Module trace 

Host-I/O trace buffer for debug_traceTransaction on Stylus programs.

Host functions call record to push a trace entry; a tracing driver installs a buffer via enable before running the program and takes the records afterwards.

Structs

HostioRecord

Single recorded host-I/O call.

Functions

disable

Clear the active buffer for the current thread.

enable

Install a buffer for the current thread. Subsequent record calls append to it until disable is called.

enter_subcall

Push a fresh sub-call frame. Subsequent record calls (until the matching exit_subcall) accumulate inside this frame.

exit_subcall

Pop the top sub-call frame and return its accumulated records. The parent CALL/CREATE hostio attaches this list as its steps.

is_active

Whether tracing is active on the current thread — cheap check the host functions can use to avoid building args/outs when disabled.

record

Push one record into the active buffer (or the open sub-frame, if any). A no-op when tracing is disabled — zero cost on the hot path.

record_ink

Record a host-function call with an ink delta captured by the caller. Used where args/outs aren’t meaningful but ink cost is.

record_leaf

Convenience wrapper for host functions that want to record the call name with optional args + outs and no ink delta (e.g., leaf host functions that never block or touch state).

record_with_steps

Like record but with pre-collected sub-frame records attached as steps (used by CALL/CREATE family hostios after popping their own sub-frame).

take

Take and clear the active buffer’s contents.