Examples with ConstFuture com.twitter.util.ConstFuture used on opensource projects

Example 1 with ConstFuture

use of com.twitter.util.ConstFuture in project distributedlog by twitter.

the class BulkWriteOp method executeOp.

@Override
protected Future<BulkWriteResponse> executeOp(AsyncLogWriter writer, Sequencer sequencer, Object txnLock) {
    // Need to convert input buffers to LogRecords.
    List<LogRecord> records;
    Future<List<Future<DLSN>>> futureList;
    synchronized (txnLock) {
        records = asRecordList(buffers, sequencer);
        futureList = writer.writeBulk(records);
    }
    // Collect into a list of tries to make it easier to extract exception or DLSN.
    Future<List<Try<DLSN>>> writes = asTryList(futureList);
    Future<BulkWriteResponse> response = writes.flatMap(new AbstractFunction1<List<Try<DLSN>>, Future<BulkWriteResponse>>() {

        @Override
        public Future<BulkWriteResponse> apply(List<Try<DLSN>> results) {
            // Considered a success at batch level even if no individual writes succeeed.
            // The reason is that its impossible to make an appropriate decision re retries without
            // individual buffer failure reasons.
            List<WriteResponse> writeResponses = new ArrayList<WriteResponse>(results.size());
            BulkWriteResponse bulkWriteResponse = ResponseUtils.bulkWriteSuccess().setWriteResponses(writeResponses);
            // failed.
            if (results.size() > 0) {
                Try<DLSN> firstResult = results.get(0);
                if (isDefiniteFailure(firstResult)) {
                    return new ConstFuture(firstResult);
                }
            }
            // Translate all futures to write responses.
            Iterator<Try<DLSN>> iterator = results.iterator();
            while (iterator.hasNext()) {
                Try<DLSN> completedFuture = iterator.next();
                try {
                    DLSN dlsn = completedFuture.get();
                    WriteResponse writeResponse = ResponseUtils.writeSuccess().setDlsn(dlsn.serialize());
                    writeResponses.add(writeResponse);
                    successRecordCounter.inc();
                } catch (Exception ioe) {
                    WriteResponse writeResponse = ResponseUtils.write(ResponseUtils.exceptionToHeader(ioe));
                    writeResponses.add(writeResponse);
                    if (StatusCode.FOUND == writeResponse.getHeader().getCode()) {
                        redirectRecordCounter.inc();
                    } else {
                        failureRecordCounter.inc();
                    }
                }
            }
            return Future.value(bulkWriteResponse);
        }
    });
    return response;
}