public int previousIndex() {
if (!coll.view.recNumAccess) {
throw new UnsupportedOperationException("Record number access not supported");
}
return hasPrevious() ? (getRecordNumber(nextIndex - 1) - coll.getIndexOffset()) : (-1);
}
public int nextIndex() {
if (!coll.view.recNumAccess) {
throw new UnsupportedOperationException("Record number access not supported");
}
return hasNext() ? (getRecordNumber(nextIndex) - coll.getIndexOffset()) : Integer.MAX_VALUE;
}
/** Sets dataObject to the iterator data for the element at dataIndex. */
private void makeDataObject() {
int i = dataIndex;
DatabaseEntry keyEntry = new DatabaseEntry(keys[i]);
DatabaseEntry priKeyEntry = (keys != priKeys) ? (new DatabaseEntry(priKeys[i])) : keyEntry;
DatabaseEntry valuesEntry = new DatabaseEntry(values[i]);
dataObject = coll.makeIteratorData(this, keyEntry, priKeyEntry, valuesEntry);
}
public void set(E value) {
if (dataObject == null) {
throw new IllegalStateException();
}
if (!coll.hasValues()) {
throw new UnsupportedOperationException();
}
DataCursor cursor = null;
boolean doAutoCommit = coll.beginAutoCommit();
try {
cursor = new DataCursor(coll.view, writeAllowed);
if (moveCursor(dataIndex, cursor)) {
cursor.putCurrent(value);
setSlot(dataIndex, cursor);
coll.closeCursor(cursor);
coll.commitAutoCommit(doAutoCommit);
} else {
throw new IllegalStateException();
}
} catch (Exception e) {
coll.closeCursor(cursor);
throw coll.handleException(e, doAutoCommit);
}
}
/** Copy constructor. */
private BlockIterator(BlockIterator<E> o) {
coll = o.coll;
writeAllowed = o.writeAllowed;
keys = copyArray(o.keys);
priKeys = coll.isSecondary() ? copyArray(o.priKeys) : keys;
values = copyArray(o.values);
nextIndex = o.nextIndex;
dataIndex = o.dataIndex;
dataObject = o.dataObject;
}
/** Creates an iterator. */
BlockIterator(StoredCollection<E> coll, boolean writeAllowed, int blockSize) {
this.coll = coll;
this.writeAllowed = writeAllowed;
keys = new byte[blockSize][];
priKeys = coll.isSecondary() ? (new byte[blockSize][]) : keys;
values = new byte[blockSize][];
nextIndex = blockSize;
dataIndex = -1;
dataObject = null;
}
public Object setValue(Object newValue) {
Object oldValue;
if (iter != null && iter.isCurrentData(this)) {
oldValue = getValue();
iter.set(newValue);
} else {
if (coll.view.dupsAllowed) {
throw new IllegalStateException("May not insert duplicates");
}
oldValue = coll.put(getKey(), newValue);
}
setValueInternal(newValue);
return oldValue;
}
public void add(E value) {
/*
* The checkIterAddAllowed method ensures that one of the following two
* conditions holds and throws UnsupportedOperationException otherwise:
* 1- This is a list iterator for a recno-renumber database.
* 2- This is a collection iterator for a duplicates database.
*/
coll.checkIterAddAllowed();
OperationStatus status = OperationStatus.SUCCESS;
DataCursor cursor = null;
boolean doAutoCommit = coll.beginAutoCommit();
try {
if (coll.view.keysRenumbered || !coll.areDuplicatesOrdered()) {
/*
* This is a recno-renumber database or a btree/hash database
* with unordered duplicates.
*/
boolean hasPrev = hasPrevious();
if (!hasPrev && !hasNext()) {
/* The collection is empty. */
if (coll.view.keysRenumbered) {
/* Append to an empty recno-renumber database. */
status = coll.view.append(value, null, null);
} else if (coll.view.dupsAllowed && coll.view.range.isSingleKey()) {
/*
* When inserting a duplicate into a single-key range,
* the main key is fixed, so we can always insert into
* an empty collection.
*/
cursor = new DataCursor(coll.view, writeAllowed);
cursor.useRangeKey();
status = cursor.putNoDupData(null, value, null, true);
coll.closeCursor(cursor);
cursor = null;
} else {
throw new IllegalStateException("Collection is empty, cannot add() duplicate");
}
/*
* Move past the record just inserted (the cursor should be
* closed above to prevent multiple open cursors in certain
* DB core modes).
*/
if (status == OperationStatus.SUCCESS) {
next();
dataIndex = nextIndex - 1;
}
} else {
/*
* The collection is non-empty. If hasPrev is true then
* the element at (nextIndex - 1) is available; otherwise
* the element at nextIndex is available.
*/
cursor = new DataCursor(coll.view, writeAllowed);
int insertIndex = hasPrev ? (nextIndex - 1) : nextIndex;
if (!moveCursor(insertIndex, cursor)) {
throw new IllegalStateException();
}
/*
* For a recno-renumber database or a database with
* unsorted duplicates, insert before the iterator 'next'
* position, or after the 'prev' position. Then adjust
* the slots to account for the inserted record.
*/
status = hasPrev ? cursor.putAfter(value) : cursor.putBefore(value);
if (status == OperationStatus.SUCCESS) {
insertSlot(nextIndex, cursor);
}
}
} else {
/* This is a btree/hash database with ordered duplicates. */
cursor = new DataCursor(coll.view, writeAllowed);
if (coll.view.range.isSingleKey()) {
/*
* When inserting a duplicate into a single-key range,
* the main key is fixed.
*/
cursor.useRangeKey();
} else {
/*
* When inserting into a multi-key range, the main key
* is the last dataIndex accessed by next(), previous()
* or add().
*/
if (dataIndex < 0 || !moveCursor(dataIndex, cursor)) {
throw new IllegalStateException();
}
}
/*
* For a hash/btree with duplicates, insert the duplicate,
* put the new record in slot zero, and set the next index
* to slot one (past the new record).
*/
status = cursor.putNoDupData(null, value, null, true);
if (status == OperationStatus.SUCCESS) {
clearSlots();
setSlot(0, cursor);
dataIndex = 0;
nextIndex = 1;
}
}
if (status == OperationStatus.KEYEXIST) {
throw new IllegalArgumentException("Duplicate value");
} else if (status != OperationStatus.SUCCESS) {
throw new IllegalArgumentException("Could not insert: " + status);
}
/* Prevent subsequent set() or remove() call. */
dataObject = null;
coll.closeCursor(cursor);
coll.commitAutoCommit(doAutoCommit);
} catch (Exception e) {
/* Catch RuntimeExceptions too. */
coll.closeCursor(cursor);
throw coll.handleException(e, doAutoCommit);
}
}
public void remove() {
if (dataObject == null) {
throw new IllegalStateException();
}
DataCursor cursor = null;
boolean doAutoCommit = coll.beginAutoCommit();
try {
cursor = new DataCursor(coll.view, writeAllowed);
if (moveCursor(dataIndex, cursor)) {
cursor.delete();
deleteSlot(dataIndex);
dataObject = null;
/*
* Repopulate the block after removing all records, using the
* cursor position of the deleted record as a starting point.
* First try moving forward, since the user was moving forward.
* (It is possible to delete all records in the block only by
* moving forward, i.e, when nextIndex is greater than
* dataIndex.)
*/
if (nextIndex == 0 && keys[0] == null) {
OperationStatus status;
for (int i = 0; i < keys.length; i += 1) {
status = coll.iterateDuplicates() ? cursor.getNext(false) : cursor.getNextNoDup(false);
if (status == OperationStatus.SUCCESS) {
setSlot(i, cursor);
} else {
break;
}
}
/*
* If no records are found past the cursor position, try
* moving backward. If no records are found before the
* cursor position, leave nextIndex set to keys.length,
* which is the same as the initial iterator state and is
* appropriate for an empty key range.
*/
if (keys[0] == null) {
nextIndex = keys.length;
for (int i = nextIndex - 1; i >= 0; i -= 1) {
status =
coll.iterateDuplicates() ? cursor.getPrev(false) : cursor.getPrevNoDup(false);
if (status == OperationStatus.SUCCESS) {
setSlot(i, cursor);
} else {
break;
}
}
}
}
coll.closeCursor(cursor);
coll.commitAutoCommit(doAutoCommit);
} else {
throw new IllegalStateException();
}
} catch (Exception e) {
coll.closeCursor(cursor);
throw coll.handleException(e, doAutoCommit);
}
}
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);
}
}
