Examples with EMPTY_BYTES org.apache.distributedlog.DistributedLogConstants.EMPTY_BYTES used on opensource projects

Example 1 with EMPTY_BYTES

use of org.apache.distributedlog.DistributedLogConstants.EMPTY_BYTES in project bookkeeper by apache.

the class ZKLogStreamMetadataStore method renameLogMetadata.

private CompletableFuture<Void> renameLogMetadata(URI uri, LogMetadataForWriter oldMetadata, String newStreamName) {
    final LinkedList<Op> createOps = Lists.newLinkedList();
    final LinkedList<Op> deleteOps = Lists.newLinkedList();
    List<ACL> acls = zooKeeperClient.getDefaultACL();
    // get the root path
    String oldRootPath = oldMetadata.getLogRootPath();
    String newRootPath = LogMetadata.getLogRootPath(uri, newStreamName, conf.getUnpartitionedStreamName());
    // 0. the log path
    deleteOps.addFirst(Op.delete(LogMetadata.getLogStreamPath(uri, oldMetadata.getLogName()), -1));
    // 1. the root path
    createOps.addLast(Op.create(newRootPath, EMPTY_BYTES, acls, CreateMode.PERSISTENT));
    deleteOps.addFirst(Op.delete(oldRootPath, -1));
    // 2. max id
    Versioned<byte[]> maxTxIdData = oldMetadata.getMaxTxIdData();
    deleteOldPathAndCreateNewPath(oldRootPath, MAX_TXID_PATH, maxTxIdData, newRootPath, DLUtils.serializeTransactionId(0L), acls, createOps, deleteOps);
    // 3. version
    createOps.addLast(Op.create(newRootPath + VERSION_PATH, intToBytes(LAYOUT_VERSION), acls, CreateMode.PERSISTENT));
    deleteOps.addFirst(Op.delete(oldRootPath + VERSION_PATH, -1));
    // 4. lock path (NOTE: if the stream is locked by a writer, then the delete will fail as you can not
    // delete the lock path if children is not empty.
    createOps.addLast(Op.create(newRootPath + LOCK_PATH, EMPTY_BYTES, acls, CreateMode.PERSISTENT));
    deleteOps.addFirst(Op.delete(oldRootPath + LOCK_PATH, -1));
    // 5. read lock path (NOTE: same reason as the write lock)
    createOps.addLast(Op.create(newRootPath + READ_LOCK_PATH, EMPTY_BYTES, acls, CreateMode.PERSISTENT));
    deleteOps.addFirst(Op.delete(oldRootPath + READ_LOCK_PATH, -1));
    // 6. allocation path
    Versioned<byte[]> allocationData = oldMetadata.getAllocationData();
    deleteOldPathAndCreateNewPath(oldRootPath, ALLOCATION_PATH, allocationData, newRootPath, EMPTY_BYTES, acls, createOps, deleteOps);
    // 7. log segments
    Versioned<byte[]> maxLSSNData = oldMetadata.getMaxLSSNData();
    deleteOldPathAndCreateNewPath(oldRootPath, LOGSEGMENTS_PATH, maxLSSNData, newRootPath, DLUtils.serializeLogSegmentSequenceNumber(UNASSIGNED_LOGSEGMENT_SEQNO), acls, createOps, deleteOps);
    // 8. copy the log segments
    CompletableFuture<List<LogSegmentMetadata>> segmentsFuture;
    if (pathExists(maxLSSNData)) {
        segmentsFuture = getLogSegments(zooKeeperClient, oldRootPath + LOGSEGMENTS_PATH);
    } else {
        segmentsFuture = FutureUtils.value(Collections.emptyList());
    }
    return segmentsFuture.thenApply(segments -> {
        for (LogSegmentMetadata segment : segments) {
            deleteOldSegmentAndCreateNewSegment(segment, newRootPath + LOGSEGMENTS_PATH, acls, createOps, deleteOps);
        }
        return null;
    }).thenCompose(ignored -> getMissingPaths(zooKeeperClient, uri, newStreamName)).thenCompose(paths -> {
        for (String path : paths) {
            createOps.addFirst(Op.create(path, EMPTY_BYTES, acls, CreateMode.PERSISTENT));
        }
        return executeRenameTxn(oldRootPath, newRootPath, createOps, deleteOps);
    });
}