T doGetAndTouch()

in evcache-core/src/main/java/com/netflix/evcache/EVCacheImpl.java [1572:1672]
96 lines of code
44 McCabe index (conditional complexity)

    <T> T doGetAndTouch(EVCacheKey evcKey, int timeToLive, Transcoder<T> tc) throws EVCacheException {
        final boolean throwExc = doThrowException();
        EVCacheClient client = _pool.getEVCacheClientForRead();
        if (client == null) {
            incrementFastFail(EVCacheMetricsFactory.NULL_CLIENT, Call.GET_AND_TOUCH);
            if (throwExc) throw new EVCacheException("Could not find a client to get and touch the data for App " + _appName);
            return null; // Fast failure
        }

        final EVCacheEvent event = createEVCacheEvent(Collections.singletonList(client), Call.GET_AND_TOUCH);
        if (event != null) {
            event.setEVCacheKeys(Arrays.asList(evcKey));
            try {
                if (shouldThrottle(event)) {
                    incrementFastFail(EVCacheMetricsFactory.THROTTLED, Call.GET_AND_TOUCH);
                    if (throwExc) throw new EVCacheException("Request Throttled for app " + _appName + " & key " + evcKey);
                    return null;
                }
            } catch(EVCacheException ex) {
                if(throwExc) throw ex;
                incrementFastFail(EVCacheMetricsFactory.THROTTLED, Call.GET_AND_TOUCH);
                return null;
            }
            event.setTTL(timeToLive);
            startEvent(event);
        }

        final long start = EVCacheMetricsFactory.getInstance().getRegistry().clock().wallTime();
        String cacheOperation = EVCacheMetricsFactory.YES;
        int tries = 1;
        String status = EVCacheMetricsFactory.SUCCESS;
        try {
            final boolean hasZF = hasZoneFallback();
            boolean throwEx = hasZF ? false : throwExc;
            T data = getData(client, evcKey, tc, throwEx, hasZF);
            if (data == null && hasZF) {
                final List<EVCacheClient> fbClients = _pool.getEVCacheClientsForReadExcluding(client.getServerGroup());
                for (int i = 0; i < fbClients.size(); i++) {
                    final EVCacheClient fbClient = fbClients.get(i);
                    if(i >= fbClients.size() - 1) throwEx = throwExc;
                    if (event != null) {
                        try {
                            if (shouldThrottle(event)) {
                                status = EVCacheMetricsFactory.THROTTLED;
                                if (throwExc) throw new EVCacheException("Request Throttled for app " + _appName + " & key " + evcKey);
                                return null;
                            }
                        } catch(EVCacheException ex) {
                            if(throwExc) throw ex;
                            status = EVCacheMetricsFactory.THROTTLED;
                            return null;
                        }
                    }
                    tries++;
                    data = getData(fbClient, evcKey, tc, throwEx, (i < fbClients.size() - 1) ? true : false);
                    if (log.isDebugEnabled() && shouldLog()) log.debug("GetAndTouch Retry for APP " + _appName + ", key [" + evcKey + (log.isTraceEnabled() ? "], Value [" + data : "")  + "], ServerGroup : " + fbClient.getServerGroup());
                    if (data != null) {
                        client = fbClient;
                        break;
                    }
                }
            }

            if (data != null) {
                if (event != null) event.setAttribute("status", "THIT");

                // touch all copies
                touchData(evcKey, timeToLive);
                if (log.isDebugEnabled() && shouldLog()) log.debug("GET_AND_TOUCH : APP " + _appName + ", key [" + evcKey + (log.isTraceEnabled() ? "], Value [" + data : "") + "], ServerGroup : " + client.getServerGroup());
            } else {
                cacheOperation = EVCacheMetricsFactory.NO;
                if (log.isInfoEnabled() && shouldLog()) log.info("GET_AND_TOUCH : APP " + _appName + " ; cache miss for key : " + evcKey);
                if (event != null) event.setAttribute("status", "TMISS");
            }
            if (event != null) endEvent(event);
            return data;
        } catch (net.spy.memcached.internal.CheckedOperationTimeoutException ex) {
            status = EVCacheMetricsFactory.TIMEOUT;
            if (event != null) {
                event.setStatus(status);
                eventError(event, ex);
            }
            if (log.isDebugEnabled() && shouldLog()) log.debug("CheckedOperationTimeoutException executing getAndTouch APP " + _appName + ", key : " + evcKey, ex);
            if (!throwExc) return null;
            throw new EVCacheException("CheckedOperationTimeoutException executing getAndTouch APP " + _appName + ", key  = " + evcKey
                    + ".\nYou can set the following property to increase the timeout " + _appName+ ".EVCacheClientPool.readTimeout=<timeout in milli-seconds>", ex);
        } catch (Exception ex) {
            status = EVCacheMetricsFactory.ERROR;
            if (log.isDebugEnabled() && shouldLog()) log.debug("Exception executing getAndTouch APP " + _appName + ", key = " + evcKey, ex);
            if (event != null) {
                event.setStatus(status);
                eventError(event, ex);
            }
            if (!throwExc) return null;
            throw new EVCacheException("Exception executing getAndTouch APP " + _appName + ", key = " + evcKey, ex);
        } finally {
            final long duration = EVCacheMetricsFactory.getInstance().getRegistry().clock().wallTime()- start;
            getTimer(Call.GET_AND_TOUCH.name(), EVCacheMetricsFactory.READ, cacheOperation, status, tries, maxReadDuration.get().intValue(), client.getServerGroup()).record(duration, TimeUnit.MILLISECONDS);
            if (log.isDebugEnabled() && shouldLog()) log.debug("Took " + duration + " milliSec to get&Touch the value for APP " + _appName + ", key " + evcKey);
        }
    }