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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

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 *

 * 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).

 *

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 * 2 along with this work; if not, write to the Free Software Foundation,

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 */

/* @test

 * @bug 8204310

 * @summary General tests of the setLength method

 * @library /test/lib

 * @build jdk.test.lib.RandomFactory

 * @run main SetLength

 * @key randomness

 */

import java.io.IOException;

import java.io.File;

import java.io.RandomAccessFile;

import jdk.test.lib.RandomFactory;

public class SetLength {

    static void checkState(RandomAccessFile f, long expectedFilePointer,

            long expectedLength)

        throws IOException

    {

        long filePointer = f.getFilePointer();

        long length = f.length();

        if (length != expectedLength) {

            throw new RuntimeException("File length " + length + " != expected "

                    + expectedLength);

        }

        if (filePointer != expectedFilePointer) {

            throw new RuntimeException("File pointer " + filePointer

                    + " != expected " + expectedFilePointer);

        }

    }

    static void test(RandomAccessFile f, long quarterLength)

        throws IOException

    {

        long halfLength = 2 * quarterLength;

        long threeQuarterLength = 3 * quarterLength;

        long fullLength = 4 * quarterLength;

        // initially, empty file

        checkState(f, 0, 0);

        // extending the file size

        f.setLength(halfLength);

        checkState(f, 0, halfLength);

        // writing from the begining

        f.write(new byte[(int)fullLength]);

        checkState(f, fullLength, fullLength);

        // setting to the same length

        f.setLength(fullLength);

        checkState(f, fullLength, fullLength);

        // truncating the file

        f.setLength(threeQuarterLength);

        checkState(f, threeQuarterLength, threeQuarterLength);

        // changing the file pointer

        f.seek(quarterLength);

        checkState(f, quarterLength, threeQuarterLength);

        // truncating the file again

        f.setLength(halfLength);

        checkState(f, quarterLength, halfLength);

        // writing from the middle with extending the file

        f.write(new byte[(int)halfLength]);

        checkState(f, threeQuarterLength, threeQuarterLength);

        // changing the file pointer

        f.seek(quarterLength);

        checkState(f, quarterLength, threeQuarterLength);

        // writing from the middle without extending the file

        f.write(new byte[(int)quarterLength]);

        checkState(f, halfLength, threeQuarterLength);

        // changing the file pointer to the end of file

        f.seek(threeQuarterLength);

        checkState(f, threeQuarterLength, threeQuarterLength);

        // writing to the end of file

        f.write(new byte[(int)quarterLength]);

        checkState(f, fullLength, fullLength);

        // truncating the file to zero

        f.setLength(0);

        checkState(f, 0, 0);

        // changing the file pointer beyond the end of file

        f.seek(threeQuarterLength);

        checkState(f, threeQuarterLength, 0);

        // writing beyont the end of file

        f.write(new byte[(int)quarterLength]);

        checkState(f, fullLength, fullLength);

        // negative file pointer

        try {

            f.seek(-1);

            throw new RuntimeException("IOE not thrown");

        } catch (IOException expected) {

        }

        checkState(f, fullLength, fullLength);

        // truncating the file after failed seek

        f.setLength(halfLength);

        checkState(f, halfLength, halfLength);

        // truncating after closing

        f.close();

        try {

            f.setLength(halfLength);

            throw new RuntimeException("IOE not thrown");

        } catch (IOException expected) {

        }

    }

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

        File f28b = new File("f28b");

        File f28K = new File("f28K");

        File frnd = new File("frnd");

        try (RandomAccessFile raf28b = new RandomAccessFile(f28b, "rw");

             RandomAccessFile raf28K = new RandomAccessFile(f28K, "rw");

             RandomAccessFile rafrnd = new RandomAccessFile(frnd, "rw")) {

            test(raf28b, 7);

            test(raf28K, 7 * 1024);

            test(rafrnd, 1 + RandomFactory.getRandom().nextInt(16000));

        }

        // truncating read-only file

        try (RandomAccessFile raf28b = new RandomAccessFile(f28b, "r")) {

            raf28b.setLength(42);

            throw new RuntimeException("IOE not thrown");

        } catch (IOException expected) {

        }

    }

}