/**
* 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);
}
/**
* Returns the SHA1 has associated with the file.
*
* @param file
* @param length
* @return
* @throws IOException
* @throws DatabaseException
*/
static MessageDigest getSHA1Digest(File file, long length) throws IOException, DatabaseException {
MessageDigest messageDigest = null;
try {
messageDigest = MessageDigest.getInstance("SHA1");
} catch (NoSuchAlgorithmException e) {
throw EnvironmentFailureException.unexpectedException(e);
}
final FileInputStream fileStream = new FileInputStream(file);
try {
ByteBuffer buffer = ByteBuffer.allocate(TRANSFER_BYTES);
for (long bytes = length; bytes > 0; ) {
int readSize = (int) Math.min(TRANSFER_BYTES, bytes);
int readBytes = fileStream.read(buffer.array(), 0, readSize);
if (readBytes == -1) {
throw new IOException("Premature EOF. Was expecting: " + readSize);
}
messageDigest.update(buffer.array(), 0, readBytes);
bytes -= readBytes;
}
} finally {
fileStream.close();
}
return messageDigest;
}
public LogFileFeeder(FeederManager feederManager, SocketChannel channel)
throws DatabaseException {
super(feederManager.getEnvImpl(), "Log File Feeder");
this.feederManager = feederManager;
logger = feederManager.logger;
this.namedChannel = new NamedChannel(channel, feederManager.nameIdPair);
try {
messageDigest = MessageDigest.getInstance("SHA1");
} catch (NoSuchAlgorithmException e) {
LoggerUtils.severe(
logger,
feederManager.getEnvImpl(),
"The SHA1 algorithm was not made available " + "by the security provider");
throw EnvironmentFailureException.unexpectedException(e);
}
}
/**
* Rollback the changes to this txn's write locked nodes up to but not including the entry at the
* specified matchpoint. When we log a transactional entry, we record the LSN of the original,
* before-this-transaction version as the abort LSN. This means that if there are multiple updates
* to a given record in a single transaction, each update only references that original version
* and its true predecessor.
*
* <p>This was done to streamline abort processing, so that an undo reverts directly to the
* original version rather than stepping through all the intermediates. The intermediates are
* skipped. However, undo to a matchpoint may need to stop at an intermediate point, so we need to
* create a true chain of versions.
*
* <p>To do so, we read the transaction backwards from the last logged LSN to reconstruct a
* transaction chain that links intermediate versions of records. For example, suppose our
* transaction looks like this and that we are undoing up to LSN 250
*
* <p>lsn=100 node=A (version 1) lsn=200 node=B (version 1) <-- matchpointLsn lsn=300 node=C
* (version 1) lsn=400 node=A (version 2) lsn=500 node=B (version 2) lsn=600 node=A (version 3)
* lsn=700 node=A (version 4)
*
* <p>To setup the old versions, We walk from LSN 700 -> 100 700 (A) rolls back to 600 600 (A)
* rolls back to 400 500 (B) rolls back to 200 400 (A) rolls back to 100 300 (C) rolls back to an
* empty slot (NULL_LSN).
*
* <p>A partial rollback also requires resetting the lastLoggedLsn field, because these operations
* are no longer in the btree and their on-disk entries are no longer valid.
*
* <p>Lastly, the appropriate write locks must be released.
*
* @param matchpointLsn the rollback should go up to but not include this LSN.
*/
private void undoWrites(long matchpointLsn, List<Long> rollbackLsns) throws DatabaseException {
/*
* Generate a map of nodeId->List of intermediate LSNs for this node.
* to re-create the transaction chain.
*/
TreeLocation location = new TreeLocation();
Long undoLsn = lastLoggedLsn;
TxnChain chain = new TxnChain(undoLsn, id, matchpointLsn, undoDatabases, envImpl);
try {
while ((undoLsn != DbLsn.NULL_LSN) && DbLsn.compareTo(undoLsn, matchpointLsn) > 0) {
UndoReader undo = new UndoReader(envImpl, undoLsn, undoDatabases);
RevertInfo revertTo = chain.pop();
logFinest(undoLsn, undo, revertTo);
/*
* When we undo this log entry, we've logically truncated
* it from the log. Remove it from the btree and mark it
* obsolete.
*/
RecoveryManager.rollbackUndo(logger, Level.FINER, undo, revertTo, location, undoLsn);
countObsoleteInexact(undoLsn, undo);
rollbackLsns.add(undoLsn);
/*
* Move on to the previous log entry for this txn and update
* what is considered to be the end of the transaction chain.
*/
undoLsn = undo.logEntry.getUserTxn().getLastLsn();
lastLoggedLsn = undoLsn;
}
/*
* Correct the fields which hold LSN and VLSN state that may
* now be changed.
*/
lastApplied = chain.getLastValidVLSN();
if (!updateLoggedForTxn()) {
firstLoggedLsn = NULL_LSN;
}
} catch (DatabaseException e) {
LoggerUtils.traceAndLogException(
envImpl, "Txn", "undo", "For LSN=" + DbLsn.getNoFormatString(undoLsn), e);
throw e;
} catch (RuntimeException e) {
throw EnvironmentFailureException.unexpectedException(
"Txn undo for LSN=" + DbLsn.getNoFormatString(undoLsn), e);
}
if (lastLoggedLsn == DbLsn.NULL_LSN) {
/*
* The whole txn is rolled back, and it may not appear again. This
* is the equivalent of an abort. Do any delete processing for an
* abort which is needed.
*
* Set database state for deletes before releasing any write
* locks.
*/
setDeletedDatabaseState(false);
}
/* Clear any write locks that are no longer needed. */
clearWriteLocks(chain.getRemainingLockedNodes());
}
