feat: Handles case where we overflow void elements.

Handles more tags and tracks.

Author: damencho

src/main/java/org/ebml/io/FileDataSource.java

@@ -2,17 +2,17 @@
  * JEBML - Java library to read/write EBML/Matroska elements.
  * Copyright (C) 2004 Jory Stone <[email protected]>
  * Based on Javatroska (C) 2002 John Cannon <[email protected]>
- * 
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
- * 
+ *
  * This library 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
  * Lesser General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
@@ -42,6 +42,15 @@ public FileDataSource(final String filename, final String mode) throws FileNotFo
     fc = file.getChannel();
   }
 
+  /**
+   * Converts a writer to a reader.
+   */
+  public FileDataSource(FileDataWriter writer) throws FileNotFoundException, IOException
+  {
+    file = writer.file;
+    fc = writer.fc;
+  }
+
   @Override
   public byte readByte()
   {

src/main/java/org/ebml/io/FileDataWriter.java

@@ -25,22 +25,32 @@
 import java.io.RandomAccessFile;
 import java.nio.ByteBuffer;
 import java.nio.channels.FileChannel;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
 
 public class FileDataWriter implements DataWriter, Closeable
 {
   RandomAccessFile file = null;
   FileChannel fc = null;
 
+  /**
+   * We need this in order to be able to replace the file with another one.
+   */
+  String filename = null;
+
   public FileDataWriter(final String filename) throws FileNotFoundException, IOException
   {
     file = new RandomAccessFile(filename, "rw");
     fc = file.getChannel();
+    this.filename = filename;
   }
 
   public FileDataWriter(final String filename, final String mode) throws FileNotFoundException, IOException
   {
     file = new RandomAccessFile(filename, mode);
     fc = file.getChannel();
+    this.filename = filename;
   }
 
   @Override
@@ -121,4 +131,26 @@ public void close() throws IOException
   {
     file.close();
   }
+
+  /**
+   * Copy data from source to source position into current file starting from the beginning.
+   */
+  public void copyToPosition(FileDataWriter src) throws IOException
+  {
+    src.fc.transferTo(0, src.fc.position(), fc);
+  }
+
+  /**
+   * Copy from current position of src to its end to the current file on current position.
+   */
+    public void copyFromPosition(FileDataWriter src) throws IOException
+    {
+        src.fc.transferTo(src.fc.position(), src.fc.size() - src.fc.position(), fc);
+    }
+
+    public void replaceWithFile(FileDataWriter dw)
+            throws IOException
+    {
+      Files.move(Path.of(dw.filename), Path.of(this.filename), StandardCopyOption.REPLACE_EXISTING);
+    }
 }

src/main/java/org/ebml/matroska/MatroskaFileTags.java

@@ -21,7 +21,8 @@ public void addTag(final MatroskaFileTagEntry tag)
     tags.add(tag);
   }
 
-  public long writeTags(final DataWriter ioDW)
+  public long writeTags(final DataWriter ioDW, boolean checkBlockSize)
+    throws VoidOutOfBoundException
   {
     myPosition = ioDW.getFilePointer();
     final MasterElement tagsElem = MatroskaDocTypes.Tags.getInstance();
@@ -30,21 +31,34 @@ public long writeTags(final DataWriter ioDW)
     {
       tagsElem.addChildElement(tag.toElement());
     }
+
+    if (checkBlockSize && BLOCK_SIZE < tagsElem.getTotalSize())
+    {
+      LOG.warn("Tags element size exceeds block size!");
+
+      throw new VoidOutOfBoundException();
+    }
+
     long len = tagsElem.writeElement(ioDW);
-    if (ioDW.isSeekable())
+
+    if (BLOCK_SIZE > tagsElem.getTotalSize())
     {
       new VoidElement(BLOCK_SIZE - tagsElem.getTotalSize()).writeElement(ioDW);
       return BLOCK_SIZE;
     }
-    return len;
+    else
+    {
+      return len;
+    }
   }
 
-  public long update(final DataWriter ioDW)
+  public long update(final DataWriter ioDW, boolean checkBlockSize)
+    throws VoidOutOfBoundException
   {
     LOG.info("Updating tags list!");
     final long start = ioDW.getFilePointer();
     ioDW.seek(myPosition);
-    long len = writeTags(ioDW);
+    long len = writeTags(ioDW, checkBlockSize);
     ioDW.seek(start);
     return len;
   }

src/main/java/org/ebml/matroska/MatroskaFileTracks.java

@@ -21,7 +21,8 @@ public void addTrack(final MatroskaFileTrack track)
     tracks.add(track);
   }
 
-  public long writeTracks(final DataWriter ioDW)
+  public long writeTracks(final DataWriter ioDW, boolean checkBlockSize)
+    throws VoidOutOfBoundException
   {
     myPosition = ioDW.getFilePointer();
     final MasterElement tracksElem = MatroskaDocTypes.Tracks.getInstance();
@@ -30,18 +31,34 @@ public long writeTracks(final DataWriter ioDW)
     {
       tracksElem.addChildElement(track.toElement());
     }
-    tracksElem.writeElement(ioDW);
-    assert BLOCK_SIZE > tracksElem.getTotalSize();
-    new VoidElement(BLOCK_SIZE - tracksElem.getTotalSize()).writeElement(ioDW);
-    return BLOCK_SIZE;
+
+    if (checkBlockSize && BLOCK_SIZE < tracksElem.getTotalSize())
+    {
+      LOG.warn("Tracks element size exceeds block size!");
+
+      throw new VoidOutOfBoundException();
+    }
+
+    long size = tracksElem.writeElement(ioDW);
+
+    if (BLOCK_SIZE > tracksElem.getTotalSize())
+    {
+      new VoidElement(BLOCK_SIZE - tracksElem.getTotalSize()).writeElement(ioDW);
+      return BLOCK_SIZE;
+    }
+    else
+    {
+        return size;
+    }
   }
 
-  public long update(final DataWriter ioDW)
+  public long update(final DataWriter ioDW, boolean checkBlockSize)
+    throws VoidOutOfBoundException
   {
     LOG.info("Updating tracks list!");
     final long start = ioDW.getFilePointer();
     ioDW.seek(myPosition);
-    long len = writeTracks(ioDW);
+    long len = writeTracks(ioDW, checkBlockSize);
     ioDW.seek(start);
     return len;
   }

src/main/java/org/ebml/matroska/MatroskaFileWriter.java

@@ -20,14 +20,17 @@
 package org.ebml.matroska;
 
 import java.io.Closeable;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.HashSet;
 import java.util.Set;
-import java.util.concurrent.*;
 
 import org.ebml.MasterElement;
 import org.ebml.StringElement;
 import org.ebml.UnsignedIntegerElement;
 import org.ebml.io.DataWriter;
+import org.ebml.io.FileDataWriter;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -88,10 +91,26 @@ void initialize()
     segmentInfoElem.writeElement(ioDW);
 
     metaSeek.addIndexedElement(MatroskaDocTypes.Tracks.getType(), ioDW.getFilePointer());
-    tracks.writeTracks(ioDW);
+    try
+    {
+      tracks.writeTracks(ioDW, false);
+    }
+    catch (VoidOutOfBoundException e)
+    {
+      // when initializing tracks are empty so this should never happen
+      LOG.error("Tracks element size exceeds block size?", e);
+    }
 
     metaSeek.addIndexedElement(MatroskaDocTypes.Tags.getType(), ioDW.getFilePointer());
-    tags.writeTags(ioDW);
+    try
+    {
+        tags.writeTags(ioDW, false);
+    }
+    catch (VoidOutOfBoundException e)
+    {
+      // when initializing tags are empty so this should never happen
+      LOG.error("Tags element size exceeds block size?", e);
+    }
 
     cluster = new MatroskaCluster();
     metaSeek.addIndexedElement(MatroskaDocTypes.Cluster.getType(), ioDW.getFilePointer());
@@ -283,13 +302,65 @@ public void close()
       segmentInfoElem.setDuration(maxSegmentTimecode - minSegmentTimecode);
       segmentLen += segmentInfoElem.update(ioDW);
 
-      segmentLen += tracks.update(ioDW);
-      segmentLen += tags.update(ioDW);
+      try
+      {
+          segmentLen += tracks.update(ioDW, true);
+      }
+      catch (VoidOutOfBoundException e)
+      {
+        LOG.info("Tracks element size exceeds block size. Will expand file.");
+
+          try (FileDataWriter dw = copyBeginningOfFile())
+          {
+            segmentLen += tracks.update(dw, false);
+            copyEndOfFileAndClose(dw);
+          }
+          catch (VoidOutOfBoundException | IOException ex)
+          {
+            throw new RuntimeException(ex);
+          }
+      }
+      try
+      {
+          segmentLen += tags.update(ioDW, true);
+      }
+      catch (VoidOutOfBoundException e)
+      {
+        LOG.info("Tags element size exceeds block size. Will expand file.");
+        try (FileDataWriter dw = copyBeginningOfFile())
+        {
+          segmentLen += tags.update(dw, false);
+          copyEndOfFileAndClose(dw);
+        }
+        catch (VoidOutOfBoundException | IOException ex)
+        {
+          throw new RuntimeException(ex);
+        }
+      }
       segmentLen += clusterLen;
 
       segmentElem.setUnknownSize(false);
       segmentElem.setSize(segmentLen);
       segmentElem.update(ioDW);
     }
   }
+
+  private FileDataWriter copyBeginningOfFile()
+    throws IOException
+  {
+    FileDataWriter dw = new FileDataWriter(Files.createTempFile("mka", ".tmp").toFile().getPath());
+    dw.copyToPosition((FileDataWriter)ioDW);
+
+    return dw;
+  }
+
+  private void copyEndOfFileAndClose(FileDataWriter dw)
+    throws IOException
+  {
+    dw.copyFromPosition((FileDataWriter)ioDW);
+
+    ((FileDataWriter) ioDW).close();
+    ((FileDataWriter) ioDW).replaceWithFile(dw);
+
+  }
 }

src/main/java/org/ebml/matroska/VoidOutOfBoundException.java

@@ -0,0 +1,5 @@
+package org.ebml.matroska;
+
+public class VoidOutOfBoundException extends Exception
+{
+}

src/test/java/org/ebml/matroska/MatroskaFileWriterTest.java

@@ -117,6 +117,65 @@ public void testMultipleTracks() throws Exception
     testDocTraversal();
   }
 
+  @Test
+  public void testMultipleTracksToFillVoidArea() throws Exception
+  {
+    final MatroskaFileWriter writer = new MatroskaFileWriter(ioDW);
+
+    for (int i = 0; i < 40; i++)
+    {
+      final MatroskaFileTrack nextTrack = new MatroskaFileTrack();
+      nextTrack.setTrackNo(i + 2);
+      nextTrack.setTrackType(TrackType.CONTROL);
+      nextTrack.setCodecID("some codec");
+      nextTrack.setDefaultDuration(4242);
+      writer.addTrack(nextTrack);
+    }
+
+    writer.addFrame(generateFrame("I know a song...", 42));
+    writer.addFrame(generateFrame("that gets on everybody's nerves", 2));
+
+    writer.close();
+
+    final FileDataSource inputDataSource = new FileDataSource(destination.getPath());
+    final MatroskaFile reader = new MatroskaFile(inputDataSource);
+    reader.readFile();
+    assertEquals(40, reader.getTrackList().length);
+    LOG.info(reader.getReport());
+    testDocTraversal();
+  }
+
+  @Test
+  public void testMultipleTags() throws Exception
+  {
+    final MatroskaFileWriter writer = new MatroskaFileWriter(ioDW);
+    writer.addTrack(testTrack);
+
+    for (int i = 0; i < 100; i++)
+    {
+      final MatroskaFileTagEntry tag = new MatroskaFileTagEntry();
+      final MatroskaFileSimpleTag simpleTag = new MatroskaFileSimpleTag();
+      simpleTag.setName("MyTITLE" + i);
+      simpleTag.setValue("MyCanon in D" + i);
+      tag.addSimpleTag(simpleTag);
+      writer.addTag(tag);
+    }
+
+    writer.addFrame(generateFrame("I know a song...", 42));
+    writer.addFrame(generateFrame("that gets on everybody's nerves", 2));
+
+    writer.close();
+
+    final FileDataSource inputDataSource = new FileDataSource(destination.getPath());
+    final MatroskaFile reader = new MatroskaFile(inputDataSource);
+    reader.readFile();
+    assertEquals(TrackType.SUBTITLE, reader.getTrackList()[0].getTrackType());
+    assertEquals(42, reader.getTrackList()[0].getTrackNo());
+    assertEquals(100, reader.getTagList().size());
+    LOG.info(reader.getReport());
+    testDocTraversal();
+  }
+
   @Test
   public void testSilentTrack() throws FileNotFoundException, IOException
   {