public Task AddAsync()

in src/Microsoft.Azure.WebJobs.Logging/Internal/LogWriter.cs [147:234]
70 lines of code
10 McCabe index (conditional complexity)

        public Task AddAsync(FunctionInstanceLogItem item, CancellationToken cancellationToken = default(CancellationToken))
        {
            if (item == null)
            {
                throw new ArgumentNullException("item");
            }
            item.Validate();
            item.FunctionId = FunctionId.Build(this._hostName, item.FunctionName);

            // Both Start and Completed log here. Completed will overwrite a Start entry. 
            lock (_lock)
            {
                // Permanent failures when flushing to storage can result in many log entries being buffered.
                // This basically becomes a memory leak. Mitigate by enforcing a max.
                if (_activeFuncs.Count >= MaxBufferedEntryCount || _completedFunctions.Count >= MaxBufferedEntryCount)
                {
                    _onException?.Invoke(new Exception($"The limit on the number of buffered log entries was reached. A total of '{MaxBufferedEntryCount}' log entries were dropped."));
                    _activeFuncs.Clear();
                    _completedFunctions.Clear();
                }

                _activeFuncs[item.FunctionInstanceId] = item;
            }

            lock (_lock)
            {
                StartBackgroundFlusher();
                if (_container == null)
                {
                    _container = new ContainerActiveLogger(_machineName, _logTableProvider);
                }
                if (_instanceLogger == null)
                {
                    int size = GetContainerSize();
                    _instanceLogger = new CloudTableInstanceCountLogger(_machineName, _logTableProvider, size);
                }
            }

            if (item.IsCompleted())
            {
                _container.Decrement(item.FunctionInstanceId);
                _instanceLogger.Decrement(item.FunctionInstanceId);

                lock (_lock)
                {
                    _completedFunctions.Add(item.FunctionInstanceId);
                }
            }
            else
            {
                _container.Increment(item.FunctionInstanceId);
                _instanceLogger.Increment(item.FunctionInstanceId);
            }

            lock (_lock)
            {
                if (_seenFunctions.Add(item.FunctionName))
                {
                    _funcDefs.Add(FunctionDefinitionEntity.New(item.FunctionId, item.FunctionName));
                }
            }

            if (item.IsCompleted())
            {
                // For completed items, aggregate total passed and failed within a time bucket. 
                // Time aggregate is flushed later. 
                // Don't flush until we've moved onto the next interval. 
                {
                    var newEntity = TimelineAggregateEntity.New(_machineName, item.FunctionId, item.StartTime, _uniqueId);
                    lock (_lock)
                    {
                        // If we already have an entity at this time slot (specified by rowkey), then use that so that 
                        // we update the existing counters. 
                        var existingEntity = _timespan.GetFromRowKey(newEntity.RowKey);
                        if (existingEntity == null)
                        {
                            _timespan.Add(newEntity);
                            existingEntity = newEntity;
                        }

                        Increment(item, existingEntity);
                    }
                }
            }

            // Results will get written on a background thread            
            return Task.FromResult(0);
        }