Hi! I found that there is significant slowdown when playing 3d character animation cache (in alembic data format) in Autodesk Maya compared to local or webdav mount (webclient) with rclone i get redraw each frame of animation at 1.7 frames per second (fps), local - 10 fps, webclient 9-10 fps and winfsp memfs gives 10-11 fps.
i think that slowdown is because of slow recognition whether region is cached or not. As there is a lot of read attempts of small chunks (8 bytes? at most). Maybe it is read itself, but maybe if to mark completely cached files and read them immediately would solve that?
although seek_speed test (subsequent, first one is much slow) is almost fine:
kalem@DESKTOP-R6MR0O4 MINGW64 ~/OneDrive/Work/home/dev/my/rclone (master)
$ go run cmd/mount/test/seek_speed.go /x/files/Users/user/cache_test/char_geo.abc
2021/08/21 01:09:32 File Open took 1.0001ms
2021/08/21 01:09:32 Reading 170511 from 30325190 took 7.9726ms
2021/08/21 01:09:32 Reading 459963 from 73226079 took 4.7003ms
2021/08/21 01:09:32 Reading 643462 from 73652441 took 2.1757ms
2021/08/21 01:09:32 Reading 578220 from 97851114 took 1.6577ms
2021/08/21 01:09:32 Reading 280484 from 63984752 took 1.0485ms
2021/08/21 01:09:32 Reading 350895 from 75692790 took 1.1963ms
2021/08/21 01:09:32 Reading 614385 from 105503506 took 2.224ms
2021/08/21 01:09:32 Reading 300314 from 96408179 took 1.0838ms
2021/08/21 01:09:32 Reading 285845 from 72643922 took 1.7028ms
2021/08/21 01:09:32 Reading 625634 from 3550622 took 2.1928ms
2021/08/21 01:09:32 Reading 67802 from 1864151 took 2.2125ms
2021/08/21 01:09:32 Reading 401042 from 22613427 took 1.4186ms
2021/08/21 01:09:32 Reading 445739 from 78765994 took 1.907ms
2021/08/21 01:09:32 Reading 85240 from 119458812 took 645µs
2021/08/21 01:09:32 Reading 923639 from 9520318 took 3.516ms
2021/08/21 01:09:32 Reading 1011576 from 10693794 took 1.9981ms
2021/08/21 01:09:32 Reading 686863 from 223581 took 4.2488ms
2021/08/21 01:09:32 Reading 756044 from 86270825 took 3.2894ms
2021/08/21 01:09:32 Reading 82935 from 87280993 took 545.4µs
2021/08/21 01:09:32 Reading 543634 from 90175470 took 2.5099ms
2021/08/21 01:09:32 Reading 180882 from 113081191 took 1.0689ms
2021/08/21 01:09:32 Reading 402243 from 56823120 took 1.0955ms
2021/08/21 01:09:32 Reading 670611 from 81200418 took 3.1726ms
2021/08/21 01:09:32 Reading 735972 from 33681801 took 3.869ms
2021/08/21 01:09:32 Reading 1025113 from 51169078 took 2.8399ms
2021/08/21 01:09:32 That took 69.8979ms for 25 iterations, 2.795916ms per iteration
kalem@DESKTOP-R6MR0O4 MINGW64 ~/OneDrive/Work/home/dev/my/rclone (master)
$ go run cmd/mount/test/seek_speed.go ~/Desktop/char_geo.abc
2021/08/21 01:09:28 File Open took 0s
2021/08/21 01:09:28 Reading 170511 from 30325190 took 0s
2021/08/21 01:09:28 Reading 459963 from 73226079 took 1.0002ms
2021/08/21 01:09:28 Reading 643462 from 73652441 took 0s
2021/08/21 01:09:28 Reading 578220 from 97851114 took 0s
2021/08/21 01:09:28 Reading 280484 from 63984752 took 0s
2021/08/21 01:09:28 Reading 350895 from 75692790 took 774.2µs
2021/08/21 01:09:28 Reading 614385 from 105503506 took 524.9µs
2021/08/21 01:09:28 Reading 300314 from 96408179 took 0s
2021/08/21 01:09:28 Reading 285845 from 72643922 took 0s
2021/08/21 01:09:28 Reading 625634 from 3550622 took 563.8µs
2021/08/21 01:09:28 Reading 67802 from 1864151 took 0s
2021/08/21 01:09:28 Reading 401042 from 22613427 took 0s
2021/08/21 01:09:28 Reading 445739 from 78765994 took 517.6µs
2021/08/21 01:09:28 Reading 85240 from 119458812 took 0s
2021/08/21 01:09:28 Reading 923639 from 9520318 took 518.8µs
2021/08/21 01:09:28 Reading 1011576 from 10693794 took 528µs
2021/08/21 01:09:28 Reading 686863 from 223581 took 1.069ms
2021/08/21 01:09:28 Reading 756044 from 86270825 took 474.7µs
2021/08/21 01:09:28 Reading 82935 from 87280993 took 516.6µs
2021/08/21 01:09:28 Reading 543634 from 90175470 took 0s
2021/08/21 01:09:28 Reading 180882 from 113081191 took 0s
2021/08/21 01:09:28 Reading 402243 from 56823120 took 0s
2021/08/21 01:09:28 Reading 670611 from 81200418 took 517.6µs
2021/08/21 01:09:28 Reading 735972 from 33681801 took 0s
2021/08/21 01:09:28 Reading 1025113 from 51169078 took 999.9µs
2021/08/21 01:09:28 That took 23.979ms for 25 iterations, 959.16µs per iteration
kalem@DESKTOP-R6MR0O4 MINGW64 ~/OneDrive/Work/home/dev/my/rclone (master)
$ go run cmd/mount/test/seek_speed.go /x/files/Users/user/cache_test/char_geo.abc
2021/08/21 01:36:39 File Open took 1.0647ms
2021/08/21 01:36:39 Reading 170511 from 30325190 took 1.0457ms
2021/08/21 01:36:39 Reading 459963 from 73226079 took 1.7631ms
2021/08/21 01:36:39 Reading 643462 from 73652441 took 1.487ms
2021/08/21 01:36:39 Reading 578220 from 97851114 took 0s
2021/08/21 01:36:39 Reading 280484 from 63984752 took 0s
2021/08/21 01:36:39 Reading 350895 from 75692790 took 2.0029ms
2021/08/21 01:36:39 Reading 614385 from 105503506 took 996.9µs
2021/08/21 01:36:39 Reading 300314 from 96408179 took 1.0006ms
2021/08/21 01:36:39 Reading 285845 from 72643922 took 1.9989ms
2021/08/21 01:36:39 Reading 625634 from 3550622 took 1.0029ms
2021/08/21 01:36:39 Reading 67802 from 1864151 took 0s
2021/08/21 01:36:39 Reading 401042 from 22613427 took 2.9981ms
2021/08/21 01:36:39 Reading 445739 from 78765994 took 1.0011ms
2021/08/21 01:36:39 Reading 85240 from 119458812 took 0s
2021/08/21 01:36:39 Reading 923639 from 9520318 took 998.6µs
2021/08/21 01:36:39 Reading 1011576 from 10693794 took 1.9999ms
2021/08/21 01:36:39 Reading 686863 from 223581 took 1.0004ms
2021/08/21 01:36:39 Reading 756044 from 86270825 took 999.9µs
2021/08/21 01:36:39 Reading 82935 from 87280993 took 0s
2021/08/21 01:36:39 Reading 543634 from 90175470 took 999.8µs
2021/08/21 01:36:39 Reading 180882 from 113081191 took 0s
2021/08/21 01:36:39 Reading 402243 from 56823120 took 1.0027ms
2021/08/21 01:36:39 Reading 670611 from 81200418 took 1.9952ms
2021/08/21 01:36:39 Reading 735972 from 33681801 took 1.0025ms
2021/08/21 01:36:39 Reading 1025113 from 51169078 took 1.9995ms
2021/08/21 01:36:39 That took 34.3038ms for 25 iterations, 1.372152ms per iteration
kalem@DESKTOP-R6MR0O4 MINGW64 ~/OneDrive/Work/home/dev/my/rclone (master)
$ go run cmd/mount/test/seek_speed.go ~/Desktop/char_geo.abc
2021/08/21 01:36:44 File Open took 0s
2021/08/21 01:36:45 Reading 170511 from 30325190 took 143.1µs
2021/08/21 01:36:45 Reading 459963 from 73226079 took 635.7µs
2021/08/21 01:36:45 Reading 643462 from 73652441 took 521.3µs
2021/08/21 01:36:45 Reading 578220 from 97851114 took 518.9µs
2021/08/21 01:36:45 Reading 280484 from 63984752 took 520.3µs
2021/08/21 01:36:45 Reading 350895 from 75692790 took 25.8µs
2021/08/21 01:36:45 Reading 614385 from 105503506 took 522.2µs
2021/08/21 01:36:45 Reading 300314 from 96408179 took 0s
2021/08/21 01:36:45 Reading 285845 from 72643922 took 532.6µs
2021/08/21 01:36:45 Reading 625634 from 3550622 took 519.2µs
2021/08/21 01:36:45 Reading 67802 from 1864151 took 0s
2021/08/21 01:36:45 Reading 401042 from 22613427 took 536.2µs
2021/08/21 01:36:45 Reading 445739 from 78765994 took 990.1µs
2021/08/21 01:36:45 Reading 85240 from 119458812 took 0s
2021/08/21 01:36:45 Reading 923639 from 9520318 took 0s
2021/08/21 01:36:45 Reading 1011576 from 10693794 took 0s
2021/08/21 01:36:45 Reading 686863 from 223581 took 1.0005ms
2021/08/21 01:36:45 Reading 756044 from 86270825 took 3.0032ms
2021/08/21 01:36:45 Reading 82935 from 87280993 took 0s
2021/08/21 01:36:45 Reading 543634 from 90175470 took 1.0025ms
2021/08/21 01:36:45 Reading 180882 from 113081191 took 0s
2021/08/21 01:36:45 Reading 402243 from 56823120 took 0s
2021/08/21 01:36:45 Reading 670611 from 81200418 took 507.4µs
2021/08/21 01:36:45 Reading 735972 from 33681801 took 0s
2021/08/21 01:36:45 Reading 1025113 from 51169078 took 512µs
2021/08/21 01:36:45 That took 32.5183ms for 25 iterations, 1.300732ms per iteration```