public long decr()

in evcache-core/src/main/java/com/netflix/evcache/EVCacheImpl.java [2957:3041]
80 lines of code
36 McCabe index (conditional complexity)

    public long decr(String key, long by, long defaultVal, int timeToLive) throws EVCacheException {
        if ((null == key) || by < 0 || defaultVal < 0 || timeToLive < 0) throw new IllegalArgumentException();
        checkTTL(timeToLive, Call.DECR);

        final boolean throwExc = doThrowException();
        final EVCacheClient[] clients = _pool.getEVCacheClientForWrite();
        if (clients.length == 0) {
            incrementFastFail(EVCacheMetricsFactory.NULL_CLIENT, Call.DECR);
            if (log.isDebugEnabled() && shouldLog()) log.debug("DECR : " + _metricPrefix + ":NULL_CLIENT");
            if (throwExc) throw new EVCacheException("Could not find a client to decr the data");
            return -1;
        }

        final EVCacheKey evcKey = getEVCacheKey(key);
        final EVCacheEvent event = createEVCacheEvent(Arrays.asList(clients), Call.DECR);
        if (event != null) {
            event.setTTL(timeToLive);
            event.setEVCacheKeys(Arrays.asList(evcKey));
            try {
                if (shouldThrottle(event)) {
                    incrementFastFail(EVCacheMetricsFactory.THROTTLED, Call.DECR);
                    if (throwExc) throw new EVCacheException("Request Throttled for app " + _appName + " & key " + key);
                    return -1;
                }
            } catch(EVCacheException ex) {
                if(throwExc) throw ex;
                incrementFastFail(EVCacheMetricsFactory.THROTTLED, Call.DECR);
                return -1;
            }
            startEvent(event);
        }

        final long start = EVCacheMetricsFactory.getInstance().getRegistry().clock().wallTime();
        String status = EVCacheMetricsFactory.SUCCESS;
        long currentValue = -1;
        try {
            final long[] vals = new long[clients.length];
            int index = 0;
            for (EVCacheClient client : clients) {
                vals[index] = client.decr(evcKey.getDerivedKey(client.isDuetClient(), client.getHashingAlgorithm(), client.shouldEncodeHashKey(), client.getMaxDigestBytes(), client.getMaxHashLength(), client.getBaseEncoder()), by, defaultVal, timeToLive);
                if (vals[index] != -1 && currentValue < vals[index]) {
                    currentValue = vals[index];
                    if (log.isDebugEnabled()) log.debug("DECR : APP " + _appName + " current value = " + currentValue + " for key : " + key + " from client : " + client);
                }
                index++;
            }

            if (currentValue != -1) {
                CachedData cd = null;
                if (log.isDebugEnabled()) log.debug("DECR : APP " + _appName + " current value = " + currentValue
                        + " for key : " + key);
                for (int i = 0; i < vals.length; i++) {
                    if (vals[i] == -1 && currentValue > -1) {
                        if (log.isDebugEnabled()) log.debug("DECR : APP " + _appName + "; Zone " + clients[i].getZone()
                                + " had a value = -1 so setting it to current value = "
                                + currentValue + " for key : " + key);
                        clients[i].decr(evcKey.getDerivedKey(clients[i].isDuetClient(), clients[i].getHashingAlgorithm(), clients[i].shouldEncodeHashKey(), clients[i].getMaxDigestBytes(), clients[i].getMaxHashLength(), clients[i].getBaseEncoder()), 0, currentValue, timeToLive);
                    } else if (vals[i] != currentValue) {
                        if(cd == null) cd = clients[i].getTranscoder().encode(currentValue);
                        if (log.isDebugEnabled()) log.debug("DECR : APP " + _appName + "; Zone " + clients[i].getZone()
                                + " had a value of " + vals[i]
                                        + " so setting it to current value = " + currentValue + " for key : " + key);
                        clients[i].set(evcKey.getDerivedKey(clients[i].isDuetClient(), clients[i].getHashingAlgorithm(), clients[i].shouldEncodeHashKey(), clients[i].getMaxDigestBytes(), clients[i].getMaxHashLength(), clients[i].getBaseEncoder()), cd, timeToLive);
                    }
                }
            }

            if (event != null) endEvent(event);
            if (log.isDebugEnabled()) log.debug("DECR : APP " + _appName + " returning value = " + currentValue + " for key : " + key);
            return currentValue;
        } catch (Exception ex) {
            status = EVCacheMetricsFactory.ERROR;
            if (log.isDebugEnabled() && shouldLog()) log.debug("Exception decrementing the value for APP " + _appName + ", key : " + key, ex);
            if (event != null) {
                event.setStatus(status);
                eventError(event, ex);
            }
            if (!throwExc) return -1;
            throw new EVCacheException("Exception decrementing value for APP " + _appName + ", key : " + key, ex);
        } finally {
            final long duration = EVCacheMetricsFactory.getInstance().getRegistry().clock().wallTime()- start;
            getTimer(Call.DECR.name(), EVCacheMetricsFactory.WRITE, null, status, 1, maxWriteDuration.get().intValue(), null).record(duration, TimeUnit.MILLISECONDS);
            if (log.isDebugEnabled() && shouldLog()) log.debug("DECR : APP " + _appName + ", Took " + duration + " milliSec for key : " + key + " with value as " + currentValue);
        }
    }