public void mergeAppend(PeekingIterator<T> data) throws JournalException {
if (lagMillis == 0) {
throw new JournalException("This journal is not configured to have lag partition");
}
beginTx();
if (data == null || data.isEmpty()) {
return;
}
long dataMaxTimestamp = getTimestamp(data.peekLast());
long hard = getAppendTimestampLo();
if (dataMaxTimestamp < hard) {
return;
}
final Partition<T> lagPartition = openOrCreateLagPartition();
this.doDiscard = true;
this.doJournal = true;
long dataMinTimestamp = getTimestamp(data.peekFirst());
long lagMaxTimestamp = getMaxTimestamp();
long lagMinTimestamp = lagPartition.size() == 0L ? 0 : getTimestamp(lagPartition.read(0));
long soft = Math.max(dataMaxTimestamp, lagMaxTimestamp) - lagMillis;
if (dataMinTimestamp > lagMaxTimestamp) {
// this could be as simple as just appending data to lag
// the only complication is that after adding records to lag it could swell beyond
// the allocated "lagSwellTimestamp"
// we should check if this is going to happen and optimise copying of data
long lagSizeMillis;
if (hard > 0L) {
lagSizeMillis = dataMaxTimestamp - hard;
} else if (lagMinTimestamp > 0L) {
lagSizeMillis = dataMaxTimestamp - lagMinTimestamp;
} else {
lagSizeMillis = 0L;
}
if (lagSizeMillis > lagSwellMillis) {
// data would be too big and would stretch outside of swell timestamp
// this is when lag partition should be split, but it is still a straight split without
// re-order
Partition<T> tempPartition = createTempPartition().open();
splitAppend(lagPartition.bufferedIterator(), hard, soft, tempPartition);
splitAppend(data, hard, soft, tempPartition);
replaceIrregularPartition(tempPartition);
} else {
// simplest case, just append to lag
lagPartition.append(data);
}
} else {
Partition<T> tempPartition = createTempPartition().open();
if (dataMinTimestamp > lagMinTimestamp && dataMaxTimestamp < lagMaxTimestamp) {
//
// overlap scenario 1: data is fully inside of lag
//
// calc boundaries of lag that intersects with data
long lagMid1 = lagPartition.indexOf(dataMinTimestamp, BSearchType.OLDER_OR_SAME);
long lagMid2 = lagPartition.indexOf(dataMaxTimestamp, BSearchType.NEWER_OR_SAME);
// copy part of lag above data
splitAppend(lagPartition.bufferedIterator(0, lagMid1), hard, soft, tempPartition);
// merge lag with data and copy result to temp partition
splitAppendMerge(
data,
lagPartition.bufferedIterator(lagMid1 + 1, lagMid2 - 1),
hard,
soft,
tempPartition);
// copy part of lag below data
splitAppend(
lagPartition.bufferedIterator(lagMid2, lagPartition.size() - 1),
hard,
soft,
tempPartition);
} else if (dataMaxTimestamp < lagMinTimestamp && dataMaxTimestamp <= lagMinTimestamp) {
//
// overlap scenario 2: data sits directly above lag
//
splitAppend(data, hard, soft, tempPartition);
splitAppend(lagPartition.bufferedIterator(), hard, soft, tempPartition);
} else if (dataMinTimestamp <= lagMinTimestamp && dataMaxTimestamp < lagMaxTimestamp) {
//
// overlap scenario 3: bottom part of data overlaps top part of lag
//
// calc overlap line
long split = lagPartition.indexOf(dataMaxTimestamp, BSearchType.NEWER_OR_SAME);
// merge lag with data and copy result to temp partition
splitAppendMerge(
data, lagPartition.bufferedIterator(0, split - 1), hard, soft, tempPartition);
// copy part of lag below data
splitAppend(
lagPartition.bufferedIterator(split, lagPartition.size() - 1),
hard,
soft,
tempPartition);
} else if (dataMinTimestamp > lagMinTimestamp && dataMaxTimestamp >= lagMaxTimestamp) {
//
// overlap scenario 4: top part of data overlaps with bottom part of lag
//
long split = lagPartition.indexOf(dataMinTimestamp, BSearchType.OLDER_OR_SAME);
// copy part of lag above overlap
splitAppend(lagPartition.bufferedIterator(0, split), hard, soft, tempPartition);
// merge lag with data and copy result to temp partition
splitAppendMerge(
data,
lagPartition.bufferedIterator(split + 1, lagPartition.size() - 1),
hard,
soft,
tempPartition);
} else if (dataMinTimestamp <= lagMinTimestamp && dataMaxTimestamp >= lagMaxTimestamp) {
//
// overlap scenario 5: lag is fully inside of data
//
// merge lag with data and copy result to temp partition
splitAppendMerge(data, lagPartition.bufferedIterator(), hard, soft, tempPartition);
} else {
throw new JournalRuntimeException(
"Unsupported overlap type: lag min/max [%s/%s] data min/max: [%s/%s]",
Dates.toString(lagMinTimestamp),
Dates.toString(lagMaxTimestamp),
Dates.toString(dataMinTimestamp),
Dates.toString(dataMaxTimestamp));
}
replaceIrregularPartition(tempPartition);
}
}
