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The documentation shows the usage of an appender or a tailer generally with a lambda, like this:

appender.writeDocument(wireOut -> wireOut.write("log").marshallable(m ->
      m.write("mkey").text(mkey)
       .write("timestamp").dateTime(now)
       .write("msg").text(data)));

For a tailer I I use:

   int count = 0;
   while (read from tailer ) { 
      wire.read("log").marshallable(m -> {
             String mkey = m.read("mkey").text();
            LocalDateTime ts = m.read("timestamp").dateTime();
             String bmsg = m.read("msg").text();
         //... do more stuff, like updating counters
             count++;
       }
   }

During the read I would like to do stuff like updating counters, but this is not possible in lambda (needs "effectively final" values/objects).

  • What is good practice for using the API without lambdas?
  • Any other ideas on how to do this? (Currently I use AtomicInteger objects)
Peter Lawrey
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vasquez
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1 Answers1

2
static class Log extends AbstractMarshallable {
    String mkey;
    LocalDateTime timestamp;
    String msg;
}

int count;

public void myMethod() {
    Log log = new Log();
    final SingleChronicleQueue q = SingleChronicleQueueBuilder.binary(new File("q4")).build();
    final ExcerptAppender appender = q.acquireAppender();
    final ExcerptTailer tailer = q.createTailer();

    try (final DocumentContext dc = appender.writingDocument()) {
        // this will store the contents of log to the queue
        dc.wire().write("log").marshallable(log);
    }

    try (final DocumentContext dc = tailer.readingDocument()) {
        if (!dc.isData())
             return;
        // this will replace the contents of log
        dc.wire().read("log").marshallable(log);
        //... do more stuff, like updating counters
        count++;
    }
}
Rob Austin
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