package granary

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Pure-OCaml SQL engine

Install 

dune-project
 Dependency

github.com Edit opam file Versions (1)

Authors

  1. T
    Tej Pochiraju <foss@tej.sh>

Maintainers

  1. T
    Tej Pochiraju <foss@tej.sh>

Sources

0.0.3.tar.gz
sha256=8b18780ea373be48301d9f333925860a2f9110fc0ac28684295118d72b65a67e
sha512=25ca3c9c5e2b528704a542502e0f37dc33ba003f65622d969b8c2b800778585f8ef0cf89b36e6679832e3993e8303aecddfc662742baf7044d6afe4a796b8f11

doc/granary.unix/Granary_unix/Fault_inject/index.html

Module Granary_unix.Fault_injectSource

Fault-injecting wrapper around Unix_file for crash-recovery tests.

Fault-injecting wrapper around the Unix_file block backend.

Wraps the standard block callbacks; the fail_after_writes counter causes the (N+1)-th write_page call to return Error "injected crash". After failure all subsequent writes also fail (simulating a downed device). Optionally, fail_on_sync forces sync to fail on first invocation.

Recovery correctness (file consistency after a mid-write crash) is NOT in scope for this module — it merely exposes the injection mechanics so that test harnesses can verify the engine does not panic in the face of I/O errors.

Sourcetype t
Sourceval pp : Format.formatter -> t -> unit

Pretty-print a wrapper's write count and fault state.

Sourcetype config = {
  1. fail_after_writes : int option;
  2. fail_on_sync : bool;
}
Sourceval default_config : config

Default: no faults injected.

Sourceval open_with_faults : path:string -> size_bytes:int -> config:config -> (t * (page_id:int64 -> Cstruct.t -> (unit, string) result Lwt.t) * (page_id:int64 -> Cstruct.t -> (unit, string) result Lwt.t) * (unit -> (unit, string) result Lwt.t) * (n_pages:int64 -> (unit, string) result Lwt.t) * int64 * (unit -> unit Lwt.t)) Lwt.t

Build a fault-injecting block backend wrapping a file at path. The file is created if absent and resized to size_bytes bytes. config controls when faults trigger. Returns the wrapper handle along with the callbacks expected by Db.open_block.

The close callback returns unit Lwt.t to match Db.open_block's signature: any error from the underlying Unix_file.close is swallowed (logged-and-discarded) at the wrapper boundary.

Sourceval writes_completed : t -> int

Number of successful underlying writes observed by this wrapper.

Sourceval faulted : t -> bool

Whether the injected fault has tripped.