Files
dtourolle f12aece07e Make storage pluggable, and prove it with a folder backend
`RemoteBackend` existed from the first release and bought nothing it was
designed for. Seven files in `dr-ui` constructed a `NextcloudBackend`
directly, an account *was* a server URL beside a DAV user id, the local
cache directory was named after a hostname, and the launch screen knew
that signing in meant a browser handshake. The trait was real; the seam
was documentation.

A trait over operations is only a quarter of it. Pluggable storage needs
four things, and this adds the other three:

- **Capabilities** — already there, and the reason the engine can drive
  two backends at the speed each actually runs at.
- **Configuration** — `dr_sync::Account`: where a library lives, in
  whatever form its connector addresses, with no server in it. Loads
  every existing config unchanged (`backend` defaults to `nextcloud`,
  `endpoint` is stored under its historical `server` key), and
  `Account::namespace()` reproduces the old catalog directory byte for
  byte, because changing it would abandon a catalog, its thumbnail
  shards, and the sidecars holding unsynced offline work.
- **Registration** — `BackendProvider` and `BackendRegistry`.
  `ui/dr-ui/src/remote.rs` is now the only file above `dr-sync` that
  names a connector.

`Connection` (an account plus an optional `Secret`) replaces the
credentials-and-user-id pair that was threaded through fifteen
signatures in an order that could be swapped. `Secret`'s inner string is
reachable only through `expose()` and its `Debug` prints `Secret(***)`,
so the indirect leak — a `{:?}` on anything holding one — no longer
compiles into a leak.

Nextcloud is unchanged and keeps every peculiarity: propagating ETags,
chunked upload v2, `oc:fileid`, the `oc:permissions` probe on a refused
PUT, the 423 retry classification, Login Flow v2. Those are what the
capability model exists to serve, not something to hide.

`dr-sync-folder` is the second connector: a local disk, a network mount,
an external drive, or a folder a Nextcloud client already syncs. No
account, no credential — the route that works where no secrets daemon
does. It declares `LocalEtags` rather than claiming propagation a POSIX
directory cannot provide, which costs nothing because 50k `stat` calls
are not 50k PROPFINDs. Identity is a path hash, not an inode: an inode
survives a rename but differs between devices and is reused after a
delete, so two machines would disagree about which photograph a
thumbnail belonged to. Re-deriving a thumbnail is a cost; showing the
wrong one is a bug.

docs/storage.md is the contract — the traits, the four steps to add a
backend, and what each connector declares. ARCH §8.0 and §8.4a, and
FR-NC-13, say why.
2026-08-29 09:57:52 +02:00

177 lines
6.1 KiB
Rust

//! One-shot write probe: PUT a tiny file, report the status, DELETE it.
use dr_plat::PlatformSecretStore;
use dr_sync::{AccountStore, RemoteBackend, RemoteId, RemotePath};
use dr_sync_nextcloud::{NextcloudBackend, NextcloudProvider};
#[tokio::main(flavor = "current_thread")]
async fn main() {
env_logger::Builder::from_env(env_logger::Env::default().default_filter_or("info")).init();
let store = AccountStore::open(Box::new(PlatformSecretStore::new()));
let Some(session) = store.current() else {
println!("no stored session");
return;
};
let creds = match store
.connection(&session, true)
.map_err(|e| e.to_string())
.and_then(|c| NextcloudProvider::credentials(&c).map_err(|e| e.to_string()))
{
Ok(c) => c,
Err(e) => {
println!("credentials: {e}");
return;
}
};
println!("account: {} root={}", session.describe(), session.root);
let backend = NextcloudBackend::new(&creds, &session.user_id).unwrap();
// Read, which we know works.
let dir = RemotePath::new(&session.root);
match backend.list(&dir, None).await {
Ok(v) => println!("READ ok: {} entries", v.len()),
Err(e) => println!("READ FAILED: {e}"),
}
// What is actually in the derived folder on the server?
{
let dir = RemotePath::new(format!("{}/.darkroom-derived", session.root));
match backend.list(&dir, None).await {
Ok(entries) => {
println!("\n[derived] {} entry/entries on the server:", entries.len());
for e in &entries {
println!(" {:<28} {:>10} bytes", e.path.name(), e.size);
}
}
Err(e) => println!("\n[derived] listing failed: {e}"),
}
}
// Probe a file the sweep reported as 423 Locked: is it the file, the
// range request, or the folder?
{
let c = dr_sync_nextcloud::http_client("DarkRoom").unwrap();
let base = format!(
"{}/remote.php/dav/files/{}",
creds.server.trim_end_matches('/'),
session.user_id
);
let f = "PhotosRaw/Darktable/20230629_no_name/20230629_0030.jpeg";
let enc: String = f
.split('/')
.map(|seg| {
seg.bytes()
.map(|b| match b {
b'A'..=b'Z' | b'a'..=b'z' | b'0'..=b'9' | b'-' | b'_' | b'.' | b'~' => {
(b as char).to_string()
}
_ => format!("%{b:02X}"),
})
.collect::<String>()
})
.collect::<Vec<_>>()
.join("/");
let url = format!("{base}/{enc}");
for (what, range) in [
("ranged 0-256k", Some("bytes=0-262143")),
("whole file", None),
] {
let mut rq = c
.get(&url)
.basic_auth(&creds.login_name, Some(&creds.app_password));
if let Some(r) = range {
rq = rq.header("Range", r);
}
match rq.send().await {
Ok(r) => println!("GET {what}: {}", r.status()),
Err(e) => println!("GET {what}: transport {e}"),
}
}
}
// Raw HTTP, to see the status the connector maps away.
{
let url = format!(
"{}/remote.php/dav/files/{}/{}/.darkroom-write-test",
creds.server.trim_end_matches('/'),
session.user_id,
session.root
);
let c = dr_sync_nextcloud::http_client("DarkRoom").unwrap();
match c
.put(&url)
.basic_auth(&creds.login_name, Some(&creds.app_password))
.body("probe")
.send()
.await
{
Ok(r) => {
println!("RAW PUT status: {}", r.status());
let body = r.text().await.unwrap_or_default();
let body = body.trim();
if !body.is_empty() {
println!("RAW body: {}", &body[..body.len().min(400)]);
}
}
Err(e) => println!("RAW PUT transport error: {e}"),
}
}
// Is it the folder or the account? Probe the account root too: a
// read-only *share* refuses writes inside it while the account writes
// freely elsewhere, which is a different fix from a credential problem.
{
let c = dr_sync_nextcloud::http_client("DarkRoom").unwrap();
let base = format!(
"{}/remote.php/dav/files/{}",
creds.server.trim_end_matches('/'),
session.user_id
);
for (what, url) in [
("account root", format!("{base}/.darkroom-write-test")),
(
"library root",
format!("{base}/{}/.darkroom-write-test", session.root),
),
] {
match c
.put(&url)
.basic_auth(&creds.login_name, Some(&creds.app_password))
.body("probe")
.send()
.await
{
Ok(r) => {
println!("PUT {what}: {}", r.status());
if r.status().is_success() {
let _ = c
.delete(&url)
.basic_auth(&creds.login_name, Some(&creds.app_password))
.send()
.await;
}
}
Err(e) => println!("PUT {what}: transport error {e}"),
}
}
}
// Write into the library root.
let p = RemotePath::new(format!("{}/.darkroom-write-test", session.root));
match backend
.put(&p, b"darkroom write probe\n".to_vec(), None)
.await
{
Ok(v) => {
println!("WRITE ok: etag={}", v.as_str());
match backend.delete(&RemoteId::Path(p.clone()), None).await {
Ok(()) => println!("CLEAN ok"),
Err(e) => println!("CLEAN failed (harmless): {e}"),
}
}
Err(e) => println!("WRITE FAILED: {e}"),
}
}