private void upgradeRatings(BinaryFormat newFormat) throws IOException {
Preconditions.checkArgument(
newFormat.getRatingSize() > format.getRatingSize(), "new format is not wider than old");
logger.info("upgrading {} ratings from {} to {}", index, format, newFormat);
ByteBuffer oldBuffer = ByteBuffer.allocateDirect(format.getRatingSize());
ByteBuffer newBuffer = ByteBuffer.allocateDirect(newFormat.getRatingSize());
MutableRating scratch = new MutableRating();
long oldPos = BinaryHeader.HEADER_SIZE + index * format.getRatingSize();
Preconditions.checkState(channel.position() == oldPos, "channel is at the wrong position");
long newPos = BinaryHeader.HEADER_SIZE + index * newFormat.getRatingSize();
channel.position(newPos);
// loop backwards, coping each rating to later in the file
for (int i = index - 1; i >= 0; i--) {
oldPos -= format.getRatingSize();
newPos -= newFormat.getRatingSize();
// read the old rating
BinaryUtils.readBuffer(channel, oldBuffer, oldPos);
oldBuffer.flip();
format.readRating(oldBuffer, scratch);
oldBuffer.clear();
// write the new rating
newFormat.renderRating(scratch, newBuffer);
newBuffer.flip();
BinaryUtils.writeBuffer(channel, newBuffer, newPos);
newBuffer.clear();
}
assert oldPos == BinaryHeader.HEADER_SIZE;
assert newPos == BinaryHeader.HEADER_SIZE;
format = newFormat;
ratingBuffer = ByteBuffer.allocateDirect(newFormat.getRatingSize());
}
/**
* Create a new binary rating packer.
*
* @param file The output file.
* @throws IOException The output exception.
*/
BinaryRatingPacker(File file, EnumSet<BinaryFormatFlag> flags) throws IOException {
format = BinaryFormat.createWithFlags(PackHeaderFlag.fromFormatFlags(flags));
outputFile = file;
logger.debug("opening binary pack file {}", outputFile);
output = new RandomAccessFile(file, "rw");
channel = output.getChannel();
userMap = new Long2ObjectOpenHashMap<IntList>();
itemMap = new Long2ObjectOpenHashMap<IntList>();
lastTimestamp = Long.MIN_VALUE;
needsSorting = false;
index = 0;
// skip the header
channel.position(BinaryHeader.HEADER_SIZE);
ratingBuffer = ByteBuffer.allocateDirect(format.getRatingSize());
}
private long ratingPos(int idx) {
long offset = format.getHeaderSize();
return offset + idx * format.getRatingSize();
}
public int getRatingDataSize() {
return getRatingCount() * format.getRatingSize();
}
