public EVCacheLatch appendOrAdd()

in evcache-core/src/main/java/com/netflix/evcache/EVCacheImpl.java [3152:3229]
74 lines of code
27 McCabe index (conditional complexity)

    public <T> EVCacheLatch appendOrAdd(String key, T value, Transcoder<T> tc, int timeToLive, Policy policy) throws EVCacheException {
        if ((null == key) || (null == value)) throw new IllegalArgumentException();
        checkTTL(timeToLive, Call.APPEND_OR_ADD);

        final boolean throwExc = doThrowException();
        final EVCacheClient[] clients = _pool.getEVCacheClientForWrite();
        if (clients.length == 0) {
            incrementFastFail(EVCacheMetricsFactory.NULL_CLIENT, Call.APPEND_OR_ADD);
            if (throwExc) throw new EVCacheException("Could not find a client to appendOrAdd the data");
            return new EVCacheLatchImpl(policy, 0, _appName); // Fast failure
        }

        final EVCacheKey evcKey = getEVCacheKey(key);
        final EVCacheEvent event = createEVCacheEvent(Arrays.asList(clients), Call.APPEND_OR_ADD);
        if (event != null) {
            event.setEVCacheKeys(Arrays.asList(evcKey));
            try {
                if (shouldThrottle(event)) {
                    incrementFastFail(EVCacheMetricsFactory.THROTTLED, Call.APPEND_OR_ADD);
                    if (throwExc) throw new EVCacheException("Request Throttled for app " + _appName + " & key " + key);
                    return new EVCacheLatchImpl(policy, 0, _appName); // Fast failure
                }
            } catch(EVCacheException ex) {
                if(throwExc) throw ex;
                incrementFastFail(EVCacheMetricsFactory.THROTTLED, Call.APPEND_OR_ADD);
                return null;
            }
            startEvent(event);
        }
        final long start = EVCacheMetricsFactory.getInstance().getRegistry().clock().wallTime();
        final EVCacheLatchImpl latch = new EVCacheLatchImpl(policy == null ? Policy.ALL_MINUS_1 : policy, clients.length - _pool.getWriteOnlyEVCacheClients().length, _appName);
        String status = EVCacheMetricsFactory.SUCCESS;
        try {
            CachedData cd = null;
            for (EVCacheClient client : clients) {
                // ensure key hashing is not enabled
                if (evcKey.getHashKey(client.isDuetClient(), client.getHashingAlgorithm(), client.shouldEncodeHashKey(), client.getMaxDigestBytes(), client.getMaxHashLength(), client.getBaseEncoder()) != null) {
                    throw new IllegalArgumentException("appendOrAdd is not supported when key hashing is enabled.");
                }

                if (cd == null) {
                    if (tc != null) {
                        cd = tc.encode(value);
                    } else if ( _transcoder != null) {
                        cd = ((Transcoder<Object>)_transcoder).encode(value);
                    } else {
                        cd = client.getTranscoder().encode(value);
                    }
                }
                final Future<Boolean> future = client.appendOrAdd(evcKey.getDerivedKey(client.isDuetClient(), client.getHashingAlgorithm(), client.shouldEncodeHashKey(), client.getMaxDigestBytes(), client.getMaxHashLength(), client.getBaseEncoder()), cd, timeToLive, latch);
                if (log.isDebugEnabled() && shouldLog()) log.debug("APPEND_OR_ADD : APP " + _appName + ", Future " + future + " for key : " + evcKey);
            }
            if (event != null) {
                event.setTTL(timeToLive);
                event.setCachedData(cd);
                if(_eventsUsingLatchFP.get()) {
                    latch.setEVCacheEvent(event);
                    latch.scheduledFutureValidation();
                } else {
                    endEvent(event);
                }
            }
            return latch;
        } catch (Exception ex) {
            status = EVCacheMetricsFactory.ERROR;
            if (log.isDebugEnabled() && shouldLog()) log.debug("Exception while appendOrAdd the data for APP " + _appName + ", key : " + evcKey, ex);
            if (event != null) {
                event.setStatus(status);
                eventError(event, ex);
            }
            if (!throwExc) return new EVCacheLatchImpl(policy, 0, _appName);
            throw new EVCacheException("Exception while appendOrAdd data for APP " + _appName + ", key : " + evcKey, ex);
        } finally {
            final long duration = EVCacheMetricsFactory.getInstance().getRegistry().clock().wallTime()- start;
            getTimer(Call.APPEND_OR_ADD.name(), EVCacheMetricsFactory.WRITE, null, status, 1, maxWriteDuration.get().intValue(), null).record(duration, TimeUnit.MILLISECONDS);
            if (log.isDebugEnabled() && shouldLog()) log.debug("APPEND_OR_ADD : APP " + _appName + ", Took " + duration + " milliSec for key : " + evcKey);
        }
    }