Examples with SystemStreamPartitionIterator org.apache.samza.system.SystemStreamPartitionIterator used on opensource projects

Example 1 with SystemStreamPartitionIterator

use of org.apache.samza.system.SystemStreamPartitionIterator in project samza by apache.

the class CoordinatorStreamSystemConsumer method bootstrap.

/**
   * Read all messages from the earliest offset, all the way to the latest.
   * Currently, this method only pays attention to config messages.
   */
public void bootstrap() {
    synchronized (bootstrapLock) {
        // Make a copy so readers aren't affected while we modify the set.
        final LinkedHashSet<CoordinatorStreamMessage> bootstrappedMessages = new LinkedHashSet<>(bootstrappedStreamSet);
        log.info("Bootstrapping configuration from coordinator stream.");
        SystemStreamPartitionIterator iterator = new SystemStreamPartitionIterator(systemConsumer, coordinatorSystemStreamPartition);
        try {
            while (iterator.hasNext()) {
                IncomingMessageEnvelope envelope = iterator.next();
                Object[] keyArray = keySerde.fromBytes((byte[]) envelope.getKey()).toArray();
                Map<String, Object> valueMap = null;
                if (envelope.getMessage() != null) {
                    valueMap = messageSerde.fromBytes((byte[]) envelope.getMessage());
                }
                CoordinatorStreamMessage coordinatorStreamMessage = new CoordinatorStreamMessage(keyArray, valueMap);
                log.debug("Received coordinator stream message: {}", coordinatorStreamMessage);
                // Remove any existing entry. Set.add() does not add if the element already exists.
                if (bootstrappedMessages.remove(coordinatorStreamMessage)) {
                    log.debug("Removed duplicate message: {}", coordinatorStreamMessage);
                }
                bootstrappedMessages.add(coordinatorStreamMessage);
                if (SetConfig.TYPE.equals(coordinatorStreamMessage.getType())) {
                    String configKey = coordinatorStreamMessage.getKey();
                    if (coordinatorStreamMessage.isDelete()) {
                        configMap.remove(configKey);
                    } else {
                        String configValue = new SetConfig(coordinatorStreamMessage).getConfigValue();
                        configMap.put(configKey, configValue);
                    }
                }
            }
            bootstrappedStreamSet = Collections.unmodifiableSet(bootstrappedMessages);
            log.debug("Bootstrapped configuration: {}", configMap);
            isBootstrapped = true;
        } catch (Exception e) {
            throw new SamzaException(e);
        }
    }
}