IMS template must contain GMT timezone, not local - "%a, %d %b %Y %H:%M:%S GMT"
create etag based on timestamp + filesize
INM header handling should have precedence over IMS
since we can't properly handle SSL beyond firts packet it does not make much sense to linger it
with proper fin/ack timewait process. A TCP RST would recycle memory much faster.
- this is wrong place to call user code from an object constructor
- it is wrong to call AsyncWebSocket's method from other's objects constructor
- the callback is executed when new object is not yet linked to server's clients list
Closes#176
Referer to https://github.com/mathieucarbou/ESPAsyncWebServer/discussions/165
Relates to #169
in-flight buffer credits are intended to moderate buffer fill callbacks in AsyncAbstractResponse
it could prevent bad designed slow user-callbacks to flood the queue in chunked responces.
for response data we need to control the queue and in-flight fragmentation. Sending small chunks could give low latency,
but flood asynctcp's queue and fragment socket buffer space for large responses.
Let's ignore polled acks and acks in case when we have more in-flight data then the available socket buff space.
That way we could balance on having half the buffer in-flight while another half is filling up, while minimizing events in asynctcp q
implement AsyncEventSourceMessage using shared std::string container
one message instance could be shared for multiple connected clients
add zero-copy overloads for message queue in AsyncEventSourceClient
message queue for the client consists of possibly shared instances of AsyncEventSourceMessage,
adding a message to the queue won't create deep-copy object
AsyncEventSource will create a single instance of data message and populate connected clients queues with a shared pointer
