$ time cat fileThis technically measures the amount of time it takes cat to write the data into the TTY, but since the buffer is a fixed 4KiB in size, it also measures the time that pangoterm takes to read all but the final 4KiB of the file, which is under 1% of the file. I managed to obtain the following timings. Before I started:
real 0m4.206s user 0m0.000s sys 0m0.036sBy optimising libvterm's moverect buffer operation with memmove() (revision -r511):
real 0m2.035s user 0m0.000s sys 0m0.048sWith pangoterm deferred updates, that delay re-rendering of the screen until all the PTY data has been read, or every 20 msec (revision -r482):
real 0m0.358s user 0m0.004s sys 0m0.016sIt's now well over 10 times faster than it used to be. Ohh.. and it beats xterm. By quite a bit.
real 0m2.294s user 0m0.000s sys 0m0.036s