/*--------------------------------------------------------------------------
 *  Copyright 2011 Taro L. Saito
 *
 *  Licensed 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.
 *--------------------------------------------------------------------------*/
//--------------------------------------
// XerialJ
//
// CalgaryTest.java
// Since: 2011/04/04 12:10:36
//
// $URL$
// $Author$
//--------------------------------------
package org.xerial.snappy;

import static org.junit.Assert.assertArrayEquals;
import static org.junit.Assert.assertEquals;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.TemporaryFolder;
import org.xerial.util.FileResource;
import org.xerial.util.log.Logger;

/**
 * Benchmark using Calgary data set
 * 
 * @author leo
 * 
 */
public class CalgaryTest
{
    private static Logger _logger = Logger.getLogger(CalgaryTest.class);
    
    @Rule
    public final TemporaryFolder tempFolder = new TemporaryFolder();

    static byte[] readFile(String file) throws IOException {
        InputStream in = FileResource.find(CalgaryTest.class, file).openStream();
        if (in == null)
            throw new IOException("file " + file + " is not found");
        try {
            return SnappyInputStreamTest.readFully(in);
        }
        finally {
            if (in != null)
                in.close();
        }
    }

    public static final String[] files = { "bib", "book1", "book2", "geo", "news", "obj1", "obj2", "paper1", "paper2",
            "paper3", "paper4", "paper5", "paper6", "pic", "progc", "progl", "progp", "trans" };

    @Test
    public void block() throws Exception {
        for (String f : files) {
            byte[] orig = readFile("testdata/calgary/" + f);

            byte[] compressed = Snappy.compress(orig);
            byte[] uncompressed = Snappy.uncompress(compressed);

            assertArrayEquals(orig, uncompressed);
        }
    }

    @Test
    public void stream() throws Exception {
        for (String f : files) {
            byte[] orig = readFile("testdata/calgary/" + f);

            ByteArrayOutputStream compressedBuf = new ByteArrayOutputStream();
            SnappyOutputStream out = new SnappyOutputStream(compressedBuf);
            out.write(orig);
            out.close();

            SnappyInputStream in = new SnappyInputStream(new ByteArrayInputStream(compressedBuf.toByteArray()));
            byte[] uncompressed = new byte[orig.length];
            int readBytes = in.read(uncompressed);
            assertEquals(orig.length, readBytes);
            assertArrayEquals(orig, uncompressed);
        }
    }

    @Test
    public void streamFramed() throws Exception {
        for (String f : files) {
            byte[] orig = readFile("testdata/calgary/" + f);

            ByteArrayOutputStream compressedBuf = new ByteArrayOutputStream();
            SnappyFramedOutputStream out = new SnappyFramedOutputStream(compressedBuf);
            out.write(orig);
            out.close();

            SnappyFramedInputStream in = new SnappyFramedInputStream(new ByteArrayInputStream(compressedBuf.toByteArray()));
            
            byte[] uncompressed = new byte[orig.length];
            int readBytes = readBytes(in, uncompressed, 0, orig.length);
            
            assertEquals(orig.length, readBytes);
            assertArrayEquals(orig, uncompressed);
        }
    }

    @Test
    public void streamFramedToFile() throws Exception {
        for (String f : files) {
            byte[] orig = readFile("testdata/calgary/" + f);

            final File tempFile = tempFolder.newFile(f);
            final FileOutputStream compressedFOS = new FileOutputStream(tempFile);
            try
            {
                SnappyFramedOutputStream out = new SnappyFramedOutputStream(compressedFOS);
                out.write(orig);
                out.close();
            }
            finally
            {
                compressedFOS.close();
            }
            
            byte[] uncompressed = new byte[orig.length];

            final FileInputStream compressedFIS = new FileInputStream(tempFile);
            try
            {
                SnappyFramedInputStream in = new SnappyFramedInputStream(compressedFIS.getChannel());
                int readBytes = readBytes(in, uncompressed, 0, orig.length);
                
                assertEquals(orig.length, readBytes);
            }
            finally
            {
                compressedFIS.close();
            }
            
            assertArrayEquals(orig, uncompressed);
        }
    }

    @Test
    public void streamFramedNoCRCVerify() throws Exception {
        for (String f : files) {
            byte[] orig = readFile("testdata/calgary/" + f);

            ByteArrayOutputStream compressedBuf = new ByteArrayOutputStream();
            SnappyFramedOutputStream out = new SnappyFramedOutputStream(compressedBuf);
            out.write(orig);
            out.close();

            SnappyFramedInputStream in = new SnappyFramedInputStream(new ByteArrayInputStream(compressedBuf.toByteArray()), false);
            
            byte[] uncompressed = new byte[orig.length];
            int readBytes = readBytes(in, uncompressed, 0, orig.length);
            
            assertEquals(orig.length, readBytes);
            assertArrayEquals(orig, uncompressed);
        }
    }

    @Test
    public void byteWiseRead() throws Exception {
        for (String f : files) {
            byte[] orig = readFile("testdata/calgary/" + f);

            ByteArrayOutputStream compressedBuf = new ByteArrayOutputStream();
            SnappyOutputStream out = new SnappyOutputStream(compressedBuf);
            out.write(orig);
            out.close();

            SnappyInputStream in = new SnappyInputStream(new ByteArrayInputStream(compressedBuf.toByteArray()));
            byte[] uncompressed = new byte[orig.length];
            int cursor = 0;
            for (;;) {
                int b = in.read();
                if (b == -1)
                    break;
                uncompressed[cursor++] = (byte) b;
            }
            assertEquals(orig.length, cursor);
            assertArrayEquals(orig, uncompressed);
        }
    }

    static final int readBytes(InputStream source, byte[] dest, int offset, int length) throws IOException
    {        
        // how many bytes were read.
        int lastRead = source.read(dest, offset, length);

        int totalRead = lastRead;

        // if we did not read as many bytes as we had hoped, try reading again.
        if (lastRead < length)
        {
            // as long the buffer is not full (remaining() == 0) and we have not reached EOF (lastRead == -1) keep reading.
            while (totalRead < length && lastRead != -1)
            {
                lastRead = source.read(dest, offset + totalRead, length - totalRead);

                // if we got EOF, do not add to total read.
                if (lastRead != -1)
                {
                    totalRead += lastRead;
                }
            }
        }
        return totalRead;
    }
}