Module scratch_file 

Offload the dropped head of an over-long PTY output to a scratch file.

When a command’s output grows past the in-memory cap the PTY keeps only the tail and drops the oldest bytes (see the truncation paths in pty.rs). That dropped head is the part the agent can no longer see. Instead of losing it, we append it to a file under <workspace>/.winx/scratch/ so the agent can recover it with ReadFiles (or grep via BashCommand). The file lives inside the workspace on purpose: those read tools are workspace-confined and pipe through the redaction layer, so a leaked secret in the log is still scrubbed on the way back out.

Everything here is best-effort: any IO error is logged at debug and swallowed so output offload can never crash the server (release builds are panic = "abort").

Functions

append_scratch

Append bytes to the scratch file, creating it if absent.

new_scratch_path

A fresh, unique scratch-file path under the workspace, creating the directory if needed and pruning stale files first so the dir does not grow without bound. Returns None on any IO error (offload is best-effort).

prune_scratch_dir

Remove scratch files whose mtime is older than max_age. Best-effort: per-entry failures are logged at debug and skipped, and a missing dir is a no-op.