public long calculateTxnLogSizeLimit() {
long snapSize = 0;
try {
snapSize = snapLog.findMostRecentSnapshot().length();
} catch (IOException e) {
LOG.error("Unable to get size of most recent snapshot");
}
return (long) (snapSize * snapshotSizeFactor);
}
/**
* Truncate the ZKDatabase to the specified zxid
*
* @param zxid the zxid to truncate zk database to
* @return true if the truncate is successful and false if not
* @throws IOException
*/
public boolean truncateLog(long zxid) throws IOException {
clear();
// truncate the log
boolean truncated = snapLog.truncateLog(zxid);
if (!truncated) {
return false;
}
loadDataBase();
return true;
}
/**
* load the database from the disk onto memory and also add the transactions to the committedlog
* in memory.
*
* @return the last valid zxid on disk
* @throws IOException
*/
public long loadDataBase() throws IOException {
PlayBackListener listener =
new PlayBackListener() {
public void onTxnLoaded(TxnHeader hdr, Record txn) {
Request r = new Request(0, hdr.getCxid(), hdr.getType(), hdr, txn, hdr.getZxid());
addCommittedProposal(r);
}
};
long zxid = snapLog.restore(dataTree, sessionsWithTimeouts, listener);
initialized = true;
return zxid;
}
/**
* Get proposals from txnlog. Only packet part of proposal is populated.
*
* @param startZxid the starting zxid of the proposal
* @param sizeLimit maximum on-disk size of txnlog to fetch 0 is unlimited, negative value means
* disable.
* @return list of proposal (request part of each proposal is null)
*/
public Iterator<Proposal> getProposalsFromTxnLog(long startZxid, long sizeLimit) {
if (sizeLimit < 0) {
LOG.debug("Negative size limit - retrieving proposal via txnlog is disabled");
return TxnLogProposalIterator.EMPTY_ITERATOR;
}
TxnIterator itr = null;
try {
itr = snapLog.readTxnLog(startZxid, false);
// If we cannot guarantee that this is strictly the starting txn
// after a given zxid, we should fail.
if ((itr.getHeader() != null) && (itr.getHeader().getZxid() > startZxid)) {
LOG.warn("Unable to find proposals from txnlog for zxid: " + startZxid);
itr.close();
return TxnLogProposalIterator.EMPTY_ITERATOR;
}
if (sizeLimit > 0) {
long txnSize = itr.getStorageSize();
if (txnSize > sizeLimit) {
LOG.info("Txnlog size: " + txnSize + " exceeds sizeLimit: " + sizeLimit);
itr.close();
return TxnLogProposalIterator.EMPTY_ITERATOR;
}
}
} catch (IOException e) {
LOG.error("Unable to read txnlog from disk", e);
try {
if (itr != null) {
itr.close();
}
} catch (IOException ioe) {
LOG.warn("Error closing file iterator", ioe);
}
return TxnLogProposalIterator.EMPTY_ITERATOR;
}
return new TxnLogProposalIterator(itr);
}