Bounded channel for STM that discards old entries when full.
This package provides a FIFO channel for STM supporting a size limit. When this limit is reached, older entries are discarded to make way for newer entries.
The motivation for this is logging. If log entries are written to a plain TChan, the program will use a lot of memory if it produces log entries faster than they can be processed. If log entries are written to a bounded channel where writes block (e.g. the stm-chans package), the program may deadlock if the log channel fills up. With Data.STM.RollingQueue, old entries will be discarded instead.
Possible improvements (not available in Data.STM.RollingQueue) include:
Discard lower-priority entries first.
Discard every other entry, so some of the older entries will still be available.