@Test
public void testLimitedView() throws IOException {
File file = folder.newFile();
FileChannel chan = new RandomAccessFile(file, "rw").getChannel();
BinaryIndexTableWriter writer = BinaryIndexTableWriter.create(BinaryFormat.create(), chan, 3);
writer.writeEntry(12, new int[] {0});
writer.writeEntry(17, new int[] {1, 3});
writer.writeEntry(19, new int[] {4, 5});
MappedByteBuffer buffer = chan.map(FileChannel.MapMode.READ_ONLY, 0, chan.size());
BinaryIndexTable tbl = BinaryIndexTable.fromBuffer(3, buffer);
tbl = tbl.createLimitedView(2);
assertThat(tbl.getKeys(), hasSize(2));
assertThat(tbl.getKeys(), contains(12L, 17L));
assertThat(tbl.getEntry(12), contains(0));
assertThat(tbl.getEntry(17), contains(1));
assertThat(tbl.getEntry(19), nullValue());
assertThat(tbl.getEntry(-1), nullValue());
BinaryIndexTable serializedTbl = SerializationUtils.clone(tbl);
assertThat(serializedTbl.getKeys(), hasSize(2));
assertThat(serializedTbl.getKeys(), contains(12L, 17L));
assertThat(serializedTbl.getEntry(12), contains(0));
assertThat(serializedTbl.getEntry(17), contains(1));
assertThat(serializedTbl.getEntry(19), nullValue());
assertThat(serializedTbl.getEntry(-1), nullValue());
}
/**
* Write a user or item index to the file.
*
* @param map The index to write.
*/
private void writeIndex(Long2ObjectMap<IntList> map) throws IOException {
LongSortedSet keys = LongUtils.packedSet(map.keySet());
BinaryIndexTableWriter tableWriter =
BinaryIndexTableWriter.create(format, channel, keys.size());
SortComparator indexComparator = new SortComparator();
LongIterator iter = keys.iterator();
while (iter.hasNext()) {
final long key = iter.nextLong();
int[] indexes = map.get(key).toIntArray();
if (needsSorting) {
IntArrays.quickSort(indexes, indexComparator);
}
if (translationMap != null) {
for (int i = 0; i < indexes.length; i++) {
indexes[i] = translationMap[indexes[i]];
}
}
logger.debug("writing {} indices for id {}", key, indexes.length);
tableWriter.writeEntry(key, indexes);
}
}
@Test
public void testSingleEntry() throws IOException {
File file = folder.newFile();
FileChannel chan = new RandomAccessFile(file, "rw").getChannel();
BinaryIndexTableWriter w = BinaryIndexTableWriter.create(BinaryFormat.create(), chan, 1);
w.writeEntry(42, new int[] {0});
MappedByteBuffer buf = chan.map(FileChannel.MapMode.READ_ONLY, 0, chan.size());
BinaryIndexTable tbl = BinaryIndexTable.fromBuffer(1, buf);
assertThat(tbl.getKeys(), contains(42L));
assertThat(tbl.getEntry(42), contains(0));
assertThat(tbl.getEntry(43), nullValue());
}