GitLab

Detail:
  Use of the RMA by PipeFS could lead to fragmentation, and is slower
  than a private dynamic area as the RMA's a very busy heap. The new
  dynamic area is set to 16MB maximum size, called "PipeFS", and the
  code is compile-time switched, not run-time.

  PipeFS has no block handling code so its get/put byte routines are
  called by the OS in a tight loop. Unfortunately for each byte it
  reads/writes it issues UpCall_ModifyingFile, and moreover does this
  without specifying a filename, so *all* directories are rescanned -
  for every single byte read or written to PipeFS. This is why PipeFS
  is so extremely slow prior to this version. Now, a callback is set,
  and the UpCall only issued when this goes off - after any block
  transfers, for example. A typical effect is a 171K file save from a
  text editor to PipeFS used to take around 20 seconds, and now takes
  less than a quarter of a second. Streaming data through PipeFS is
  now a sensible option.

  There are two variants of the callback code; one maintans an array
  of filename pointers and goes through the list each time the call-
  back fires; the other just issues a general UpCall each time. The
  first one should work OK, and is there in case anyone ever works
  out how to use R1 properly for the UpCall.
Admin:
  Copied files into PipeFS up to the DA limit and verified sensible
  behaviour at this point; memory released as expected on file
  removal; files appear to be intact; MP3 streaming at 128kbps from
  network or disc through PipeFS is reliable; Filer window behaviour
  with "full info" on and Task Manager display of dynamic area size
  act as expected.

  By default, the compile-time options mean the module will only run on
  RISC OS 3.5 or later. Tested on RISC OS 3.70 only.

Version 0.19. Tagged as 'PipeFS-0_19'