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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

 * 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.

 *

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 */

/* @test

 * @bug 8164900

 * @summary Test read method of FileChannel with DirectIO

 * (use -Dseed=X to set PRNG seed)

 * @library .. /test/lib

 * @build jdk.test.lib.RandomFactory

 *        DirectIOTest

 * @run main/othervm ReadDirect

 * @key randomness

 */

import java.io.*;

import java.nio.ByteBuffer;

import java.nio.CharBuffer;

import java.nio.channels.*;

import java.nio.file.Files;

import java.nio.file.FileStore;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.nio.file.StandardOpenOption;

import java.util.Random;

import com.sun.nio.file.ExtendedOpenOption;

import jdk.test.lib.RandomFactory;

public class ReadDirect {

    private static PrintStream err = System.err;

    private static Random generator = RandomFactory.getRandom();

    private static int charsPerGroup = -1;

    private static int alignment = -1;

    private static boolean initTests() throws Exception {

        Path p = DirectIOTest.createTempFile();

        if (!DirectIOTest.isDirectIOSupportedByFS(p)) {

            Files.delete(p);

            return false;

        }

        try {

            FileStore fs = Files.getFileStore(p);

            alignment = (int)fs.getBlockSize();

            charsPerGroup = alignment;

        } finally {

            Files.delete(p);

        }

        return true;

    }

    private static void testWithSingleBuffer() throws Exception {

        StringBuffer sb = new StringBuffer();

        sb.setLength(2);

        Path p = DirectIOTest.createTempFile();

        initTestFile(p);

        try (FileChannel fc = FileChannel.open(p,

            StandardOpenOption.READ, StandardOpenOption.DELETE_ON_CLOSE,

            ExtendedOpenOption.DIRECT)) {

            ByteBuffer block = ByteBuffer.allocateDirect(charsPerGroup

                + alignment - 1).alignedSlice(alignment);

            for (int x = 0; x < 100; x++) {

                block.clear();

                long offset = x * charsPerGroup;

                long expectedResult = offset / charsPerGroup;

                fc.read(block);

                for (int i = 0; i < 2; i++) {

                    byte aByte = block.get(i);

                    sb.setCharAt(i, (char)aByte);

                }

                int result = Integer.parseInt(sb.toString());

                if (result != expectedResult) {

                    err.println("I expected " + expectedResult);

                    err.println("I got " + result);

                    throw new Exception("Read test failed");

                }

            }

        }

    }

    private static void testWithNotAlignedBufferSize() throws Exception {

        int bufferSize = charsPerGroup - 1;

        Path p = DirectIOTest.createTempFile();

        try (OutputStream fos = Files.newOutputStream(p)) {

            fos.write(new byte[bufferSize]);

        }

        try (FileChannel fc = FileChannel.open(p,

            StandardOpenOption.READ, StandardOpenOption.DELETE_ON_CLOSE,

            ExtendedOpenOption.DIRECT)) {

            ByteBuffer block = ByteBuffer.allocate(bufferSize);

            try {

                fc.read(block);

                throw new RuntimeException("Expected exception not thrown");

            } catch (IOException e) {

                if (!e.getMessage().contains("Number of remaining bytes ("

                    + bufferSize + ") is not a multiple of the block size ("

                    + alignment + ")"))

                    throw new Exception("Read test failed");

            }

        }

    }

    private static void testWithNotAlignedBufferOffset() throws Exception {

        int bufferSize = charsPerGroup * 2;

        int pos = alignment - 1;

        Path p = DirectIOTest.createTempFile();

        try (OutputStream fos = Files.newOutputStream(p)) {

            fos.write(new byte[bufferSize]);

        }

        try (FileChannel fc = FileChannel.open(p,

            StandardOpenOption.READ, StandardOpenOption.DELETE_ON_CLOSE,

            ExtendedOpenOption.DIRECT)) {

            ByteBuffer block = ByteBuffer.allocateDirect(bufferSize);

            block.position(pos);

            block.limit(bufferSize - 1);

            try {

                fc.read(block);

                throw new RuntimeException("Expected exception not thrown");

            } catch (IOException e) {

                if (!e.getMessage().contains("Current location of the bytebuffer "

                    +  "(" + pos + ") is not a multiple of the block size ("

                    + alignment + ")"))

                    throw new Exception("Read test failed");

            }

        }

    }

    private static void testWithArrayOfBuffer() throws Exception {

        StringBuffer sb = new StringBuffer();

        sb.setLength(2);

        ByteBuffer[] dests = new ByteBuffer[4];

        Path p = DirectIOTest.createTempFile();

        initTestFile(p);

        try (FileChannel fc = FileChannel.open(p,

            StandardOpenOption.READ, StandardOpenOption.DELETE_ON_CLOSE,

            ExtendedOpenOption.DIRECT)) {

            int randomNumber = -1;

            for (int i = 0; i < 4; i++) {

                dests[i] = ByteBuffer.allocateDirect

                    (charsPerGroup + alignment - 1).alignedSlice(alignment);

                for (int j = 0; j < charsPerGroup; j++) {

                    dests[i].put(j, (byte)'a');

                }

            }

            long offset =  randomNumber * charsPerGroup;

            fc.position(offset);

            fc.read(dests, 1, 2);

            for (int i = 0; i < 4; i++) {

                if (i == 1 || i == 2) {

                    for (int j = 0; j < 2; j++) {

                        byte aByte = dests[i].get(j);

                        sb.setCharAt(j, (char)aByte);

                    }

                    int result = Integer.parseInt(sb.toString());

                    int expectedResult = randomNumber + i - 1;

                    if (result != expectedResult) {

                        err.println("I expected " + expectedResult);

                        err.println("I got " + result);

                        throw new Exception("Read test failed");

                    }

                } else {

                    for (int k = 0; k < charsPerGroup; k++) {

                        if (dests[i].get(k) != (byte)'a')

                            throw new RuntimeException("Read test failed");

                    }

                }

            }

        }

    }

    public static void testOnEOF() throws Exception {

        int bufferSize = charsPerGroup / 2;

        Path p = DirectIOTest.createTempFile();

        try (OutputStream fos = Files.newOutputStream(p)) {

            byte[] writeBlock = new byte[bufferSize];

            for (int i = 0; i < bufferSize; i++) {

                writeBlock[i] = ((byte)'a');

            }

            fos.write(writeBlock);

        }

        try (FileChannel fc = FileChannel.open(p,

            StandardOpenOption.READ, StandardOpenOption.DELETE_ON_CLOSE,

            ExtendedOpenOption.DIRECT)) {

            ByteBuffer block = ByteBuffer.allocateDirect(

                    (bufferSize / alignment + 1) * alignment + alignment - 1)

                    .alignedSlice(alignment);

            int result = fc.read(block);

            if (result != bufferSize) {

                err.println("Number of bytes to read " + bufferSize);

                err.println("I read " + result);

                throw new Exception("Read test failed");

            }

            for (int j = 0; j < bufferSize; j++) {

                if (block.get(j) != (byte)'a')

                    throw new RuntimeException("Read test failed");

            }

        }

    }

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

        if (initTests()) {

            testWithSingleBuffer();

            testWithNotAlignedBufferSize();

            testWithNotAlignedBufferOffset();

            testWithArrayOfBuffer();

            testOnEOF();

        }

    }

    private static void initTestFile(Path p)

            throws Exception {

        try (OutputStream fos = Files.newOutputStream(p)) {

            try (BufferedWriter awriter

                 = new BufferedWriter(new OutputStreamWriter(fos, "8859_1"))) {

                for (int i = 0; i < 100; i++) {

                    String number = new Integer(i).toString();

                    for (int h = 0; h < 2 - number.length(); h++)

                        awriter.write("0");

                    awriter.write("" + i);

                    for (int j = 0; j < (charsPerGroup - 2); j++)

                        awriter.write("0");

                }

                awriter.flush();

            }

        }

    }

}