/*

 * Copyright (c) 2010, 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.

 */

/* @test

 * @summary Ensure that InputStreamReader reads as many characters as possible

 */

// InputStreamReader is not required by its spec to read as many characters as

// possible upon each invocation of read(char[], int, int), but many programs

// (e.g., javac) depend upon this behavior.

import java.io.*;

public class FullRead {

    static int MAX_LEN = 1 << 16;

    static void test(File f, int len) throws Exception {

        FileOutputStream fo = new FileOutputStream(f);

        for (int i = 0; i < len; i++)

            fo.write('x');

        fo.close();

        FileInputStream fi = new FileInputStream(f);

        Reader rd = new InputStreamReader(fi, "US-ASCII");

        char[] cb = new char[MAX_LEN + 100];

        int n = rd.read(cb, 0, cb.length);

        System.out.println(len + " : " + n);

        if (len != n)

            throw new Exception("Expected " + len + ", read " + n);

    }

    public static void main(String[] args) throws Exception {

        File f = File.createTempFile("foo", "bar");

        f.deleteOnExit();

        System.out.println(f);

        for (int i = 4; i <= MAX_LEN; i <<= 1)

            test(f, i);

    }

}