We spend quite a bit of time in libsecp256k1 moving them to and from
DER encoding. With a bit of care, we can transfer the raw bytes from
gossipd and manually decode them so a malformed one can't make us
abort().
Before:
real 0m0.629000-0.695000(0.64985+/-0.019)s
After:
real 0m0.359000-0.433000(0.37645+/-0.023)s
At this point, the main issues are 11% of time spent in ccan/io's
backend_wake (I tried using a hash table there, but that actually makes
the small-number-of-fds case slower), and 65% of gossipd's time is
in marshalling the response (all those tal_resize add up!).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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