Examples with LogRecordSelector com.twitter.distributedlog.selector.LogRecordSelector used on opensource projects

Example 1 with LogRecordSelector

use of com.twitter.distributedlog.selector.LogRecordSelector in project distributedlog by twitter.

the class ReadUtils method asyncReadFirstUserRecord.

/**
     * Read first record from a ledger with a DLSN larger than that given.
     *
     * @param streamName
     *          fully qualified stream name (used for logging)
     * @param l
     *          ledger descriptor.
     * @param scanStartBatchSize
     *          first num entries used for read last record scan
     * @param scanMaxBatchSize
     *          max num entries used for read last record scan
     * @param numRecordsScanned
     *          num of records scanned to get last record
     * @param executorService
     *          executor service used for processing entries
     * @param dlsn
     *          threshold dlsn
     * @return a future with last record.
     */
public static Future<LogRecordWithDLSN> asyncReadFirstUserRecord(final String streamName, final LogSegmentMetadata l, final int scanStartBatchSize, final int scanMaxBatchSize, final AtomicInteger numRecordsScanned, final ExecutorService executorService, final LedgerHandleCache handleCache, final DLSN dlsn) {
    long startEntryId = 0L;
    if (l.getLogSegmentSequenceNumber() == dlsn.getLogSegmentSequenceNo()) {
        startEntryId = dlsn.getEntryId();
    }
    final LogRecordSelector selector = new FirstDLSNNotLessThanSelector(dlsn);
    return asyncReadRecord(streamName, l, false, false, false, scanStartBatchSize, scanMaxBatchSize, numRecordsScanned, executorService, handleCache, selector, false, /* backward */
    startEntryId);
}

Example 2 with LogRecordSelector

use of com.twitter.distributedlog.selector.LogRecordSelector in project distributedlog by twitter.

the class ReadUtils method getLogRecordNotLessThanTxIdFromEntries.

/**
     * Find the log record whose transaction id is not less than provided <code>transactionId</code> from
     * entries between <code>startEntryId</code> and <code>endEntryId</code>.
     *
     * @param logName
     *          name of the log
     * @param segment
     *          log segment
     * @param transactionId
     *          provided transaction id to search
     * @param executorService
     *          executor service
     * @param handleCache
     *          handle cache
     * @param entriesToSearch
     *          list of entries to search
     * @param nWays
     *          how many entries to search in parallel
     * @param prevFoundRecord
     *          the log record found in previous search
     * @param promise
     *          promise to satisfy the result
     */
private static void getLogRecordNotLessThanTxIdFromEntries(final String logName, final LedgerDescriptor ld, final LogSegmentMetadata segment, final long transactionId, final ExecutorService executorService, final LedgerHandleCache handleCache, final List<Long> entriesToSearch, final int nWays, final Optional<LogRecordWithDLSN> prevFoundRecord, final Promise<Optional<LogRecordWithDLSN>> promise) {
    final List<Future<LogRecordWithDLSN>> searchResults = Lists.newArrayListWithExpectedSize(entriesToSearch.size());
    for (Long entryId : entriesToSearch) {
        LogRecordSelector selector = new FirstTxIdNotLessThanSelector(transactionId);
        Future<LogRecordWithDLSN> searchResult = asyncReadRecordFromEntries(logName, ld, handleCache, segment, executorService, new SingleEntryScanContext(entryId), selector);
        searchResults.add(searchResult);
    }
    FutureEventListener<List<LogRecordWithDLSN>> processSearchResultsListener = new FutureEventListener<List<LogRecordWithDLSN>>() {

        @Override
        public void onSuccess(List<LogRecordWithDLSN> resultList) {
            processSearchResults(logName, ld, segment, transactionId, executorService, handleCache, resultList, nWays, prevFoundRecord, promise);
        }

        @Override
        public void onFailure(Throwable cause) {
            promise.setException(cause);
        }
    };
    Future.collect(searchResults).addEventListener(FutureEventListenerRunnable.of(processSearchResultsListener, executorService));
}