@Override
public Object convertToNetty() throws IOException {
if (conf.lazyFileDescriptor()) {
return new LazyFileRegion(file, offset, length);
} else {
FileChannel fileChannel = new FileInputStream(file).getChannel();
return new DefaultFileRegion(fileChannel, offset, length);
}
}
@Override
public ByteBuffer nioByteBuffer() throws IOException {
FileChannel channel = null;
try {
channel = new RandomAccessFile(file, "r").getChannel();
// Just copy the buffer if it's sufficiently small, as memory mapping has a high overhead.
if (length < conf.memoryMapBytes()) {
ByteBuffer buf = ByteBuffer.allocate((int) length);
channel.position(offset);
while (buf.remaining() != 0) {
if (channel.read(buf) == -1) {
throw new IOException(
String.format(
"Reached EOF before filling buffer\n" + "offset=%s\nfile=%s\nbuf.remaining=%s",
offset, file.getAbsoluteFile(), buf.remaining()));
}
}
buf.flip();
return buf;
} else {
return channel.map(FileChannel.MapMode.READ_ONLY, offset, length);
}
} catch (IOException e) {
try {
if (channel != null) {
long size = channel.size();
throw new IOException(
"Error in reading " + this + " (actual file length " + size + ")", e);
}
} catch (IOException ignored) {
// ignore
}
throw new IOException("Error in opening " + this, e);
} finally {
JavaUtils.closeQuietly(channel);
}
}