@Override
public Cursor find(Session session, SearchRow first, SearchRow last) {
ValueLong min, max;
if (first == null) {
min = MIN;
} else if (mainIndexColumn < 0) {
min = ValueLong.get(first.getKey());
} else {
ValueLong v = (ValueLong) first.getValue(mainIndexColumn);
if (v == null) {
min = ValueLong.get(first.getKey());
} else {
min = v;
}
}
if (last == null) {
max = MAX;
} else if (mainIndexColumn < 0) {
max = ValueLong.get(last.getKey());
} else {
ValueLong v = (ValueLong) last.getValue(mainIndexColumn);
if (v == null) {
max = ValueLong.get(last.getKey());
} else {
max = v;
}
}
TransactionMap<Value, Value> map = getMap(session);
return new MVStoreCursor(session, map.entryIterator(min), max);
}
/**
* Compare the positions of two rows.
*
* @param rowData the first row
* @param compare the second row
* @return 0 if both rows are equal, -1 if the first row is smaller, otherwise 1
*/
int compareKeys(SearchRow rowData, SearchRow compare) {
long k1 = rowData.getKey();
long k2 = compare.getKey();
if (k1 == k2) {
if (isMultiVersion) {
int v1 = rowData.getVersion();
int v2 = compare.getVersion();
return MathUtils.compareInt(v2, v1);
}
return 0;
}
return k1 > k2 ? 1 : -1;
}
@Override
public boolean next() {
synchronized (sync) {
if (SysProperties.CHECK && end) {
DbException.throwInternalError();
}
while (true) {
if (needNewDelta) {
loadNext(false);
needNewDelta = false;
}
if (needNewBase) {
loadNext(true);
needNewBase = false;
}
if (deltaRow == null) {
if (baseRow == null) {
end = true;
return false;
}
onBase = true;
needNewBase = true;
return true;
}
int sessionId = deltaRow.getSessionId();
boolean isThisSession = sessionId == session.getId();
boolean isDeleted = deltaRow.isDeleted();
if (isThisSession && isDeleted) {
needNewDelta = true;
continue;
}
if (baseRow == null) {
if (isDeleted) {
if (isThisSession) {
end = true;
return false;
}
// the row was deleted by another session: return it
onBase = false;
needNewDelta = true;
return true;
}
DbException.throwInternalError();
}
int compare = index.compareRows(deltaRow, baseRow);
if (compare == 0) {
// can't use compareKeys because the
// version would be compared as well
long k1 = deltaRow.getKey();
long k2 = baseRow.getKey();
compare = MathUtils.compareLong(k1, k2);
}
if (compare == 0) {
if (isDeleted) {
if (isThisSession) {
DbException.throwInternalError();
}
// another session updated the row
} else {
if (isThisSession) {
onBase = false;
needNewBase = true;
needNewDelta = true;
return true;
}
// another session inserted the row: ignore
needNewBase = true;
needNewDelta = true;
continue;
}
}
if (compare > 0) {
onBase = true;
needNewBase = true;
return true;
}
onBase = false;
needNewDelta = true;
return true;
}
}
}