void setPosition(long startLsn)
throws ChecksumException, FileNotFoundException, DatabaseException {
if (startLsn == DbLsn.NULL_LSN) {
return;
}
/*
* An assertion: a reposition should never make the reader lose ground.
*/
if (forward) {
if (DbLsn.compareTo(getLastLsn(), startLsn) > 0) {
throw EnvironmentFailureException.unexpectedState(
"Feeder forward scanning should not be repositioned to "
+ " a position earlier than the current position. Current"
+ " lsn = "
+ DbLsn.getNoFormatString(getLastLsn())
+ " reposition = "
+ DbLsn.getNoFormatString(startLsn));
}
} else {
if (DbLsn.compareTo(getLastLsn(), startLsn) < 0) {
throw EnvironmentFailureException.unexpectedState(
"Feeder backward scanning should not be repositioned to "
+ " a position later than the current position. Current"
+ " lsn = "
+ DbLsn.getNoFormatString(getLastLsn())
+ " reposition = "
+ DbLsn.getNoFormatString(startLsn));
}
}
long fileNum = DbLsn.getFileNumber(startLsn);
long offset = DbLsn.getFileOffset(startLsn);
if (window.containsLsn(fileNum, offset)) {
window.positionBuffer(offset);
} else {
window.slideAndFill(fileNum, offset, offset);
}
if (forward) {
nextEntryOffset = offset;
} else {
currentEntryPrevOffset = offset;
}
nReposition++;
}
/*
* Reposition to the specified file, and fill starting at
* startOffset. Position the window's buffer to point at the log entry
* indicated by targetOffset
*/
public void slideAndFill(
long windowfileNum, long windowStartOffset, long targetOffset, boolean forward)
throws ChecksumException, FileNotFoundException, DatabaseException {
FileHandle fileHandle = fileManager.getFileHandle(windowfileNum);
try {
startOffset = windowStartOffset;
setFileNum(windowfileNum, fileHandle.getLogVersion());
boolean foundData = fillFromFile(fileHandle, targetOffset);
/*
* When reading backwards, we need to guarantee there is no log
* gap, throws out an EnvironmentFailreException if it exists.
*/
if (!foundData && !forward) {
throw EnvironmentFailureException.unexpectedState(
"Detected a log file gap when reading backwards. "
+ "Target position = "
+ DbLsn.getNoFormatString(DbLsn.makeLsn(windowfileNum, targetOffset))
+ " starting position = "
+ DbLsn.getNoFormatString(DbLsn.makeLsn(windowfileNum, windowStartOffset))
+ " end position = "
+ DbLsn.getNoFormatString(DbLsn.makeLsn(windowfileNum, endOffset)));
}
} finally {
fileHandle.release();
}
}
/**
* Something is wrong with this file. If there is no data in this file (the header is <= the file
* header size) then move this last file aside and search the next "last" file. If the last file
* does have data in it, return null and throw an exception back to the application, since we're
* not sure what to do now.
*
* @param cause is a DatabaseException or ChecksumException.
*/
private Long attemptToMoveBadFile(Exception cause)
throws IOException, ChecksumException, DatabaseException {
String fileName = fileManager.getFullFileNames(window.currentFileNum())[0];
File problemFile = new File(fileName);
if (problemFile.length() <= FileManager.firstLogEntryOffset()) {
fileManager.clear(); // close all existing files
/* Move this file aside. */
Long lastNum = fileManager.getFollowingFileNum(window.currentFileNum(), false);
if (!fileManager.renameFile(window.currentFileNum(), FileManager.BAD_SUFFIX)) {
throw EnvironmentFailureException.unexpectedState(
"Could not rename file: 0x" + Long.toHexString(window.currentFileNum()));
}
return lastNum;
}
/* There's data in this file, throw up to the app. */
if (cause instanceof DatabaseException) {
throw (DatabaseException) cause;
}
if (cause instanceof ChecksumException) {
throw (ChecksumException) cause;
}
throw EnvironmentFailureException.unexpectedException(cause);
}
public void update(NameIdPair other) {
if (!name.equals(other.getName())) {
throw EnvironmentFailureException.unexpectedState(
"Pair name mismatch: " + name + " <> " + other.getName());
}
setId(other.getId());
}
/**
* Commits the txn being replayed.
*
* @param syncPolicy to be used for the commit.
* @param clientRepContext the replication context it encapsulates the VLSN associated with the
* txn.
* @return the commit LSN
* @throws DatabaseException
*/
public long commit(
SyncPolicy syncPolicy, ReplicationContext clientRepContext, int commitMasterNodeId)
throws DatabaseException {
LoggerUtils.fine(logger, envImpl, "commit called for " + getId());
setRepContext(clientRepContext);
Durability durability = null;
if (syncPolicy == SyncPolicy.SYNC) {
durability = Durability.COMMIT_SYNC;
} else if (syncPolicy == SyncPolicy.NO_SYNC) {
durability = Durability.COMMIT_NO_SYNC;
} else if (syncPolicy == SyncPolicy.WRITE_NO_SYNC) {
durability = Durability.COMMIT_WRITE_NO_SYNC;
} else {
throw EnvironmentFailureException.unexpectedState("Unknown sync policy: " + syncPolicy);
}
/*
* Set the master id before commit is called, so getReplicatorNodeId()
* will return this value and write the originating node's id into
* the commit record on this log.
*/
this.masterNodeId = commitMasterNodeId;
long lsn = super.commit(durability);
endTime = System.currentTimeMillis();
return lsn;
}
/**
* Rollback all write operations that are logged with an LSN > the matchpointLsn parameter. This
* is logically a truncation of the log entries written by this transaction. Any log entries
* created by this transaction are marked obsolete.
*
* <p>Note that this is by no means a complete implementation of what would be needed to support
* user visible savepoints. This method only rolls back write operations and doesn't handle other
* types of state, like read locks and open cursors.
*
* <p>There are several key assumptions: - the transaction does not hold read locks. - the
* transaction will either be resumed, and any rolled back operations will be repeated, or the
* transaction will be aborted in its entirety.
*
* <p>If all operations in the transaction are rolled back, this transaction is also unregistered
* and closed.
*
* <p>Rolling back a log entry through rollback is akin to truncating the transactional log. The
* on-disk entries should not be referred to by anything in the in-memory tree or the transaction
* chain. JE's append only storage and the fact that the transactional log entries are intertwined
* through the physical log prohibits any log truncation. To mimic log truncation, any rolled back
* log entry is marked as obsolete. Since only the last version of any data record is alive, any
* future uses of this transaction must use the obsoleteDupsAllowed option (see
* Txn.countObsoleteExact) to prevent asserts about duplicate obsolete offsets. For example,
* suppose the transaction logs this:
*
* <p>100 LNa (version1) 200 LNa (version2) 300 LNa (version3)
*
* <p>At this point in time, LSN 100 and 200 are obsolete.
*
* <p>Now, suppose we roll back to LSN 100. LSNs 200 and 300 are marked obsolete by the
* rollback.(although LSN 200 was already obsolete). It is true that for an instance in time LSN
* 100 is incorrectly marked as obsolete, when it's really alive. But this transaction is going to
* either abort or resume exactly as it was before, so LSN 100 is going to be obsolete again.
*
* <p>Suppose txn.abort() is called. The abort() logic will mark LSN 100 as obsolete, since it is
* the latest version of the record in the transaction. Using the obsoleteDupsAllowed option
* avoids an assertion on the double recording of LSN 100.
*
* <p>Alternatively, suppose LNa (version2) is retransmitted and logged as LSN 400. Normal
* execution of LN.log() marks LSN 100 as obsolete, which would trigger the assertion were it not
* for obsoleteDupsAllowed.
*
* @return list of LSNs that were rolled back
*/
public Collection<Long> rollback(long matchpointLsn) throws DatabaseException {
List<Long> rollbackLsns = new ArrayList<Long>();
LoggerUtils.finest(logger, envImpl, "Partial Rollback of " + this);
synchronized (this) {
checkState(true);
/* This transaction didn't log anything, nothing to rollback. */
if (lastLoggedLsn == NULL_LSN) {
return rollbackLsns;
}
/*
* This transaction doesn't include any operations that are after
* the matchpointLsn. There is nothing to rollback.
*/
if (DbLsn.compareTo(lastLoggedLsn, matchpointLsn) <= 0) {
return rollbackLsns;
}
setRollback();
undoWrites(matchpointLsn, rollbackLsns);
}
/*
* The call to undoWrites() may have rolled everything back, and set
* lastLoggedLsn to NULL_LSN.
*/
if (lastLoggedLsn == NULL_LSN) {
/* Everything was rolled back. */
try {
/*
* Purge any databaseImpls not needed as a result of the abort.
* Be sure to do this outside the synchronization block, to
* avoid conflict w/checkpointer.
*/
cleanupDatabaseImpls(false);
} finally {
close(false /* isCommit */);
}
}
/*
* We don't expect there to be any database handles associated with
* a ReplayTxn, because only DatabaseImpls are used. Because of that,
* there should be no cleanup needed.
*/
if (handleToHandleLockMap != null) {
throw EnvironmentFailureException.unexpectedState(
"Replay Txn " + getId() + " has a handleToHandleLockMap");
}
/*
* There is no need to call cleanupDatabaseImpls if the txn still holds
* locks. The operations in this txn will either be entirely aborted,
* or will be repeated, so any cleanup will happen when the txn ends.
*/
return rollbackLsns;
}
public NameIdPair(String name, int id) {
if (name == null) {
throw EnvironmentFailureException.unexpectedState("name argument was null");
}
this.name = name;
this.id = id;
}
/** @return true if the current entry is part of replication stream. */
public boolean entryIsReplicated() {
if (currentEntryHeader == null) {
throw EnvironmentFailureException.unexpectedState(
"entryIsReplicated should not be used before reader is " + "initialized");
}
return currentEntryHeader.getReplicated();
}
public void setLastAppliedVLSN(VLSN justApplied) {
if (justApplied.compareTo(lastApplied) <= 0) {
throw EnvironmentFailureException.unexpectedState(
"Txn "
+ getId()
+ " attempted VLSN = "
+ justApplied
+ " txnLastApplied = "
+ lastApplied);
}
this.lastApplied = justApplied;
}
/**
* Acquire a latch for exclusive/write access. If the thread already holds the latch for shared
* access, it cannot be upgraded and EnvironmentFailureException will be thrown.
*
* <p>Wait for the latch if some other thread is holding it. If there are threads waiting for
* access, they will be granted the latch on a FIFO basis if fair latches are enabled (as of JE
* 5.0 they are never enabled). When the method returns, the latch is held for exclusive access.
*
* @throws EnvironmentFailureException if the latch is already held by the current thread for
* shared access.
*/
public void acquireExclusive() {
try {
if (isWriteLockedByCurrentThread()) {
throw EnvironmentFailureException.unexpectedState("Latch already held: " + name);
}
writeLock().lock();
assert (noteLatch ? noteLatch() : true); // intentional side effect;
} finally {
assert EnvironmentImpl.maybeForceYield();
}
}
/**
* Converts the given DBIN slot, leaving bin/index set to the inserted BIN slot.
*
* <p>Enter/leave with bin field latched, although bin field may change.
*
* <p>If slot is inserted into current bin, leave bin field unchanged and set index field to
* inserted slot.
*
* <p>If slot is inserted into a different bin, set bin/index fields to inserted slot.
*/
private void convertDbinSlot(final DBIN dbin, final int dbinIndex, final byte[] binKey) {
final byte[] newKey = DupKeyData.replaceData(binKey, dbin.getKey(dbinIndex));
if (DEBUG) {
System.out.println("DupConvert DBIN LN " + Key.dumpString(newKey, 0));
}
/*
* If the current BIN can hold the new slot, don't bother to do a
* search to find it.
*/
if (bin.needsSplitting() || !bin.isKeyInBounds(newKey)) {
/* Compact keys after finishing with a BIN. */
bin.compactMemory();
/* Evict without latches, before moving to a new BIN. */
bin.releaseLatch();
envImpl.daemonEviction(false /*backgroundIO*/);
/* Find a BIN for insertion, split if necessary. */
bin = dbin.getDatabase().getTree().searchSplitsAllowed(newKey, CacheMode.UNCHANGED);
}
final int newIndex =
bin.insertEntry1(
null /*ln*/,
newKey,
null /*data*/,
dbin.getLsn(dbinIndex),
dbin.getState(dbinIndex),
false);
if ((newIndex & IN.INSERT_SUCCESS) == 0) {
throw EnvironmentFailureException.unexpectedState(
"Key not inserted: " + Key.dumpString(newKey, 0) + " DB: " + dbin.getDatabase().getId());
}
index = newIndex & ~IN.INSERT_SUCCESS;
/*
* Evict LN from DBIN slot. Although we don't explicitly load DBIN LNs,
* it may have been loaded by recovery.
*/
dbin.detachNode(dbinIndex, false /*updateLsn*/, -1 /*lsn*/);
nConverted += 1;
}
/**
* Probe a latch for exclusive access, but don't block if it's not available.
*
* @return true if the latch was acquired, false if it is not available.
* @throws EnvironmentFailureException if the latch is already held by the calling thread.
*/
public boolean acquireExclusiveNoWait() {
try {
if (isWriteLockedByCurrentThread()) {
throw EnvironmentFailureException.unexpectedState("Latch already held: " + name);
}
boolean ret = writeLock().tryLock();
/* Intentional side effect. */
assert ((noteLatch & ret) ? noteLatch() : true);
return ret;
} finally {
assert EnvironmentImpl.maybeForceYield();
}
}
/**
* Attempt to acquire a lock of <i>type</i> on <i>nodeId</i>. If the lock acquisition would result
* in a deadlock, throw an exception.<br>
* If the requested lock is not currently available, block until it is or until timeout
* milliseconds have elapsed.<br>
* If a lock of <i>type</i> is already held, return EXISTING.<br>
* If a WRITE lock is held and a READ lock is requested, return PROMOTION.<br>
* If a lock request is for a lock that is not currently held, return either NEW or DENIED
* depending on whether the lock is granted or not.<br>
*
* @param nodeId The NodeId to lock.
* @param locker The Locker to lock this on behalf of.
* @param type The lock type requested.
* @param timeout milliseconds to time out after if lock couldn't be obtained. 0 means block
* indefinitely. Not used if nonBlockingRequest is true.
* @param nonBlockingRequest if true, means don't block if lock can't be acquired, and ignore the
* timeout parameter.
* @return a LockGrantType indicating whether the request was fulfilled or not. LockGrantType.NEW
* means the lock grant was fulfilled and the caller did not previously hold the lock.
* PROMOTION means the lock was granted and it was a promotion from READ to WRITE. EXISTING
* means the lock was already granted (not a promotion). DENIED means the lock was not granted
* because the timeout passed without acquiring the lock or timeout was 0 and the lock was not
* immediately available.
* @throws LockConflictException if lock could not be acquired.
* @throws IllegalArgumentException via db/cursor read/write methods, if non-transactional access
* to a replicated environment is attempted, and read-uncommitted is not specified.
*/
public LockGrantType lock(
long nodeId,
Locker locker,
LockType type,
long timeout,
boolean nonBlockingRequest,
DatabaseImpl database)
throws LockConflictException, DatabaseException {
assert timeout >= 0;
/* No lock needed for dirty-read, return as soon as possible. */
if (type == LockType.NONE) {
return LockGrantType.NONE_NEEDED;
}
/*
* Assert that a replication-defined locker is used for locks on
* replicated databases. Two cases are exempt from this rule:
* - Only NameLNs that identify replicated DBs are replicated, not
* all NameLNs in the naming DB, so the naming DB is exempt.
* - Non-preemption is permissible for selected internal operations
* because we can ensure that they are not long running and will not
* hold locks interminably. A BasicLocker is often used internally
* in such cases.
*/
if (envImpl.isReplicated()
&& database != null
&& database.isReplicated()
&& !database.getId().equals(DbTree.NAME_DB_ID)
&& (locker.getPreemptable() || type.isWriteLock())
&& !locker.isReplicationDefined()) {
throw EnvironmentFailureException.unexpectedState("Locker: " + locker.getClass().getName());
}
/*
* Lock on locker before latching the lockTable to avoid having another
* notifier perform the notify before the waiter is actually waiting.
*/
synchronized (locker) {
LockGrantType ret = null;
ret = lockInternal(nodeId, locker, type, timeout, nonBlockingRequest, database);
return ret;
}
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
NameIdPair other = (NameIdPair) obj;
if (id != other.id) {
return false;
}
if (!name.equals(other.name)) {
throw EnvironmentFailureException.unexpectedState(
"Ids: " + id + " were equal." + " But names: " + name + ", " + other.name + " weren't!");
}
return true;
}
/**
* Transfer a lock from another transaction to this one. Used for master-> replica transitions,
* when a node has to transform a MasterTxn into a ReplayTxn. Another approach would be to have
* this importunate ReplayTxn call lock() on the lsn, but that path is not available because we do
* not have a handle on a databaseImpl.
*/
public void stealLockFromMasterTxn(Long lsn) {
LockAttemptResult result = lockManager.stealLock(lsn, this, LockType.WRITE);
/*
* Assert, and if something strange happened, opt to invalidate
* the environment and wipe the slate clean.
*/
if (!result.success) {
throw EnvironmentFailureException.unexpectedState(
envImpl,
"Transferring from master to replica state, txn "
+ getId()
+ " was unable to transfer lock for "
+ DbLsn.getNoFormatString(lsn)
+ ", lock grant type="
+ result.lockGrant);
}
addLock(Long.valueOf(lsn), LockType.WRITE, result.lockGrant);
addLogInfo(lsn);
}
/**
* Release an exclusive or shared latch. If there are other thread(s) waiting for the latch, they
* are woken up and granted the latch.
*/
public void release() {
try {
if (isWriteLockedByCurrentThread()) {
writeLock().unlock();
/* Intentional side effect. */
assert (noteLatch ? unNoteLatch() : true);
return;
}
if (exclusiveOnly) {
return;
}
boolean assertionsEnabled = false;
assert assertionsEnabled = true;
if (assertionsEnabled) {
if (readers.remove(Thread.currentThread())) {
readLock().unlock();
} else {
throw EnvironmentFailureException.unexpectedState("Latch not held: " + name);
}
} else {
/*
* There's no way to tell if a readlock is held by the current
* thread so just try unlocking it.
*/
readLock().unlock();
}
/* Intentional side effect. */
assert (noteLatch ? unNoteLatch() : true);
} catch (IllegalMonitorStateException IMSE) {
IMSE.printStackTrace();
return;
}
}
/** @see Loggable#getLogSize */
@Override
public int getLogSize() {
throw EnvironmentFailureException.unexpectedState();
}
@Override
@SuppressWarnings("unused")
public long commit(Durability durability) {
throw EnvironmentFailureException.unexpectedState(
"Replay Txn abort semantics require use of internal commit api");
}
public void setId(int id) {
if ((id != this.id) && !hasNullId()) {
throw EnvironmentFailureException.unexpectedState("Id was already not null: " + this.id);
}
this.id = id;
}
@Override
public void abort() {
throw EnvironmentFailureException.unexpectedState(
"Replay Txn abort semantics require use of internal abort api");
}
@Override
@SuppressWarnings("unused")
public void setId(int id) {
throw EnvironmentFailureException.unexpectedState("Read only NameIdPair");
}
@Override
@SuppressWarnings("unused")
public long abort(boolean forceFlush) {
throw EnvironmentFailureException.unexpectedState(
"Replay Txn abort semantics require use of internal abort api");
}
/**
* Send files in response to request messages. The request sequence looks like the following:
*
* <p>[FileReq | StatReq]+ Done
*
* <p>The response sequence to a FileReq looks like:
*
* <p>FileStart <file byte stream> FileEnd
*
* <p>and that for a StatReq, is simply a StatResp
*/
private void sendRequestedFiles(Protocol protocol)
throws IOException, ProtocolException, DatabaseException {
try {
while (true) {
FileReq fileReq = protocol.read(namedChannel.getChannel(), FileReq.class);
final String fileName = fileReq.getFileName();
/*
* Calculate the full path for a specified log file name,
* especially when this Feeder is configured to run with sub
* directories.
*/
FileManager fMgr = feederManager.getEnvImpl().getFileManager();
File file = new File(fMgr.getFullFileName(fileName));
if (!file.exists()) {
throw EnvironmentFailureException.unexpectedState("Log file not found: " + fileName);
}
/* Freeze the length and last modified date. */
final long length = file.length();
final long lastModified = file.lastModified();
byte digest[] = null;
FileInfoResp resp = null;
Protocol.FileInfoResp cachedResp = feederManager.statResponses.get(fileName);
byte cachedDigest[] =
((cachedResp != null)
&& (cachedResp.getFileLength() == length)
&& (cachedResp.getLastModifiedTime() == lastModified))
? cachedResp.getDigestSHA1()
: null;
if (fileReq instanceof FileInfoReq) {
if (cachedDigest != null) {
digest = cachedDigest;
} else if (((FileInfoReq) fileReq).getNeedSHA1()) {
digest = getSHA1Digest(file, length).digest();
} else {
// Digest not requested
digest = new byte[0];
}
resp = protocol.new FileInfoResp(fileName, length, lastModified, digest);
} else {
protocol.write(protocol.new FileStart(fileName, length, lastModified), namedChannel);
digest = sendFileContents(file, length);
if ((cachedDigest != null) && !Arrays.equals(cachedDigest, digest)) {
throw EnvironmentFailureException.unexpectedState(
"Inconsistent cached and computed digests");
}
resp = protocol.new FileEnd(fileName, length, lastModified, digest);
}
/* Cache for subsequent requests, if it was computed. */
if (digest.length > 0) {
feederManager.statResponses.put(fileName, resp);
}
protocol.write(resp, namedChannel);
}
} catch (ProtocolException pe) {
if (pe.getUnexpectedMessage() instanceof Protocol.Done) {
return;
}
throw pe;
}
}
/** @see Loggable#writeToLog */
@Override
public void writeToLog(ByteBuffer logBuffer) {
throw EnvironmentFailureException.unexpectedState();
}