Once a Frida session reached its 16 MiB capture budget, every new message
evicted the oldest one with Array#shift, re-serialized it to recover its
byte charge, and searched and spliced its per-script array. Each of
those is linear in the retained messages, so with about 188k small
messages retained the cost per message rose from 0.14 µs to 32 µs and
capped the main thread at roughly 31k messages per second, which a
hooked hot function can exceed.
Keep both queues as head-offset FIFOs that compact once half their slots
are evicted, and record each message's charge when it is admitted.
Arrival order already makes the globally oldest message the oldest one
of its script, so per-script eviction becomes a head check. Eviction is
now amortized O(1) at about 0.14 µs per message; retained messages,
their order and the truncation flag are unchanged.
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
