OXYGENHUB
# f9466021286a oxygen / crates / oxy-core / src / repo / mod.rs
73.3 KiB · Rust · last changed Commit: cheaper bookkeeping around a change (refs #41) 1 month ago source blame history raw
98286406 Andy McCall ↶ 1 
//! A repository on disk: the `.oxy` directory, one workspace, the operation
2 
//! log, and the working-copy change (spec §12, §13.1).
3 
//!
83e0677b Andy McCall ↶ 4 
//! Not yet implemented from the spec: packs, checkpoints, multiple
5 
//! workspaces, multi-signer policy updates, and the `objects`/`checkpoint`
6 
//! endpoints. A repository without a policy is unverified and accepts
7 
//! unsigned pushes; with one, everything received is checked (spec §14.5). Changes are signed individually when `core.sign` is
98286406 Andy McCall ↶ 8 
//! `change`; the default `seal` leaves them unsigned until push exists.
9
10 
use crate::attest::{Attest, AttestBody};
11 
use crate::diff::{ranges, split_lines, text_edits};
12 
use crate::hash::{hash_object, ChangeHash, KeyId, ObjectRef, ObjectType};
13 
use crate::identity::{verify as verify_signature, Domain, Identity, SecretKey, Signature};
14 
use crate::ids::{ChangeId, NodeId, WorkspaceId};
75167672 Andy McCall 15 
use crate::objects::{
16 
    Blob, Change, ChangeKind, Edit, Hlc, Mode, NodeKind, OpRef, StateObject, TreeOp,
17 
};
98286406 Andy McCall ↶ 18 
use crate::oplog::{Format1Op, Op, View, SNAPSHOT_SUFFIX};
75167672 Andy McCall 19 
use crate::protocol::{
20 
    open_remote, Bundle, RefResult, RefUpdate, RefsResponse, RemoteOptions, RemoteRef,
21 
    SignedAttest, SignedPolicy,
22 
};
98286406 Andy McCall ↶ 23 
use crate::state::{FileContent, Snapshot, State};
24 
use crate::store::{Store, StoreError};
75167672 Andy McCall 25 
#[allow(unused_imports)]
26 
use crate::subrepo::Pin;
98286406 Andy McCall ↶ 27 
use crate::tree::OpKey;
28 
use rand::RngCore;
cc7a0056 Andy McCall ↶ 29 
use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};
98286406 Andy McCall ↶ 30 
use std::fs;
31 
use std::io::Write;
32 
use std::path::{Path, PathBuf};
33
34 
pub const OXY_DIR: &str = ".oxy";
35 
pub const FORMAT_LINE: &str = "oxy repository format 2\n";
36 
const FORMAT1_LINE: &str = "oxy repository format 1\n";
37 
const BINARY_SNIFF: usize = 8 * 1024;
d02e545d Andy McCall ↶ 38 
/// Loose objects tolerated before a commit packs them (spec §13.4).
39 
pub const AUTOPACK_THRESHOLD: usize = 4096;
98286406 Andy McCall ↶ 40
41 
#[derive(Debug, thiserror::Error)]
42 
pub enum RepoError {
43 
    #[error("io: {0}")]
44 
    Io(#[from] std::io::Error),
45 
    #[error(transparent)]
46 
    Store(#[from] StoreError),
47 
    #[error(transparent)]
48 
    Object(#[from] crate::objects::ObjectError),
49 
    #[error(transparent)]
50 
    State(#[from] crate::state::StateError),
51 
    #[error("{0}")]
52 
    Msg(String),
53 
}
54
55 
pub type Result<T> = std::result::Result<T, RepoError>;
56
57 
fn fail<T>(s: impl Into<String>) -> Result<T> {
58 
    Err(RepoError::Msg(s.into()))
59 
}
60
7b9809e6 Andy McCall ↶ 61 
mod bookmarks;
98286406 Andy McCall ↶ 62 
mod checkout;
252e8cb2 Andy McCall ↶ 63 
mod checkpoint;
98286406 Andy McCall ↶ 64 
mod config;
3e5772cc Andy McCall ↶ 65 
mod doctor;
387335ff Andy McCall ↶ 66 
mod fsck;
ba160f60 Andy McCall ↶ 67 
mod gc;
79ab8528 Andy McCall ↶ 68 
mod git;
614541c3 Andy McCall ↶ 69 
mod history;
6d3eefbc Andy McCall ↶ 70 
mod hooks;
84b9e9ac Andy McCall ↶ 71 
mod hosted;
75167672 Andy McCall 72 
mod identity;
957fee30 Andy McCall ↶ 73 
mod inspect;
83e0677b Andy McCall ↶ 74 
mod policy;
135212de Andy McCall ↶ 75 
mod prompt;
fc1a466a Andy McCall ↶ 76 
mod receipts;
98286406 Andy McCall ↶ 77 
mod snapshot;
75167672 Andy McCall 78 
mod subrepos;
98286406 Andy McCall ↶ 79 
mod sync;
132b884b Andy McCall ↶ 80 
mod tags;
98286406 Andy McCall ↶ 81 
#[cfg(test)]
82 
mod tests;
76740263 Andy McCall ↶ 83 
mod walk;
75167672 Andy McCall 84 
mod workspace;
98286406 Andy McCall ↶ 85
4fe7d604 Andy McCall ↶ 86 
pub use bookmarks::{BookmarkInfo, MergeReport, StateGap};
98286406 Andy McCall ↶ 87 
pub use checkout::CheckoutReport;
b3c5a59a Andy McCall ↶ 88 
pub use config::{parse_size, read_config_file, Config};
3e5772cc Andy McCall ↶ 89 
pub use doctor::{Check, DoctorReport, Health};
387335ff Andy McCall ↶ 90 
pub use fsck::{FsckReport, Problem, Severity};
ba160f60 Andy McCall ↶ 91 
pub use gc::GcReport;
62794ecc Andy McCall ↶ 92 
pub use git::{GitExportReport, GitImportReport, GitVerifyReport};
75167672 Andy McCall 93 
pub use hooks::{json_array, json_str, HookOutcome};
84b9e9ac Andy McCall ↶ 94 
pub use hosted::FileEdit;
28fc23d7 Andy McCall ↶ 95 
pub use identity::{Rotation, SignatureStatus};
6a81dbab Andy McCall ↶ 96 
pub use inspect::{BisectStep, BlameLine, Description};
28fc23d7 Andy McCall ↶ 97 
pub use policy::PolicyUpdate;
75167672 Andy McCall 98 
pub use prompt::{PromptInfo, DEFAULT_PROMPT_FORMAT, GLYPH_PROMPT_FORMAT};
fc1a466a Andy McCall ↶ 99 
pub use receipts::ReceiptInfo;
75167672 Andy McCall 100 
pub use snapshot::{
101 
    added_node_paths, diff_files_of, has_conflict_markers, is_binary, referenced_changes,
102 
    render_change, render_hunks, similarity, ChangeStatus, DiffHunk, FileDiff, Hunk, PathStatus,
103 
    Selection, SnapshotResult,
104 
};
105 
pub use subrepos::{SubrepoInfo, SubrepoSync};
7aa2dc93 Andy McCall ↶ 106 
pub use sync::{FetchReport, PullReport, PushReport, RefUpdated};
132b884b Andy McCall ↶ 107 
pub use tags::TagInfo;
6caacfff Andy McCall ↶ 108 
pub use workspace::{FileLock, SnapshotLock, WorkingCopyLock, WorkspaceInfo};
98286406 Andy McCall ↶ 109
54cd08a1 Andy McCall ↶ 110 
/// The file name under which per-bookmark or per-tag data is kept: `/`
111 
/// (and `%`) escaped, so `feature/x` is one file beside `feature` rather
112 
/// than a directory that would clash with it.
113 
pub(crate) fn name_file(name: &str) -> String {
114 
    name.replace('%', "%25").replace('/', "%2F")
115 
}
116
117 
/// The name a [`name_file`] file name stands for.
118 
pub(crate) fn file_name_to_name(file: &str) -> String {
119 
    file.replace("%2F", "/").replace("%25", "%")
120 
}
121
98286406 Andy McCall ↶ 122 
fn write_atomic(path: &Path, data: &[u8]) -> Result<()> {
4dcb8c09 Andy McCall ↶ 123 
    Ok(crate::durable::write_atomic(path, data)?)
98286406 Andy McCall ↶ 124 
}
125
f9466021 Andy McCall ↶ 126 
/// Replace a cache file: whole or not at all, but without waiting for the
127 
/// disk. A cache checks its own bytes when read, so one a crash leaves
128 
/// short or stale is rebuilt rather than trusted.
129 
/// How many changes a state index may fall behind its working copy before
130 
/// it is written again; until then each load replays them.
131 
const INDEX_REPLAY_LIMIT: usize = 16;
132 
const INDEX_REPLAY_TIME: std::time::Duration = std::time::Duration::from_millis(50);
133
134 
pub(crate) fn write_cache(path: &Path, data: &[u8]) -> Result<()> {
135 
    let tmp = path.with_extension(format!("tmp-{}", std::process::id()));
136 
    fs::write(&tmp, data)?;
137 
    fs::rename(&tmp, path)?;
138 
    Ok(())
139 
}
140
98286406 Andy McCall ↶ 141 
pub struct LogEntry {
142 
    pub hash: ChangeHash,
2863456a Andy McCall ↶ 143 
    /// Metadata from the state; the full change may be absent in a shallow repository.
144 
    pub change: crate::state::ChangeMeta,
98286406 Andy McCall ↶ 145 
    pub is_working_copy: bool,
146 
    pub is_head: bool,
147 
}
148
992467d3 Andy McCall ↶ 149 
/// A text file's base graph key, by path, as a walk asks for it.
1966f5db Andy McCall ↶ 150 
pub(crate) type KeyOf<'a> = dyn Fn(&str) -> Option<[u8; 32]> + Sync + 'a;
992467d3 Andy McCall ↶ 151
c3069537 Andy McCall ↶ 152 
/// A file as found on disk or in an imported tree.
153 
pub(crate) struct FsEntry {
154 
    pub kind: NodeKind,
155 
    pub exec: bool,
b7f102fc Andy McCall ↶ 156 
    /// File content, or a symlink's target. Empty when `blob` is set.
40a40bb7 Andy McCall ↶ 157 
    /// Shared, so a new file's insert holds it without a copy.
158 
    pub content: std::sync::Arc<Vec<u8>>,
b7f102fc Andy McCall ↶ 159 
    /// The stored blob of an opaque file whose size and mtime are unchanged
160 
    /// since the last manifest (spec §12.3 stat cache); the content was not
161 
    /// read.
162 
    pub blob: Option<ObjectRef>,
163 
    /// BLAKE3 of the content, carried over from the manifest when the stat
164 
    /// is unchanged, so the manifest can be rewritten without rehashing.
1966f5db Andy McCall ↶ 165 
    pub content_hash: Option<[u8; 32]>,
cc7a0056 Andy McCall ↶ 166 
    /// A text file known equal to the base's rendering without reading it:
167 
    /// its stat matches the manifest and the manifest recorded it equal to
168 
    /// a base file graph with the same key (spec §12.3). `content` is empty.
169 
    pub unchanged: bool,
170 
    /// The base graph key this file equals, for the next manifest.
1966f5db Andy McCall ↶ 171 
    pub graph_key: Option<[u8; 32]>,
0554aaa7 Andy McCall ↶ 172 
    /// Size and mtime already known to be current (a checkout leaving the
173 
    /// file as it was), so the manifest need not stat it again.
174 
    pub stat: Option<(u64, u128)>,
98286406 Andy McCall ↶ 175 
}
176
b7f102fc Andy McCall ↶ 177 
impl FsEntry {
178 
    pub(crate) fn new(kind: NodeKind, exec: bool, content: Vec<u8>) -> FsEntry {
75167672 Andy McCall 179 
        FsEntry {
180 
            kind,
181 
            exec,
40a40bb7 Andy McCall ↶ 182 
            content: std::sync::Arc::new(content),
75167672 Andy McCall 183 
            blob: None,
184 
            content_hash: None,
cc7a0056 Andy McCall ↶ 185 
            unchanged: false,
186 
            graph_key: None,
0554aaa7 Andy McCall ↶ 187 
            stat: None,
75167672 Andy McCall 188 
        }
b7f102fc Andy McCall ↶ 189 
    }
190 
}
191
98286406 Andy McCall ↶ 192 
pub struct Repo {
4dee277c Andy McCall ↶ 193 
    /// Oxygen-pinned subrepos skipped by the running Git export.
194 
    pub(crate) git_export_skipped: std::cell::Cell<usize>,
d0990c2b Andy McCall ↶ 195 
    /// The manifest as last read, with the file identity it was read from,
196 
    /// so one command parses it once (see `read_manifest`).
197 
    pub(crate) manifest_cache: std::cell::RefCell<Option<prompt::CachedManifest>>,
76740263 Andy McCall ↶ 198 
    /// A listing of the working copy left by a failed clean check, for the
199 
    /// snapshot that follows it to reuse; taken by the next walk and
200 
    /// dropped whenever the manifest is written.
201 
    pub(crate) listing_cache: std::cell::RefCell<Option<walk::Listing>>,
98286406 Andy McCall ↶ 202 
    root: PathBuf,
203 
    oxy: PathBuf,
204 
    store: Store,
205 
    workspace: WorkspaceId,
e02bf0cd Andy McCall ↶ 206 
    /// A hosted repository with no working copy (spec §12.2, hub spec §4.1).
207 
    bare: bool,
98286406 Andy McCall ↶ 208 
    keys_dir: PathBuf,
209 
    user_config: PathBuf,
210 
    pub config: Config,
c863c7a7 Andy McCall ↶ 211 
    /// What the working copy's file system can represent (spec §7.7).
212 
    platform: crate::portable::Platform,
519c7c06 Andy McCall ↶ 213 
    /// The encoding of the change last read for its inline inserts.
214 
    last_change: std::cell::RefCell<Option<(ChangeHash, std::sync::Arc<Vec<u8>>)>>,
98286406 Andy McCall ↶ 215 
}
216
e02bf0cd Andy McCall ↶ 217 
/// Marker file of a bare repository, inside `.oxy/`.
218 
const BARE_MARKER: &str = "bare";
75167672 Andy McCall 219 
/// Marker of a hosted repository that has no id yet: the first push binds
220 
/// it to the pusher's id (spec §16.1).
221 
const UNBOUND_MARKER: &str = "unbound";
e02bf0cd Andy McCall ↶ 222
98286406 Andy McCall ↶ 223 
/// The user's oxy directory: `$OXY_HOME`, else `$XDG_CONFIG_HOME/oxy`, else
224 
/// `~/.config/oxy`. It holds `config.toml` (spec §19) and `keys/`.
225 
pub fn default_home() -> PathBuf {
226 
    if let Ok(h) = std::env::var("OXY_HOME") {
227 
        return PathBuf::from(h);
228 
    }
229 
    if let Ok(x) = std::env::var("XDG_CONFIG_HOME") {
230 
        return PathBuf::from(x).join("oxy");
231 
    }
232 
    let home = std::env::var("HOME").unwrap_or_else(|_| ".".into());
233 
    PathBuf::from(home).join(".config").join("oxy")
234 
}
235
236 
pub fn default_keys_dir() -> PathBuf {
237 
    default_home().join("keys")
238 
}
239
240 
pub fn default_user_config() -> PathBuf {
241 
    default_home().join("config.toml")
242 
}
243
244 
/// Where `create_identity` records the author.
245 
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
246 
pub enum IdentityScope {
247 
    /// The user file: every repository of this user signs with it.
248 
    User,
249 
    /// This repository only.
250 
    Repo,
251 
}
252
253 
impl Repo {
254 
    // ------------------------------------------------------------ lifecycle
255
256 
    pub fn init(root: &Path) -> Result<Repo> {
257 
        let mut id = [0u8; 16];
258 
        rand::rngs::OsRng.fill_bytes(&mut id);
259 
        Self::init_with_id(root, id)
260 
    }
261
262 
    /// Initialize a repository with a given repository ID (clones share the
263 
    /// ID of their origin, spec §14.4).
264 
    pub fn init_with_id(root: &Path, id: [u8; 16]) -> Result<Repo> {
265 
        fs::create_dir_all(root)?;
266 
        let root = root.canonicalize().unwrap_or_else(|_| root.to_path_buf());
267 
        let oxy = root.join(OXY_DIR);
268 
        if oxy.exists() {
269 
            return fail(format!("{} is already an oxy repository", root.display()));
270 
        }
271 
        fs::create_dir_all(oxy.join("ops"))?;
272 
        write_atomic(&oxy.join("format"), FORMAT_LINE.as_bytes())?;
273 
        write_atomic(&oxy.join("id"), hex::encode(id).as_bytes())?;
274 
        let config = Config::load(Some(&default_user_config()), &oxy.join("config"))?;
275 
        config.save(&oxy.join("config"))?;
276 
        let workspace = WorkspaceId::random();
277 
        write_atomic(&oxy.join("workspace"), workspace.to_hex().as_bytes())?;
278 
        let store = Store::open(oxy.join("objects"))?;
75167672 Andy McCall 279 
        let repo = Repo {
519c7c06 Andy McCall ↶ 280 
            last_change: Default::default(),
75167672 Andy McCall 281 
            git_export_skipped: Default::default(),
d0990c2b Andy McCall ↶ 282 
            manifest_cache: Default::default(),
76740263 Andy McCall ↶ 283 
            listing_cache: Default::default(),
75167672 Andy McCall 284 
            root,
285 
            oxy,
286 
            store,
287 
            workspace,
288 
            bare: false,
289 
            keys_dir: default_keys_dir(),
c863c7a7 Andy McCall ↶ 290 
            platform: crate::portable::Platform::current(),
75167672 Andy McCall 291 
            user_config: default_user_config(),
292 
            config,
293 
        };
4e88e774 Andy McCall ↶ 294 
        repo.register_workspace(&workspace, &repo.root)?;
98286406 Andy McCall ↶ 295
296 
        let wc = repo.new_working_copy(vec![], "");
297 
        let wc_hash = repo.store.put_change(&wc)?;
298 
        let mut view = View::default();
75167672 Andy McCall 299 
        view.bookmarks.insert(
300 
            repo.config.bookmark.clone(),
301 
            repo.store.put_state(&StateObject::new(vec![]))?,
302 
        );
98286406 Andy McCall ↶ 303 
        view.workspaces.insert(workspace, wc_hash);
304 
        repo.record_op(&[], "oxy init", view)?;
305 
        Ok(repo)
306 
    }
307
e02bf0cd Andy McCall ↶ 308 
    /// Create a bare repository: an object store, operation log and
309 
    /// references with no workspace and no working copy, for hosting
310 
    /// (hub spec §4.1). `root` holds `.oxy/` and nothing else.
311 
    pub fn init_bare(root: &Path) -> Result<Repo> {
312 
        let mut id = [0u8; 16];
313 
        rand::rngs::OsRng.fill_bytes(&mut id);
314 
        Self::init_bare_with_id(root, id)
315 
    }
316
317 
    pub fn init_bare_with_id(root: &Path, id: [u8; 16]) -> Result<Repo> {
318 
        fs::create_dir_all(root)?;
319 
        let root = root.canonicalize().unwrap_or_else(|_| root.to_path_buf());
320 
        let oxy = root.join(OXY_DIR);
321 
        if oxy.exists() {
322 
            return fail(format!("{} is already an oxy repository", root.display()));
323 
        }
324 
        fs::create_dir_all(oxy.join("ops"))?;
325 
        write_atomic(&oxy.join("format"), FORMAT_LINE.as_bytes())?;
326 
        write_atomic(&oxy.join("id"), hex::encode(id).as_bytes())?;
327 
        write_atomic(&oxy.join(BARE_MARKER), b"")?;
328 
        let config = Config::load(Some(&default_user_config()), &oxy.join("config"))?;
329 
        config.save(&oxy.join("config"))?;
330 
        let store = Store::open(oxy.join("objects"))?;
75167672 Andy McCall 331 
        let repo = Repo {
519c7c06 Andy McCall ↶ 332 
            last_change: Default::default(),
75167672 Andy McCall 333 
            git_export_skipped: Default::default(),
d0990c2b Andy McCall ↶ 334 
            manifest_cache: Default::default(),
76740263 Andy McCall ↶ 335 
            listing_cache: Default::default(),
75167672 Andy McCall 336 
            root,
337 
            oxy,
338 
            store,
339 
            workspace: WorkspaceId::ZERO,
340 
            bare: true,
341 
            keys_dir: default_keys_dir(),
c863c7a7 Andy McCall ↶ 342 
            platform: crate::portable::Platform::current(),
75167672 Andy McCall 343 
            user_config: default_user_config(),
344 
            config,
345 
        };
e02bf0cd Andy McCall ↶ 346 
        let mut view = View::default();
75167672 Andy McCall 347 
        view.bookmarks.insert(
348 
            repo.config.bookmark.clone(),
349 
            repo.store.put_state(&StateObject::new(vec![]))?,
350 
        );
e02bf0cd Andy McCall ↶ 351 
        repo.record_op(&[], "oxy init --bare", view)?;
352 
        Ok(repo)
353 
    }
354
75167672 Andy McCall 355 
    /// A bare repository with no id yet. Its `id()` is all zero until the
356 
    /// first push binds it (`bind_id`), so an existing repository can be
357 
    /// pushed to a freshly created hosted one and keep its identity.
358 
    pub fn init_bare_unbound(root: &Path) -> Result<Repo> {
359 
        let repo = Self::init_bare_with_id(root, [0; 16])?;
360 
        fs::remove_file(repo.oxy.join("id"))?;
361 
        write_atomic(&repo.oxy.join(UNBOUND_MARKER), b"")?;
362 
        Ok(repo)
363 
    }
364
365 
    pub fn is_unbound(&self) -> bool {
366 
        self.oxy.join(UNBOUND_MARKER).is_file()
367 
    }
368
369 
    /// Give an unbound repository its id.
370 
    pub fn bind_id(&self, id: [u8; 16]) -> Result<()> {
371 
        if !self.is_unbound() {
372 
            return fail("this repository already has an id");
373 
        }
374 
        if id == [0; 16] {
375 
            return fail("a repository id cannot be all zero");
376 
        }
377 
        write_atomic(&self.oxy.join("id"), hex::encode(id).as_bytes())?;
378 
        fs::remove_file(self.oxy.join(UNBOUND_MARKER))?;
379 
        Ok(())
380 
    }
381
e02bf0cd Andy McCall ↶ 382 
    /// Whether this repository has no working copy (`init_bare`).
383 
    pub fn is_bare(&self) -> bool {
384 
        self.bare
385 
    }
386
98286406 Andy McCall ↶ 387 
    /// Open the repository containing `start` (searching upwards).
388 
    pub fn open(start: &Path) -> Result<Repo> {
389 
        let start = start.canonicalize()?;
390 
        let mut dir: Option<&Path> = Some(&start);
391 
        while let Some(d) = dir {
392 
            let oxy = d.join(OXY_DIR);
4e88e774 Andy McCall ↶ 393 
            if oxy.is_file() {
394 
                // A secondary workspace (spec §12.2): the file points at the repository.
395 
                let text = fs::read_to_string(&oxy)?;
396 
                let Some((shared, workspace)) = workspace::parse_workspace_file(&text) else {
397 
                    return fail(format!("{} is not a valid workspace file", oxy.display()));
398 
                };
399 
                let format = fs::read_to_string(shared.join("format"))?;
400 
                if format != FORMAT_LINE {
401 
                    return fail(format!("unsupported repository format: {}", format.trim()));
402 
                }
403 
                let config = Config::load(Some(&default_user_config()), &shared.join("config"))?;
404 
                let store = Store::open(shared.join("objects"))?;
75167672 Andy McCall 405 
                let mut repo = Repo {
519c7c06 Andy McCall ↶ 406 
                    last_change: Default::default(),
75167672 Andy McCall 407 
                    git_export_skipped: Default::default(),
d0990c2b Andy McCall ↶ 408 
                    manifest_cache: Default::default(),
76740263 Andy McCall ↶ 409 
                    listing_cache: Default::default(),
75167672 Andy McCall 410 
                    root: d.to_path_buf(),
411 
                    oxy: shared,
412 
                    store,
413 
                    workspace,
414 
                    bare: false,
415 
                    keys_dir: default_keys_dir(),
c863c7a7 Andy McCall ↶ 416 
                    platform: crate::portable::Platform::current(),
75167672 Andy McCall 417 
                    user_config: default_user_config(),
418 
                    config,
419 
                };
7b9809e6 Andy McCall ↶ 420 
                repo.apply_workspace_bookmark();
421 
                return Ok(repo);
4e88e774 Andy McCall ↶ 422 
            }
98286406 Andy McCall ↶ 423 
            if oxy.is_dir() {
424 
                let format = fs::read_to_string(oxy.join("format"))?;
425 
                let config = Config::load(Some(&default_user_config()), &oxy.join("config"))?;
e02bf0cd Andy McCall ↶ 426 
                let bare = oxy.join(BARE_MARKER).is_file();
427 
                let workspace = if bare {
428 
                    WorkspaceId::ZERO
429 
                } else {
75167672 Andy McCall 430 
                    WorkspaceId::from_hex(fs::read_to_string(oxy.join("workspace"))?.trim())
431 
                        .ok_or_else(|| RepoError::Msg("corrupt .oxy/workspace".into()))?
e02bf0cd Andy McCall ↶ 432 
                };
98286406 Andy McCall ↶ 433 
                let store = Store::open(oxy.join("objects"))?;
75167672 Andy McCall 434 
                let mut repo = Repo {
519c7c06 Andy McCall ↶ 435 
                    last_change: Default::default(),
75167672 Andy McCall 436 
                    git_export_skipped: Default::default(),
d0990c2b Andy McCall ↶ 437 
                    manifest_cache: Default::default(),
76740263 Andy McCall ↶ 438 
                    listing_cache: Default::default(),
75167672 Andy McCall 439 
                    root: d.to_path_buf(),
440 
                    oxy,
441 
                    store,
442 
                    workspace,
443 
                    bare,
444 
                    keys_dir: default_keys_dir(),
c863c7a7 Andy McCall ↶ 445 
                    platform: crate::portable::Platform::current(),
75167672 Andy McCall 446 
                    user_config: default_user_config(),
447 
                    config,
448 
                };
e02bf0cd Andy McCall ↶ 449 
                if !bare {
450 
                    repo.apply_workspace_bookmark();
451 
                }
98286406 Andy McCall ↶ 452 
                if format == FORMAT1_LINE {
453 
                    repo.migrate_format1()?;
454 
                } else if format != FORMAT_LINE {
455 
                    return fail(format!("unsupported repository format: {}", format.trim()));
456 
                }
457 
                return Ok(repo);
458 
            }
459 
            dir = d.parent();
460 
        }
75167672 Andy McCall 461 
        fail(format!(
3e5772cc Andy McCall ↶ 462 
            "no oxy repository found at or above {}; start one with `oxy init` or `oxy clone URL`",
75167672 Andy McCall 463 
            start.display()
464 
        ))
98286406 Andy McCall ↶ 465 
    }
466
467 
    /// Rewrite a format-1 operation log, whose bookmarks were head lists,
468 
    /// into format 2, where each bookmark names a `state` object.
469 
    fn migrate_format1(&self) -> Result<()> {
470 
        let hex = fs::read_to_string(self.oxy.join("ops").join("head"))?;
75167672 Andy McCall 471 
        let head = ObjectRef::from_hex(hex.trim())
472 
            .ok_or_else(|| RepoError::Msg("corrupt .oxy/ops/head".into()))?;
98286406 Andy McCall ↶ 473 
        // Collect the chain root-first.
474 
        let mut chain: Vec<Format1Op> = Vec::new();
475 
        let mut cur = Some(head);
476 
        while let Some(r) = cur {
477 
            let op = Op::decode_format1(&self.store.get_typed(&r, ObjectType::Op)?)?;
478 
            cur = op.parents.first().copied();
479 
            chain.push(op);
480 
        }
481 
        chain.reverse();
482 
        let mut new_parent: Option<ObjectRef> = None;
483 
        for old in chain {
484 
            let mut view = View::default();
485 
            for (name, heads) in &old.view.bookmarks {
75167672 Andy McCall 486 
                view.bookmarks.insert(
487 
                    name.clone(),
488 
                    self.store.put_state(&StateObject::new(heads.clone()))?,
489 
                );
98286406 Andy McCall ↶ 490 
            }
491 
            view.workspaces = old.view.workspaces.clone();
75167672 Andy McCall 492 
            let op = Op {
493 
                parents: new_parent.into_iter().collect(),
494 
                hlc: old.hlc,
495 
                command: old.command,
496 
                view,
497 
            };
98286406 Andy McCall ↶ 498 
            new_parent = Some(self.store.put(ObjectType::Op, &op.encode())?);
499 
        }
75167672 Andy McCall 500 
        write_atomic(
501 
            &self.oxy.join("ops").join("head"),
502 
            new_parent.unwrap().to_hex().as_bytes(),
503 
        )?;
98286406 Andy McCall ↶ 504 
        write_atomic(&self.oxy.join("format"), FORMAT_LINE.as_bytes())?;
505 
        Ok(())
d02e545d Andy McCall ↶ 506 
    }
507
508 
    /// Pack automatically once many loose objects have accumulated.
509 
    pub(crate) fn maybe_autopack(&self) -> Result<()> {
510 
        if self.store.loose_count()? > AUTOPACK_THRESHOLD {
511 
            self.store.pack_loose()?;
135212de Andy McCall ↶ 512 
            self.store.merge_packs()?;
d02e545d Andy McCall ↶ 513 
        }
514 
        Ok(())
515 
    }
516
98286406 Andy McCall ↶ 517 
    /// The repository ID (spec §14.4). Repositories made before IDs existed get one on first use.
518 
    pub fn id(&self) -> Result<[u8; 16]> {
75167672 Andy McCall 519 
        if self.is_unbound() {
520 
            return Ok([0; 16]);
521 
        }
98286406 Andy McCall ↶ 522 
        let path = self.oxy.join("id");
523 
        match fs::read_to_string(&path) {
75167672 Andy McCall 524 
            Ok(h) => hex::decode(h.trim())
525 
                .ok()
526 
                .and_then(|v| v.try_into().ok())
527 
                .ok_or_else(|| RepoError::Msg("corrupt .oxy/id".into())),
98286406 Andy McCall ↶ 528 
            Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
529 
                let mut id = [0u8; 16];
530 
                rand::rngs::OsRng.fill_bytes(&mut id);
531 
                write_atomic(&path, hex::encode(id).as_bytes())?;
532 
                Ok(id)
533 
            }
534 
            Err(e) => Err(e.into()),
535 
        }
536 
    }
537
538 
    pub fn root(&self) -> &Path {
539 
        &self.root
540 
    }
541 
    pub fn store(&self) -> &Store {
542 
        &self.store
543 
    }
544 
    pub fn workspace(&self) -> WorkspaceId {
545 
        self.workspace
546 
    }
547
548 
    /// Use a different user directory for keys and the user config file
549 
    /// (tests, or `$OXY_HOME`). Reloads the effective configuration.
c863c7a7 Andy McCall ↶ 550 
    /// Act as if the working copy were on another platform's file system
551 
    /// (tests of Windows and macOS behaviour on any host).
552 
    pub fn with_platform(mut self, platform: crate::portable::Platform) -> Repo {
553 
        self.platform = platform;
554 
        self
555 
    }
556
557 
    pub fn platform(&self) -> crate::portable::Platform {
558 
        self.platform
559 
    }
560
98286406 Andy McCall ↶ 561 
    pub fn with_home(mut self, dir: impl Into<PathBuf>) -> Repo {
562 
        let dir = dir.into();
563 
        self.keys_dir = dir.join("keys");
564 
        self.user_config = dir.join("config.toml");
565 
        if let Ok(c) = Config::load(Some(&self.user_config), &self.oxy.join("config")) {
566 
            self.config = c;
567 
        }
7b9809e6 Andy McCall ↶ 568 
        self.apply_workspace_bookmark();
98286406 Andy McCall ↶ 569 
        self
570 
    }
571
7b9809e6 Andy McCall ↶ 572 
    /// The workspace's current bookmark (spec §10.1) overrides the
573 
    /// configured default when `oxy bookmark switch` has recorded one.
574 
    fn apply_workspace_bookmark(&mut self) {
75167672 Andy McCall 575 
        if let Ok(b) = fs::read_to_string(
576 
            self.oxy
577 
                .join("workspaces")
578 
                .join(self.workspace.to_hex())
579 
                .join("bookmark"),
580 
        ) {
7b9809e6 Andy McCall ↶ 581 
            let b = b.trim();
582 
            if !b.is_empty() {
583 
                self.config.bookmark = b.to_string();
584 
            }
585 
        }
586 
    }
587
98286406 Andy McCall ↶ 588 
    pub fn user_config_path(&self) -> &Path {
589 
        &self.user_config
590 
    }
591
592 
    /// Set a key in the user file and refresh the effective configuration.
593 
    pub fn set_user_config(&mut self, key: &str, value: &str) -> Result<()> {
594 
        Config::set_user(&self.user_config, key, value)?;
595 
        self.config = Config::load(Some(&self.user_config), &self.oxy.join("config"))?;
596 
        Ok(())
597 
    }
598
599 
    pub fn save_config(&self) -> Result<()> {
600 
        self.config.save(&self.oxy.join("config"))
601 
    }
602
603 
    fn author(&self) -> KeyId {
604 
        self.config.author_key.unwrap_or(ObjectRef::ZERO)
605 
    }
606 
}
607
608 
impl Repo {
609 
    fn new_working_copy(&self, deps: Vec<ChangeHash>, message: &str) -> Change {
610 
        let mut c = Change {
6f8aeb99 Andy McCall ↶ 611 
            version: crate::objects::CHANGE_VERSION,
98286406 Andy McCall ↶ 612 
            change_id: ChangeId::random(),
613 
            deps,
614 
            author: self.author(),
615 
            hlc: Hlc::now(),
616 
            message: message.into(),
617 
            tree_ops: vec![],
618 
            edits: vec![],
619 
            kind: ChangeKind::WorkingCopy,
620 
        };
621 
        c.normalize();
622 
        c
623 
    }
624
625 
    // ------------------------------------------------------------ operation log
626
627 
    pub fn head_op(&self) -> Result<(ObjectRef, Op)> {
628 
        let hex = fs::read_to_string(self.oxy.join("ops").join("head"))?;
75167672 Andy McCall 629 
        let r = ObjectRef::from_hex(hex.trim())
630 
            .ok_or_else(|| RepoError::Msg("corrupt .oxy/ops/head".into()))?;
98286406 Andy McCall ↶ 631 
        let op = Op::decode(&self.store.get_typed(&r, ObjectType::Op)?)?;
632 
        Ok((r, op))
633 
    }
634
635 
    pub fn view(&self) -> Result<View> {
636 
        Ok(self.head_op()?.1.view)
637 
    }
638
639 
    fn record_op(&self, parents: &[ObjectRef], command: &str, view: View) -> Result<ObjectRef> {
75167672 Andy McCall 640 
        let op = Op {
641 
            parents: parents.to_vec(),
642 
            hlc: Hlc::now(),
643 
            command: command.into(),
644 
            view,
645 
        };
98286406 Andy McCall ↶ 646 
        let r = self.store.put(ObjectType::Op, &op.encode())?;
4dcb8c09 Andy McCall ↶ 647 
        // The head is the commit point: everything it names must be on disk first.
648 
        self.store.flush()?;
19555025 Andy McCall ↶ 649 
        // Compare and swap under a short lock (spec §12.1): when another
650 
        // process recorded an operation since this one read the head, the
651 
        // two are merged instead of one overwriting the other.
652 
        let _lock = self.lock_ops()?;
653 
        let current = match parents.first() {
654 
            // The first operation (init): there is no head yet.
655 
            None => None,
656 
            Some(_) => Some(self.head_ref()?),
657 
        };
658 
        let Some(current) = current.filter(|c| Some(c) != parents.first()) else {
659 
            write_atomic(&self.oxy.join("ops").join("head"), r.to_hex().as_bytes())?;
660 
            return Ok(r);
661 
        };
662 
        let base = match parents.first() {
663 
            Some(p) => Op::decode(&self.store.get_typed(p, ObjectType::Op)?)?.view,
664 
            None => View::default(),
665 
        };
666 
        let theirs = Op::decode(&self.store.get_typed(&current, ObjectType::Op)?)?.view;
667 
        let merged = Op {
668 
            parents: vec![current, r],
669 
            hlc: Hlc::now(),
670 
            command: format!("{command} (merged with a concurrent operation)"),
671 
            view: self.merge_views(&base, &op.view, &theirs)?,
672 
        };
673 
        let m = self.store.put(ObjectType::Op, &merged.encode())?;
674 
        self.store.flush()?;
675 
        write_atomic(&self.oxy.join("ops").join("head"), m.to_hex().as_bytes())?;
676 
        Ok(m)
677 
    }
678
679 
    /// The operation head's lock, held only while the head pointer moves.
680 
    fn lock_ops(&self) -> Result<FileLock> {
681 
        fs::create_dir_all(self.oxy.join("ops"))?;
682 
        FileLock::acquire(
683 
            self.oxy.join("ops").join("lock"),
684 
            "another oxy process holds the operation log",
685 
        )
686 
    }
687
688 
    fn head_ref(&self) -> Result<ObjectRef> {
689 
        let hex = fs::read_to_string(self.oxy.join("ops").join("head"))?;
690 
        ObjectRef::from_hex(hex.trim())
691 
            .ok_or_else(|| RepoError::Msg("corrupt .oxy/ops/head".into()))
692 
    }
693
694 
    /// Three-way merge of two views that both started from `base` (spec
695 
    /// §12.1). A reference only one side changed takes that side's value.
696 
    /// When both changed it differently: a bookmark keeps both sides'
6caacfff Andy McCall ↶ 697 
    /// heads (it may then have several), a change beats a deletion, a
698 
    /// workspace changed by both is an error (only one of them matches the
699 
    /// files on disk), and otherwise this process's value wins for remote
19555025 Andy McCall ↶ 700 
    /// references and the policy, the first value for a tag (tags never
701 
    /// move).
702 
    fn merge_views(&self, base: &View, ours: &View, theirs: &View) -> Result<View> {
703 
        fn pick<K: Ord + Clone, V: Clone + PartialEq>(
704 
            b: &BTreeMap<K, V>,
705 
            o: &BTreeMap<K, V>,
706 
            t: &BTreeMap<K, V>,
707 
            mut both: impl FnMut(&V, &V) -> Result<V>,
708 
        ) -> Result<BTreeMap<K, V>> {
709 
            let keys: BTreeSet<&K> = b.keys().chain(o.keys()).chain(t.keys()).collect();
710 
            let mut out = BTreeMap::new();
711 
            for k in keys {
712 
                let (bv, ov, tv) = (b.get(k), o.get(k), t.get(k));
713 
                let v = if ov == tv || tv == bv {
714 
                    ov.cloned()
715 
                } else if ov == bv {
716 
                    tv.cloned()
717 
                } else {
718 
                    match (ov, tv) {
719 
                        (Some(x), Some(y)) => Some(both(x, y)?),
720 
                        (Some(x), None) | (None, Some(x)) => Some(x.clone()),
721 
                        (None, None) => None,
722 
                    }
723 
                };
724 
                if let Some(v) = v {
725 
                    out.insert(k.clone(), v);
726 
                }
727 
            }
728 
            Ok(out)
729 
        }
730 
        let bookmarks = pick(
731 
            &base.bookmarks,
732 
            &ours.bookmarks,
733 
            &theirs.bookmarks,
734 
            |x, y| {
735 
                let mut heads = self.store.get_state(x)?.heads;
736 
                heads.extend(self.store.get_state(y)?.heads);
737 
                let heads = self.load_state(&heads)?.maximal(&heads);
738 
                Ok(self.store.put_state(&StateObject::new(heads))?)
739 
            },
740 
        )?;
6caacfff Andy McCall ↶ 741 
        // Two operations that both replaced one workspace's working copy
742 
        // cannot both be right: the files on disk match only one of them.
743 
        // The working-copy lock keeps this from happening; should it happen
744 
        // anyway, this operation is not recorded.
19555025 Andy McCall ↶ 745 
        let workspaces = pick(
746 
            &base.workspaces,
747 
            &ours.workspaces,
748 
            &theirs.workspaces,
6caacfff Andy McCall ↶ 749 
            |_, _| {
750 
                fail(
751 
                    "another oxy process changed this working copy at the same time; \
752 
                     this command was not recorded: check `oxy status` and run it again",
753 
                )
754 
            },
19555025 Andy McCall ↶ 755 
        )?;
756 
        let tags = pick(&base.tags, &ours.tags, &theirs.tags, |_, y| Ok(*y))?;
757 
        let empty = BTreeMap::new();
758 
        let names: BTreeSet<&String> = base
759 
            .remotes
760 
            .keys()
761 
            .chain(ours.remotes.keys())
762 
            .chain(theirs.remotes.keys())
763 
            .collect();
764 
        let mut remotes = BTreeMap::new();
765 
        for n in names {
766 
            let m = pick(
767 
                base.remotes.get(n).unwrap_or(&empty),
768 
                ours.remotes.get(n).unwrap_or(&empty),
769 
                theirs.remotes.get(n).unwrap_or(&empty),
770 
                |x, _| Ok(*x),
771 
            )?;
772 
            if !m.is_empty() {
773 
                remotes.insert(n.clone(), m);
774 
            }
775 
        }
776 
        let policy = if ours.policy == theirs.policy || theirs.policy == base.policy {
777 
            ours.policy
778 
        } else if ours.policy == base.policy {
779 
            theirs.policy
780 
        } else {
781 
            ours.policy.or(theirs.policy)
782 
        };
783 
        self.store.flush()?;
784 
        Ok(View {
785 
            bookmarks,
786 
            workspaces,
787 
            remotes,
788 
            policy,
789 
            tags,
790 
        })
98286406 Andy McCall ↶ 791 
    }
792
793 
    pub fn op_log(&self) -> Result<Vec<(ObjectRef, Op)>> {
794 
        let mut out = Vec::new();
795 
        let (mut r, mut op) = self.head_op()?;
796 
        loop {
797 
            let next = op.parents.first().copied();
798 
            out.push((r, op));
799 
            match next {
800 
                Some(p) => {
801 
                    r = p;
802 
                    op = Op::decode(&self.store.get_typed(&r, ObjectType::Op)?)?;
803 
                }
804 
                None => break,
805 
            }
806 
        }
807 
        Ok(out)
808 
    }
809
810 
    /// Undo the last user command (spec §12.1). Operations that only recorded
811 
    /// a working-copy snapshot are skipped, since the files are still on disk
812 
    /// and the next snapshot recreates them.
813 
    pub fn undo(&self) -> Result<Op> {
6caacfff Andy McCall ↶ 814 
        let _wc = self.lock_working_copy()?;
19555025 Andy McCall ↶ 815 
        let (read_head, mut op) = self.head_op()?;
98286406 Andy McCall ↶ 816 
        while op.is_snapshot() {
75167672 Andy McCall 817 
            let Some(parent) = op.parents.first() else {
818 
                break;
819 
            };
98286406 Andy McCall ↶ 820 
            op = Op::decode(&self.store.get_typed(parent, ObjectType::Op)?)?;
821 
        }
822 
        let Some(parent) = op.parents.first() else {
823 
            return fail("nothing to undo");
824 
        };
825 
        let parent_op = Op::decode(&self.store.get_typed(parent, ObjectType::Op)?)?;
19555025 Andy McCall ↶ 826 
        let _lock = self.lock_ops()?;
827 
        if self.head_ref()? != read_head {
828 
            return fail("another oxy command ran while undoing; run undo again");
829 
        }
75167672 Andy McCall 830 
        write_atomic(
831 
            &self.oxy.join("ops").join("head"),
832 
            parent.to_hex().as_bytes(),
833 
        )?;
135212de Andy McCall ↶ 834 
        self.drop_manifest();
98286406 Andy McCall ↶ 835 
        Ok(parent_op)
836 
    }
837
838 
    /// The last operation that was not a snapshot.
839 
    pub fn last_command(&self) -> Result<Op> {
840 
        let (_, mut op) = self.head_op()?;
841 
        while op.is_snapshot() {
75167672 Andy McCall 842 
            let Some(parent) = op.parents.first() else {
843 
                break;
844 
            };
98286406 Andy McCall ↶ 845 
            op = Op::decode(&self.store.get_typed(parent, ObjectType::Op)?)?;
846 
        }
847 
        Ok(op)
848 
    }
849
850 
    // ------------------------------------------------------------ states
851
252e8cb2 Andy McCall ↶ 852 
    /// Load the dependency closure of `heads`, through a checkpoint when one applies.
98286406 Andy McCall ↶ 853 
    pub fn load_state(&self, heads: &[ChangeHash]) -> Result<State> {
252e8cb2 Andy McCall ↶ 854 
        if let Some(st) = self.load_state_checkpointed(heads)? {
855 
            return Ok(st);
856 
        }
857 
        self.load_state_full(heads)
858 
    }
859
e8d38e47 Andy McCall ↶ 860 
    /// The state of `heads` for its history (changes, tree, metadata) with
861 
    /// no file graph built: much cheaper than [`Repo::load_state`] for log
862 
    /// and friends. Build the graphs a command needs with
863 
    /// [`Repo::load_graphs_of`].
864 
    pub fn load_state_history(&self, heads: &[ChangeHash]) -> Result<State> {
865 
        if let Some(st) = self.load_state_checkpointed_as(heads, true)? {
866 
            return Ok(st);
867 
        }
868 
        self.load_state_replayed(heads, State::new_history_only())
869 
    }
870
871 
    /// Build these file graphs in a history-only state.
872 
    pub fn load_graphs_of(&self, state: &mut State, nodes: &[crate::ids::NodeId]) -> Result<()> {
a4fad5b0 Andy McCall ↶ 873 
        Ok(state.load_graphs(
874 
            nodes,
875 
            |refs| {
876 
                self.read_blobs(refs).map_err(|e| {
877 
                    crate::objects::ObjectError::Schema(format!("graph and text blobs: {e}"))
878 
                })
879 
            },
880 
            |h| self.change_bytes(h),
881 
        )?)
cc7a0056 Andy McCall ↶ 882 
    }
883
57d8dc05 Andy McCall ↶ 884 
    /// The graphs of `nodes` of a history-only state, built beside it (see
885 
    /// [`State::build_graphs_detached`]).
886 
    pub fn build_graphs_detached(
887 
        &self,
888 
        state: &State,
889 
        nodes: &[crate::ids::NodeId],
890 
    ) -> Result<HashMap<crate::ids::NodeId, crate::graph::FileGraph>> {
891 
        Ok(state
892 
            .build_graphs_detached(
893 
                nodes,
894 
                |refs| {
895 
                    self.read_blobs(refs).map_err(|e| {
896 
                        crate::objects::ObjectError::Schema(format!("graph and text blobs: {e}"))
897 
                    })
898 
                },
899 
                |h| self.change_bytes(h),
900 
            )?
901 
            .into_iter()
902 
            .collect())
903 
    }
904
cc7a0056 Andy McCall ↶ 905 
    /// Build every graph a history-only state still lacks, making it full.
906 
    pub fn load_all_graphs(&self, state: &mut State) -> Result<()> {
a4fad5b0 Andy McCall ↶ 907 
        Ok(state.load_all_graphs(
908 
            |refs| {
909 
                self.read_blobs(refs).map_err(|e| {
910 
                    crate::objects::ObjectError::Schema(format!("graph and text blobs: {e}"))
911 
                })
912 
            },
913 
            |h| self.change_bytes(h),
914 
        )?)
915 
    }
916
519c7c06 Andy McCall ↶ 917 
    /// A change's encoding, for building graphs of its inline inserts. The
918 
    /// last one read is kept: a checkout building graphs a batch at a time
919 
    /// reads the same large change for every batch.
a4fad5b0 Andy McCall ↶ 920 
    fn change_bytes(
921 
        &self,
922 
        h: &ChangeHash,
519c7c06 Andy McCall ↶ 923 
    ) -> std::result::Result<std::sync::Arc<Vec<u8>>, crate::objects::ObjectError> {
924 
        if let Some((k, b)) = &*self.last_change.borrow() {
925 
            if k == h {
926 
                return Ok(b.clone());
927 
            }
928 
        }
929 
        let b = std::sync::Arc::new(self.store.get_typed(h, ObjectType::Change).map_err(|e| {
a4fad5b0 Andy McCall ↶ 930 
            crate::objects::ObjectError::Schema(format!("change {}: {e}", h.short(12)))
519c7c06 Andy McCall ↶ 931 
        })?);
932 
        *self.last_change.borrow_mut() = Some((*h, b.clone()));
933 
        Ok(b)
e8d38e47 Andy McCall ↶ 934 
    }
935
252e8cb2 Andy McCall ↶ 936 
    /// Load the dependency closure of `heads` change by change.
937 
    pub fn load_state_full(&self, heads: &[ChangeHash]) -> Result<State> {
e8d38e47 Andy McCall ↶ 938 
        self.load_state_replayed(heads, State::new())
939 
    }
940
941 
    fn load_state_replayed(&self, heads: &[ChangeHash], mut state: State) -> Result<State> {
86e1824f Andy McCall ↶ 942 
        let history = state.is_history_only();
98286406 Andy McCall ↶ 943 
        let mut stack: Vec<ChangeHash> = heads.to_vec();
944 
        let mut seen: BTreeSet<ChangeHash> = BTreeSet::new();
0bdc3f91 Andy McCall ↶ 945 
        {
946 
            let _t = crate::timing::phase("load: read and add changes");
d0d52107 Andy McCall ↶ 947 
            let (mut read, mut add, mut fetch) = (
948 
                std::time::Duration::ZERO,
949 
                std::time::Duration::ZERO,
950 
                std::time::Duration::ZERO,
951 
            );
0bdc3f91 Andy McCall ↶ 952 
            while let Some(h) = stack.pop() {
f9466021 Andy McCall ↶ 953 
                // A change the state holds brings its history with it.
954 
                if !seen.insert(h) || state.contains(&h) {
0bdc3f91 Andy McCall ↶ 955 
                    continue;
956 
                }
957 
                let t0 = std::time::Instant::now();
86e1824f Andy McCall ↶ 958 
                // A history-only state reads text only for the graphs it
959 
                // builds; either way the hash is the one asked for.
960 
                let (c, texts) = if history {
d0d52107 Andy McCall ↶ 961 
                    let bytes = self.store.get_typed(&h, ObjectType::Change)?;
962 
                    fetch += t0.elapsed();
963 
                    Change::decode_skeleton(&bytes, h)
964 
                        .map_err(|e| crate::store::StoreError::Corrupt(h, e.to_string()))?
86e1824f Andy McCall ↶ 965 
                } else {
966 
                    (self.store.get_change(&h)?, Vec::new())
967 
                };
0bdc3f91 Andy McCall ↶ 968 
                read += t0.elapsed();
969 
                stack.extend(c.deps.iter().copied());
970 
                let t1 = std::time::Instant::now();
86e1824f Andy McCall ↶ 971 
                state.add_known(h, c, texts);
0bdc3f91 Andy McCall ↶ 972 
                add += t1.elapsed();
98286406 Andy McCall ↶ 973 
            }
0bdc3f91 Andy McCall ↶ 974 
            crate::timing::record("load:   of which reading", read);
d0d52107 Andy McCall ↶ 975 
            crate::timing::record("load:     of which fetching", fetch);
0bdc3f91 Andy McCall ↶ 976 
            crate::timing::record("load:   of which applying", add);
98286406 Andy McCall ↶ 977 
        }
0bdc3f91 Andy McCall ↶ 978 
        let _t = crate::timing::phase("load: validate");
98286406 Andy McCall ↶ 979 
        state.validate()?;
980 
        Ok(state)
981 
    }
982
983 
    pub fn working_copy(&self) -> Result<(ChangeHash, Change)> {
e02bf0cd Andy McCall ↶ 984 
        if self.bare {
985 
            return fail("this is a bare repository: it has no working copy");
986 
        }
98286406 Andy McCall ↶ 987 
        let view = self.view()?;
988 
        let h = *view
989 
            .workspaces
990 
            .get(&self.workspace)
991 
            .ok_or_else(|| RepoError::Msg("this workspace is not in the current view".into()))?;
992 
        Ok((h, self.store.get_change(&h)?))
993 
    }
994
995 
    /// Heads of a bookmark's state (spec §10.1).
996 
    pub fn heads_of(&self, view: &View, bookmark: &str) -> Result<Vec<ChangeHash>> {
997 
        match view.bookmarks.get(bookmark) {
998 
            Some(st) => Ok(self.store.get_state(st)?.heads),
999 
            None => Ok(vec![]),
1000 
        }
1001 
    }
1002
1003 
    pub fn bookmark_heads(&self) -> Result<Vec<ChangeHash>> {
1004 
        self.heads_of(&self.view()?, &self.config.bookmark)
1005 
    }
1006
1007 
    // ------------------------------------------------------------ blobs
1008
1009 
    fn blob_for(content: &[u8]) -> Blob {
6f8aeb99 Andy McCall ↶ 1010 
        Blob::of(content)
98286406 Andy McCall ↶ 1011 
    }
1012
1013 
    pub fn blob_ref(content: &[u8]) -> ObjectRef {
1014 
        Self::blob_for(content).hash()
1015 
    }
1016
1017 
    pub fn store_blob(&self, content: &[u8]) -> Result<ObjectRef> {
1018 
        for c in crate::chunk::chunks(content) {
1019 
            self.store.put_chunk(c)?;
1020 
        }
75167672 Andy McCall 1021 
        Ok(self
1022 
            .store
1023 
            .put(ObjectType::Blob, &Self::blob_for(content).encode())?)
98286406 Andy McCall ↶ 1024 
    }
1025
afaba5f1 Andy McCall ↶ 1026 
    /// Read many blobs at once (checkpoint graphs): the blob objects, then
1027 
    /// all their chunks, are read in parallel; a blob the store lacks goes
1028 
    /// through [`Repo::read_blob`], which may fetch it lazily.
1029 
    pub fn read_blobs(&self, refs: &[ObjectRef]) -> Result<Vec<Vec<u8>>> {
1030 
        let mut blobs: Vec<Option<Blob>> = Vec::with_capacity(refs.len());
1031 
        for (r, got) in refs.iter().zip(self.store.get_many(refs)) {
1032 
            blobs.push(match got {
1033 
                Ok((ObjectType::Blob, body)) => Some(Blob::decode(&body)?),
1034 
                Ok((ty, _)) => return fail(format!("{} is a {ty:?}, not a blob", r.short(12))),
1035 
                Err(crate::store::StoreError::NotFound(_)) => None,
1036 
                Err(e) => return Err(e.into()),
1037 
            });
1038 
        }
1039 
        let chunk_refs: Vec<ObjectRef> = blobs
1040 
            .iter()
1041 
            .flatten()
1042 
            .flat_map(|b| b.chunks.iter().copied())
1043 
            .collect();
1044 
        let mut chunks = self.store.get_many(&chunk_refs).into_iter();
1045 
        let mut out = Vec::with_capacity(refs.len());
1046 
        for (r, blob) in refs.iter().zip(blobs) {
1047 
            match blob {
1048 
                None => out.push(self.read_blob(r)?),
1049 
                Some(b) => {
1050 
                    let mut content = Vec::with_capacity(b.length as usize);
1051 
                    for c in &b.chunks {
1052 
                        match chunks.next() {
1053 
                            Some(Ok((ObjectType::Chunk, body))) => content.extend(body),
1054 
                            Some(Ok(_)) => return fail(format!("{} is not a chunk", c.short(12))),
1055 
                            Some(Err(e)) => return Err(e.into()),
1056 
                            None => return fail("chunk list ended early"),
1057 
                        }
1058 
                    }
1059 
                    out.push(content);
1060 
                }
1061 
            }
1062 
        }
1063 
        Ok(out)
1064 
    }
1065
b3c5a59a Andy McCall ↶ 1066 
    /// Read a blob's content, fetching it from the remote that withheld it
1067 
    /// when it is lazily absent (spec §13.5).
98286406 Andy McCall ↶ 1068 
    pub fn read_blob(&self, r: &ObjectRef) -> Result<Vec<u8>> {
b3c5a59a Andy McCall ↶ 1069 
        if !self.store.has(r) && self.lazy_remote(r).is_some() {
1070 
            self.fetch_lazy_blob(r)?;
1071 
        }
98286406 Andy McCall ↶ 1072 
        let blob = Blob::decode(&self.store.get_typed(r, ObjectType::Blob)?)?;
1073 
        let mut out = Vec::with_capacity(blob.length as usize);
1074 
        for c in &blob.chunks {
1075 
            out.extend(self.store.get_typed(c, ObjectType::Chunk)?);
1076 
        }
1077 
        Ok(out)
1078 
    }
1079
1080 
    // ------------------------------------------------------------ working copy
1081
cdb5beba Andy McCall ↶ 1082 
    /// Attributes from the `.oxyattributes` files in the working directory.
1083 
    pub fn disk_attributes(&self) -> crate::attributes::Attributes {
f9466021 Andy McCall ↶ 1084 
        // Nested repositories and ignored paths are left out, as in a walk.
1085 
        let listing = walk::list(&self.root, &|p: &str| is_attributes(p)).unwrap_or_default();
1086 
        let files: Vec<(String, Vec<u8>)> = listing
1087 
            .files
1088 
            .into_iter()
1089 
            .filter_map(|(rel, path, _)| Some((rel, fs::read(path).ok()?)))
1090 
            .collect();
75167672 Andy McCall 1091 
        crate::attributes::Attributes::from_files(
1092 
            files.iter().map(|(p, c)| (p.as_str(), c.as_slice())),
1093 
        )
cdb5beba Andy McCall ↶ 1094 
    }
1095
1096 
    /// Attributes from a materialized state's `.oxyattributes` files.
1097 
    pub fn state_attributes(snapshot: &Snapshot) -> crate::attributes::Attributes {
75167672 Andy McCall 1098 
        crate::attributes::Attributes::from_files(snapshot.files.iter().filter_map(|(p, f)| {
1099 
            match &f.content {
1100 
                FileContent::Text { bytes, .. }
1101 
                    if p == ".oxyattributes" || p.ends_with("/.oxyattributes") =>
1102 
                {
1103 
                    Some((p.as_str(), bytes.as_slice()))
1104 
                }
1105 
                _ => None,
1106 
            }
cdb5beba Andy McCall ↶ 1107 
        }))
1108 
    }
1109
1110 
    /// Store a blob, raw when the path is `nocompress`.
1111 
    pub fn store_blob_for(&self, content: &[u8], nocompress: bool) -> Result<ObjectRef> {
1112 
        if !nocompress {
1113 
            return self.store_blob(content);
1114 
        }
1115 
        for c in crate::chunk::chunks(content) {
1116 
            self.store.put_chunk_nocompress(c)?;
1117 
        }
75167672 Andy McCall 1118 
        Ok(self
1119 
            .store
1120 
            .put(ObjectType::Blob, &Self::blob_for(content).encode())?)
cdb5beba Andy McCall ↶ 1121 
    }
1122
f9575918 Andy McCall ↶ 1123 
    /// This workspace's state index (oxygen#41): its working copy's base,
1124 
    /// saved so a snapshot reads it rather than replaying history.
1125 
    fn state_index_path(&self) -> PathBuf {
1126 
        self.oxy
1127 
            .join("index")
1128 
            .join(format!("state-{}", self.workspace.to_hex()))
1129 
    }
1130
1131 
    /// The history-only state of `deps` (as [`Repo::load_state_history`]),
1132 
    /// from this workspace's state index when it holds that history: every
1133 
    /// one of `deps` is in it and their heads are its heads. Otherwise it
1134 
    /// is loaded from history and indexed for next time.
1135 
    pub fn load_state_indexed(&self, deps: &[ChangeHash]) -> Result<State> {
f9466021 Andy McCall ↶ 1136 
        if let Some((st, heads)) = self.read_state_index() {
1137 
            let mut have = st.maximal(deps);
1138 
            have.sort();
1139 
            if deps.iter().all(|d| st.contains(d)) && have == heads {
1140 
                #[cfg(test)]
1141 
                assert_eq!(
1142 
                    st.write_index(),
1143 
                    self.load_state_history(deps)?.write_index(),
1144 
                    "a state index holds the state history gives"
1145 
                );
1146 
                return Ok(st);
1147 
            }
1148 
            // An index a few changes behind (a commit, a pull since): add
1149 
            // what it lacks, as long as all it holds is history of `deps`.
1150 
            // Anything amiss (a change beyond a shallow boundary) takes the
1151 
            // long way instead.
1152 
            let (indexed, started) = (st.len(), std::time::Instant::now());
1153 
            if let Ok(st) = self.load_state_replayed(deps, st) {
1154 
                let mut all = deps.to_vec();
1155 
                all.extend(heads.iter().copied());
1156 
                let (mut within, mut want) = (st.maximal(&all), st.maximal(deps));
1157 
                within.sort();
1158 
                want.sort();
1159 
                if within == want {
1160 
                    #[cfg(test)]
1161 
                    self.assert_same_state(&st, &self.load_state_history(deps)?);
1162 
                    // Writing the index costs far more than replaying a
1163 
                    // few small changes: it is rewritten once it falls
1164 
                    // behind, or when replaying took long (large changes).
1165 
                    if st.len() - indexed > INDEX_REPLAY_LIMIT
1166 
                        || started.elapsed() > INDEX_REPLAY_TIME
1167 
                    {
1168 
                        self.write_state_index(deps, &st);
1169 
                    }
1170 
                    return Ok(st);
1171 
                }
1172 
            }
f9575918 Andy McCall ↶ 1173 
        }
1174 
        let st = self.load_state_history(deps)?;
1175 
        self.write_state_index(deps, &st);
1176 
        Ok(st)
f9466021 Andy McCall ↶ 1177 
    }
1178
1179 
    /// Two history-only states hold the same changes and render the same
1180 
    /// files. Their indexes may differ: one loaded from a checkpoint keeps
1181 
    /// the checkpoint's graphs as the bases of its files' histories.
1182 
    #[cfg(test)]
1183 
    fn assert_same_state(&self, a: &State, b: &State) {
1184 
        let ids = |s: &State| s.changes().map(|(h, _)| *h).collect::<BTreeSet<_>>();
1185 
        assert_eq!(ids(a), ids(b), "the same changes");
1186 
        let files = |s: &State| {
1187 
            let mut s = s.clone();
1188 
            self.load_all_graphs(&mut s).unwrap();
1189 
            s.materialize().files
1190 
        };
1191 
        assert_eq!(files(a), files(b), "the same files");
f9575918 Andy McCall ↶ 1192 
    }
1193
4cce912a Andy McCall ↶ 1194 
    /// The state index file: its heads, a hash of its changes block and one
1195 
    /// of the rest, then the body [`State::write_index`] gives, whose first
1196 
    /// block is the changes. Hashed in two parts so the log can read and
1197 
    /// check the changes alone.
f9466021 Andy McCall ↶ 1198 
    fn read_state_index(&self) -> Option<(State, Vec<ChangeHash>)> {
f9575918 Andy McCall ↶ 1199 
        let _t = crate::timing::phase("load: state index");
1200 
        let bytes = fs::read(self.state_index_path()).ok()?;
1201 
        let mut r = crate::flat::Reader::new(&bytes);
1202 
        let mut heads = Vec::new();
1203 
        for _ in 0..r.count().ok()? {
1204 
            heads.push(r.object().ok()?);
1205 
        }
4cce912a Andy McCall ↶ 1206 
        let (changes_sum, rest_sum) = (r.object().ok()?, r.object().ok()?);
1207 
        let body = &bytes[4 + 32 * heads.len() + 64..];
1208 
        let split = 4 + r.count().ok()?;
1209 
        // Checked whole, so a part decoded later (the tree's maps, a
1210 
        // file's history) can trust its bytes.
1211 
        let (changes, rest) = (body.get(..split)?, body.get(split..)?);
05059d43 Andy McCall ↶ 1212 
        let mut h = blake3::Hasher::new();
4cce912a Andy McCall ↶ 1213 
        h.update_rayon(rest);
1214 
        if *blake3::hash(changes).as_bytes() != changes_sum.0
1215 
            || *h.finalize().as_bytes() != rest_sum.0
1216 
        {
f9575918 Andy McCall ↶ 1217 
            return None;
1218 
        }
f9466021 Andy McCall ↶ 1219 
        Some((State::read_index(body).ok()?, heads))
4cce912a Andy McCall ↶ 1220 
    }
1221
1222 
    /// The changes of this workspace's state index (the closure of its
1223 
    /// heads), read without the rest of the index.
1224 
    pub(crate) fn read_state_index_changes(
1225 
        &self,
1226 
    ) -> Option<std::collections::HashMap<ChangeHash, std::sync::Arc<crate::state::ChangeMeta>>>
1227 
    {
1228 
        use std::io::Read;
1229 
        let _t = crate::timing::phase("load: state index changes");
1230 
        let mut f = fs::File::open(self.state_index_path()).ok()?;
1231 
        let mut word = [0u8; 4];
1232 
        f.read_exact(&mut word).ok()?;
1233 
        let n = u32::from_le_bytes(word) as usize;
1234 
        let mut head = vec![0u8; 32 * n + 64 + 4];
1235 
        f.read_exact(&mut head).ok()?;
1236 
        let sum = &head[32 * n..32 * n + 32];
1237 
        let len = u32::from_le_bytes(head[32 * n + 64..].try_into().unwrap()) as usize;
1238 
        let mut changes = vec![0u8; 4 + len];
1239 
        changes[..4].copy_from_slice(&head[32 * n + 64..]);
1240 
        f.read_exact(&mut changes[4..]).ok()?;
1241 
        if blake3::hash(&changes).as_bytes() != sum {
1242 
            return None;
1243 
        }
1244 
        State::read_index_changes(&changes[4..]).ok()
f9575918 Andy McCall ↶ 1245 
    }
1246
1247 
    /// Save `st`, the history-only state of `deps`, as this workspace's
1248 
    /// state index; quietly nothing when it cannot be (it is only a cache).
1249 
    pub(crate) fn write_state_index(&self, deps: &[ChangeHash], st: &State) {
1250 
        let _t = crate::timing::phase("write: state index");
f9466021 Andy McCall ↶ 1251 
        let encoding = crate::timing::phase("write:   of which encoding");
f9575918 Andy McCall ↶ 1252 
        let Some(body) = st.write_index() else {
1253 
            return;
1254 
        };
f9466021 Andy McCall ↶ 1255 
        drop(encoding);
3f1b8fe2 Andy McCall ↶ 1256 
        #[cfg(test)]
1257 
        assert_eq!(
1258 
            State::read_index(&body).ok().and_then(|s| s.write_index()),
1259 
            Some(body.clone()),
1260 
            "a state index reads back as written"
1261 
        );
f9575918 Andy McCall ↶ 1262 
        let mut heads = st.maximal(deps);
1263 
        heads.sort();
1264 
        let mut w = crate::flat::Writer::default();
1265 
        w.count(heads.len());
1266 
        for h in &heads {
1267 
            w.object(h);
1268 
        }
4cce912a Andy McCall ↶ 1269 
        let split = 4 + u32::from_le_bytes(body[..4].try_into().unwrap()) as usize;
1270 
        w.fixed(blake3::hash(&body[..split]).as_bytes());
05059d43 Andy McCall ↶ 1271 
        let mut sum = blake3::Hasher::new();
4cce912a Andy McCall ↶ 1272 
        sum.update_rayon(&body[split..]);
05059d43 Andy McCall ↶ 1273 
        w.fixed(sum.finalize().as_bytes());
f9575918 Andy McCall ↶ 1274 
        w.fixed(&body);
1275 
        let path = self.state_index_path();
f9466021 Andy McCall ↶ 1276 
        let _ = fs::create_dir_all(self.oxy.join("index"));
1277 
        let _ = write_cache(&path, &w.0);
f9575918 Andy McCall ↶ 1278 
    }
1279
cdb5beba Andy McCall ↶ 1280 
    fn locks_dir(&self) -> PathBuf {
1281 
        self.oxy.join("locks")
1282 
    }
1283
1284 
    /// Whether `path` is locked locally for editing (spec §18, advisory).
1285 
    pub fn is_locked(&self, path: &str) -> bool {
1286 
        self.locks_dir().join(path.replace('/', "%2F")).exists()
1287 
    }
1288
1289 
    /// Take the advisory local lock on a `lockable` file and make it writable.
1290 
    pub fn lock_path(&self, path: &str) -> Result<()> {
1291 
        let attrs = self.disk_attributes();
1292 
        if !attrs.lookup(path).lockable {
1293 
            return fail(format!("{path} is not marked lockable in .oxyattributes"));
1294 
        }
1295 
        fs::create_dir_all(self.locks_dir())?;
75167672 Andy McCall 1296 
        write_atomic(
1297 
            &self.locks_dir().join(path.replace('/', "%2F")),
1298 
            std::process::id().to_string().as_bytes(),
1299 
        )?;
cdb5beba Andy McCall ↶ 1300 
        set_readonly(&self.root.join(path), false)?;
1301 
        Ok(())
1302 
    }
1303
1304 
    /// Release the local lock and make the file read-only again.
1305 
    pub fn unlock_path(&self, path: &str) -> Result<()> {
1306 
        let _ = fs::remove_file(self.locks_dir().join(path.replace('/', "%2F")));
1307 
        if self.root.join(path).exists() {
1308 
            set_readonly(&self.root.join(path), true)?;
1309 
        }
1310 
        Ok(())
1311 
    }
1312
7421309f Andy McCall ↶ 1313 
    /// Whether a repository path is inside the sparse filter (spec §17).
1314 
    pub fn in_scope(&self, path: &str) -> bool {
75167672 Andy McCall 1315 
        self.config.sparse_paths.is_empty()
1316 
            || self
1317 
                .config
1318 
                .sparse_paths
1319 
                .iter()
1320 
                .any(|p| path == p || path.starts_with(&format!("{p}/")))
7421309f Andy McCall ↶ 1321 
    }
1322
98286406 Andy McCall ↶ 1323 
    fn walk_working_copy(&self) -> Result<BTreeMap<String, FsEntry>> {
696bbf29 Andy McCall ↶ 1324 
        self.walk_working_copy_with(None, &BTreeMap::new(), None)
4dee277c Andy McCall ↶ 1325 
    }
1326
b7f102fc Andy McCall ↶ 1327 
    /// Walk the working copy; with a manifest, a file whose size and mtime
cc7a0056 Andy McCall ↶ 1328 
    /// match it is not read: an opaque file yields its known blob, and a
1329 
    /// text file whose recorded graph key equals its base graph's key in
1330 
    /// `keys` (path → key) is marked unchanged; other text files are read
1331 
    /// but keep their known hash. Files modified within two seconds of the
1332 
    /// manifest are never trusted (a racy stat).
1333 
    ///
1334 
    /// `.oxyattributes` files are always read, since their content is
1335 
    /// needed; and when any of them is not known unchanged (added, removed,
1336 
    /// edited, or changed in the base), no text file is taken as unchanged,
1337 
    /// because attributes decide how a file compares with the base.
9ac1fbe2 Andy McCall ↶ 1338 
    ///
1339 
    /// `.oxyignore` applies to untracked paths only: every path in `tracked`
1340 
    /// (the base state's files) that exists on disk is included even when
1341 
    /// an ignore rule matches it, as in Git.
75167672 Andy McCall 1342 
    fn walk_working_copy_with(
1343 
        &self,
1344 
        cache: Option<&prompt::Manifest>,
1345 
        tracked: &BTreeMap<String, (NodeKind, Option<ObjectRef>)>,
992467d3 Andy McCall ↶ 1346 
        keys: Option<&KeyOf>,
75167672 Andy McCall 1347 
    ) -> Result<BTreeMap<String, FsEntry>> {
98286406 Andy McCall ↶ 1348 
        let mut out = BTreeMap::new();
76740263 Andy McCall ↶ 1349 
        let sparse = &self.config.sparse_paths;
8b276e01 Andy McCall ↶ 1350 
        let in_scope = |p: &str| {
1351 
            sparse.is_empty()
1352 
                || sparse
1353 
                    .iter()
1354 
                    .any(|s| p == s || p.starts_with(&format!("{s}/")))
1355 
        };
76740263 Andy McCall ↶ 1356 
        let walk_phase = crate::timing::phase("walk:   of which listing");
1357 
        let walk::Listing {
1358 
            files,
1359 
            symlinks,
1360 
            nested,
1361 
        } = match self.listing_cache.take() {
1362 
            Some(l) => l,
1363 
            None => walk::list(&self.root, &in_scope)?,
1364 
        };
1365 
        for (rel, target) in symlinks {
1366 
            out.insert(rel, FsEntry::new(NodeKind::Symlink, false, target));
e7ddd552 Andy McCall ↶ 1367 
        }
cc7a0056 Andy McCall ↶ 1368 
        let keys = keys.filter(|k| {
1369 
            let on_disk: HashSet<&str> = files.iter().map(|(r, _, _)| r.as_str()).collect();
1370 
            let attrs_unchanged =
1371 
                files
1372 
                    .iter()
1373 
                    .filter(|(r, _, _)| is_attributes(r))
1374 
                    .all(|(rel, _, meta)| {
1375 
                        stat_cached(rel, meta, cache)
992467d3 Andy McCall ↶ 1376 
                            .is_some_and(|e| e.graph.is_some() && e.graph == k(rel))
cc7a0056 Andy McCall ↶ 1377 
                    });
1378 
            let none_removed = tracked
1379 
                .keys()
1380 
                .filter(|r| is_attributes(r))
1381 
                .all(|r| on_disk.contains(r.as_str()));
1382 
            attrs_unchanged && none_removed
1383 
        });
76740263 Andy McCall ↶ 1384 
        drop(walk_phase);
1385 
        let _read_phase = crate::timing::phase("walk:   of which stat and compare");
e7ddd552 Andy McCall ↶ 1386 
        // Reading files is most of a walk's cost; do it in parallel.
1387 
        {
1388 
            use rayon::prelude::*;
1389 
            let read: Vec<(String, FsEntry)> = files
1390 
                .par_iter()
1391 
                .map(|(rel, path, meta)| {
992467d3 Andy McCall ↶ 1392 
                    // A key is worked out only for a file the manifest
1393 
                    // knows with the same stat and a key of its own.
cc7a0056 Andy McCall ↶ 1394 
                    let key = keys
1395 
                        .filter(|_| !is_attributes(rel))
992467d3 Andy McCall ↶ 1396 
                        .filter(|_| {
1397 
                            stat_cached(rel, meta, cache).is_some_and(|e| e.graph.is_some())
1398 
                        })
1399 
                        .and_then(|k| k(rel));
1966f5db Andy McCall ↶ 1400 
                    Ok((rel.clone(), read_file_entry(rel, path, meta, cache, key)?))
e7ddd552 Andy McCall ↶ 1401 
                })
1402 
                .collect::<Result<Vec<_>>>()?;
1403 
            for (rel, mut e) in read {
1404 
                // A cached blob the store lost (gc, a partial clone): read the file after all.
1405 
                if e.content.is_empty() && e.blob.is_some_and(|b| !self.store.has(&b)) {
40a40bb7 Andy McCall ↶ 1406 
                    e.content = std::sync::Arc::new(fs::read(self.root.join(&rel))?);
e7ddd552 Andy McCall ↶ 1407 
                    e.blob = None;
1408 
                }
9ac1fbe2 Andy McCall ↶ 1409 
                out.insert(rel, e);
98286406 Andy McCall ↶ 1410 
            }
1411 
        }
76740263 Andy McCall ↶ 1412 
        drop(_read_phase);
1413 
        let _rest = crate::timing::phase("walk:   of which subrepos and hidden");
4dee277c Andy McCall ↶ 1414 
        // Nested repositories (spec §7.8): registered in `.oxymodules` or
1415 
        // already tracked as subrepo nodes, they contribute their pin;
1416 
        // unregistered ones are left alone.
1417 
        let modules = self.modules_on_disk();
1418 
        let removed = self.removed_subrepos();
1419 
        for rel in &removed {
1420 
            if tracked.get(rel).map(|(k, _)| *k) != Some(NodeKind::Subrepo) {
1421 
                self.clear_removed_subrepo(rel);
1422 
            }
1423 
        }
76740263 Andy McCall ↶ 1424 
        for dir in nested {
4dee277c Andy McCall ↶ 1425 
            let rel = self.rel_path(&dir);
1426 
            if !self.in_scope(&rel) || removed.contains(&rel) {
1427 
                continue;
1428 
            }
1429 
            let registered = modules.entries.get(&rel);
75167672 Andy McCall 1430 
            if registered.is_none() && tracked.get(&rel).map(|(k, _)| *k) != Some(NodeKind::Subrepo)
1431 
            {
4dee277c Andy McCall ↶ 1432 
                continue;
1433 
            }
1434 
            let pin = subrepos::read_pin(&dir, registered.and_then(|m| m.bookmark.as_deref()))?;
1435 
            out.insert(rel, FsEntry::new(NodeKind::Subrepo, false, pin.encode()));
1436 
        }
9ac1fbe2 Andy McCall ↶ 1437 
        // Tracked paths the ignore rules hid.
4dee277c Andy McCall ↶ 1438 
        for (rel, (kind, blob)) in tracked {
9ac1fbe2 Andy McCall ↶ 1439 
            if out.contains_key(rel) || !self.in_scope(rel) {
1440 
                continue;
1441 
            }
1442 
            let path = self.root.join(rel);
4dee277c Andy McCall ↶ 1443 
            if *kind == NodeKind::Subrepo {
1444 
                if removed.contains(rel) {
1445 
                    continue;
1446 
                }
75167672 Andy McCall 1447 
                let present =
1448 
                    path.is_dir() && (path.join(OXY_DIR).exists() || path.join(".git").exists());
4dee277c Andy McCall ↶ 1449 
                if present {
75167672 Andy McCall 1450 
                    let pin = subrepos::read_pin(
1451 
                        &path,
1452 
                        modules.entries.get(rel).and_then(|m| m.bookmark.as_deref()),
1453 
                    )?;
1454 
                    out.insert(
1455 
                        rel.clone(),
1456 
                        FsEntry::new(NodeKind::Subrepo, false, pin.encode()),
1457 
                    );
4dee277c Andy McCall ↶ 1458 
                } else if let Some(b) = blob {
1459 
                    // Not cloned (or emptied): the pin stays as recorded, as a
1460 
                    // Git gitlink does when its directory is absent.
75167672 Andy McCall 1461 
                    out.insert(
1462 
                        rel.clone(),
1463 
                        FsEntry {
1464 
                            blob: Some(*b),
cc7a0056 Andy McCall ↶ 1465 
                            ..FsEntry::new(NodeKind::Subrepo, false, vec![])
75167672 Andy McCall 1466 
                        },
1467 
                    );
4dee277c Andy McCall ↶ 1468 
                }
1469 
                continue;
1470 
            }
75167672 Andy McCall 1471 
            let Ok(meta) = fs::symlink_metadata(&path) else {
1472 
                continue;
1473 
            };
9ac1fbe2 Andy McCall ↶ 1474 
            let ft = meta.file_type();
1475 
            if ft.is_symlink() {
1476 
                let target = fs::read_link(&path)?;
75167672 Andy McCall 1477 
                out.insert(
1478 
                    rel.clone(),
1479 
                    FsEntry::new(
1480 
                        NodeKind::Symlink,
1481 
                        false,
1482 
                        target.to_string_lossy().as_bytes().to_vec(),
1483 
                    ),
1484 
                );
9ac1fbe2 Andy McCall ↶ 1485 
            } else if ft.is_file() {
1486 
                let e = self.file_entry(rel, &path, &meta, cache)?;
1487 
                out.insert(rel.clone(), e);
1488 
            }
1489 
        }
98286406 Andy McCall ↶ 1490 
        Ok(out)
1491 
    }
9ac1fbe2 Andy McCall ↶ 1492
1493 
    /// The entry for one regular file, read or served from the stat cache.
75167672 Andy McCall 1494 
    fn file_entry(
1495 
        &self,
1496 
        rel: &str,
1497 
        path: &Path,
1498 
        meta: &fs::Metadata,
1499 
        cache: Option<&prompt::Manifest>,
1500 
    ) -> Result<FsEntry> {
696bbf29 Andy McCall ↶ 1501 
        let mut e = read_file_entry(rel, path, meta, cache, None)?;
e7ddd552 Andy McCall ↶ 1502 
        if e.content.is_empty() && e.blob.is_some_and(|b| !self.store.has(&b)) {
40a40bb7 Andy McCall ↶ 1503 
            e.content = std::sync::Arc::new(fs::read(path)?);
e7ddd552 Andy McCall ↶ 1504 
            e.blob = None;
1505 
        }
1506 
        Ok(e)
9ac1fbe2 Andy McCall ↶ 1507 
    }
1508
4dee277c Andy McCall ↶ 1509 
    /// The non-directory paths of a snapshot with their kinds, for the
1510 
    /// walker's `tracked` set.
75167672 Andy McCall 1511 
    pub(crate) fn tracked_kinds(
1512 
        snapshot: &Snapshot,
1513 
    ) -> BTreeMap<String, (NodeKind, Option<ObjectRef>)> {
4dee277c Andy McCall ↶ 1514 
        snapshot
1515 
            .files
1516 
            .iter()
1517 
            .filter(|(_, f)| f.kind != NodeKind::Dir)
1518 
            .map(|(p, f)| {
1519 
                let blob = match &f.content {
1520 
                    FileContent::Opaque { blobs } => blobs.first().copied(),
1521 
                    _ => None,
1522 
                };
1523 
                (p.clone(), (f.kind, blob))
1524 
            })
1525 
            .collect()
1526 
    }
1527
1528 
    /// A path under the root as a `/`-separated relative string.
1529 
    pub(crate) fn rel_path(&self, path: &Path) -> String {
75167672 Andy McCall 1530 
        path.strip_prefix(&self.root)
1531 
            .unwrap_or(path)
1532 
            .components()
1533 
            .map(|c| c.as_os_str().to_string_lossy().to_string())
1534 
            .collect::<Vec<_>>()
1535 
            .join("/")
9ac1fbe2 Andy McCall ↶ 1536 
    }
98286406 Andy McCall ↶ 1537 
}
1538
1539 
impl Repo {
1540 
    /// Changes reachable from the bookmark and the working copy, newest first.
1541 
    pub fn log(&self) -> Result<Vec<LogEntry>> {
e02bf0cd Andy McCall ↶ 1542 
        let heads = self.bookmark_heads()?;
1543 
        if self.bare {
1544 
            return self.log_state(&heads);
1545 
        }
98286406 Andy McCall ↶ 1546 
        let (wc_hash, _) = self.working_copy()?;
e02bf0cd Andy McCall ↶ 1547 
        let mut all = heads.clone();
1548 
        all.push(wc_hash);
1549 
        let head_set: BTreeSet<ChangeHash> = heads.into_iter().collect();
252e8cb2 Andy McCall ↶ 1550 
        let mut entries: Vec<LogEntry> = Vec::new();
4d6c9c1b Andy McCall ↶ 1551 
        // A shallow clone knows changes beyond its boundary from a
1552 
        // checkpoint's metadata only: its log comes from the state.
1553 
        let metas = if self.is_shallow() {
1554 
            self.load_state_history(&all)?
1555 
                .changes()
1556 
                .map(|(h, m)| (*h, m.clone()))
1557 
                .collect()
1558 
        } else {
1559 
            self.metas_of(&all)?
1560 
        };
1561 
        for (h, meta) in metas {
75167672 Andy McCall 1562 
            entries.push(LogEntry {
4d6c9c1b Andy McCall ↶ 1563 
                hash: h,
1564 
                change: meta,
1565 
                is_working_copy: h == wc_hash,
1566 
                is_head: head_set.contains(&h),
75167672 Andy McCall 1567 
            });
252e8cb2 Andy McCall ↶ 1568 
        }
75167672 Andy McCall 1569 
        entries.sort_by(|a, b| {
1570 
            b.is_working_copy
1571 
                .cmp(&a.is_working_copy)
1572 
                .then(b.change.hlc.cmp(&a.change.hlc))
1573 
                .then(b.hash.cmp(&a.hash))
1574 
        });
98286406 Andy McCall ↶ 1575 
        Ok(entries)
1576 
    }
1577
119bbf50 Andy McCall ↶ 1578 
    /// A window of `log_state`: entries `offset..offset+limit` and the total
1579 
    /// count, for paginated views.
9d333fc9 Andy McCall ↶ 1580 
    pub fn log_window(
1581 
        &self,
1582 
        heads: &[ChangeHash],
1583 
        offset: usize,
1584 
        limit: usize,
1585 
    ) -> Result<(Vec<LogEntry>, usize)> {
119bbf50 Andy McCall ↶ 1586 
        let all = self.log_state(heads)?;
1587 
        let total = all.len();
1588 
        Ok((all.into_iter().skip(offset).take(limit).collect(), total))
1589 
    }
1590
e02bf0cd Andy McCall ↶ 1591 
    /// The log of the state with these heads, newest first, with no working
1592 
    /// copy involved (for hosted repositories and any explicit state).
1593 
    pub fn log_state(&self, heads: &[ChangeHash]) -> Result<Vec<LogEntry>> {
4d6c9c1b Andy McCall ↶ 1594 
        // The log needs change metadata only: neither graphs nor the tree.
1595 
        if self.is_shallow() {
1596 
            return Ok(self.log_of(&self.load_state_history(heads)?));
1597 
        }
1598 
        let metas = self.metas_of(heads)?;
1599 
        let depended: BTreeSet<ChangeHash> = metas
1600 
            .iter()
1601 
            .flat_map(|(_, m)| m.deps.iter().copied())
1602 
            .collect();
1603 
        let mut entries: Vec<LogEntry> = metas
1604 
            .into_iter()
1605 
            .map(|(h, meta)| LogEntry {
1606 
                hash: h,
1607 
                is_head: !depended.contains(&h),
1608 
                change: meta,
1609 
                is_working_copy: false,
1610 
            })
1611 
            .collect();
1612 
        entries.sort_by(|a, b| b.change.hlc.cmp(&a.change.hlc).then(b.hash.cmp(&a.hash)));
1613 
        Ok(entries)
1614 
    }
1615
1616 
    /// Every change of the state with these heads and its metadata, read
1617 
    /// without its operations ([`Store::get_change_meta`]). A change beyond
1618 
    /// a shallow clone's boundary is left out.
1619 
    pub fn metas_of(
1620 
        &self,
1621 
        heads: &[ChangeHash],
1622 
    ) -> Result<Vec<(ChangeHash, crate::state::ChangeMeta)>> {
1623 
        let boundary = self.boundary();
4cce912a Andy McCall ↶ 1624 
        // The state index holds the metadata of its heads' closure: a
1625 
        // change found there is not read from the store (a change object
1626 
        // can be as large as the tree it adds).
1627 
        let indexed = self.read_state_index_changes();
1628 
        let (mut stored, mut from_store) = (0usize, std::time::Duration::ZERO);
4d6c9c1b Andy McCall ↶ 1629 
        let mut seen: HashSet<ChangeHash> = HashSet::new();
1630 
        let mut stack: Vec<ChangeHash> = heads.to_vec();
1631 
        let mut out = Vec::new();
1632 
        while let Some(h) = stack.pop() {
1633 
            if !seen.insert(h) {
1634 
                continue;
1635 
            }
4cce912a Andy McCall ↶ 1636 
            if let Some(meta) = indexed.as_ref().and_then(|m| m.get(&h)) {
1637 
                #[cfg(test)]
1638 
                assert_eq!(
1639 
                    **meta,
1640 
                    self.store.get_change_meta(&h)?,
1641 
                    "the state index holds a change's metadata"
1642 
                );
1643 
                stack.extend(meta.deps.iter().copied());
1644 
                out.push((h, (**meta).clone()));
1645 
                continue;
1646 
            }
1647 
            let started = std::time::Instant::now();
4d6c9c1b Andy McCall ↶ 1648 
            let meta = match self.store.get_change_meta(&h) {
1649 
                Ok(m) => m,
1650 
                Err(crate::store::StoreError::NotFound(_)) if boundary.contains(&h) => continue,
1651 
                Err(e) => return Err(e.into()),
1652 
            };
4cce912a Andy McCall ↶ 1653 
            stored += 1;
1654 
            from_store += started.elapsed();
4d6c9c1b Andy McCall ↶ 1655 
            stack.extend(meta.deps.iter().copied());
1656 
            out.push((h, meta));
4cce912a Andy McCall ↶ 1657 
        }
1658 
        if stored > 0 && crate::timing::enabled() {
1659 
            eprintln!("timing metadata: {stored} changes read whole, {from_store:.2?}");
4d6c9c1b Andy McCall ↶ 1660 
        }
1661 
        Ok(out)
bc489b6c Andy McCall ↶ 1662 
    }
1663
1664 
    /// The log of a state already loaded, newest first.
83d61e80 Andy McCall ↶ 1665 
    /// The history of lines `first..=last` (1-based) of `path` in the
1666 
    /// state `heads` make (spec §27): every change that inserted or
1667 
    /// deleted one of their atoms, or an atom deleted from between them,
1668 
    /// newest first. Exact, as atoms keep their identity across edits.
1669 
    pub fn line_history(
1670 
        &self,
1671 
        heads: &[ChangeHash],
1672 
        path: &str,
1673 
        first: usize,
1674 
        last: usize,
1675 
    ) -> Result<Vec<LogEntry>> {
1676 
        if first == 0 || last < first {
1677 
            return fail(format!(
1678 
                "lines {first},{last}: expected FIRST,LAST from 1 with FIRST ≤ LAST"
1679 
            ));
1680 
        }
1681 
        let mut state = self.load_state_history(heads)?;
1682 
        let Some(node) = state.tree().view().entries.get(path).map(|e| e.node) else {
1683 
            return fail(format!("{path} is not in that state"));
1684 
        };
1685 
        self.load_graphs_of(&mut state, &[node])?;
1686 
        let live = state.live_lines(&node);
1687 
        if last > live.len() {
1688 
            return fail(format!(
1689 
                "{path} has {} lines; asked for {first},{last}",
1690 
                live.len()
1691 
            ));
1692 
        }
1693 
        let Some(g) = state.file(&node) else {
1694 
            return fail(format!("{path} is not a text file"));
1695 
        };
1696 
        let atoms = g.between(&live[first - 1].0, &live[last - 1].0);
1697 
        let touched = g.touching(&atoms);
1698 
        Ok(self
1699 
            .log_of(&state)
1700 
            .into_iter()
1701 
            .filter(|e| touched.contains(&e.hash))
1702 
            .collect())
1703 
    }
1704
bc489b6c Andy McCall ↶ 1705 
    pub fn log_of(&self, state: &crate::state::State) -> Vec<LogEntry> {
e02bf0cd Andy McCall ↶ 1706 
        let head_set: BTreeSet<ChangeHash> = state.heads().into_iter().collect();
1707 
        let mut entries: Vec<LogEntry> = state
1708 
            .changes()
75167672 Andy McCall 1709 
            .map(|(h, meta)| LogEntry {
1710 
                hash: *h,
1711 
                change: meta.clone(),
1712 
                is_working_copy: false,
1713 
                is_head: head_set.contains(h),
1714 
            })
e02bf0cd Andy McCall ↶ 1715 
            .collect();
1716 
        entries.sort_by(|a, b| b.change.hlc.cmp(&a.change.hlc).then(b.hash.cmp(&a.hash)));
bc489b6c Andy McCall ↶ 1717 
        entries
e02bf0cd Andy McCall ↶ 1718 
    }
1719
132b884b Andy McCall ↶ 1720 
    /// Resolve a spec to a set of heads: a tag name, the current bookmark's
1721 
    /// name, or a single change (`resolve_change`).
1722 
    pub fn resolve_heads(&self, spec: &str) -> Result<Vec<ChangeHash>> {
7b9809e6 Andy McCall ↶ 1723 
        let view = self.view()?;
1724 
        if let Some(st) = view.bookmarks.get(spec) {
1725 
            return Ok(self.store.get_state(st)?.heads);
132b884b Andy McCall ↶ 1726 
        }
1727 
        if let Some(heads) = self.tag_heads(spec)? {
1728 
            return Ok(heads);
1729 
        }
1730 
        Ok(vec![self.resolve_change(spec)?])
1731 
    }
1732
6a81dbab Andy McCall ↶ 1733 
    /// Resolve a change by ChangeId prefix, `#hash` prefix, `@` (working
1734 
    /// copy), bookmark or tag (the one head of its state).
98286406 Andy McCall ↶ 1735 
    pub fn resolve_change(&self, spec: &str) -> Result<ChangeHash> {
1736 
        if spec == "@" {
1737 
            return Ok(self.working_copy()?.0);
1738 
        }
6a81dbab Andy McCall ↶ 1739 
        let named = match self.view()?.bookmarks.get(spec) {
1740 
            Some(st) => Some(("bookmark", self.store.get_state(st)?.heads)),
1741 
            None => self.tag_heads(spec)?.map(|h| ("tag", h)),
1742 
        };
1743 
        if let Some((kind, heads)) = named {
7b9809e6 Andy McCall ↶ 1744 
            return match heads.len() {
1745 
                1 => Ok(heads[0]),
6a81dbab Andy McCall ↶ 1746 
                n => fail(format!("{kind} {spec} has {n} heads; name a change, or use it where a state is expected")),
7b9809e6 Andy McCall ↶ 1747 
            };
1748 
        }
98286406 Andy McCall ↶ 1749 
        if spec.is_empty() || spec == "#" {
1750 
            return fail("empty change specifier");
1751 
        }
1752 
        let entries = self.log()?;
1753 
        let matches: Vec<&LogEntry> = if let Some(hp) = spec.strip_prefix('#') {
75167672 Andy McCall 1754 
            entries
1755 
                .iter()
1756 
                .filter(|e| e.hash.starts_with_hex(hp))
1757 
                .collect()
98286406 Andy McCall ↶ 1758 
        } else {
75167672 Andy McCall 1759 
            entries
1760 
                .iter()
1761 
                .filter(|e| e.change.change_id.starts_with_hex(spec))
1762 
                .collect()
98286406 Andy McCall ↶ 1763 
        };
1764 
        match matches.len() {
1765 
            1 => Ok(matches[0].hash),
1766 
            0 => fail(format!("no change matches {spec:?}")),
1767 
            _ => {
1768 
                let ids: BTreeSet<ChangeId> = matches.iter().map(|e| e.change.change_id).collect();
1769 
                if ids.len() == 1 {
75167672 Andy McCall 1770 
                    fail(format!(
1771 
                        "change {spec} is divergent: {} variants",
1772 
                        matches.len()
1773 
                    ))
98286406 Andy McCall ↶ 1774 
                } else {
1775 
                    fail(format!("{spec:?} is ambiguous"))
1776 
                }
1777 
            }
1778 
        }
1779 
    }
1780
1781 
    /// Human-readable description of what a change does, with line content.
1782 
    pub fn describe_change(&self, hash: &ChangeHash) -> Result<String> {
1783 
        let change = self.store.get_change(hash)?;
8ab265dc Andy McCall ↶ 1784 
        let (base, base_snapshot) = self.change_base(&change)?;
98286406 Andy McCall ↶ 1785 
        Ok(render_change(&change, &base, &base_snapshot))
8ab265dc Andy McCall ↶ 1786 
    }
1787
1788 
    /// The base state of `change` (its dependencies) and its rendering, as
1789 
    /// much as showing the change needs: the whole tree, and the graphs and
1790 
    /// contents of the files the change edits. Other text files are left
1791 
    /// unrendered ([`Snapshot::unrendered`]).
1792 
    pub fn change_base(&self, change: &Change) -> Result<(State, Snapshot)> {
1793 
        let mut base = self.load_state_history(&change.deps)?;
1794 
        let edited: std::collections::HashSet<NodeId> =
1795 
            change.edits.iter().map(|e| e.node()).collect();
1796 
        let nodes: Vec<NodeId> = edited.iter().copied().collect();
1797 
        self.load_graphs_of(&mut base, &nodes)?;
1798 
        let skip: std::collections::HashSet<NodeId> = base
1799 
            .tree()
1800 
            .view()
1801 
            .entries
1802 
            .values()
1803 
            .filter(|e| e.kind == crate::objects::NodeKind::File && !edited.contains(&e.node))
1804 
            .map(|e| e.node)
1805 
            .collect();
1806 
        let snapshot = base.materialize_except(&skip);
1807 
        Ok((base, snapshot))
98286406 Andy McCall ↶ 1808 
    }
1809 
}
1810
1811 
fn remove_any(path: &Path) -> std::io::Result<()> {
1812 
    let m = fs::symlink_metadata(path)?;
75167672 Andy McCall 1813 
    if m.is_dir() {
1814 
        fs::remove_dir_all(path)
1815 
    } else {
1816 
        fs::remove_file(path)
1817 
    }
98286406 Andy McCall ↶ 1818 
}
1819
cdb5beba Andy McCall ↶ 1820 
fn set_readonly(path: &Path, readonly: bool) -> std::io::Result<()> {
1821 
    let mut perms = fs::metadata(path)?.permissions();
1822 
    perms.set_readonly(readonly);
1823 
    fs::set_permissions(path, perms)
1824 
}
1825
98286406 Andy McCall ↶ 1826 
#[cfg(unix)]
1827 
fn set_executable(path: &Path, exec: bool) -> std::io::Result<()> {
1828 
    use std::os::unix::fs::PermissionsExt;
1829 
    let mut perms = fs::metadata(path)?.permissions();
1830 
    let mode = perms.mode();
1831 
    let want = if exec { mode | 0o111 } else { mode & !0o111 };
1832 
    if want != mode {
1833 
        perms.set_mode(want);
1834 
        fs::set_permissions(path, perms)?;
1835 
    }
1836 
    Ok(())
1837 
}
1838 
#[cfg(not(unix))]
1839 
fn set_executable(_path: &Path, _exec: bool) -> std::io::Result<()> {
1840 
    Ok(())
1841 
}
1842
1843 
#[cfg(unix)]
1844 
fn is_executable(m: &fs::Metadata) -> bool {
1845 
    use std::os::unix::fs::PermissionsExt;
1846 
    m.permissions().mode() & 0o111 != 0
1847 
}
1848 
#[cfg(not(unix))]
1849 
fn is_executable(_m: &fs::Metadata) -> bool {
1850 
    false
1851 
}
1852
1853 
fn op_ref(k: OpKey) -> OpRef {
75167672 Andy McCall 1854 
    OpRef {
1855 
        change: k.0,
1856 
        index: k.1,
1857 
    }
98286406 Andy McCall ↶ 1858 
}
1859
1860 
fn split_path(path: &str) -> (&str, &str) {
1861 
    match path.rfind('/') {
1862 
        Some(i) => (&path[..i], &path[i + 1..]),
1863 
        None => ("", path),
1864 
    }
cc7a0056 Andy McCall ↶ 1865 
}
1866
1867 
/// Whether `rel` is an attributes file (spec §7.6).
1868 
fn is_attributes(rel: &str) -> bool {
1869 
    rel == ".oxyattributes" || rel.ends_with("/.oxyattributes")
98286406 Andy McCall ↶ 1870 
}
e7ddd552 Andy McCall ↶ 1871
cc7a0056 Andy McCall ↶ 1872 
/// The manifest entry for `rel` when its size and mtime match it outside
1873 
/// the racy window.
1874 
fn stat_cached<'m>(
1875 
    rel: &str,
1876 
    meta: &fs::Metadata,
1877 
    cache: Option<&'m prompt::Manifest>,
1878 
) -> Option<&'m prompt::ManifestEntry> {
1879 
    let m = cache?;
1880 
    let e = m.entries.get(rel)?;
1881 
    let mtime_ns = prompt::mtime_ns(meta);
1882 
    let racy = mtime_ns + 2_000_000_000 >= m.written_ns;
1883 
    (e.size == meta.len() && e.mtime_ns == mtime_ns && !racy).then_some(e)
1884 
}
1885
1886 
/// Read one working-copy file, or serve it from the stat cache (spec
1887 
/// §12.3). With a manifest whose stat for it is unchanged (and not racy),
1888 
/// an opaque file is not read at all (its stored blob stands in), and a
1889 
/// text file the manifest recorded equal to a base graph whose key is
1890 
/// `key`, the key the base has now, is not read either: equal keys mean
1891 
/// equal renderings, so it still equals the base. Touches no repository
1892 
/// state, so the walk runs it in parallel; the caller checks that a cached
1893 
/// blob is still in the store.
e7ddd552 Andy McCall ↶ 1894 
fn read_file_entry(
1895 
    rel: &str,
1896 
    path: &Path,
1897 
    meta: &fs::Metadata,
1898 
    cache: Option<&prompt::Manifest>,
1966f5db Andy McCall ↶ 1899 
    key: Option<[u8; 32]>,
e7ddd552 Andy McCall ↶ 1900 
) -> Result<FsEntry> {
1901 
    let exec = is_executable(meta);
8b276e01 Andy McCall ↶ 1902 
    let stat = Some((meta.len(), prompt::mtime_ns(meta)));
1903 
    let mut e = match stat_cached(rel, meta, cache) {
e7ddd552 Andy McCall ↶ 1904 
        Some(e) if e.blob.is_some() => FsEntry {
1905 
            blob: e.blob,
1966f5db Andy McCall ↶ 1906 
            content_hash: Some(e.hash),
cc7a0056 Andy McCall ↶ 1907 
            ..FsEntry::new(NodeKind::File, exec, vec![])
1908 
        },
1966f5db Andy McCall ↶ 1909 
        Some(e) if key.is_some() && e.graph == key => FsEntry {
1910 
            content_hash: Some(e.hash),
cc7a0056 Andy McCall ↶ 1911 
            unchanged: true,
1966f5db Andy McCall ↶ 1912 
            graph_key: e.graph,
cc7a0056 Andy McCall ↶ 1913 
            ..FsEntry::new(NodeKind::File, exec, vec![])
1914 
        },
1915 
        Some(e) => FsEntry {
1966f5db Andy McCall ↶ 1916 
            content_hash: Some(e.hash),
cc7a0056 Andy McCall ↶ 1917 
            ..FsEntry::new(NodeKind::File, exec, fs::read(path)?)
e7ddd552 Andy McCall ↶ 1918 
        },
1919 
        None => FsEntry::new(NodeKind::File, exec, fs::read(path)?),
8b276e01 Andy McCall ↶ 1920 
    };
1921 
    // The stat the manifest records: taken before the read, so a file that
1922 
    // changes meanwhile is read again next time.
1923 
    e.stat = stat;
1924 
    Ok(e)
e7ddd552 Andy McCall ↶ 1925 
}