@Override
protected SortedSet<Long> compute() {
SortedSet<Long> index = new TreeSet<>();
try {
if (length < threshold) {
BufferedAccessFile raf = null;
try {
raf = new BufferedAccessFile(file, "r");
raf.seek(start);
// Add the position for 1st line
if (raf.getFilePointer() == 0L) {
index.add(raf.getFilePointer());
}
while (raf.getFilePointer() < end) {
raf.getNextLine();
index.add(raf.getFilePointer());
}
} finally {
if (raf != null) {
raf.close();
}
}
} else {
long start1 = start;
long end1 = start + (length / 2);
long end2 = end;
IndexingTask task1 = new IndexingTask(file, start1, end1, threshold);
task1.fork();
IndexingTask task2 = new IndexingTask(file, end1, end2, threshold);
index.addAll(task2.compute());
index.addAll(task1.join());
}
} catch (IOException ex) {
throw new FileReaderException("Error while index file:" + ex.getMessage(), ex);
}
return index;
}
