Module file 

Available on crate feature pager and Unix only.

File backend for the pager. See mz_ore::pager for the public API.

Stale-scratch cleanup is intentionally out of scope: production runs on Kubernetes with per-pod ephemeral volumes, so a crashed predecessor’s files are reclaimed with the volume. Local dev tooling is responsible for sweeping leftovers from crashed processes.

Structs

FileInner 🔒

Storage for a file-backed handle. The file at scratch_path(id) holds the bytes for non-empty handles. For len_u64s == 0, no file is created; drop is a no-op. No file descriptor is retained.

Statics

INIT_LOCK 🔒

Serializes set_scratch_dir callers so init failures can be retried on the next call. A plain Once would burn the only retry opportunity.

SCRATCH_DIR 🔒

SCRATCH_ID 🔒

SUBDIR 🔒

Functions

alloc_scratch_id 🔒

coalesce 🔒

init_subdir 🔒

pageout_file 🔒

read_at_file 🔒

scratch_path 🔒

set_scratch_dir

Configures the scratch directory for the file backend.

take_file 🔒

try_pageout_file 🔒

Fallible counterpart to pageout_file. Returns the underlying I/O error instead of falling back to a different backend, so callers can distinguish “scratch volume is broken” from “everything is fine.”

try_read_at_file 🔒

Fallible counterpart to read_at_file. Returns Err instead of panicking on I/O failure (open/pread errors). Bounds violations and non-file handles still panic — those are caller bugs, not I/O failures.

try_take_file 🔒

Fallible counterpart to take_file. Returns Err instead of panicking on I/O failure. The handle is consumed in either case; on Err, dst may hold partial data and the scratch file is unlinked when the inner is dropped.

write_all_vectored 🔒

write_chunks 🔒