce a cartesian product from a small fixed number of sets
List<Object[]> tuples = Collections.synchronizedList(new LinkedList<>());
for (Integer len : lens)
for (Integer off : offs)
for (String s : contents)
for (Integer size : sizes)
for (Function<String, Reader> f : fs)
tuples.add(new Object[]{f.apply(s), size, off, len});
return tuples.iterator();
}
private void read(Reader r, int size, int off, int len) throws IOException {
IndexOutOfBoundsException ex = null;
try {
r.read(new char[size], off, len);
} catch (IndexOutOfBoundsException e) {
ex = e;
}
boolean incorrectBounds = off < 0 || len < 0 || len > size - off;
boolean exceptionThrown = ex != null;
if (incorrectBounds != exceptionThrown) { // incorrectBounds iff exceptionThrown
throw new AssertionError(format("r=%s, size=%s, off=%s, len=%s, incorrectBounds=%s, exceptionThrown=%s",
r, size, off, len, incorrectBounds, exceptionThrown));
}
}
private static PipedReader newPipedReader(String contents) {
try (PipedWriter w = new PipedWriter()) {
PipedReader r = new PipedReader(w);
w.write(contents);
return r;
} catch (IOException e) {
throw new UncheckedIOException(e);
}
}
private FileReader newFileReader(String contents) {
try {
// To not create an enormous amount of files
File f = cache.computeIfAbsent(contents,
ReaderBulkReadContract::createTempFileWithContents);
return new FileReader(f);
} catch (IOException e) {
throw new UncheckedIOException(e);
}
}
private static File createTempFileWithContents(String contents) {
try {
File testDir = new File(System.getProperty("test.dir", "."));
File file = File.createTempFile("ReaderContract", "", testDir);
try (FileWriter w = new FileWriter(file)) {
w.write(contents);
}
return file;
} catch (IOException e) {
throw new UncheckedIOException(e);
}
}
//
// To avoid myriads of tiny files a cache is used.
// ConcurrentHashMap.computeIfAbsent promises a crucial thing:
//
// ...The entire method invocation is performed atomically, so the
// function is applied at most once per key...
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
private final ConcurrentHashMap<String, File> cache = new ConcurrentHashMap<>();
}