private Future getGetFuture()

in evcache-core/src/main/java/com/netflix/evcache/EVCacheImpl.java [1795:1885]
83 lines of code
22 McCabe index (conditional complexity)

    private <T> Future<T> getGetFuture(final EVCacheClient client, final String key, final Transcoder<T> tc, final boolean throwExc) throws EVCacheException {
        final EVCacheKey evcKey = getEVCacheKey(key);
        final EVCacheEvent event = createEVCacheEvent(Collections.singletonList(client), Call.ASYNC_GET);
        if (event != null) {
            event.setEVCacheKeys(Arrays.asList(evcKey));
            try {
                if (shouldThrottle(event)) {
                    incrementFastFail(EVCacheMetricsFactory.THROTTLED, Call.ASYNC_GET);
                    if (throwExc) throw new EVCacheException("Request Throttled for app " + _appName + " & key " + key);
                    return null;
                }
            } catch(EVCacheException ex) {
                if(throwExc) throw ex;
                incrementFastFail(EVCacheMetricsFactory.THROTTLED, Call.ASYNC_GET);
                return null;
            }
            startEvent(event);
        }
        String status = EVCacheMetricsFactory.SUCCESS;
        final Future<T> r;
        final long start = EVCacheMetricsFactory.getInstance().getRegistry().clock().wallTime();
        try {
            String hashKey = evcKey.getHashKey(client.isDuetClient(), client.getHashingAlgorithm(), client.shouldEncodeHashKey(), client.getMaxDigestBytes(), client.getMaxHashLength(), client.getBaseEncoder());
            String canonicalKey = evcKey.getCanonicalKey(client.isDuetClient());
            if(hashKey != null) {
                final Future<Object> objFuture = client.asyncGet(hashKey, evcacheValueTranscoder, throwExc, false);
                r = new Future<T> () {

                    @Override
                    public boolean cancel(boolean mayInterruptIfRunning) {
                        return objFuture.cancel(mayInterruptIfRunning);
                    }

                    @Override
                    public boolean isCancelled() {
                        return objFuture.isCancelled();
                    }

                    @Override
                    public boolean isDone() {
                        return objFuture.isDone();
                    }

                    @Override
                    public T get() throws InterruptedException, ExecutionException {
                        return getFromObj(objFuture.get());
                    }

                    private T getFromObj(Object obj) {
                        if(obj != null && obj instanceof EVCacheValue) {
                            final EVCacheValue val = (EVCacheValue)obj;
                            if(!val.getKey().equals(canonicalKey)) {
                                incrementFailure(EVCacheMetricsFactory.KEY_HASH_COLLISION, Call.ASYNC_GET.name(), EVCacheMetricsFactory.READ);
                                return null;
                            }
                            final CachedData cd = new CachedData(val.getFlags(), val.getValue(), CachedData.MAX_SIZE);
                            final Transcoder<T> transcoder = (tc == null) ? ((_transcoder == null) ? (Transcoder<T>) client.getTranscoder() : (Transcoder<T>) _transcoder) : tc;
                            return transcoder.decode(cd);
                        } else {
                            return null;
                        }

                    }

                    @Override
                    public T get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {
                        return getFromObj(objFuture.get(timeout, unit));
                    }
                };
            } else {
                final Transcoder<T> transcoder = (tc == null) ? ((_transcoder == null) ? (Transcoder<T>) client.getTranscoder() : (Transcoder<T>) _transcoder) : tc;
                r = client.asyncGet(canonicalKey, transcoder, throwExc, false);
            }
            if (event != null) endEvent(event);
        } catch (Exception ex) {
            status = EVCacheMetricsFactory.ERROR;
            if (log.isDebugEnabled() && shouldLog()) log.debug( "Exception while getting data for keys Asynchronously APP " + _appName + ", key : " + key, ex);
            if (event != null) {
                event.setStatus(status);
                eventError(event, ex);
            }
            if (!throwExc) return null;
            throw new EVCacheException("Exception getting data for APP " + _appName + ", key : " + key, ex);
        } finally {
            final long duration = EVCacheMetricsFactory.getInstance().getRegistry().clock().wallTime()- start;
            getTimer(Call.ASYNC_GET.name(), EVCacheMetricsFactory.READ, null, status, 1, maxReadDuration.get().intValue(), client.getServerGroup()).record(duration, TimeUnit.MILLISECONDS);
            if (log.isDebugEnabled() && shouldLog()) log.debug("Took " + duration + " milliSec to execute AsyncGet the value for APP " + _appName + ", key " + key);
        }

        return r;
    }