/*
* See the file LICENSE for redistribution information.
*
* Copyright (c) 2002-2006
* Sleepycat Software. All rights reserved.
*
* $Id: CursorImpl.java,v 1.1 2006/05/06 09:00:27 ckaestne Exp $
*/
package com.sleepycat.je.dbi;
import java.util.Comparator;
import java.util.logging.Level;
import java.util.logging.Logger;
import com.sleepycat.je.DatabaseEntry;
import com.sleepycat.je.DatabaseException;
import com.sleepycat.je.LockStats;
import com.sleepycat.je.OperationStatus;
import com.sleepycat.je.RunRecoveryException;
import com.sleepycat.je.latch.LatchNotHeldException;
import com.sleepycat.je.latch.LatchSupport;
import com.sleepycat.je.log.LogUtils;
import com.sleepycat.je.tree.BIN;
import com.sleepycat.je.tree.BINBoundary;
import com.sleepycat.je.tree.DBIN;
import com.sleepycat.je.tree.DIN;
import com.sleepycat.je.tree.DupCountLN;
import com.sleepycat.je.tree.IN;
import com.sleepycat.je.tree.Key;
import com.sleepycat.je.tree.LN;
import com.sleepycat.je.tree.Node;
import com.sleepycat.je.tree.Tree;
import com.sleepycat.je.tree.TreeWalkerStatsAccumulator;
import com.sleepycat.je.txn.BasicLocker;
import com.sleepycat.je.txn.LockGrantType;
import com.sleepycat.je.txn.LockResult;
import com.sleepycat.je.txn.LockType;
import com.sleepycat.je.txn.Locker;
import com.sleepycat.je.txn.ThreadLocker;
import com.sleepycat.je.utilint.DbLsn;
import com.sleepycat.je.utilint.TestHook;
import com.sleepycat.je.utilint.TestHookExecute;
/**
* A CursorImpl is the internal implementation of the cursor.
*/
public class CursorImpl implements Cloneable {
private static final boolean DEBUG = false;
private static final byte CURSOR_NOT_INITIALIZED = 1;
private static final byte CURSOR_INITIALIZED = 2;
private static final byte CURSOR_CLOSED = 3;
private static final String TRACE_DELETE = "Delete";
private static final String TRACE_MOD = "Mod:";
/*
* Cursor location in the database, represented by a BIN and an index in
* the BIN. bin/index must have a non-null/non-negative value if dupBin is
* set to non-null.
*/
volatile private BIN bin;
volatile private int index;
/*
* Cursor location in a given duplicate set. If the cursor is not
* referencing a duplicate set then these are null.
*/
volatile private DBIN dupBin;
volatile private int dupIndex;
/*
* BIN and DBIN that are no longer referenced by this cursor but have not
* yet been removed. If non-null, the BIN/DBIN will be removed soon.
* BIN.adjustCursors should ignore cursors that are to be removed.
*/
volatile private BIN binToBeRemoved;
volatile private DBIN dupBinToBeRemoved;
/*
* The cursor location used for a given operation.
*/
private BIN targetBin;
private int targetIndex;
private byte[] dupKey;
/* The database behind the handle. */
private DatabaseImpl database;
/* Owning transaction. */
private Locker locker;
private CursorImpl lockerPrev; // lockPrev, lockNext used for simple Locker
private CursorImpl lockerNext; // chain.
/*
* Do not release non-transactional locks when cursor is closed. This flag
* is used to support handle locks, which may be non-transactional but must
* be retained across cursor operations and cursor close.
*/
private boolean retainNonTxnLocks;
/* State of the cursor. See CURSOR_XXX above. */
private byte status;
private boolean allowEviction = true;
private TestHook testHook;
private boolean nonCloning = false;
/*
* Unique id that we can return as a hashCode to prevent calls to
* Object.hashCode(). [#13896]
*/
private int thisId;
/*
* Allocate hashCode ids from this. [#13896]
*/
private static long lastAllocatedId = 0;
private ThreadLocal treeStatsAccumulatorTL = new ThreadLocal();
/*
* Allocate a new hashCode id. Doesn't need to be synchronized since it's
* ok for two objects to have the same hashcode.
*/
private static long getNextCursorId() {
return ++lastAllocatedId;
}
public int hashCode() {
return thisId;
}
private TreeWalkerStatsAccumulator getTreeStatsAccumulator() {
if (EnvironmentImpl.getThreadLocalReferenceCount() > 0) {
return (TreeWalkerStatsAccumulator) treeStatsAccumulatorTL.get();
} else {
return null;
}
}
public void incrementLNCount() {
TreeWalkerStatsAccumulator treeStatsAccumulator =
getTreeStatsAccumulator();
if (treeStatsAccumulator != null) {
treeStatsAccumulator.incrementLNCount();
}
}
public void setNonCloning(boolean nonCloning) {
this.nonCloning = nonCloning;
}
/**
* public for Cursor et al
*/
public static class SearchMode {
public static final SearchMode SET =
new SearchMode(true, false, "SET");
public static final SearchMode BOTH =
new SearchMode(true, true, "BOTH");
public static final SearchMode SET_RANGE =
new SearchMode(false, false, "SET_RANGE");
public static final SearchMode BOTH_RANGE =
new SearchMode(false, true, "BOTH_RANGE");
private boolean exactSearch;
private boolean dataSearch;
private String name;
private SearchMode(boolean exactSearch,
boolean dataSearch,
String name) {
this.exactSearch = exactSearch;
this.dataSearch = dataSearch;
this.name = "SearchMode." + name;
}
/**
* Returns true when the key or key/data search is exact, i.e., for SET
* and BOTH.
*/
public final boolean isExactSearch() {
return exactSearch;
}
/**
* Returns true when the data value is included in the search, i.e.,
* for BOTH and BOTH_RANGE.
*/
public final boolean isDataSearch() {
return dataSearch;
}
public String toString() {
return name;
}
}
/**
* Holder for an OperationStatus and a keyChange flag. Is used for search
* and getNextWithKeyChangeStatus operations.
*/
public static class KeyChangeStatus {
/**
* Operation status;
*/
public OperationStatus status;
/**
* Whether the operation moved to a new key.
*/
public boolean keyChange;
public KeyChangeStatus(OperationStatus status, boolean keyChange) {
this.status = status;
this.keyChange = keyChange;
}
}
/**
* Creates a cursor with retainNonTxnLocks=true.
*/
public CursorImpl(DatabaseImpl database, Locker locker)
throws DatabaseException {
this(database, locker, true);
}
/**
* Creates a cursor.
*
* @param retainNonTxnLocks is true if non-transactional locks should be
* retained (not released automatically) when the cursor is closed.
*/
public CursorImpl(DatabaseImpl database,
Locker locker,
boolean retainNonTxnLocks)
throws DatabaseException {
thisId = (int) getNextCursorId();
bin = null;
index = -1;
dupBin = null;
dupIndex = -1;
// retainNonTxnLocks=true should not be used with a ThreadLocker
assert !(retainNonTxnLocks && (locker instanceof ThreadLocker));
// retainNonTxnLocks=false should not be used with a BasicLocker
assert !(!retainNonTxnLocks && locker.getClass() == BasicLocker.class);
this.retainNonTxnLocks = retainNonTxnLocks;
// Associate this cursor with the database
this.database = database;
this.locker = locker;
this.locker.registerCursor(this);
status = CURSOR_NOT_INITIALIZED;
/*
* Do not perform eviction here because we may be synchronized on the
* Database instance. For example, this happens when we call
* Database.openCursor(). Also eviction may be disabled after the
* cursor is constructed.
*/
}
/**
* Disables or enables eviction during cursor operations for an internal
* cursor. For example, a cursor used to implement eviction should not
* itself perform eviction. Eviction is enabled by default.
*/
public void setAllowEviction(boolean allowed) {
allowEviction = allowed;
}
/**
* Shallow copy. addCursor() is optionally called.
*/
public CursorImpl cloneCursor(boolean addCursor)
throws DatabaseException {
return cloneCursor(addCursor, null);
}
/**
* Shallow copy. addCursor() is optionally called. Allows inheriting the
* BIN position from some other cursor.
*/
public CursorImpl cloneCursor(boolean addCursor, CursorImpl usePosition)
throws DatabaseException {
CursorImpl ret = null;
if (nonCloning) {
ret = this;
} else {
try {
latchBINs();
ret = (CursorImpl) super.clone();
if (!retainNonTxnLocks) {
ret.locker = locker.newNonTxnLocker();
}
ret.locker.registerCursor(ret);
if (usePosition != null &&
usePosition.status == CURSOR_INITIALIZED) {
ret.bin = usePosition.bin;
ret.index = usePosition.index;
ret.dupBin = usePosition.dupBin;
ret.dupIndex = usePosition.dupIndex;
}
if (addCursor) {
ret.addCursor();
}
} catch (CloneNotSupportedException cannotOccur) {
return null;
} finally {
releaseBINs();
}
}
/* Perform eviction before and after each cursor operation. */
if (allowEviction) {
database.getDbEnvironment().getEvictor().doCriticalEviction();
}
return ret;
}
public int getIndex() {
return index;
}
public void setIndex(int idx) {
index = idx;
}
public BIN getBIN() {
return bin;
}
public void setBIN(BIN newBin) {
bin = newBin;
}
public BIN getBINToBeRemoved() {
return binToBeRemoved;
}
public int getDupIndex() {
return dupIndex;
}
public void setDupIndex(int dupIdx) {
dupIndex = dupIdx;
}
public DBIN getDupBIN() {
return dupBin;
}
public void setDupBIN(DBIN newDupBin) {
dupBin = newDupBin;
}
public DBIN getDupBINToBeRemoved() {
return dupBinToBeRemoved;
}
public void setTreeStatsAccumulator(TreeWalkerStatsAccumulator tSA) {
treeStatsAccumulatorTL.set(tSA);
}
/**
* Figure out which BIN/index set to use.
*/
private boolean setTargetBin() {
targetBin = null;
targetIndex = 0;
boolean isDup = (dupBin != null);
dupKey = null;
if (isDup) {
targetBin = dupBin;
targetIndex = dupIndex;
dupKey = dupBin.getDupKey();
} else {
targetBin = bin;
targetIndex = index;
}
return isDup;
}
/**
* Advance a cursor. Used so that verify can advance a cursor even in the
* face of an exception [12932].
* @param key on return contains the key if available, or null.
* @param data on return contains the data if available, or null.
*/
public boolean advanceCursor(DatabaseEntry key, DatabaseEntry data) {
BIN oldBin = bin;
BIN oldDupBin = dupBin;
int oldIndex = index;
int oldDupIndex = dupIndex;
key.setData(null);
data.setData(null);
try {
getNext(key, data, LockType.NONE,
true /* forward */,
false /* alreadyLatched */);
} catch (DatabaseException ignored) {
/* Klockwork - ok */
}
/*
* If the position changed, regardless of an exception, then we believe
* that we have advanced the cursor.
*/
if (bin != oldBin ||
dupBin != oldDupBin ||
index != oldIndex ||
dupIndex != oldDupIndex) {
/*
* Return the key and data from the BIN entries, if we were not
* able to read it above.
*/
if (key.getData() == null &&
bin != null &&
index > 0) {
setDbt(key, bin.getKey(index));
}
if (data.getData() == null &&
dupBin != null &&
dupIndex > 0) {
setDbt(data, dupBin.getKey(dupIndex));
}
return true;
} else {
return false;
}
}
public BIN latchBIN()
throws DatabaseException {
while (bin != null) {
BIN waitingOn = bin;
waitingOn.latch();
if (bin == waitingOn) {
return bin;
}
waitingOn.releaseLatch();
}
return null;
}
public void releaseBIN()
throws LatchNotHeldException {
if (bin != null) {
bin.releaseLatchIfOwner();
}
}
public void latchBINs()
throws DatabaseException {
latchBIN();
latchDBIN();
}
public void releaseBINs()
throws LatchNotHeldException {
releaseBIN();
releaseDBIN();
}
public DBIN latchDBIN()
throws DatabaseException {
while (dupBin != null) {
BIN waitingOn = dupBin;
waitingOn.latch();
if (dupBin == waitingOn) {
return dupBin;
}
waitingOn.releaseLatch();
}
return null;
}
public void releaseDBIN()
throws LatchNotHeldException {
if (dupBin != null) {
dupBin.releaseLatchIfOwner();
}
}
public Locker getLocker() {
return locker;
}
public void addCursor(BIN bin) {
if (bin != null) {
assert bin.isLatchOwner();
bin.addCursor(this);
}
}
/**
* Add to the current cursor. (For dups)
*/
public void addCursor() {
if (dupBin != null) {
addCursor(dupBin);
}
if (bin != null) {
addCursor(bin);
}
}
/*
* Update a cursor to refer to a new BIN or DBin following an insert.
* Don't bother removing this cursor from the previous bin. Cursor will do
* that with a cursor swap thereby preventing latch deadlocks down here.
*/
public void updateBin(BIN bin, int index)
throws DatabaseException {
removeCursorDBIN();
setDupIndex(-1);
setDupBIN(null);
setIndex(index);
setBIN(bin);
addCursor(bin);
}
public void updateDBin(DBIN dupBin, int dupIndex) {
setDupIndex(dupIndex);
setDupBIN(dupBin);
addCursor(dupBin);
}
private void removeCursor()
throws DatabaseException {
removeCursorBIN();
removeCursorDBIN();
}
private void removeCursorBIN()
throws DatabaseException {
BIN abin = latchBIN();
if (abin != null) {
abin.removeCursor(this);
abin.releaseLatch();
}
}
private void removeCursorDBIN()
throws DatabaseException {
DBIN abin = latchDBIN();
if (abin != null) {
abin.removeCursor(this);
abin.releaseLatch();
}
}
/**
* Clear the reference to the dup tree, if any.
*/
public void clearDupBIN(boolean alreadyLatched)
throws DatabaseException {
if (dupBin != null) {
if (alreadyLatched) {
dupBin.removeCursor(this);
dupBin.releaseLatch();
} else {
removeCursorDBIN();
}
dupBin = null;
dupIndex = -1;
}
}
public void dumpTree()
throws DatabaseException {
database.getTree().dump();
}
/**
* @return true if this cursor is closed
*/
public boolean isClosed() {
return (status == CURSOR_CLOSED);
}
/**
* @return true if this cursor is not initialized
*/
public boolean isNotInitialized() {
return (status == CURSOR_NOT_INITIALIZED);
}
/**
* Reset a cursor to an uninitialized state, but unlike close(), allow it
* to be used further.
*/
public void reset()
throws DatabaseException {
removeCursor();
if (!retainNonTxnLocks) {
locker.releaseNonTxnLocks();
}
bin = null;
index = -1;
dupBin = null;
dupIndex = -1;
status = CURSOR_NOT_INITIALIZED;
/* Perform eviction before and after each cursor operation. */
if (allowEviction) {
database.getDbEnvironment().getEvictor().doCriticalEviction();
}
}
/**
* Close a cursor.
* @throws DatabaseException if the cursor was previously closed.
*/
public void close()
throws DatabaseException {
assert assertCursorState(false) : dumpToString(true);
removeCursor();
locker.unRegisterCursor(this);
if (!retainNonTxnLocks) {
locker.releaseNonTxnLocks();
}
status = CURSOR_CLOSED;
/* Perform eviction before and after each cursor operation. */
if (allowEviction) {
database.getDbEnvironment().getEvictor().doCriticalEviction();
}
}
public int count(LockType lockType)
throws DatabaseException {
assert assertCursorState(true) : dumpToString(true);
if (!database.getSortedDuplicates()) {
return 1;
}
if (bin == null) {
return 0;
}
latchBIN();
try {
if (bin.getNEntries() <= index) {
return 0;
}
/* If fetchTarget returns null, a deleted LN was cleaned. */
Node n = bin.fetchTarget(index);
if (n != null && n.containsDuplicates()) {
DIN dupRoot = (DIN) n;
/* Latch couple down the tree. */
dupRoot.latch();
releaseBIN();
DupCountLN dupCountLN = (DupCountLN)
dupRoot.getDupCountLNRef().fetchTarget(database, dupRoot);
/* We can't hold latches when we acquire locks. */
dupRoot.releaseLatch();
/*
* Call lock directly. There is no need to call lockLN because
* the node ID cannot change (a slot cannot be reused) for a
* DupCountLN.
*/
if (lockType != LockType.NONE) {
locker.lock
(dupCountLN.getNodeId(), lockType, false /*noWait*/,
database);
}
return dupCountLN.getDupCount();
} else {
/* If an LN is in the slot, the count is one. */
return 1;
}
} finally {
releaseBIN();
}
}
/**
* Delete the item pointed to by the cursor. If cursor is not initialized
* or item is already deleted, return appropriate codes. Returns with
* nothing latched. bin and dupBin are latched as appropriate.
*
* @return 0 on success, appropriate error code otherwise.
*/
public OperationStatus delete()
throws DatabaseException {
assert assertCursorState(true) : dumpToString(true);
boolean isDup = setTargetBin();
/* If nothing at current position, return. */
if (targetBin == null) {
return OperationStatus.KEYEMPTY;
}
/*
* Check if this is already deleted. We may know that the record is
* deleted w/out seeing the LN.
*/
if (targetBin.isEntryKnownDeleted(targetIndex)) {
releaseBINs();
return OperationStatus.KEYEMPTY;
}
/* If fetchTarget returns null, a deleted LN was cleaned. */
LN ln = (LN) targetBin.fetchTarget(targetIndex);
if (ln == null) {
releaseBINs();
return OperationStatus.KEYEMPTY;
}
/* Get a write lock. */
LockResult lockResult = lockLN(ln, LockType.WRITE);
ln = lockResult.getLN();
/* Check LN deleted status under the protection of a write lock. */
if (ln == null) {
releaseBINs();
return OperationStatus.KEYEMPTY;
}
/* Lock the DupCountLN before logging any LNs. */
LockResult dclLockResult = null;
DIN dupRoot = null;
try {
isDup = (dupBin != null);
if (isDup) {
dupRoot = getLatchedDupRoot(true /*isDBINLatched*/);
dclLockResult = lockDupCountLN(dupRoot, LockType.WRITE);
/*
* Refresh the dupRoot variable because it may have changed
* during locking, but is sure to be resident and latched by
* lockDupCountLN.
*/
dupRoot = (DIN) bin.getTarget(index);
/* Release BIN to increase concurrency. */
releaseBIN();
}
/*
* Between the release of the BIN latch and acquiring the write
* lock any number of operations may have executed which would
* result in a new abort LSN for this record. Therefore, wait until
* now to get the abort LSN.
*/
setTargetBin();
long oldLsn = targetBin.getLsn(targetIndex);
byte[] lnKey = targetBin.getKey(targetIndex);
lockResult.setAbortLsn
(oldLsn, targetBin.isEntryKnownDeleted(targetIndex));
/* Log the LN. */
long oldLNSize = ln.getMemorySizeIncludedByParent();
long newLsn = ln.delete(database, lnKey, dupKey, oldLsn, locker);
long newLNSize = ln.getMemorySizeIncludedByParent();
/*
* Now update the parent of the LN (be it BIN or DBIN) to correctly
* reference the LN and adjust the memory sizing. Be sure to do
* this update of the LSN before updating the dup count LN. In case
* we encounter problems there we need the LSN to match the latest
* version to ensure that undo works.
*/
targetBin.updateEntry(targetIndex, newLsn, oldLNSize, newLNSize);
targetBin.setPendingDeleted(targetIndex);
releaseBINs();
if (isDup) {
dupRoot.incrementDuplicateCount
(dclLockResult, dupKey, locker, false /*increment*/);
dupRoot.releaseLatch();
dupRoot = null;
locker.addDeleteInfo(dupBin, new Key(lnKey));
} else {
locker.addDeleteInfo(bin, new Key(lnKey));
}
trace(Level.FINER, TRACE_DELETE, targetBin,
ln, targetIndex, oldLsn, newLsn);
} finally {
if (dupRoot != null) {
dupRoot.releaseLatchIfOwner();
}
}
return OperationStatus.SUCCESS;
}
/**
* Return a new copy of the cursor. If position is true, position the
* returned cursor at the same position.
*/
public CursorImpl dup(boolean samePosition)
throws DatabaseException {
assert assertCursorState(false) : dumpToString(true);
CursorImpl ret = cloneCursor(samePosition);
if (!samePosition) {
ret.bin = null;
ret.index = -1;
ret.dupBin = null;
ret.dupIndex = -1;
ret.status = CURSOR_NOT_INITIALIZED;
}
return ret;
}
/**
* Evict the LN node at the cursor position. This is used for internal
* databases only.
*/
public void evict()
throws DatabaseException {
try {
latchBINs();
setTargetBin();
targetBin.evictLN(targetIndex);
} finally {
releaseBINs();
}
}
/*
* Puts
*/
/**
* Search for the next key (or duplicate) following the given key (and
* datum), and acquire a range insert lock on it. If there are no more
* records following the given key and datum, lock the special EOF node
* for the database.
*/
public void lockNextKeyForInsert(DatabaseEntry key, DatabaseEntry data)
throws DatabaseException {
DatabaseEntry tempKey = new DatabaseEntry
(key.getData(), key.getOffset(), key.getSize());
DatabaseEntry tempData = new DatabaseEntry
(data.getData(), data.getOffset(), data.getSize());
tempKey.setPartial(0, 0, true);
tempData.setPartial(0, 0, true);
boolean lockedNextKey = false;
/* Don't search for data if duplicates are not configured. */
SearchMode searchMode = database.getSortedDuplicates() ?
SearchMode.BOTH_RANGE : SearchMode.SET_RANGE;
boolean latched = true;
try {
/* Search. */
int searchResult = searchAndPosition
(tempKey, tempData, searchMode, LockType.RANGE_INSERT);
if ((searchResult & FOUND) != 0 &&
(searchResult & FOUND_LAST) == 0) {
/*
* If searchAndPosition found a record (other than the last
* one), in all cases we should advance to the next record:
*
* 1- found a deleted record,
* 2- found an exact match, or
* 3- found the record prior to the given key/data.
*
* If we didn't match the key, skip over duplicates to the next
* key with getNextNoDup.
*/
OperationStatus status;
if ((searchResult & EXACT_KEY) != 0) {
status = getNext
(tempKey, tempData, LockType.RANGE_INSERT, true, true);
} else {
status = getNextNoDup
(tempKey, tempData, LockType.RANGE_INSERT, true, true);
}
if (status == OperationStatus.SUCCESS) {
lockedNextKey = true;
}
latched = false;
}
} finally {
if (latched) {
releaseBINs();
}
}
/* Lock the EOF node if no next key was found. */
if (!lockedNextKey) {
lockEofNode(LockType.RANGE_INSERT);
}
}
/**
* Insert the given LN in the tree or return KEYEXIST if the key is already
* present.
*
* <p>This method is called directly internally for putting tree map LNs
* and file summary LNs. It should not be used otherwise, and in the
* future we should find a way to remove this special case.</p>
*/
public OperationStatus putLN(byte[] key, LN ln, boolean allowDuplicates)
throws DatabaseException {
assert assertCursorState(false) : dumpToString(true);
assert LatchSupport.countLatchesHeld() == 0;
LockResult lockResult = locker.lock
(ln.getNodeId(), LockType.WRITE, false /*noWait*/, database);
/*
* We'll set abortLsn down in Tree.insert when we know whether we're
* re-using a BIN entry or not.
*/
if (database.getTree().insert
(ln, key, allowDuplicates, this, lockResult)) {
status = CURSOR_INITIALIZED;
return OperationStatus.SUCCESS;
} else {
locker.releaseLock(ln.getNodeId());
return OperationStatus.KEYEXIST;
}
}
/**
* Insert or overwrite the key/data pair.
* @param key
* @param data
* @return 0 if successful, failure status value otherwise
*/
public OperationStatus put(DatabaseEntry key,
DatabaseEntry data,
DatabaseEntry foundData)
throws DatabaseException {
assert assertCursorState(false) : dumpToString(true);
OperationStatus result = putLN
(Key.makeKey(key), new LN(data), database.getSortedDuplicates());
if (result == OperationStatus.KEYEXIST) {
status = CURSOR_INITIALIZED;
/*
* If dups are allowed and putLN() returns KEYEXIST, the duplicate
* already exists. However, we still need to get a write lock, and
* calling putCurrent does that. Without duplicates, we have to
* update the data of course.
*/
result = putCurrent(data, null, foundData);
}
return result;
}
/**
* Insert the key/data pair in No Overwrite mode.
* @param key
* @param data
* @return 0 if successful, failure status value otherwise
*/
public OperationStatus putNoOverwrite(DatabaseEntry key,
DatabaseEntry data)
throws DatabaseException {
assert assertCursorState(false) : dumpToString(true);
return putLN(Key.makeKey(key), new LN(data), false);
}
/**
* Insert the key/data pair as long as no entry for key/data exists yet.
*/
public OperationStatus putNoDupData(DatabaseEntry key, DatabaseEntry data)
throws DatabaseException {
assert assertCursorState(false) : dumpToString(true);
if (!database.getSortedDuplicates()) {
throw new DatabaseException
("putNoDupData() called, but database is not configured " +
"for duplicate data.");
}
return putLN(Key.makeKey(key), new LN(data), true);
}
/**
* Modify the current record with this data.
* @param data
*/
public OperationStatus putCurrent(DatabaseEntry data,
DatabaseEntry foundKey,
DatabaseEntry foundData)
throws DatabaseException {
assert assertCursorState(true) : dumpToString(true);
if (foundKey != null) {
foundKey.setData(null);
}
if (foundData != null) {
foundData.setData(null);
}
if (bin == null) {
return OperationStatus.KEYEMPTY;
}
latchBINs();
boolean isDup = setTargetBin();
try {
/*
* Find the existing entry and get a reference to all BIN fields
* while latched.
*/
LN ln = (LN) targetBin.fetchTarget(targetIndex);
byte[] lnKey = targetBin.getKey(targetIndex);
Comparator userComparisonFcn = targetBin.getKeyComparator();
/* If fetchTarget returned null, a deleted LN was cleaned. */
if (targetBin.isEntryKnownDeleted(targetIndex) ||
ln == null) {
releaseBINs();
return OperationStatus.NOTFOUND;
}
/* Get a write lock. */
LockResult lockResult = lockLN(ln, LockType.WRITE);
ln = lockResult.getLN();
/* Check LN deleted status under the protection of a write lock. */
if (ln == null) {
releaseBINs();
return OperationStatus.NOTFOUND;
}
/*
* If cursor points at a dup, then we can only replace the entry
* with a new entry that is "equal" to the old one. Since a user
* defined comparison function may actually compare equal for two
* byte sequences that are actually different we still have to do
* the replace. Arguably we could skip the replacement if there is
* no user defined comparison function and the new data is the
* same.
*/
byte[] foundDataBytes;
byte[] foundKeyBytes;
isDup = setTargetBin();
if (isDup) {
foundDataBytes = lnKey;
foundKeyBytes = targetBin.getDupKey();
} else {
foundDataBytes = ln.getData();
foundKeyBytes = lnKey;
}
byte[] newData;
/* Resolve partial puts. */
if (data.getPartial()) {
int dlen = data.getPartialLength();
int doff = data.getPartialOffset();
int origlen = (foundDataBytes != null) ?
foundDataBytes.length : 0;
int oldlen = (doff + dlen > origlen) ? doff + dlen : origlen;
int len = oldlen - dlen + data.getSize();
if (len == 0) {
newData = LogUtils.ZERO_LENGTH_BYTE_ARRAY;
} else {
newData = new byte[len];
}
int pos = 0;
/*
* Keep 0..doff of the old data (truncating if doff > length).
*/
int slicelen = (doff < origlen) ? doff : origlen;
if (slicelen > 0)
System.arraycopy(foundDataBytes, 0, newData,
pos, slicelen);
pos += doff;
/* Copy in the new data. */
slicelen = data.getSize();
System.arraycopy(data.getData(), data.getOffset(),
newData, pos, slicelen);
pos += slicelen;
/* Append the rest of the old data (if any). */
slicelen = origlen - (doff + dlen);
if (slicelen > 0)
System.arraycopy(foundDataBytes, doff + dlen, newData, pos,
slicelen);
} else {
int len = data.getSize();
if (len == 0) {
newData = LogUtils.ZERO_LENGTH_BYTE_ARRAY;
} else {
newData = new byte[len];
}
System.arraycopy(data.getData(), data.getOffset(),
newData, 0, len);
}
if (database.getSortedDuplicates()) {
/* Check that data compares equal before replacing it. */
boolean keysEqual = false;
if (foundDataBytes != null) {
keysEqual = Key.compareKeys
(foundDataBytes, newData, userComparisonFcn) == 0;
}
if (!keysEqual) {
revertLock(ln, lockResult);
throw new DatabaseException
("Can't replace a duplicate with different data.");
}
}
if (foundData != null) {
setDbt(foundData, foundDataBytes);
}
if (foundKey != null) {
setDbt(foundKey, foundKeyBytes);
}
/*
* Between the release of the BIN latch and acquiring the write
* lock any number of operations may have executed which would
* result in a new abort LSN for this record. Therefore, wait until
* now to get the abort LSN.
*/
long oldLsn = targetBin.getLsn(targetIndex);
lockResult.setAbortLsn
(oldLsn, targetBin.isEntryKnownDeleted(targetIndex));
/*
* The modify has to be inside the latch so that the BIN is updated
* inside the latch.
*/
long oldLNSize = ln.getMemorySizeIncludedByParent();
byte[] newKey = (isDup ? targetBin.getDupKey() : lnKey);
long newLsn = ln.modify(newData, database, newKey, oldLsn, locker);
long newLNSize = ln.getMemorySizeIncludedByParent();
/* Update the parent BIN. */
targetBin.updateEntry(targetIndex, newLsn, oldLNSize, newLNSize);
releaseBINs();
trace(Level.FINER, TRACE_MOD, targetBin,
ln, targetIndex, oldLsn, newLsn);
status = CURSOR_INITIALIZED;
return OperationStatus.SUCCESS;
} finally {
releaseBINs();
}
}
/*
* Gets
*/
/**
* Retrieve the current record.
*/
public OperationStatus getCurrent(DatabaseEntry foundKey,
DatabaseEntry foundData,
LockType lockType)
throws DatabaseException {
assert assertCursorState(true) : dumpToString(true);
// If not pointing at valid entry, return failure
if (bin == null) {
return OperationStatus.KEYEMPTY;
}
if (dupBin == null) {
latchBIN();
} else {
latchDBIN();
}
return getCurrentAlreadyLatched(foundKey, foundData, lockType, true);
}
/**
* Retrieve the current record. Assume the bin is already latched. Return
* with the target bin unlatched.
*/
public OperationStatus getCurrentAlreadyLatched(DatabaseEntry foundKey,
DatabaseEntry foundData,
LockType lockType,
boolean first)
throws DatabaseException {
assert assertCursorState(true) : dumpToString(true);
assert checkAlreadyLatched(true) : dumpToString(true);
try {
return fetchCurrent(foundKey, foundData, lockType, first);
} finally {
releaseBINs();
}
}
/**
* Retrieve the current LN, return with the target bin unlatched.
*/
public LN getCurrentLN(LockType lockType)
throws DatabaseException {
assert assertCursorState(true) : dumpToString(true);
if (bin == null) {
return null;
} else {
latchBIN();
return getCurrentLNAlreadyLatched(lockType);
}
}
/**
* Retrieve the current LN, assuming the BIN is already latched. Return
* with the target BIN unlatched.
*/
public LN getCurrentLNAlreadyLatched(LockType lockType)
throws DatabaseException {
try {
assert assertCursorState(true) : dumpToString(true);
assert checkAlreadyLatched(true) : dumpToString(true);
if (bin == null) {
return null;
}
/*
* Get a reference to the LN under the latch. Check the deleted
* flag in the BIN. If fetchTarget returns null, a deleted LN was
* cleaned.
*/
LN ln = null;
if (!bin.isEntryKnownDeleted(index)) {
ln = (LN) bin.fetchTarget(index);
}
if (ln == null) {
releaseBIN();
return null;
}
addCursor(bin);
/* Lock LN. */
LockResult lockResult = lockLN(ln, lockType);
ln = lockResult.getLN();
/* Don't set abort LSN for a read operation! */
return ln;
} finally {
releaseBINs();
}
}
public OperationStatus getNext(DatabaseEntry foundKey,
DatabaseEntry foundData,
LockType lockType,
boolean forward,
boolean alreadyLatched)
throws DatabaseException {
return getNextWithKeyChangeStatus
(foundKey, foundData, lockType, forward, alreadyLatched).status;
}
/**
* Move the cursor forward and return the next record. This will cross BIN
* boundaries and dip into duplicate sets.
*
* @param foundKey DatabaseEntry to use for returning key
*
* @param foundData DatabaseEntry to use for returning data
*
* @param forward if true, move forward, else move backwards
*
* @param alreadyLatched if true, the bin that we're on is already
* latched.
*
* @return the status and an indication of whether we advanced to a new
* key during the operation.
*/
public KeyChangeStatus
getNextWithKeyChangeStatus(DatabaseEntry foundKey,
DatabaseEntry foundData,
LockType lockType,
boolean forward,
boolean alreadyLatched)
throws DatabaseException {
assert assertCursorState(true) : dumpToString(true);
assert checkAlreadyLatched(alreadyLatched) : dumpToString(true);
KeyChangeStatus result =
new KeyChangeStatus(OperationStatus.NOTFOUND, true);
try {
while (bin != null) {
/* Are we positioned on a DBIN? */
if (dupBin != null) {
if (DEBUG) {
verifyCursor(dupBin);
}
if (getNextDuplicate(foundKey, foundData, lockType,
forward, alreadyLatched) ==
OperationStatus.SUCCESS) {
result.status = OperationStatus.SUCCESS;
/* We returned a duplicate. */
result.keyChange = false;
break;
} else {
removeCursorDBIN();
alreadyLatched = false;
dupBin = null;
dupIndex = -1;
continue;
}
}
assert checkAlreadyLatched(alreadyLatched) :
dumpToString(true);
if (!alreadyLatched) {
latchBIN();
} else {
alreadyLatched = false;
}
if (DEBUG) {
verifyCursor(bin);
}
/* Is there anything left on this BIN? */
if ((forward && ++index < bin.getNEntries()) ||
(!forward && --index > -1)) {
OperationStatus ret =
getCurrentAlreadyLatched(foundKey, foundData,
lockType, forward);
if (ret == OperationStatus.SUCCESS) {
incrementLNCount();
result.status = OperationStatus.SUCCESS;
break;
} else {
assert LatchSupport.countLatchesHeld() == 0;
if (binToBeRemoved != null) {
flushBINToBeRemoved();
}
continue;
}
} else {
/*
* PriorBIN is used to release a BIN earlier in the
* traversal chain when we move onto the next BIN. When
* we traverse across BINs, there is a point when two BINs
* point to the same cursor.
*
* Example: BINa(empty) BINb(empty) BINc(populated)
* Cursor (C) is traversing
* loop, leaving BINa:
* priorBIN is null, C points to BINa, BINa points to C
* set priorBin to BINa
* find BINb, make BINb point to C
* note that BINa and BINb point to C.
* loop, leaving BINb:
* priorBIN == BINa, remove C from BINa
* set priorBin to BINb
* find BINc, make BINc point to C
* note that BINb and BINc point to C
* finally, when leaving this method, remove C from BINb.
*/
if (binToBeRemoved != null) {
releaseBIN();
flushBINToBeRemoved();
latchBIN();
}
binToBeRemoved = bin;
bin = null;
BIN newBin;
/*
* SR #12736
* Prune away oldBin. Assert has intentional side effect
*/
assert TestHookExecute.doHookIfSet(testHook);
if (forward) {
newBin = database.getTree().getNextBin
(binToBeRemoved,
false /* traverseWithinDupTree */);
} else {
newBin = database.getTree().getPrevBin
(binToBeRemoved,
false /* traverseWithinDupTree */);
}
if (newBin == null) {
result.status = OperationStatus.NOTFOUND;
break;
} else {
if (forward) {
index = -1;
} else {
index = newBin.getNEntries();
}
addCursor(newBin);
/* Ensure that setting bin is under newBin's latch */
bin = newBin;
alreadyLatched = true;
}
}
}
} finally {
assert LatchSupport.countLatchesHeld() == 0 :
LatchSupport.latchesHeldToString();
if (binToBeRemoved != null) {
flushBINToBeRemoved();
}
}
return result;
}
private void flushBINToBeRemoved()
throws DatabaseException {
binToBeRemoved.latch();
binToBeRemoved.removeCursor(this);
binToBeRemoved.releaseLatch();
binToBeRemoved = null;
}
public OperationStatus getNextNoDup(DatabaseEntry foundKey,
DatabaseEntry foundData,
LockType lockType,
boolean forward,
boolean alreadyLatched)
throws DatabaseException {
assert assertCursorState(true) : dumpToString(true);
if (dupBin != null) {
clearDupBIN(alreadyLatched);
alreadyLatched = false;
}
return getNext(foundKey, foundData, lockType, forward, alreadyLatched);
}
/**
* Retrieve the first duplicate at the current cursor position.
*/
public OperationStatus getFirstDuplicate(DatabaseEntry foundKey,
DatabaseEntry foundData,
LockType lockType)
throws DatabaseException {
assert assertCursorState(true) : dumpToString(true);
/*
* By clearing the dupBin, the next call to fetchCurrent will move to
* the first duplicate.
*/
if (dupBin != null) {
removeCursorDBIN();
dupBin = null;
dupIndex = -1;
}
return getCurrent(foundKey, foundData, lockType);
}
/**
* Enter with dupBin unlatched. Pass foundKey == null to just advance
* cursor to next duplicate without fetching data.
*/
public OperationStatus getNextDuplicate(DatabaseEntry foundKey,
DatabaseEntry foundData,
LockType lockType,
boolean forward,
boolean alreadyLatched)
throws DatabaseException {
assert assertCursorState(true) : dumpToString(true);
assert checkAlreadyLatched(alreadyLatched) : dumpToString(true);
try {
while (dupBin != null) {
if (!alreadyLatched) {
latchDBIN();
} else {
alreadyLatched = false;
}
if (DEBUG) {
verifyCursor(dupBin);
}
/* Are we still on this DBIN? */
if ((forward && ++dupIndex < dupBin.getNEntries()) ||
(!forward && --dupIndex > -1)) {
OperationStatus ret = OperationStatus.SUCCESS;
if (foundKey != null) {
ret = getCurrentAlreadyLatched(foundKey, foundData,
lockType, forward);
} else {
releaseDBIN();
}
if (ret == OperationStatus.SUCCESS) {
incrementLNCount();
return ret;
} else {
assert LatchSupport.countLatchesHeld() == 0;
if (dupBinToBeRemoved != null) {
flushDBINToBeRemoved();
}
continue;
}
} else {
/*
* We need to go to the next DBIN. Remove the cursor and
* be sure to change the dupBin field after removing the
* cursor.
*/
if (dupBinToBeRemoved != null) {
flushDBINToBeRemoved();
}
dupBinToBeRemoved = dupBin;
dupBin = null;
dupBinToBeRemoved.releaseLatch();
TreeWalkerStatsAccumulator treeStatsAccumulator =
getTreeStatsAccumulator();
if (treeStatsAccumulator != null) {
latchBIN();
try {
if (index < 0) {
/* This duplicate tree has been deleted. */
return OperationStatus.NOTFOUND;
}
DIN duplicateRoot = (DIN) bin.fetchTarget(index);
duplicateRoot.latch();
try {
DupCountLN dcl = duplicateRoot.getDupCountLN();
if (dcl != null) {
dcl.accumulateStats(treeStatsAccumulator);
}
} finally {
duplicateRoot.releaseLatch();
}
} finally {
releaseBIN();
}
}
assert (LatchSupport.countLatchesHeld() == 0);
dupBinToBeRemoved.latch();
DBIN newDupBin;
if (forward) {
newDupBin = (DBIN) database.getTree().getNextBin
(dupBinToBeRemoved,
true /* traverseWithinDupTree*/);
} else {
newDupBin = (DBIN) database.getTree().getPrevBin
(dupBinToBeRemoved,
true /* traverseWithinDupTree*/);
}
if (newDupBin == null) {
return OperationStatus.NOTFOUND;
} else {
if (forward) {
dupIndex = -1;
} else {
dupIndex = newDupBin.getNEntries();
}
addCursor(newDupBin);
/*
* Ensure that setting dupBin is under newDupBin's
* latch.
*/
dupBin = newDupBin;
alreadyLatched = true;
}
}
}
} finally {
assert LatchSupport.countLatchesHeld() == 0;
if (dupBinToBeRemoved != null) {
flushDBINToBeRemoved();
}
}
return OperationStatus.NOTFOUND;
}
private void flushDBINToBeRemoved()
throws DatabaseException {
dupBinToBeRemoved.latch();
dupBinToBeRemoved.removeCursor(this);
dupBinToBeRemoved.releaseLatch();
dupBinToBeRemoved = null;
}
/**
* Position the cursor at the first or last record of the database. It's
* okay if this record is deleted. Returns with the target BIN latched.
*
* @return true if a first or last position is found, false if the
* tree being searched is empty.
*/
public boolean positionFirstOrLast(boolean first, DIN duplicateRoot)
throws DatabaseException {
assert assertCursorState(false) : dumpToString(true);
IN in = null;
boolean found = false;
try {
if (duplicateRoot == null) {
removeCursorBIN();
if (first) {
in = database.getTree().getFirstNode();
} else {
in = database.getTree().getLastNode();
}
if (in != null) {
assert (in instanceof BIN);
dupBin = null;
dupIndex = -1;
bin = (BIN) in;
index = (first ? 0 : (bin.getNEntries() - 1));
addCursor(bin);
TreeWalkerStatsAccumulator treeStatsAccumulator =
getTreeStatsAccumulator();
if (bin.getNEntries() == 0) {
/*
* An IN was found. Even if it's empty, let Cursor
* handle moving to the first non-deleted entry.
*/
found = true;
} else {
/*
* See if we need to descend further. If fetchTarget
* returns null, a deleted LN was cleaned.
*/
Node n = null;
if (!in.isEntryKnownDeleted(index)) {
n = in.fetchTarget(index);
}
if (n != null && n.containsDuplicates()) {
DIN dupRoot = (DIN) n;
dupRoot.latch();
in.releaseLatch();
in = null;
found = positionFirstOrLast(first, dupRoot);
} else {
/*
* Even if the entry is deleted, just leave our
* position here and return.
*/
if (treeStatsAccumulator != null) {
if (n == null || ((LN) n).isDeleted()) {
treeStatsAccumulator.
incrementDeletedLNCount();
} else {
treeStatsAccumulator.
incrementLNCount();
}
}
found = true;
}
}
}
} else {
removeCursorDBIN();
if (first) {
in = database.getTree().getFirstNode(duplicateRoot);
} else {
in = database.getTree().getLastNode(duplicateRoot);
}
if (in != null) {
/*
* An IN was found. Even if it's empty, let Cursor handle
* moving to the first non-deleted entry.
*/
assert (in instanceof DBIN);
dupBin = (DBIN) in;
dupIndex = (first ? 0 : (dupBin.getNEntries() - 1));
addCursor(dupBin);
found = true;
}
}
status = CURSOR_INITIALIZED;
return found;
} catch (DatabaseException e) {
/* Release latch on error. */
if (in != null) {
in.releaseLatch();
}
throw e;
}
}
public static final int FOUND = 0x1;
/* Exact match on the key portion. */
public static final int EXACT_KEY = 0x2;
/* Exact match on the DATA portion when searchAndPositionBoth used. */
public static final int EXACT_DATA = 0x4;
/* Record found is the last one in the database. */
public static final int FOUND_LAST = 0x8;
/**
* Position the cursor at the key. This returns a three part value that's
* bitwise or'ed into the int. We find out if there was any kind of match
* and if the match was exact. Note that this match focuses on whether the
* searching criteria (key, or key and data, depending on the search type)
* is met.
*
* <p>Note this returns with the BIN latched!</p>
*
* <p>If this method returns without the FOUND bit set, the caller can
* assume that no match is possible. Otherwise, if the FOUND bit is set,
* the caller should check the EXACT_KEY and EXACT_DATA bits. If EXACT_KEY
* is not set (or for BOTH and BOTH_RANGE, if EXACT_DATA is not set), an
* approximate match was found. In an approximate match, the cursor is
* always positioned before the target key/data. This allows the caller to
* perform a 'next' operation to advance to the value that is equal or
* higher than the target key/data.</p>
*
* <p>Even if the search returns an exact result, the record may be
* deleted. The caller must therefore check for both an approximate match
* and for whether the cursor is positioned on a deleted record.</p>
*
* <p>If SET or BOTH is specified, the FOUND bit will only be returned if
* an exact match is found. However, the record found may be deleted.</p>
*
* <p>There is one special case where this method may be called without
* checking the EXACT_KEY (and EXACT_DATA) bits and without checking for a
* deleted record: If SearchMode.SET is specified then only the FOUND bit
* need be checked. When SET is specified and FOUND is returned, it is
* guaranteed to be an exact match on a non-deleted record. It is for this
* case only that this method is public.</p>
*
* <p>If FOUND is set, FOUND_LAST may also be set if the cursor is
* positioned on the last record in the database. Note that this state can
* only be counted on as long as the BIN is latched, so it is not set if
* this method must release the latch to lock the record. Therefore, it
* should only be used for optimizations. If FOUND_LAST is set, the cursor
* is positioned on the last record and the BIN is latched. If FOUND_LAST
* is not set, the cursor may or may not be positioned on the last record.
* Note that exact searches always perform an unlatch and a lock, so
* FOUND_LAST will only be set for inexact (range) searches.</p>
*
* <p>Be aware that when an approximate match is returned, the index or
* dupIndex may be set to -1. This is done intentionally so that a 'next'
* operation will increment it.</p>
*/
public int searchAndPosition(DatabaseEntry matchKey,
DatabaseEntry matchData,
SearchMode searchMode,
LockType lockType)
throws DatabaseException {
assert assertCursorState(false) : dumpToString(true);
removeCursor();
bin = null;
boolean foundSomething = false;
boolean foundExactKey = false;
boolean foundExactData = false;
boolean foundLast = false;
boolean exactSearch = searchMode.isExactSearch();
BINBoundary binBoundary = new BINBoundary();
try {
byte[] key = Key.makeKey(matchKey);
bin = (BIN) database.getTree().search
(key, Tree.SearchType.NORMAL, -1, binBoundary,
true /*updateGeneration*/);
if (bin != null) {
addCursor(bin);
/*
* If we're doing an exact search, tell bin.findEntry we
* require an exact match. If it's a range search, we don't
* need that exact match.
*/
index = bin.findEntry(key, true, exactSearch);
/*
* If we're doing an exact search, as a starting point, we'll
* assume that we haven't found anything. If this is a range
* search, we'll assume the opposite, that we have found a
* record. That's because for a range search, the higher level
* will take care of sorting out whether anything is really
* there or not.
*/
foundSomething = !exactSearch;
dupBin = null;
dupIndex = -1;
boolean containsDuplicates = false;
if (index >= 0) {
if ((index & IN.EXACT_MATCH) != 0) {
/*
* The binary search told us we had an exact match.
* Note that this really only tells us that the key
* matched. The underlying LN may be deleted or the
* reference may be knownDeleted, or maybe there's a
* dup tree w/no entries, but the next layer up will
* find these cases.
*/
foundExactKey = true;
/*
* Now turn off the exact match bit so the index will
* be a valid value, before we use it to retrieve the
* child reference from the bin.
*/
index &= ~IN.EXACT_MATCH;
}
/*
* If fetchTarget returns null, a deleted LN was cleaned.
*/
Node n = null;
if (!bin.isEntryKnownDeleted(index)) {
n = bin.fetchTarget(index);
}
if (n != null) {
containsDuplicates = n.containsDuplicates();
if (searchMode.isDataSearch()) {
if (foundExactKey) {
/* If the key matches, try the data. */
int searchResult = searchAndPositionBoth
(containsDuplicates, n, matchData,
exactSearch, lockType, bin.getLsn(index));
foundSomething =
(searchResult & FOUND) != 0;
foundExactData =
(searchResult & EXACT_DATA) != 0;
}
} else {
foundSomething = true;
if (!containsDuplicates && exactSearch) {
/* Lock LN, check if deleted. */
LN ln = (LN) n;
LockResult lockResult = lockLN(ln, lockType);
ln = lockResult.getLN();
if (ln == null) {
foundSomething = false;
}
/*
* Note that we must not set the abort LSN for
* a read operation, lest false obsoletes are
* set. [13158]
*/
}
}
}
/*
* Determine whether the last record was found. This is
* only possible when we don't lock the record, and when
* there are no duplicates.
*/
foundLast = (searchMode == SearchMode.SET_RANGE &&
foundSomething &&
!containsDuplicates &&
binBoundary.isLastBin &&
index == bin.getNEntries() - 1);
}
}
status = CURSOR_INITIALIZED;
/* Return a two part status value */
return (foundSomething ? FOUND : 0) |
(foundExactKey ? EXACT_KEY : 0) |
(foundExactData ? EXACT_DATA : 0) |
(foundLast ? FOUND_LAST : 0);
} catch (DatabaseException e) {
/* Release latch on error. */
releaseBIN();
throw e;
}
}
/**
* For this type of search, we need to match both key and data. This
* method is called after the key is matched to perform the data portion of
* the match. We may be matching just against an LN, or doing further
* searching into the dup tree. See searchAndPosition for more details.
*/
private int searchAndPositionBoth(boolean containsDuplicates,
Node n,
DatabaseEntry matchData,
boolean exactSearch,
LockType lockType,
long oldLsn)
throws DatabaseException {
assert assertCursorState(false) : dumpToString(true);
boolean found = false;
boolean exact = false;
assert (matchData != null);
byte[] data = Key.makeKey(matchData);
if (containsDuplicates) {
/* It's a duplicate tree. */
DIN duplicateRoot = (DIN) n;
duplicateRoot.latch();
releaseBIN();
dupBin = (DBIN) database.getTree().searchSubTree
(duplicateRoot, data, Tree.SearchType.NORMAL, -1, null,
true /*updateGeneration*/);
if (dupBin != null) {
/* Find an exact match. */
addCursor(dupBin);
dupIndex = dupBin.findEntry(data, true, exactSearch);
if (dupIndex >= 0) {
if ((dupIndex & IN.EXACT_MATCH) != 0) {
exact = true;
}
dupIndex &= ~IN.EXACT_MATCH;
found = true;
} else {
/*
* The first duplicate is greater than the target data.
* Set index so that a 'next' operation moves to the first
* duplicate.
*/
dupIndex = -1;
found = !exactSearch;
}
}
} else {
/* Not a duplicate, but checking for both key and data match. */
LN ln = (LN) n;
/* Lock LN, check if deleted. */
LockResult lockResult = lockLN(ln, lockType);
ln = lockResult.getLN();
if (ln == null) {
found = !exactSearch;
} else {
/* Don't set abort LSN for read operation. [#13158] */
dupBin = null;
dupIndex = -1;
/*
* The comparison logic below mimics IN.findEntry as used above
* for duplicates.
*/
int cmp = Key.compareKeys
(ln.getData(), data, database.getDuplicateComparator());
if (cmp == 0 || (cmp <= 0 && !exactSearch)) {
if (cmp == 0) {
exact = true;
}
found = true;
} else {
/*
* The current record's data is greater than the target
* data. Set index so that a 'next' operation moves to the
* current record.
*/
index--;
found = !exactSearch;
}
}
}
return (found ? FOUND : 0) |
(exact ? EXACT_DATA : 0);
}
/*
* Lock and copy current record into the key and data DatabaseEntry. Enter
* with the BIN/DBIN latched.
*/
private OperationStatus fetchCurrent(DatabaseEntry foundKey,
DatabaseEntry foundData,
LockType lockType,
boolean first)
throws DatabaseException {
TreeWalkerStatsAccumulator treeStatsAccumulator =
getTreeStatsAccumulator();
boolean duplicateFetch = setTargetBin();
if (targetBin == null) {
return OperationStatus.NOTFOUND;
}
assert targetBin.isLatchOwner();
/*
* Check the deleted flag in the BIN and make sure this isn't an empty
* BIN. The BIN could be empty by virtue of the compressor running the
* size of this BIN to 0 but not having yet deleted it from the tree.
*
* The index may be negative if we're at an intermediate stage in an
* higher level operation, and we expect a higher level method to do a
* next or prev operation after this returns KEYEMPTY. [#11700]
*/
Node n = null;
if (targetIndex < 0 ||
targetIndex >= targetBin.getNEntries() ||
targetBin.isEntryKnownDeleted(targetIndex)) {
/* Node is no longer present. */
} else {
/*
* If we encounter a pendingDeleted entry, add it to the compressor
* queue.
*/
if (targetBin.isEntryPendingDeleted(targetIndex)) {
EnvironmentImpl envImpl = database.getDbEnvironment();
envImpl.addToCompressorQueue
(targetBin, new Key(targetBin.getKey(targetIndex)), false);
}
/* If fetchTarget returns null, a deleted LN was cleaned. */
try {
n = targetBin.fetchTarget(targetIndex);
} catch (DatabaseException DE) {
targetBin.releaseLatchIfOwner();
throw DE;
}
}
if (n == null) {
if (treeStatsAccumulator != null) {
treeStatsAccumulator.incrementDeletedLNCount();
}
targetBin.releaseLatchIfOwner();
return OperationStatus.KEYEMPTY;
}
/*
* Note that since we have the BIN/DBIN latched, we can safely check
* the node type. Any conversions from an LN to a dup tree must have
* the bin latched.
*/
addCursor(targetBin);
if (n.containsDuplicates()) {
assert !duplicateFetch;
/* Descend down duplicate tree, doing latch coupling. */
DIN duplicateRoot = (DIN) n;
duplicateRoot.latch();
targetBin.releaseLatch();
if (positionFirstOrLast(first, duplicateRoot)) {
try {
return fetchCurrent(foundKey, foundData, lockType, first);
} catch (DatabaseException DE) {
releaseBINs();
throw DE;
}
} else {
return OperationStatus.NOTFOUND;
}
}
LN ln = (LN) n;
assert TestHookExecute.doHookIfSet(testHook);
/*
* Lock the LN. For dirty-read, the data of the LN can be set to null
* at any time. Cache the data in a local variable so its state does
* not change before calling setDbt further below.
*/
LockResult lockResult = lockLN(ln, lockType);
try {
ln = lockResult.getLN();
byte[] lnData = (ln != null) ? ln.getData() : null;
if (ln == null || lnData == null) {
if (treeStatsAccumulator != null) {
treeStatsAccumulator.incrementDeletedLNCount();
}
return OperationStatus.KEYEMPTY;
}
duplicateFetch = setTargetBin();
/*
* Don't set the abort LSN here since we are not logging yet, even
* if this is a write lock. Tree.insert depends on the fact that
* the abortLSN is not already set for deleted items.
*/
if (duplicateFetch) {
if (foundData != null) {
setDbt(foundData, targetBin.getKey(targetIndex));
}
if (foundKey != null) {
setDbt(foundKey, targetBin.getDupKey());
}
} else {
if (foundData != null) {
setDbt(foundData, lnData);
}
if (foundKey != null) {
setDbt(foundKey, targetBin.getKey(targetIndex));
}
}
return OperationStatus.SUCCESS;
} finally {
releaseBINs();
}
}
/**
* Locks the given LN's node ID; a deleted LN will not be locked or
* returned. Attempts to use a non-blocking lock to avoid
* unlatching/relatching. Retries if necessary, to handle the case where
* the LN is changed while the BIN is unlatched.
*
* Preconditions: The target BIN must be latched. When positioned in a dup
* tree, the BIN may be latched on entry also and if so it will be latched
* on exit.
*
* Postconditions: The target BIN is latched. When positioned in a dup
* tree, the BIN will be latched if it was latched on entry or a blocking
* lock was needed. Therefore, when positioned in a dup tree, releaseDBIN
* should be called.
*
* @param ln the LN to be locked.
* @param lockType the type of lock requested.
* @return the LockResult containing the LN that was locked, or containing
* a null LN if the LN was deleted or cleaned. If the LN is deleted, a
* lock will not be held.
*/
private LockResult lockLN(LN ln, LockType lockType)
throws DatabaseException {
LockResult lockResult = lockLNDeletedAllowed(ln, lockType);
ln = lockResult.getLN();
if (ln != null) {
setTargetBin();
if (targetBin.isEntryKnownDeleted(targetIndex) ||
ln.isDeleted()) {
revertLock(ln.getNodeId(), lockResult.getLockGrant());
lockResult.setLN(null);
}
}
return lockResult;
}
/**
* Locks the given LN's node ID; a deleted LN will be locked and returned.
* Attempts to use a non-blocking lock to avoid unlatching/relatching.
* Retries if necessary, to handle the case where the LN is changed while
* the BIN is unlatched.
*
* Preconditions: The target BIN must be latched. When positioned in a dup
* tree, the BIN may be latched on entry also and if so it will be latched
* on exit.
*
* Postconditions: The target BIN is latched. When positioned in a dup
* tree, the BIN will be latched if it was latched on entry or a blocking
* lock was needed. Therefore, when positioned in a dup tree, releaseDBIN
* should be called.
*
* @param ln the LN to be locked.
* @param lockType the type of lock requested.
* @return the LockResult containing the LN that was locked, or containing
* a null LN if the LN was cleaned.
*/
public LockResult lockLNDeletedAllowed(LN ln, LockType lockType)
throws DatabaseException {
LockResult lockResult;
/* For dirty-read, there is no need to fetch the node. */
if (lockType == LockType.NONE) {
lockResult = new LockResult(LockGrantType.NONE_NEEDED, null);
lockResult.setLN(ln);
return lockResult;
}
/*
* Try a non-blocking lock first, to avoid unlatching. If the default
* is no-wait, use the standard lock method so LockNotHeldException is
* thrown; there is no need to try a non-blocking lock twice.
*/
if (locker.getDefaultNoWait()) {
lockResult = locker.lock
(ln.getNodeId(), lockType, true /*noWait*/, database);
} else {
lockResult = locker.nonBlockingLock
(ln.getNodeId(), lockType, database);
}
if (lockResult.getLockGrant() != LockGrantType.DENIED) {
lockResult.setLN(ln);
return lockResult;
}
/*
* Unlatch, get a blocking lock, latch, and get the current node from
* the slot. If the node ID changed while unlatched, revert the lock
* and repeat.
*/
while (true) {
/* Save the node ID we're locking and request a lock. */
long nodeId = ln.getNodeId();
releaseBINs();
lockResult = locker.lock
(nodeId, lockType, false /*noWait*/, database);
/* Fetch the current node after locking. */
latchBINs();
setTargetBin();
ln = (LN) targetBin.fetchTarget(targetIndex);
if (ln != null && nodeId != ln.getNodeId()) {
/* If the node ID changed, revert the lock and try again. */
revertLock(nodeId, lockResult.getLockGrant());
continue;
} else {
/* If null (cleaned) or locked correctly, return the LN. */
lockResult.setLN(ln);
return lockResult;
}
}
}
/**
* Locks the DupCountLN for the given duplicate root. Attempts to use a
* non-blocking lock to avoid unlatching/relatching.
*
* Preconditions: The dupRoot, BIN and DBIN are latched.
* Postconditions: The dupRoot, BIN and DBIN are latched.
*
* Note that the dupRoot may change during locking and should be refetched
* if needed.
*
* @param dupRoot the duplicate root containing the DupCountLN to be
* locked.
* @param lockType the type of lock requested.
* @return the LockResult containing the LN that was locked.
*/
public LockResult lockDupCountLN(DIN dupRoot, LockType lockType)
throws DatabaseException {
DupCountLN ln = dupRoot.getDupCountLN();
LockResult lockResult;
/*
* Try a non-blocking lock first, to avoid unlatching. If the default
* is no-wait, use the standard lock method so LockNotHeldException is
* thrown; there is no need to try a non-blocking lock twice.
*/
if (locker.getDefaultNoWait()) {
lockResult = locker.lock
(ln.getNodeId(), lockType, true /*noWait*/, database);
} else {
lockResult = locker.nonBlockingLock
(ln.getNodeId(), lockType, database);
}
if (lockResult.getLockGrant() == LockGrantType.DENIED) {
/* Release all latches. */
dupRoot.releaseLatch();
releaseBINs();
/* Request a blocking lock. */
lockResult = locker.lock
(ln.getNodeId(), lockType, false /*noWait*/, database);
/* Reacquire all latches. */
latchBIN();
dupRoot = (DIN) bin.fetchTarget(index);
dupRoot.latch();
latchDBIN();
ln = dupRoot.getDupCountLN();
}
lockResult.setLN(ln);
return lockResult;
}
/**
* Fetch, latch and return the DIN root of the duplicate tree at the cursor
* position.
*
* Preconditions: The BIN must be latched and the current BIN entry must
* contain a DIN.
*
* Postconditions: The BIN and DIN will be latched. The DBIN will remain
* latched if isDBINLatched is true.
*
* @param isDBINLatched is true if the DBIN is currently latched.
*/
public DIN getLatchedDupRoot(boolean isDBINLatched)
throws DatabaseException {
assert bin != null;
assert bin.isLatchOwner();
assert index >= 0;
DIN dupRoot = (DIN) bin.fetchTarget(index);
if (isDBINLatched) {
/*
* The BIN and DBIN are currently latched and we need to latch the
* dupRoot, which is between the BIN and DBIN in the tree. First
* trying latching the dupRoot no-wait; if this works, we have
* latched out of order, but in a way that does not cause
* deadlocks. If we don't get the no-wait latch, then release the
* DBIN latch and latch in the proper order down the tree.
*/
if (!dupRoot.latchNoWait()) {
releaseDBIN();
dupRoot.latch();
latchDBIN();
}
} else {
dupRoot.latch();
}
return dupRoot;
}
/**
* Helper to return a Data DBT from a BIN.
*/
private void setDbt(DatabaseEntry data, byte[] bytes) {
if (bytes != null) {
boolean partial = data.getPartial();
int off = partial ? data.getPartialOffset() : 0;
int len = partial ? data.getPartialLength() : bytes.length;
if (off + len > bytes.length) {
len = (off > bytes.length) ? 0 : bytes.length - off;
}
byte[] newdata = null;
if (len == 0) {
newdata = LogUtils.ZERO_LENGTH_BYTE_ARRAY;
} else {
newdata = new byte[len];
System.arraycopy(bytes, off, newdata, 0, len);
}
data.setData(newdata);
data.setOffset(0);
data.setSize(len);
} else {
data.setData(null);
data.setOffset(0);
data.setSize(0);
}
}
/*
* For debugging. Verify that a BINs cursor set refers to the BIN.
*/
private void verifyCursor(BIN bin)
throws DatabaseException {
if (!bin.getCursorSet().contains(this)) {
throw new DatabaseException("BIN cursorSet is inconsistent.");
}
}
/**
* Calls checkCursorState and returns false is an exception is thrown.
*/
private boolean assertCursorState(boolean mustBeInitialized) {
try {
checkCursorState(mustBeInitialized);
return true;
} catch (DatabaseException e) {
return false;
}
}
/**
* Check that the cursor is open and optionally if it is initialized.
*/
public void checkCursorState(boolean mustBeInitialized)
throws DatabaseException {
if (status == CURSOR_INITIALIZED) {
if (DEBUG) {
if (bin != null) {
verifyCursor(bin);
}
if (dupBin != null) {
verifyCursor(dupBin);
}
}
return;
} else if (status == CURSOR_NOT_INITIALIZED) {
if (mustBeInitialized) {
throw new DatabaseException
("Cursor Not Initialized.");
}
} else if (status == CURSOR_CLOSED) {
throw new DatabaseException
("Cursor has been closed.");
} else {
throw new DatabaseException
("Unknown cursor status: " + status);
}
}
/**
* Return this lock to its prior status. If the lock was just obtained,
* release it. If it was promoted, demote it.
*/
private void revertLock(LN ln, LockResult lockResult)
throws DatabaseException {
revertLock(ln.getNodeId(), lockResult.getLockGrant());
}
/**
* Return this lock to its prior status. If the lock was just obtained,
* release it. If it was promoted, demote it.
*/
private void revertLock(long nodeId, LockGrantType lockStatus)
throws DatabaseException {
if ((lockStatus == LockGrantType.NEW) ||
(lockStatus == LockGrantType.WAIT_NEW)) {
locker.releaseLock(nodeId);
} else if ((lockStatus == LockGrantType.PROMOTION) ||
(lockStatus == LockGrantType.WAIT_PROMOTION)){
locker.demoteLock(nodeId);
}
}
/**
* Locks the logical EOF node for the database.
*/
public void lockEofNode(LockType lockType)
throws DatabaseException {
locker.lock
(database.getEofNodeId(), lockType, false /*noWait*/, database);
}
/**
* @throws RunRecoveryException if the underlying environment is invalid.
*/
public void checkEnv()
throws RunRecoveryException {
database.getDbEnvironment().checkIfInvalid();
}
/*
* Support for linking cursors onto lockers.
*/
public CursorImpl getLockerPrev() {
return lockerPrev;
}
public CursorImpl getLockerNext() {
return lockerNext;
}
public void setLockerPrev(CursorImpl p) {
lockerPrev = p;
}
public void setLockerNext(CursorImpl n) {
lockerNext = n;
}
/**
* Dump the cursor for debugging purposes. Dump the bin and dbin that the
* cursor refers to if verbose is true.
*/
public void dump(boolean verbose) {
System.out.println(dumpToString(verbose));
}
/**
* dump the cursor for debugging purposes.
*/
public void dump() {
System.out.println(dumpToString(true));
}
/*
* dumper
*/
private String statusToString(byte status) {
switch(status) {
case CURSOR_NOT_INITIALIZED:
return "CURSOR_NOT_INITIALIZED";
case CURSOR_INITIALIZED:
return "CURSOR_INITIALIZED";
case CURSOR_CLOSED:
return "CURSOR_CLOSED";
default:
return "UNKNOWN (" + Byte.toString(status) + ")";
}
}
/*
* dumper
*/
public String dumpToString(boolean verbose) {
StringBuffer sb = new StringBuffer();
sb.append("<Cursor idx=\"").append(index).append("\"");
if (dupBin != null) {
sb.append(" dupIdx=\"").append(dupIndex).append("\"");
}
sb.append(" status=\"").append(statusToString(status)).append("\"");
sb.append(">\n");
if (verbose) {
sb.append((bin == null) ? "" : bin.dumpString(2, true));
sb.append((dupBin == null) ? "" : dupBin.dumpString(2, true));
}
sb.append("\n</Cursor>");
return sb.toString();
}
/*
* For unit tests
*/
public LockStats getLockStats()
throws DatabaseException {
return locker.collectStats(new LockStats());
}
/**
* Send trace messages to the java.util.logger. Don't rely on the logger
* alone to conditionalize whether we send this message, we don't even want
* to construct the message if the level is not enabled.
*/
private void trace(Level level,
String changeType,
BIN theBin,
LN ln,
int lnIndex,
long oldLsn,
long newLsn) {
Logger logger = database.getDbEnvironment().getLogger();
if (logger.isLoggable(level)) {
StringBuffer sb = new StringBuffer();
sb.append(changeType);
sb.append(" bin=");
sb.append(theBin.getNodeId());
sb.append(" ln=");
sb.append(ln.getNodeId());
sb.append(" lnIdx=");
sb.append(lnIndex);
sb.append(" oldLnLsn=");
sb.append(DbLsn.getNoFormatString(oldLsn));
sb.append(" newLnLsn=");
sb.append(DbLsn.getNoFormatString(newLsn));
logger.log(level, sb.toString());
}
}
/* For unit testing only. */
public void setTestHook(TestHook hook) {
testHook = hook;
}
/* Check that the target bin is latched. For use in assertions. */
private boolean checkAlreadyLatched(boolean alreadyLatched) {
if (alreadyLatched) {
if (dupBin != null) {
return dupBin.isLatchOwner();
} else if (bin != null) {
return bin.isLatchOwner();
}
}
return true;
}
}