XLEN key
Time complexity: O(1)
Returns the number of entries inside a stream. If the specified key does not exist the command returns zero, as if the stream was empty. However note that unlike other Redis types, zero-length streams are possible, so you should call or EXISTS in order to check if a key exists or not.
: the number of entries of the stream at .
*Examples
redis> XADD mystream * item 1
redis> XADD mystream * item 3
redis> XLEN mystream
redis>