public boolean hasPrevious() {
if (isPrevAvailable()) {
return true;
}
if (!isNextAvailable()) {
return false;
}
DataCursor cursor = null;
try {
cursor = new DataCursor(coll.view, writeAllowed);
int last = keys.length - 1;
int next = nextIndex;
boolean found = false;
/* Reposition to the last known key/data pair. */
int repos = cursor.repositionRange(keys[next], priKeys[next], values[next], false);
if (repos == DataCursor.REPOS_EXACT || repos == DataCursor.REPOS_NEXT) {
/*
* The last known key/data pair, or the record following it,
* was found and will now be in the last slot.
*/
found = true;
nextIndex = last;
/* The data object is now in the last slot or not available. */
if (dataIndex == next && repos == DataCursor.REPOS_EXACT) {
dataIndex = last;
} else {
dataIndex = -1;
dataObject = null;
}
} else {
if (repos != DataCursor.REPOS_EOF) {
throw new IllegalStateException();
}
}
if (found) {
/* Clear all slots first in case an exception occurs below. */
clearSlots();
/* Attempt to fill all slots with records. */
int i = last;
boolean done = false;
while (!done) {
setSlot(i, cursor);
i -= 1;
if (i >= 0) {
OperationStatus status =
coll.iterateDuplicates() ? cursor.getPrev(false) : cursor.getPrevNoDup(false);
if (status != OperationStatus.SUCCESS) {
done = true;
}
} else {
done = true;
}
}
}
/*
* Make sure we retrieved the preceding record after the reposition
* above.
*/
return isPrevAvailable();
} catch (DatabaseException e) {
throw StoredContainer.convertException(e);
} finally {
closeCursor(cursor);
}
}
public boolean hasNext() {
if (isNextAvailable()) {
return true;
}
DataCursor cursor = null;
try {
cursor = new DataCursor(coll.view, writeAllowed);
int prev = nextIndex - 1;
boolean found = false;
if (keys[prev] == null) {
/* Get the first record for an uninitialized iterator. */
OperationStatus status = cursor.getFirst(false);
if (status == OperationStatus.SUCCESS) {
found = true;
nextIndex = 0;
}
} else {
/* Reposition to the last known key/data pair. */
int repos = cursor.repositionRange(keys[prev], priKeys[prev], values[prev], false);
if (repos == DataCursor.REPOS_EXACT) {
/*
* The last known key/data pair was found and will now be
* in slot zero.
*/
found = true;
nextIndex = 1;
/* The data object is now in slot zero or not available. */
if (dataIndex == prev) {
dataIndex = 0;
} else {
dataIndex = -1;
dataObject = null;
}
} else if (repos == DataCursor.REPOS_NEXT) {
/*
* The last known key/data pair was not found, but the
* following record was found and it will be in slot zero.
*/
found = true;
nextIndex = 0;
/* The data object is no longer available. */
dataIndex = -1;
dataObject = null;
} else {
if (repos != DataCursor.REPOS_EOF) {
throw new IllegalStateException();
}
}
}
if (found) {
/* Clear all slots first in case an exception occurs below. */
clearSlots();
/* Attempt to fill all slots with records. */
int i = 0;
boolean done = false;
while (!done) {
setSlot(i, cursor);
i += 1;
if (i < keys.length) {
OperationStatus status =
coll.iterateDuplicates() ? cursor.getNext(false) : cursor.getNextNoDup(false);
if (status != OperationStatus.SUCCESS) {
done = true;
}
} else {
done = true;
}
}
}
/*
* If REPOS_EXACT was returned above, make sure we retrieved
* the following record.
*/
return isNextAvailable();
} catch (DatabaseException e) {
throw StoredContainer.convertException(e);
} finally {
closeCursor(cursor);
}
}
