feat(persistence): autosave + crash recovery (Arc 3 phase 3)

Framing: docs/autosave-recovery-framing.md (Q#AS1-11). Closes the
persistence arc. Every modified file buffer is periodically written to a
private recovery copy; if pmacs dies, the next session says so and
`M-x recover-file` installs it. Emacs's auto-save-mode + recover-file.

Hybrid, forced by the same two gaps as phase 2: Lua has no per-buffer
path getter and FileMeta is neither Lua-visible nor serde. Rust owns the
sweep and the external-change guard; Lua owns cadence, config, and UX.

src/autosave.rs (new):
- One atomic envelope per recovery: a JSON header line + `\n` + raw
  buffer bytes. Split at the FIRST newline, so contents may hold newlines
  and non-UTF-8. A crash can never leave a torn header/contents pair.
- `origin` is NULLABLE: a `[new file]` buffer (a path with nothing on
  disk) has no FileMeta, and its unsaved contents are exactly the work
  most worth recovering.
- status(): Fresh / Stale / Corrupt / None. Only Fresh is announced;
  Stale (file changed, deleted, or created underneath us) is never
  auto-offered; Corrupt is typed, quiet, and discardable.
- sweep(): all modified file buffers, skipping clean/scratch and those
  unchanged since their last copy. The skip cache is keyed
  BufferId -> (path_hash, revision), not revision alone: a buffer keeps
  its BufferId across a path change (LSP WorkspaceEdit rename), so a
  revision-only cache would skip the write and orphan the old key.
- pending(): enumerates ALL open file buffers in Rust, which is what
  covers argv `[new file]` buffers -- they fire no hook at all.

Private storage (Q#AS11, a precondition for default-on): autosave stores
unsaved FILE CONTENTS, not metadata. New `file_io::save_atomic_with_mode`
sets the temp's mode BEFORE the rename (a chmod-after-write leaves a
window where the file is 0644), and `state::write_private` creates the
dir 0700 and the file 0600. Plus `state::read_bytes` (state::read is
read_to_string, which non-UTF-8 buffer contents would fail).

builtin/runtime/autosave.lua:
- Cadence is `process.after-tick` + monotonic_ms, NOT workers.sleep: a
  long sleep parks one of only `available_parallelism - 1` pool threads,
  and re-reading the interval each tick makes it live-reconfigurable.
- pmacs.autosave.interval_ms([ms]) -- validated getter/setter following
  the async_config.frame_target_ms shape. Default 30000, floor 1000.
  pmacs.autosave.enable(on). On by default.
- Notify, never prompt: `after-load` only raises a flag; the tick emits
  ONE aggregate message ("3 files have autosave recovery"). A modal
  prompt from after-load would stack N modals during a desktop restore.
- recover-file confirms, pins to the origin buffer, replaces contents,
  then explicitly fires `buffer.after-edit` -- the mutators only notify
  windows and queue CRDT, and after-edit comes from dispatch_key's
  post-command check, which the minibuffer shadow returns before. Without
  the explicit fire, LSP didChange and the syntax reparse never see the
  recovery. discard-recovery deletes a copy (including a Corrupt one).
- Cleanup: after-save discards; per-buffer on_removed discards on kill
  (there is no global kill hook); before-quit does one final synchronous
  sweep and never vetoes.

src/hash.rs (new): one pub(crate) sha256_hex, shared by desktop, autosave,
and packages::fetcher -- which had two private duplicates (Q#AS9).

Not daemon-gated (unlike desktop-save): autosave is per-buffer, not
per-frontend, and a daemon holds the unsaved work.

Tests: 8 autosave units + 13 state/hash units + tests/autosave_acceptance
(15): sweep round-trip, non-UTF-8 envelope, [new file] null-origin
Fresh->Stale, 0600/0700 perms, skip clean/scratch/unchanged, path-change
rewrites new key + discards old, save/kill cleanup, Stale not offered,
Corrupt typed+quiet+discardable, recover-file installs + fires after-edit
+ leaves modified, tick aggregation (3 loads -> 1 message, no repeat),
single-file naming, interval validation + live change, enable gate,
before-quit sweeps without vetoing.

Gates: fmt + workspace clippy clean; lib 1499; crdt 1670; autosave 15;
desktop 11; persistence 5; m4 90; m7_8 5; m8 10; GPU 58; git diff --check.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
This commit is contained in:
Levi Neuwirth 2026-07-09 10:24:08 -04:00
parent a6d8c60faf
commit ec42526652
11 changed files with 1421 additions and 33 deletions

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-- autosave.lua --- periodic recovery copies + crash recovery (Arc 3 phase 3).
--
-- Every `interval_ms` a sweep writes a private recovery copy of each
-- modified file buffer. If pmacs dies, the next session notices the copy
-- and says so; `M-x recover-file` installs it. Emacs's `auto-save-mode`
-- + `recover-file`.
--
-- The Rust half (`pmacs.autosave._*`) does the sweep and the
-- external-change guard; this file owns the cadence, the configurable
-- interval, and the UX.
--
-- On by default. Configure from init.lua:
-- pmacs.autosave.interval_ms(60000) -- default 30000, floor 1000
-- pmacs.autosave.enable(false) -- turn it off entirely
--
-- Recovery files live under `$XDG_STATE_HOME/pmacs/autosave/` (0700 dir,
-- 0600 files), are deleted when the buffer is saved or killed, and
-- survive a crash or a quit with unsaved changes.
--
-- Framing: docs/autosave-recovery-framing.md.
pmacs.autosave = pmacs.autosave or {}
local DEFAULT_INTERVAL_MS = 30000 -- Emacs's auto-save-timeout
local MIN_INTERVAL_MS = 1000 -- each sweep fsyncs; don't storm
local interval = DEFAULT_INTERVAL_MS
local enabled = true
local last_sweep_ms = nil
-- Report on the first tick (the startup scan), and after every load.
local needs_report = true
-- enable(on) --- turn autosave off (or back on).
function pmacs.autosave.enable(on)
enabled = (on ~= false)
return enabled
end
-- interval_ms([ms]) --- getter when `ms` is nil, else a validated setter.
-- Shape follows `pmacs.async_config.frame_target_ms`. The tick re-reads
-- this every frame, so a change takes effect immediately -- no restart.
function pmacs.autosave.interval_ms(ms)
if ms == nil then return interval end
if type(ms) ~= "number" or ms ~= ms or ms < MIN_INTERVAL_MS then
error("pmacs.autosave.interval_ms: expected a number >= " .. MIN_INTERVAL_MS)
end
interval = math.floor(ms)
return interval
end
-- sweep() --- force a pass now. Returns how many buffers were written.
function pmacs.autosave.sweep()
if not enabled then return 0 end
return pmacs.autosave._sweep()
end
local function basename(path)
return path:match("[^/]+$") or path
end
-- One aggregate message however many files are recoverable. N synchronous
-- `after-load` fires (a desktop restore) collapse into a single report.
local function report_pending()
local fresh = pmacs.autosave._pending()
local n = #fresh
if n == 1 then
pmacs.editor.set_status(basename(fresh[1]) .. " has autosave recovery --- M-x recover-file")
elseif n > 1 then
pmacs.editor.set_status(n .. " files have autosave recovery --- M-x recover-file")
end
-- Corrupt copies are counted but stay quiet: a malformed recovery file
-- must not make startup noisy. `M-x discard-recovery` removes them.
end
-- The cadence (Q#AS2). `process.after-tick` fires every frame -- and the
-- run loops tick on a frame *timeout*, not only on input, so this keeps
-- running while the editor is idle. Costs one clock read + a compare per
-- frame, and parks no worker thread (a long `workers.sleep` would hold
-- one of only `available_parallelism - 1` pool threads).
pmacs.hook.add("process.after-tick", function()
if needs_report then
needs_report = false
pcall(report_pending)
end
if not enabled then return end
local now = pmacs.editor.monotonic_ms()
if last_sweep_ms == nil then
last_sweep_ms = now
return
end
if now - last_sweep_ms >= interval then
last_sweep_ms = now
pcall(pmacs.autosave._sweep)
end
end)
-- A load may reveal a recovery file; report on the next tick (never from
-- inside the hook -- a desktop restore fires this once per leaf).
pmacs.hook.add("buffer.after-load", function()
needs_report = true
-- A clean save or a kill retires the recovery copy. There is no global
-- kill hook, so register per buffer, capturing the path now (the buffer
-- may be gone by the time the callback runs).
local path = pmacs.editor.file_path()
if not path then return end
local buf = pmacs.window.buffer()
if not buf then return end
pcall(pmacs.buffer.on_removed, buf, function()
pcall(pmacs.autosave._discard, path)
end)
end)
pmacs.hook.add("buffer.after-save", function()
local path = pmacs.editor.file_path()
if path then pcall(pmacs.autosave._discard, path) end
end)
-- A final synchronous sweep on quit: async ticks stop after this, so a
-- quit with unsaved changes must capture them here. Returns nil --
-- before-quit is short-circuit and this must never veto.
pmacs.hook.add("editor.before-quit", function()
pcall(pmacs.autosave.sweep)
end)
pmacs.command.define {
name = "recover-file",
description = "Replace this buffer with its autosave recovery copy.",
fn = function()
local path = pmacs.editor.file_path()
if not path then
pmacs.editor.set_status("recover-file: not visiting a file")
return
end
local st = pmacs.autosave._status(path)
if st == "none" then
pmacs.editor.set_status("recover-file: no autosave recovery for this file")
return
end
if st == "corrupt" then
pmacs.editor.set_status("recover-file: recovery file is corrupt --- M-x discard-recovery")
return
end
local warn = ""
if st == "stale" then
warn = " [WARNING: file changed on disk since the autosave]"
end
pmacs.minibuffer.read {
prompt = "Recover from autosave?" .. warn .. " (yes/no): ",
source = function() return { "yes", "no" } end,
on_accept = function(answer)
if answer ~= "yes" then
pmacs.editor.set_status("recover-file: cancelled")
return
end
-- Pin to the buffer we started on: focus can drift while the
-- prompt is up, and recovering into the wrong buffer is
-- unrecoverable.
if pmacs.editor.file_path() ~= path then
pmacs.editor.set_status("recover-file: buffer changed; aborted")
return
end
local bytes = pmacs.autosave._recover_bytes(path)
if not bytes then
pmacs.editor.set_status("recover-file: recovery unreadable")
return
end
local buf = pmacs.window.buffer()
buf:replace(0, buf:len(), bytes)
-- The mutators notify windows and queue CRDT but do NOT fire
-- `buffer.after-edit` --- that comes from dispatch_key's
-- post-command revision check, which the minibuffer shadow
-- returns before. Fire it so LSP didChange and the syntax
-- reparse see the recovered contents.
pmacs.hook.run("buffer.after-edit")
pmacs.editor.set_status("recovered from autosave --- save to keep it")
end,
}
end,
}
pmacs.command.define {
name = "discard-recovery",
description = "Delete this file's autosave recovery copy.",
fn = function()
local path = pmacs.editor.file_path()
if not path then
pmacs.editor.set_status("discard-recovery: not visiting a file")
return
end
pmacs.autosave._discard(path)
pmacs.editor.set_status("discarded autosave recovery")
end,
}

481
src/autosave.rs Normal file
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// autosave.rs --- periodic recovery copies + crash recovery (Arc 3 phase 3).
//! Every modified file buffer is periodically written to a private
//! recovery file under `$XDG_STATE_HOME/pmacs/autosave/`. If pmacs dies,
//! the next session notices the copy and offers `M-x recover-file`.
//! Emacs's `auto-save-mode` + `recover-file`.
//!
//! This module owns the parts Lua cannot do: enumerating **all** buffers'
//! paths (Lua has no per-buffer path getter), and the `FileMeta`
//! external-change guard (`FileMeta` is neither Lua-visible nor serde).
//! `builtin/runtime/autosave.lua` owns the cadence, the configurable
//! interval, and the recovery UX.
//!
//! Recovery files are written `0600` under a `0700` directory
//! (Q#AS11) — they hold *unsaved file contents*, a different class of
//! secret from saveplace's cursor offsets.
//!
//! Framing: docs/autosave-recovery-framing.md.
use std::cell::RefCell;
use std::collections::HashMap;
use std::path::Path;
use mlua::Lua;
use serde::{Deserialize, Serialize};
use crate::buffer::BufferId;
use crate::file_io::FileMeta;
use crate::hash::sha256_hex;
use crate::lua_bindings::{SharedCore, StateDir};
/// Bump when the envelope shape changes incompatibly. A recovery file
/// with an unrecognized version reads as [`RecoveryStatus::Corrupt`] —
/// never silently applied.
pub const AUTOSAVE_VERSION: u32 = 1;
/// The header of a recovery file: one line of JSON, then `\n`, then the
/// raw buffer bytes (Q#AS4). One atomic write, so a crash can never leave
/// a torn header/contents pair.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
struct Header {
version: u32,
/// The buffer's path, for provenance and orphan inspection.
path: String,
/// The origin file's identity when this copy was taken.
///
/// **Nullable**: a `[new file]` buffer (a path that does not exist on
/// disk yet) has no `file_meta`, and its unsaved contents are exactly
/// the work most worth recovering. `None` means "there was no file on
/// disk when this was autosaved".
origin: Option<Origin>,
}
/// `FileMeta` hand-serialized — it is not serde, and `SystemTime` has no
/// stable wire form. Stored as an offset from the Unix epoch so the
/// comparison is exact; we never reconstruct a `SystemTime`, only compare
/// these parts.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
struct Origin {
mtime_secs: i64,
mtime_nanos: u32,
size: u64,
}
impl Origin {
fn from_meta(m: &FileMeta) -> Self {
let (mtime_secs, mtime_nanos) = match m.mtime.duration_since(std::time::UNIX_EPOCH) {
Ok(d) => (
i64::try_from(d.as_secs()).unwrap_or(i64::MAX),
d.subsec_nanos(),
),
// Pre-epoch mtimes are exotic but representable.
Err(e) => {
let d = e.duration();
(
i64::try_from(d.as_secs()).map_or(i64::MIN, |s| -s),
d.subsec_nanos(),
)
}
};
Self {
mtime_secs,
mtime_nanos,
size: m.size,
}
}
}
/// What a recovery file means for a given path (Q#AS5).
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum RecoveryStatus {
/// No recovery file.
None,
/// The on-disk file is unchanged since the copy was taken (or is
/// still absent, for a `[new file]`), so the recovery is strictly
/// newer. The only status that is announced.
Fresh,
/// The file changed underneath us — externally edited, deleted, or
/// (for a `[new file]`) created by someone else. Never auto-offered:
/// silently clobbering it is the one unrecoverable mistake here.
Stale,
/// Unparseable or unrecognized version. Never offered, never errors;
/// `discard-recovery` removes it.
Corrupt,
}
impl RecoveryStatus {
/// The lowercase name Lua sees.
#[must_use]
pub fn as_str(self) -> &'static str {
match self {
RecoveryStatus::None => "none",
RecoveryStatus::Fresh => "fresh",
RecoveryStatus::Stale => "stale",
RecoveryStatus::Corrupt => "corrupt",
}
}
}
/// The `pmacs.state` key a path's recovery file lives under.
#[must_use]
pub fn key_for(path: &Path) -> String {
format!("autosave/{}", sha256_hex(&path.display().to_string()))
}
/// Skip cache: `BufferId → (path_hash, revision)` (Q#AS8).
///
/// Keyed on the **path hash as well as the revision**, not the revision
/// alone: a buffer keeps its `BufferId` across a path change (an LSP
/// `WorkspaceEdit` rename calls `set_buffer_path`), so a revision-only
/// cache would skip the write, never create the recovery file under the
/// new key, and orphan the old one.
#[derive(Default)]
pub struct AutosaveCache(RefCell<HashMap<BufferId, (String, u64)>>);
/// Encode a header + contents into the one-file envelope.
fn encode(header: &Header, contents: &[u8]) -> Result<Vec<u8>, String> {
// serde_json's compact form never contains a raw newline, so the
// first `\n` unambiguously ends the header.
let mut out = serde_json::to_vec(header).map_err(|e| e.to_string())?;
debug_assert!(!out.contains(&b'\n'));
out.push(b'\n');
out.extend_from_slice(contents);
Ok(out)
}
/// Split an envelope at its **first** newline. Contents may contain
/// newlines and arbitrary non-UTF-8 bytes, so only the first one counts.
/// Returns `None` for anything malformed — the caller maps that to
/// [`RecoveryStatus::Corrupt`].
fn decode(bytes: &[u8]) -> Option<(Header, &[u8])> {
let nl = bytes.iter().position(|&b| b == b'\n')?;
let header: Header = serde_json::from_slice(&bytes[..nl]).ok()?;
if header.version != AUTOSAVE_VERSION {
return None;
}
Some((header, &bytes[nl + 1..]))
}
/// The configured state dir, if any (absent under tests / no HOME).
fn base_dir(lua: &Lua) -> Option<std::path::PathBuf> {
lua.app_data_ref::<StateDir>().map(|d| d.0.clone())
}
/// Classify the recovery file for `path` (Q#AS5's table).
#[must_use]
pub fn status(base: &Path, path: &Path) -> RecoveryStatus {
let key = key_for(path);
let Ok(Some(bytes)) = crate::state::read_bytes(base, &key) else {
return RecoveryStatus::None;
};
let Some((header, _)) = decode(&bytes) else {
return RecoveryStatus::Corrupt;
};
let on_disk = crate::file_io::current_meta(path).ok();
match (header.origin, on_disk) {
// Had an origin, file still there: fresh iff identity matches.
(Some(o), Some(cur)) if o == Origin::from_meta(&cur) => RecoveryStatus::Fresh,
// `[new file]`: fresh while it is still absent.
(None, None) => RecoveryStatus::Fresh,
// Everything else changed underneath us: the file was edited
// externally, deleted, or (for a `[new file]`) created by someone
// else. Never auto-offered.
_ => RecoveryStatus::Stale,
}
}
/// The recovered contents for `path`, if a parseable recovery exists.
/// Returns bytes for `Stale` too — the command warns and confirms.
#[must_use]
pub fn recover_bytes(base: &Path, path: &Path) -> Option<Vec<u8>> {
let bytes = crate::state::read_bytes(base, &key_for(path))
.ok()
.flatten()?;
let (_, contents) = decode(&bytes)?;
Some(contents.to_vec())
}
/// Delete the recovery file for `path` (idempotent).
pub fn discard(base: &Path, path: &Path) -> bool {
crate::state::remove(base, &key_for(path)).is_ok()
}
/// A buffer that needs a recovery copy written, gathered under the core
/// borrow so all IO happens after it is released.
struct Pending {
id: BufferId,
path: String,
path_hash: String,
revision: u64,
origin: Option<Origin>,
contents: Vec<u8>,
}
/// One autosave pass: write a recovery copy of every modified file
/// buffer whose contents changed since its last copy. Returns how many
/// were written.
///
/// Runs on the main thread; the two skips in Q#AS8 keep that bounded.
/// Unlike desktop-save this is **not** daemon-gated — autosave is
/// per-buffer, not per-frontend, and a daemon holds the unsaved work.
///
/// # Errors
/// A state-write failure. Individual buffers never abort the pass.
pub fn sweep(lua: &Lua) -> Result<usize, String> {
let Some(base) = base_dir(lua) else {
return Ok(0);
};
let core = lua
.app_data_ref::<SharedCore>()
.ok_or("no editor core")?
.clone();
// Gather under a borrow; do all IO after releasing it.
let mut writes: Vec<Pending> = Vec::new();
let mut orphans: Vec<String> = Vec::new();
let mut live: Vec<BufferId> = Vec::new();
{
let cache = lua
.app_data_ref::<AutosaveCache>()
.ok_or("no autosave cache")?;
let cache = cache.0.borrow();
let c = core.borrow();
let reg = c.registry.borrow();
for &id in reg.ids() {
let Ok(buf) = reg.get(id) else { continue };
live.push(id);
// Skips scratch / *special* (no path). Includes `[new file]`
// buffers: path set, `file_meta` absent.
let Some(path) = buf.file_path() else {
continue;
};
if !buf.is_modified() {
continue;
}
let path_s = path.display().to_string();
let path_hash = sha256_hex(&path_s);
let revision = buf.revision();
if let Some((prev_hash, prev_rev)) = cache.get(&id) {
if prev_hash == &path_hash && *prev_rev == revision {
continue; // unchanged since its last copy
}
if prev_hash != &path_hash {
// The path moved: the old key is now an orphan.
orphans.push(prev_hash.clone());
}
}
let len = buf.len();
let mut contents = vec![0u8; usize::try_from(len).unwrap_or(0)];
if len > 0 {
buf.snapshot_rope().slice(0, len, &mut contents);
}
writes.push(Pending {
id,
path: path_s,
path_hash,
revision,
origin: buf.file_meta().map(Origin::from_meta),
contents,
});
}
}
for old in orphans {
let _ = crate::state::remove(&base, &format!("autosave/{old}"));
}
let mut written = 0usize;
{
let cache = lua
.app_data_ref::<AutosaveCache>()
.ok_or("no autosave cache")?;
let mut cache = cache.0.borrow_mut();
// Drop entries for buffers that no longer exist.
cache.retain(|id, _| live.contains(id));
for p in writes {
let header = Header {
version: AUTOSAVE_VERSION,
path: p.path,
origin: p.origin,
};
let bytes = encode(&header, &p.contents)?;
crate::state::write_private(&base, &format!("autosave/{}", p.path_hash), &bytes)
.map_err(|e| e.to_string())?;
cache.insert(p.id, (p.path_hash, p.revision));
written += 1;
}
}
Ok(written)
}
/// Every open file buffer that has a recovery file, with its status
/// (Q#AS6). Enumerating in Rust is what makes this cover argv
/// `[new file]` buffers, which fire no hook at all — the Lua reporter
/// never has to know they exist.
///
/// Returns `(fresh_paths, corrupt_count)`.
#[must_use]
pub fn pending(lua: &Lua) -> (Vec<String>, usize) {
let mut fresh = Vec::new();
let mut corrupt = 0usize;
let (Some(base), Some(core)) = (base_dir(lua), lua.app_data_ref::<SharedCore>()) else {
return (fresh, corrupt);
};
// Collect paths first so the guard drops before any IO re-entrancy.
let paths: Vec<std::path::PathBuf> = {
let c = core.borrow();
let reg = c.registry.borrow();
reg.ids()
.iter()
.filter_map(|&id| reg.get(id).ok()?.file_path().map(Path::to_path_buf))
.collect()
};
for p in paths {
match status(&base, &p) {
RecoveryStatus::Fresh => fresh.push(p.display().to_string()),
RecoveryStatus::Corrupt => corrupt += 1,
RecoveryStatus::None | RecoveryStatus::Stale => {}
}
}
(fresh, corrupt)
}
#[cfg(test)]
mod tests {
use super::*;
fn header(origin: Option<Origin>) -> Header {
Header {
version: AUTOSAVE_VERSION,
path: "/tmp/a.rs".into(),
origin,
}
}
#[test]
fn envelope_round_trips_arbitrary_bytes() {
// Contents with newlines AND invalid UTF-8 — the reason we split
// at the first newline and read bytes, not a String.
let contents = [0xffu8, b'\n', b'a', 0x00, b'\n'];
let h = header(Some(Origin {
mtime_secs: 5,
mtime_nanos: 7,
size: 5,
}));
let bytes = encode(&h, &contents).unwrap();
let (got_h, got_c) = decode(&bytes).unwrap();
assert_eq!(got_h, h);
assert_eq!(got_c, &contents[..]);
}
#[test]
fn envelope_round_trips_null_origin() {
// A `[new file]` buffer: no origin meta.
let h = header(None);
let bytes = encode(&h, b"draft").unwrap();
let (got_h, got_c) = decode(&bytes).unwrap();
assert!(got_h.origin.is_none());
assert_eq!(got_c, b"draft");
}
#[test]
fn decode_rejects_malformed_and_wrong_version() {
assert!(decode(b"no newline at all").is_none());
assert!(decode(b"{not json}\nbody").is_none());
assert!(decode(b"\nbody").is_none(), "empty header");
let bad_version = br#"{"version":999,"path":"/x","origin":null}"#;
let mut bytes = bad_version.to_vec();
bytes.push(b'\n');
assert!(decode(&bytes).is_none(), "unrecognized version → corrupt");
}
#[test]
fn key_is_a_valid_state_key() {
let k = key_for(Path::new("/home/u/a b.rs"));
assert!(k.starts_with("autosave/"));
assert!(crate::state::validate_name(&k).is_ok());
}
#[test]
fn status_none_when_no_recovery_file() {
let dir = std::env::temp_dir().join(format!("pmacs-as-none-{}", std::process::id()));
std::fs::create_dir_all(&dir).unwrap();
assert_eq!(
status(&dir, Path::new("/tmp/nonexistent.rs")),
RecoveryStatus::None
);
std::fs::remove_dir_all(&dir).ok();
}
#[test]
fn status_corrupt_for_garbage_envelope() {
let dir = std::env::temp_dir().join(format!("pmacs-as-corrupt-{}", std::process::id()));
std::fs::create_dir_all(&dir).unwrap();
let target = Path::new("/tmp/whatever.rs");
crate::state::write_private(&dir, &key_for(target), b"garbage, no newline").unwrap();
assert_eq!(status(&dir, target), RecoveryStatus::Corrupt);
// And it is discardable.
assert!(discard(&dir, target));
assert_eq!(status(&dir, target), RecoveryStatus::None);
std::fs::remove_dir_all(&dir).ok();
}
#[test]
fn new_file_status_is_fresh_until_the_file_appears() {
let dir = std::env::temp_dir().join(format!("pmacs-as-newfile-{}", std::process::id()));
std::fs::create_dir_all(&dir).unwrap();
let target = dir.join("draft.rs");
// origin: null — a `[new file]` buffer.
let bytes = encode(
&Header {
version: AUTOSAVE_VERSION,
path: target.display().to_string(),
origin: None,
},
b"unsaved draft",
)
.unwrap();
crate::state::write_private(&dir, &key_for(&target), &bytes).unwrap();
assert_eq!(status(&dir, &target), RecoveryStatus::Fresh, "file absent");
assert_eq!(
recover_bytes(&dir, &target).as_deref(),
Some(&b"unsaved draft"[..])
);
// Someone created the file meanwhile → stale, never auto-offered.
std::fs::write(&target, b"someone else's content").unwrap();
assert_eq!(status(&dir, &target), RecoveryStatus::Stale);
std::fs::remove_dir_all(&dir).ok();
}
#[test]
fn existing_file_fresh_until_it_changes_on_disk() {
let dir = std::env::temp_dir().join(format!("pmacs-as-exist-{}", std::process::id()));
std::fs::create_dir_all(&dir).unwrap();
let target = dir.join("a.rs");
std::fs::write(&target, b"on disk").unwrap();
let meta = crate::file_io::current_meta(&target).unwrap();
let bytes = encode(
&Header {
version: AUTOSAVE_VERSION,
path: target.display().to_string(),
origin: Some(Origin::from_meta(&meta)),
},
b"unsaved edits",
)
.unwrap();
crate::state::write_private(&dir, &key_for(&target), &bytes).unwrap();
assert_eq!(status(&dir, &target), RecoveryStatus::Fresh);
// Touch the file (different size ⇒ different identity).
std::fs::write(&target, b"changed underneath us").unwrap();
assert_eq!(status(&dir, &target), RecoveryStatus::Stale);
// Delete it entirely → still stale (the base is gone).
std::fs::remove_file(&target).unwrap();
assert_eq!(status(&dir, &target), RecoveryStatus::Stale);
std::fs::remove_dir_all(&dir).ok();
}
}

View File

@ -20,10 +20,10 @@ use std::path::Path;
use mlua::Lua;
use serde::{Deserialize, Serialize};
use sha2::{Digest, Sha256};
use crate::buffer::BufferId;
use crate::editor_core::EditorCore;
use crate::hash::sha256_hex;
use crate::lua_bindings::{LocalInstanceInfo, SharedCore, StateDir, fire_after_load_hook};
use crate::protocol::FrontendId;
use crate::text_view::TextView;
@ -141,18 +141,6 @@ pub fn desktop_state_key(session_key: &str) -> String {
format!("desktop/{session_key}")
}
fn sha256_hex(s: &str) -> String {
let mut h = Sha256::new();
h.update(s.as_bytes());
let digest = h.finalize();
let mut out = String::with_capacity(digest.len() * 2);
for b in digest {
use std::fmt::Write as _;
let _ = write!(out, "{b:02x}");
}
out
}
/// Build the serializable layout tree from a core [`LayoutNode`],
/// resolving each leaf window to a [`SavedLeaf`] (returning `None` for a
/// non-file leaf, which is dropped and its split collapsed).

View File

@ -321,6 +321,12 @@ impl EditorState {
include_str!("../builtin/runtime/desktop.lua"),
)
.expect("load desktop builtin chunk");
lua_host
.eval(
Some("@pmacs/builtin/runtime/autosave.lua"),
include_str!("../builtin/runtime/autosave.lua"),
)
.expect("load autosave builtin chunk");
// T M7.11 bundled-package bootstrap. Through M7.10 the REPL
// was loaded directly via `eval(include_str!(...))`; the
// M7.11 deliverable migrates it to the package system so it

View File

@ -130,7 +130,32 @@ impl Drop for TempCleanup {
/// identity for future change-detection comparisons.
///
/// Threading: any thread.
///
/// # Errors
/// See [`SaveError`].
pub fn save_atomic(path: &Path, content: &[u8]) -> Result<FileMeta, SaveError> {
save_atomic_with_mode(path, content, None)
}
/// [`save_atomic`], but forcing the target's Unix mode to `mode` instead
/// of inheriting the existing file's mode (or the umask default for a new
/// file).
///
/// The mode is applied to the **temp file before the rename**, so the
/// target never exists — not even momentarily — at a laxer mode. A
/// `chmod` after the write would leave exactly that window, which matters
/// because autosave (Arc 3 Q#AS11) stores *unsaved file contents*: a
/// recovery copy must never be briefly world-readable.
///
/// `mode` is ignored on non-Unix platforms (the write is still atomic).
///
/// # Errors
/// See [`SaveError`].
pub fn save_atomic_with_mode(
path: &Path,
content: &[u8],
mode: Option<u32>,
) -> Result<FileMeta, SaveError> {
// `Path::parent` returns:
// * `None` for `/` or `""` --- no place to put a sibling temp file;
// * `Some("")` for a bare filename like `notes.txt` --- means cwd, fine;
@ -140,10 +165,22 @@ pub fn save_atomic(path: &Path, content: &[u8]) -> Result<FileMeta, SaveError> {
return Err(SaveError::NoParent(path.to_path_buf()));
}
// Snapshot the target's current permissions so an existing file keeps
// its mode across the replace (F-006) — e.g. a `0755` script stays
// executable. `None` for a new file, which then gets the default mode.
let existing_perms = fs::metadata(path).ok().map(|m| m.permissions());
// An explicit `mode` wins; otherwise snapshot the target's current
// permissions so an existing file keeps its mode across the replace
// (F-006) — e.g. a `0755` script stays executable. `None` for a new
// file, which then gets the default mode.
#[cfg(unix)]
let existing_perms = mode
.map(|m| {
use std::os::unix::fs::PermissionsExt as _;
fs::Permissions::from_mode(m)
})
.or_else(|| fs::metadata(path).ok().map(|m| m.permissions()));
#[cfg(not(unix))]
let existing_perms = {
let _ = mode; // no mode concept; the write is still atomic
fs::metadata(path).ok().map(|m| m.permissions())
};
// Open a fresh temp, retrying on the rare name collision (a stale temp
// left by a crashed prior run whose pid+nanos recurs) instead of

58
src/hash.rs Normal file
View File

@ -0,0 +1,58 @@
// hash.rs --- shared content hashing (Arc 3 phase 3, Q#AS9).
//! One `sha256_hex` for the whole crate. Three call sites want a stable,
//! filename-safe digest of a string:
//!
//! * [`crate::desktop`] — the desktop session key,
//! * [`crate::autosave`] — the recovery-file key (a hash of the path),
//! * `crate::packages::fetcher` — the package cache/mirror key.
//!
//! Each had grown (or was about to grow) its own private copy. A
//! *cryptographic* digest matters for the fetcher: a non-cryptographic
//! hash is trivially collidable, and a deliberate collision would make
//! two URLs share one bare mirror + lock file.
//!
//! Lowercase hex, so the output passes
//! [`crate::state::validate_name`]'s `[A-Za-z0-9._-]` charset.
use sha2::{Digest, Sha256};
/// Lowercase-hex SHA-256 of `s`.
pub(crate) fn sha256_hex(s: &str) -> String {
use std::fmt::Write as _;
let mut hasher = Sha256::new();
hasher.update(s.as_bytes());
let digest = hasher.finalize();
let mut out = String::with_capacity(digest.len() * 2);
for b in digest {
let _ = write!(out, "{b:02x}");
}
out
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn known_vector_and_charset() {
// The canonical empty-string SHA-256.
assert_eq!(
sha256_hex(""),
"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
);
let h = sha256_hex("/home/u/a.rs");
assert_eq!(h.len(), 64);
assert!(
h.bytes()
.all(|b| b.is_ascii_lowercase() || b.is_ascii_digit())
);
// Filename-safe: passes the state-key charset.
assert!(crate::state::validate_name(&format!("autosave/{h}")).is_ok());
}
#[test]
fn distinct_inputs_distinct_digests() {
assert_ne!(sha256_hex("a"), sha256_hex("b"));
}
}

View File

@ -45,6 +45,7 @@ pub mod attach;
pub mod attach_dispatch;
pub mod attach_reconnect;
pub mod audit;
pub mod autosave;
pub mod buffer;
pub mod buffer_registry;
pub mod builtin_packages;
@ -75,6 +76,7 @@ pub mod file_io;
pub mod formatting;
pub mod frontend;
pub mod fs;
mod hash;
pub mod help;
pub mod highlight;
pub mod hook;

View File

@ -1963,10 +1963,75 @@ pub fn install(
pmacs.set("packages", install_packages_module(lua)?)?;
pmacs.set("state", install_state_module(lua)?)?;
pmacs.set("session", install_session_module(lua)?)?;
pmacs.set("autosave", install_autosave_module(lua)?)?;
lua.globals().set("pmacs", pmacs)?;
Ok(())
}
/// `pmacs.autosave.*` — the Rust half of autosave + crash recovery
/// (Arc 3 phase 3). Lua cannot enumerate non-active buffers' paths, and
/// `FileMeta` is neither Lua-visible nor serde, so the sweep and the
/// external-change guard live in Rust (Q#AS1). `autosave.lua` layers the
/// cadence, the configurable interval, and the recovery UX on top.
///
/// The `_`-prefixed names are the raw primitives; `autosave.lua` adds the
/// public `enable` / `interval_ms` / `sweep` onto the same table.
fn install_autosave_module(lua: &Lua) -> mlua::Result<Table> {
// The skip cache lives for the life of the VM.
lua.set_app_data(crate::autosave::AutosaveCache::default());
let m = lua.create_table()?;
m.set(
"_sweep",
lua.create_function(|lua, ()| crate::autosave::sweep(lua).map_err(mlua::Error::external))?,
)?;
m.set(
"_status",
lua.create_function(|lua, path: String| {
let Some(base) = lua.app_data_ref::<StateDir>().map(|d| d.0.clone()) else {
return Ok("none");
};
Ok(crate::autosave::status(&base, std::path::Path::new(&path)).as_str())
})?,
)?;
m.set(
"_recover_bytes",
lua.create_function(|lua, path: String| {
let Some(base) = lua.app_data_ref::<StateDir>().map(|d| d.0.clone()) else {
return Ok(None);
};
match crate::autosave::recover_bytes(&base, std::path::Path::new(&path)) {
Some(bytes) => Ok(Some(lua.create_string(&bytes)?)),
None => Ok(None),
}
})?,
)?;
m.set(
"_discard",
lua.create_function(|lua, path: String| {
let Some(base) = lua.app_data_ref::<StateDir>().map(|d| d.0.clone()) else {
return Ok(false);
};
Ok(crate::autosave::discard(&base, std::path::Path::new(&path)))
})?,
)?;
// _pending() -> (fresh_paths, corrupt_count). Enumerates in Rust so
// argv `[new file]` buffers — which fire no hook — are covered too.
m.set(
"_pending",
lua.create_function(|lua, ()| {
let (fresh, corrupt) = crate::autosave::pending(lua);
Ok((fresh, corrupt))
})?,
)?;
Ok(m)
}
/// Marker app-data set by `pmacs.session.arm_restore()` (Arc 3 phase 2,
/// Q#DS7). Its presence tells the `RunLocal` startup trigger to attempt
/// a desktop restore; `desktop_mode(true)` in init.lua arms it.

View File

@ -62,7 +62,6 @@ use std::process::{Child, Command, ExitStatus, Stdio};
use std::thread;
use std::time::{Duration, Instant};
use sha2::{Digest, Sha256};
use thiserror::Error;
// ---------------------------------------------------------------------------
@ -512,19 +511,11 @@ fn dot_git_strip_applies(u: &str) -> bool {
/// The cache dir is keyed by a hash of the (attacker-adjacent) repo URL,
/// so a *cryptographic* digest is used: a non-cryptographic hash like the
/// former 64-bit FNV-1a is trivially collidable, and a deliberate
/// collision would make two URLs share one bare mirror + lock file. `sha2`
/// is already a dependency (M7.6 lockfile content hashing).
fn sha256_hex(s: &str) -> String {
use std::fmt::Write as _;
let mut hasher = Sha256::new();
hasher.update(s.as_bytes());
let digest = hasher.finalize();
let mut out = String::with_capacity(digest.len() * 2);
for b in digest {
let _ = write!(out, "{b:02x}");
}
out
}
/// collision would make two URLs share one bare mirror + lock file.
///
/// The implementation now lives in [`crate::hash`] — shared with the
/// desktop session key and the autosave recovery key (Q#AS9).
use crate::hash::sha256_hex;
// ---------------------------------------------------------------------------
// LockGuard --- per-cache-entry flock(2)

View File

@ -182,14 +182,76 @@ pub fn read(base: &Path, name: &str) -> Result<Option<String>, StateError> {
/// # Errors
/// Invalid key, or a save failure.
pub fn write(base: &Path, name: &str, content: &[u8]) -> Result<(), StateError> {
write_inner(base, name, content, None)
}
/// Like [`write`], but the parent directory is created `0700` and the
/// file written `0600` (Arc 3 Q#AS11).
///
/// Autosave stores **unsaved file contents**, a different class of secret
/// from saveplace's cursor offsets or recentf's path list. The default
/// path would give a new recovery file the umask default (typically
/// `0644`) and its directory `0755` — leaving a recovery copy of an
/// unsaved edit to a `0600` file *more exposed than the original*. The
/// mode is applied to the temp before the rename, so there is no window
/// at a laxer mode.
///
/// Permissions are Unix-only; elsewhere this is [`write`].
///
/// # Errors
/// Invalid key, or a save failure.
pub fn write_private(base: &Path, name: &str, content: &[u8]) -> Result<(), StateError> {
write_inner(base, name, content, Some(0o600))
}
fn write_inner(
base: &Path,
name: &str,
content: &[u8],
mode: Option<u32>,
) -> Result<(), StateError> {
let path = resolve(base, name).map_err(StateError::Name)?;
if let Some(parent) = path.parent() {
std::fs::create_dir_all(parent).map_err(StateError::Io)?;
create_dir_all_with_mode(parent, mode.map(|_| 0o700)).map_err(StateError::Io)?;
}
crate::file_io::save_atomic(&path, content).map_err(StateError::Save)?;
crate::file_io::save_atomic_with_mode(&path, content, mode).map_err(StateError::Save)?;
Ok(())
}
/// `create_dir_all`, optionally forcing the mode of directories this call
/// creates. An already-existing directory keeps its mode (we do not
/// re-mode a directory the user already has).
fn create_dir_all_with_mode(dir: &Path, mode: Option<u32>) -> std::io::Result<()> {
#[cfg(unix)]
if let Some(m) = mode {
use std::os::unix::fs::DirBuilderExt as _;
return std::fs::DirBuilder::new()
.recursive(true)
.mode(m)
.create(dir);
}
#[cfg(not(unix))]
let _ = mode;
std::fs::create_dir_all(dir)
}
/// Read a state file's raw bytes, or `Ok(None)` when it does not exist.
///
/// [`read`] returns a `String` (`read_to_string`), which fails on
/// non-UTF-8 content. pmacs buffers hold arbitrary bytes, so an autosave
/// recovery file cannot be read that way (Arc 3 Q#AS4).
///
/// # Errors
/// Invalid key, or an IO error other than not-found.
pub fn read_bytes(base: &Path, name: &str) -> Result<Option<Vec<u8>>, StateError> {
let path = resolve(base, name).map_err(StateError::Name)?;
match std::fs::read(&path) {
Ok(b) => Ok(Some(b)),
Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(None),
Err(e) => Err(StateError::Io(e)),
}
}
/// Remove a state file. Missing file is success (idempotent).
///
/// # Errors
@ -343,6 +405,55 @@ mod tests {
std::fs::remove_dir_all(&dir).ok();
}
#[test]
fn read_bytes_round_trips_non_utf8() {
let dir = std::env::temp_dir().join(format!("pmacs-bytes-{}", std::process::id()));
std::fs::create_dir_all(&dir).unwrap();
// Invalid UTF-8 — what `read` (read_to_string) would choke on.
let raw = [0xffu8, 0xfe, b'\n', 0x00, b'a'];
write(&dir, "blob", &raw).unwrap();
assert_eq!(read_bytes(&dir, "blob").unwrap().as_deref(), Some(&raw[..]));
assert!(read(&dir, "blob").is_err(), "read_to_string rejects it");
assert!(read_bytes(&dir, "absent").unwrap().is_none());
std::fs::remove_dir_all(&dir).ok();
}
#[cfg(unix)]
#[test]
fn write_private_uses_0700_dir_and_0600_file() {
use std::os::unix::fs::PermissionsExt as _;
let dir = std::env::temp_dir().join(format!("pmacs-priv-{}", std::process::id()));
std::fs::remove_dir_all(&dir).ok();
std::fs::create_dir_all(&dir).unwrap();
write_private(&dir, "autosave/secret", b"unsaved contents").unwrap();
let file = dir.join("autosave").join("secret");
let fmode = std::fs::metadata(&file).unwrap().permissions().mode() & 0o777;
assert_eq!(fmode, 0o600, "recovery file is 0600, not umask default");
let dmode = std::fs::metadata(dir.join("autosave"))
.unwrap()
.permissions()
.mode()
& 0o777;
assert_eq!(dmode, 0o700, "autosave dir is 0700");
// Rewriting keeps the private mode (save_atomic inherits it).
write_private(&dir, "autosave/secret", b"more").unwrap();
let fmode = std::fs::metadata(&file).unwrap().permissions().mode() & 0o777;
assert_eq!(fmode, 0o600);
// The plain `write` path is unchanged (umask default, not 0600).
write(&dir, "plain", b"x").unwrap();
let pmode = std::fs::metadata(dir.join("plain"))
.unwrap()
.permissions()
.mode()
& 0o777;
assert_ne!(pmode, 0o600, "plain write keeps existing behavior");
std::fs::remove_dir_all(&dir).ok();
}
#[test]
fn blank_xdg_falls_through_to_home_not_a_relative_path() {
// The Q#PS2 fix: an empty / whitespace XDG_STATE_HOME must NOT

View File

@ -0,0 +1,456 @@
//! Autosave + crash-recovery acceptance (Arc 3 phase 3).
//!
//! Each test injects a private tempdir `StateDir` (integration tests link
//! the lib without `cfg(test)`), so nothing touches a developer's real
//! state dir. Sweeps are driven directly rather than through the timer,
//! so the 1-second interval floor never slows the suite.
//!
//! Framing: `docs/autosave-recovery-framing.md`.
use pmacs::editor::EditorState;
use pmacs::lua_bindings::StateDir;
use std::path::PathBuf;
use std::sync::atomic::{AtomicUsize, Ordering};
fn fresh_state_dir() -> PathBuf {
static SEQ: AtomicUsize = AtomicUsize::new(0);
let dir = std::env::temp_dir().join(format!(
"pmacs-autosave-{}-{}",
std::process::id(),
SEQ.fetch_add(1, Ordering::Relaxed)
));
std::fs::create_dir_all(&dir).unwrap();
dir
}
fn editor(state_dir: &std::path::Path) -> EditorState {
let s = EditorState::new();
s.lua_host.lua().remove_app_data::<StateDir>();
s.lua_host
.lua()
.set_app_data(StateDir(state_dir.to_path_buf()));
s
}
fn write_file(dir: &std::path::Path, name: &str, body: &str) -> String {
let p = dir.join(name);
std::fs::write(&p, body).unwrap();
p.display().to_string()
}
fn exec(s: &EditorState, src: &str) {
s.lua_host.lua().load(src.to_string()).exec().unwrap();
}
fn eval<T: mlua::FromLuaMulti>(s: &EditorState, src: &str) -> T {
s.lua_host.lua().load(src.to_string()).eval().unwrap()
}
/// Force a sweep; returns how many buffers were written.
fn sweep(s: &EditorState) -> i64 {
eval(s, "return pmacs.autosave.sweep()")
}
fn status(s: &EditorState, path: &str) -> String {
eval(s, &format!("return pmacs.autosave._status({path:?})"))
}
/// Open a file and dirty it by `n` inserted bytes at the front.
fn open_and_dirty(s: &EditorState, path: &str, text: &str) {
exec(
s,
&format!("pmacs.buffer.find_or_open({path:?}); pmacs.window.buffer():insert(0, {text:?})"),
);
}
#[test]
fn sweep_writes_recovery_for_a_modified_file_buffer() {
let dir = fresh_state_dir();
let s = editor(&dir);
let f = write_file(&dir, "a.txt", "on disk\n");
open_and_dirty(&s, &f, "unsaved ");
assert_eq!(sweep(&s), 1, "one modified file buffer written");
assert_eq!(status(&s, &f), "fresh");
// The recovery contents are the buffer's, not the file's.
let bytes: mlua::String = eval(&s, &format!("return pmacs.autosave._recover_bytes({f:?})"));
assert_eq!(&*bytes.as_bytes(), b"unsaved on disk\n");
std::fs::remove_dir_all(&dir).ok();
}
#[test]
fn envelope_round_trips_non_utf8_contents() {
let dir = fresh_state_dir();
let s = editor(&dir);
let f = write_file(&dir, "bin.dat", "");
// 0xff is invalid UTF-8; the envelope reads bytes, not a String.
exec(
&s,
&format!(
"pmacs.buffer.find_or_open({f:?}); pmacs.window.buffer():insert(0, '\\255\\n\\0a')"
),
);
assert_eq!(sweep(&s), 1);
let bytes: mlua::String = eval(&s, &format!("return pmacs.autosave._recover_bytes({f:?})"));
assert_eq!(&*bytes.as_bytes(), &[0xffu8, b'\n', 0x00, b'a'][..]);
std::fs::remove_dir_all(&dir).ok();
}
#[test]
fn sweep_skips_clean_scratch_and_unchanged_buffers() {
let dir = fresh_state_dir();
let s = editor(&dir);
let f = write_file(&dir, "a.txt", "hello\n");
// A clean file buffer + the scratch buffer: nothing to write.
exec(&s, &format!("pmacs.buffer.find_or_open({f:?})"));
assert_eq!(sweep(&s), 0, "clean buffer and scratch are skipped");
// Dirty it → one write. Sweeping again with no further edit → zero
// (the (path_hash, revision) skip cache).
exec(&s, "pmacs.window.buffer():insert(0, 'x')");
assert_eq!(sweep(&s), 1);
assert_eq!(sweep(&s), 0, "unchanged since last copy → no rewrite");
// Another edit → written again.
exec(&s, "pmacs.window.buffer():insert(0, 'y')");
assert_eq!(sweep(&s), 1);
std::fs::remove_dir_all(&dir).ok();
}
#[test]
fn path_change_writes_new_key_and_discards_the_old() {
let dir = fresh_state_dir();
let s = editor(&dir);
let old = write_file(&dir, "old.txt", "body\n");
let new = dir.join("new.txt").display().to_string();
open_and_dirty(&s, &old, "dirty ");
assert_eq!(sweep(&s), 1);
assert_eq!(status(&s, &old), "fresh");
// Rename WITHOUT editing the buffer — what an LSP WorkspaceEdit
// rename does: the file moves on disk (preserving mtime/size) and the
// buffer keeps its BufferId *and* its revision, only its path changes.
std::fs::rename(&old, &new).unwrap();
{
let id = s.core.borrow().active_buffer_id();
s.core
.borrow_mut()
.set_buffer_path(id, Some(PathBuf::from(&new)));
}
// A revision-only cache would skip this write, never create the
// recovery under the new key, and orphan the old one.
assert_eq!(sweep(&s), 1, "path change forces a rewrite");
assert_eq!(status(&s, &new), "fresh", "new key written");
assert_eq!(status(&s, &old), "none", "old key discarded");
let bytes: mlua::String = eval(
&s,
&format!("return pmacs.autosave._recover_bytes({new:?})"),
);
assert_eq!(&*bytes.as_bytes(), b"dirty body\n");
std::fs::remove_dir_all(&dir).ok();
}
#[test]
fn new_file_buffer_is_swept_with_null_origin_and_recovers() {
let dir = fresh_state_dir();
let s = editor(&dir);
// A `[new file]`: a path with no file on disk, so no `file_meta`.
// Lua's find_or_open *errors* on a missing path, so this is built the
// way argv `pmacs draft.txt` does — an empty buffer with a path.
let missing = dir.join("draft.txt");
exec(
&s,
"_G.nb = pmacs.buffer.create('draft.txt'); pmacs.window.switch_buffer(_G.nb)",
);
{
let id = s.core.borrow().active_buffer_id();
s.core
.borrow_mut()
.set_buffer_path(id, Some(missing.clone()));
}
// Typing into it is what makes it modified (and worth recovering).
exec(&s, "pmacs.window.buffer():insert(0, 'unsaved draft')");
let p = missing.display().to_string();
assert_eq!(sweep(&s), 1, "a new-file buffer is swept");
// origin is null → fresh while the file is still absent.
assert_eq!(status(&s, &p), "fresh");
let bytes: mlua::String = eval(&s, &format!("return pmacs.autosave._recover_bytes({p:?})"));
assert_eq!(&*bytes.as_bytes(), b"unsaved draft");
// Someone creates the file meanwhile → stale, never auto-offered.
std::fs::write(&missing, b"theirs").unwrap();
assert_eq!(status(&s, &p), "stale");
std::fs::remove_dir_all(&dir).ok();
}
#[test]
fn external_change_makes_recovery_stale() {
let dir = fresh_state_dir();
let s = editor(&dir);
let f = write_file(&dir, "a.txt", "original\n");
open_and_dirty(&s, &f, "mine ");
assert_eq!(sweep(&s), 1);
assert_eq!(status(&s, &f), "fresh");
// Someone else edits the file on disk.
std::fs::write(&f, b"theirs, quite different\n").unwrap();
assert_eq!(status(&s, &f), "stale", "never auto-offered");
std::fs::remove_dir_all(&dir).ok();
}
#[test]
fn corrupt_recovery_is_typed_quiet_and_discardable() {
let dir = fresh_state_dir();
let s = editor(&dir);
let f = write_file(&dir, "a.txt", "body\n");
exec(&s, &format!("pmacs.buffer.find_or_open({f:?})"));
// Plant a malformed envelope under the right key.
let key = pmacs::autosave::key_for(std::path::Path::new(&f));
pmacs::state::write_private(&dir, &key, b"garbage without a newline").unwrap();
assert_eq!(status(&s, &f), "corrupt");
// The aggregate report must not error or announce it.
let (fresh, corrupt): (Vec<String>, i64) = eval(&s, "return pmacs.autosave._pending()");
assert!(fresh.is_empty(), "corrupt is never offered");
assert_eq!(corrupt, 1, "counted separately");
// And it is discardable.
exec(&s, &format!("pmacs.autosave._discard({f:?})"));
assert_eq!(status(&s, &f), "none");
std::fs::remove_dir_all(&dir).ok();
}
#[test]
fn pending_aggregates_and_names_a_single_file() {
let dir = fresh_state_dir();
let s = editor(&dir);
let mut paths = Vec::new();
for i in 0..3 {
let f = write_file(&dir, &format!("f{i}.txt"), "body\n");
open_and_dirty(&s, &f, "x");
paths.push(f);
}
assert_eq!(sweep(&s), 3);
let (fresh, corrupt): (Vec<String>, i64) = eval(&s, "return pmacs.autosave._pending()");
assert_eq!(fresh.len(), 3, "all three reported in ONE call");
assert_eq!(corrupt, 0);
std::fs::remove_dir_all(&dir).ok();
}
#[test]
fn tick_reports_recoveries_once_aggregated() {
let dir = fresh_state_dir();
// Seed three recovery copies, then "crash" and reopen the files.
let s1 = editor(&dir);
let mut paths = Vec::new();
for i in 0..3 {
let f = write_file(&dir, &format!("f{i}.txt"), "body\n");
open_and_dirty(&s1, &f, "x");
paths.push(f);
}
assert_eq!(sweep(&s1), 3);
let s2 = editor(&dir);
for f in &paths {
exec(&s2, &format!("pmacs.buffer.find_or_open({f:?})"));
}
// Each `after-load` only raises a flag; the tick does the reporting,
// so three loads collapse into ONE aggregate message.
exec(&s2, "pmacs.hook.run('process.after-tick')");
let status = s2.core.borrow().status.clone();
assert!(
status.contains("3 files have autosave recovery"),
"one aggregated message, not three: {status:?}"
);
// A second tick does not re-report (the flag was cleared).
s2.core.borrow_mut().status.clear();
exec(&s2, "pmacs.hook.run('process.after-tick')");
assert!(s2.core.borrow().status.is_empty(), "no repeat report");
std::fs::remove_dir_all(&dir).ok();
}
#[test]
fn tick_names_the_file_when_exactly_one_is_recoverable() {
let dir = fresh_state_dir();
let s1 = editor(&dir);
let f = write_file(&dir, "solo.txt", "body\n");
open_and_dirty(&s1, &f, "x");
assert_eq!(sweep(&s1), 1);
let s2 = editor(&dir);
exec(&s2, &format!("pmacs.buffer.find_or_open({f:?})"));
exec(&s2, "pmacs.hook.run('process.after-tick')");
let status = s2.core.borrow().status.clone();
assert!(
status.contains("solo.txt") && status.contains("recover-file"),
"single recovery names the file: {status:?}"
);
std::fs::remove_dir_all(&dir).ok();
}
#[test]
fn save_and_kill_delete_the_recovery_copy() {
let dir = fresh_state_dir();
let s = editor(&dir);
// Clean save deletes it (buffer.after-save).
let f = write_file(&dir, "a.txt", "body\n");
open_and_dirty(&s, &f, "x");
assert_eq!(sweep(&s), 1);
exec(&s, "pmacs.command.invoke('buffer.save')");
assert_eq!(status(&s, &f), "none", "clean save retires the recovery");
// Kill deletes it (per-buffer on_removed registered at after-load).
let g = write_file(&dir, "b.txt", "body\n");
exec(&s, &format!("_G.gb = pmacs.buffer.find_or_open({g:?})"));
exec(&s, "pmacs.window.buffer():insert(0, 'x')");
assert_eq!(sweep(&s), 1);
assert_eq!(status(&s, &g), "fresh");
exec(&s, "pmacs.buffer.kill(_G.gb)");
assert_eq!(status(&s, &g), "none", "kill retires the recovery");
std::fs::remove_dir_all(&dir).ok();
}
#[test]
fn recover_file_installs_contents_fires_after_edit_and_leaves_modified() {
let dir = fresh_state_dir();
let s = editor(&dir);
let f = write_file(&dir, "a.txt", "on disk\n");
open_and_dirty(&s, &f, "recovered ");
assert_eq!(sweep(&s), 1);
// Simulate the crash-then-reopen: a fresh editor over the same store,
// opening the file whose on-disk contents are the OLD ones.
let s2 = editor(&dir);
exec(
&s2,
r#"
_G.after_edit = 0
pmacs.hook.add("buffer.after-edit", function() _G.after_edit = _G.after_edit + 1 end)
"#,
);
exec(&s2, &format!("pmacs.buffer.find_or_open({f:?})"));
assert_eq!(status(&s2, &f), "fresh");
// The buffer still holds the on-disk contents (no silent substitution).
let before: mlua::String = eval(
&s2,
"local b = pmacs.window.buffer(); return b:slice(0, b:len())",
);
assert_eq!(&*before.as_bytes(), b"on disk\n");
// Drive recover-file's accept path directly (the command opens a
// minibuffer; we exercise what its on_accept does).
exec(
&s2,
&format!(
r#"
local bytes = pmacs.autosave._recover_bytes({f:?})
local b = pmacs.window.buffer()
b:replace(0, b:len(), bytes)
pmacs.hook.run("buffer.after-edit")
"#
),
);
let after: mlua::String = eval(
&s2,
"local b = pmacs.window.buffer(); return b:slice(0, b:len())",
);
assert_eq!(&*after.as_bytes(), b"recovered on disk\n");
let fired: i64 = eval(&s2, "return _G.after_edit");
assert!(
fired >= 1,
"after-edit fired so LSP/syntax see the recovery"
);
let modified: bool = eval(&s2, "return pmacs.window.buffer():is_modified()");
assert!(
modified,
"recovered buffer is dirty; user must save to keep"
);
std::fs::remove_dir_all(&dir).ok();
}
#[test]
fn recovery_files_are_private_0600_under_a_0700_dir() {
#[cfg(unix)]
{
use std::os::unix::fs::PermissionsExt as _;
let dir = fresh_state_dir();
let s = editor(&dir);
let f = write_file(&dir, "secret.txt", "");
open_and_dirty(&s, &f, "unsaved secret");
assert_eq!(sweep(&s), 1);
let key = pmacs::autosave::key_for(std::path::Path::new(&f));
let file = dir.join(&key);
let fmode = std::fs::metadata(&file).unwrap().permissions().mode() & 0o777;
assert_eq!(fmode, 0o600, "recovery file holds unsaved contents");
let dmode = std::fs::metadata(dir.join("autosave"))
.unwrap()
.permissions()
.mode()
& 0o777;
assert_eq!(dmode, 0o700);
std::fs::remove_dir_all(&dir).ok();
}
}
#[test]
fn interval_is_a_validated_getter_setter_and_enable_gates_the_sweep() {
let dir = fresh_state_dir();
let s = editor(&dir);
let default_ms: i64 = eval(&s, "return pmacs.autosave.interval_ms()");
assert_eq!(default_ms, 30000, "Emacs's auto-save-timeout");
let set: i64 = eval(&s, "return pmacs.autosave.interval_ms(60000)");
assert_eq!(set, 60000);
let read_back: i64 = eval(&s, "return pmacs.autosave.interval_ms()");
assert_eq!(read_back, 60000, "change takes effect immediately");
// Floats floor; bad values error.
let floored: i64 = eval(&s, "return pmacs.autosave.interval_ms(1500.9)");
assert_eq!(floored, 1500);
for bad in ["'soon'", "0", "999", "-1", "{}"] {
let ok: bool = eval(
&s,
&format!("return (pcall(pmacs.autosave.interval_ms, {bad}))"),
);
assert!(!ok, "interval_ms({bad}) must be rejected");
}
// A rejected set leaves the previous value intact.
let still: i64 = eval(&s, "return pmacs.autosave.interval_ms()");
assert_eq!(still, 1500);
// enable(false) makes sweep a no-op even with a dirty buffer.
let f = write_file(&dir, "a.txt", "body\n");
open_and_dirty(&s, &f, "x");
exec(&s, "pmacs.autosave.enable(false)");
assert_eq!(sweep(&s), 0, "disabled → no sweep");
assert_eq!(status(&s, &f), "none");
exec(&s, "pmacs.autosave.enable(true)");
assert_eq!(sweep(&s), 1, "re-enabled → sweeps");
std::fs::remove_dir_all(&dir).ok();
}
#[test]
fn before_quit_sweeps_synchronously_without_vetoing() {
let dir = fresh_state_dir();
let s = editor(&dir);
let f = write_file(&dir, "a.txt", "body\n");
open_and_dirty(&s, &f, "unsaved ");
// Not swept yet.
assert_eq!(status(&s, &f), "none");
// before-quit is short-circuit: a `true` result means "not vetoed".
let not_vetoed: bool = eval(&s, "return pmacs.hook.run('editor.before-quit')");
assert!(not_vetoed, "autosave must never veto quit");
assert_eq!(
status(&s, &f),
"fresh",
"quitting with unsaved changes leaves a recovery copy"
);
std::fs::remove_dir_all(&dir).ok();
}