public Single get()

in evcache-core/src/main/java/com/netflix/evcache/EVCacheImpl.java [1140:1213]
67 lines of code
26 McCabe index (conditional complexity)

    public <T> Single<T> get(String key, Transcoder<T> tc, Scheduler scheduler) {
        if (null == key) return Single.error(new IllegalArgumentException("Key cannot be null"));

        final boolean throwExc = doThrowException();
        final EVCacheClient client = _pool.getEVCacheClientForRead();
        if (client == null) {
            incrementFastFail(EVCacheMetricsFactory.NULL_CLIENT, Call.GET);
            return Single.error(new EVCacheException("Could not find a client to get the data APP " + _appName));
        }

        final EVCacheKey evcKey = getEVCacheKey(key);
        final EVCacheEvent event = createEVCacheEvent(Collections.singletonList(client), Call.GET);
        if (event != null) {
            event.setEVCacheKeys(Arrays.asList(evcKey));
            if (shouldThrottle(event)) {
                incrementFastFail(EVCacheMetricsFactory.THROTTLED, Call.GET);
                return Single.error(new EVCacheException("Request Throttled for app " + _appName + " & key " + key));
            }
            startEvent(event);
        }

        final long start = EVCacheMetricsFactory.getInstance().getRegistry().clock().wallTime();
        final boolean hasZF = hasZoneFallback();
        final boolean throwEx = hasZF ? false : throwExc;
        return getData(client, evcKey, tc, throwEx, hasZF, scheduler).flatMap(data -> {
            if (data == null && hasZF) {
                final List<EVCacheClient> fbClients = _pool.getEVCacheClientsForReadExcluding(client.getServerGroup());
                if (fbClients != null && !fbClients.isEmpty()) {
                    return Observable.concat(Observable.from(fbClients).map(
                            fbClient -> getData(fbClients.indexOf(fbClient), fbClients.size(), fbClient, evcKey, tc, throwEx, throwExc, false, scheduler) //TODO : for the last one make sure to pass throwExc
                            //.doOnSuccess(fbData -> increment("RETRY_" + ((fbData == null) ? "MISS" : "HIT")))
                            .toObservable()))
                            .firstOrDefault(null, fbData -> (fbData != null)).toSingle();
                }
            }
            return Single.just(data);
        }).map(data -> {
            //increment("GetCall");
            if (data != null) {
                //increment("GetHit");
                if (event != null) event.setAttribute("status", "GHIT");
            } else {
                //increment("GetMiss");
                if (event != null) event.setAttribute("status", "GMISS");
                if (log.isInfoEnabled() && shouldLog()) log.info("GET : APP " + _appName + " ; cache miss for key : " + evcKey);
            }
            if (log.isDebugEnabled() && shouldLog()) log.debug("GET : APP " + _appName + ", key [" + evcKey + (log.isTraceEnabled() ? "], Value [" + data : "")  + "], ServerGroup : " + client .getServerGroup());
            if (event != null) endEvent(event);
            return data;
        }).onErrorReturn(ex -> {
            if (ex instanceof net.spy.memcached.internal.CheckedOperationTimeoutException) {
                if (event != null) {
                    event.setStatus(EVCacheMetricsFactory.TIMEOUT);
                    eventError(event, ex);
                }
                if (!throwExc) return null;
                throw sneakyThrow(new EVCacheException("CheckedOperationTimeoutException getting data for APP " + _appName + ", key = "
                        + evcKey
                        + ".\nYou can set the following property to increase the timeout " + _appName
                        + ".EVCacheClientPool.readTimeout=<timeout in milli-seconds>", ex));
            } else {
                if (event != null) {
                    event.setStatus(EVCacheMetricsFactory.ERROR);
                    eventError(event, ex);
                }
                if (!throwExc) return null;
                throw sneakyThrow(new EVCacheException("Exception getting data for APP " + _appName + ", key = " + evcKey, ex));
            }
        }).doAfterTerminate(() -> {
            final long duration = EVCacheMetricsFactory.getInstance().getRegistry().clock().wallTime()- start;
            getTimer(Call.GET_AND_TOUCH.name(), EVCacheMetricsFactory.READ, null, EVCacheMetricsFactory.SUCCESS, 1, maxReadDuration.get().intValue(), client.getServerGroup()).record(duration, TimeUnit.MILLISECONDS);
            if (log.isDebugEnabled() && shouldLog()) log.debug("GET : APP " + _appName + ", Took " + duration + " milliSec.");
        });
    }