crates/oxy-core/src/repo/inspect.rs at c3d2ef6104c2 · andymccall/oxygen

# c3d2ef6104c2 oxygen / crates / oxy-core / src / repo / inspect.rs

16.3 KiB · Rust · last changed Log, blame and fsck at the scale of the Linux tree 1 month ago source blame history raw

//! Inspection (spec §27): blame from atom keys, and bisect over
//! dependency-closed prefixes of the candidates between a good and a bad
//! state.

use super::*;

/// One line of `oxy blame`.
#[derive(Clone, Debug)]
pub struct BlameLine {
    pub line: usize,
    pub hash: ChangeHash,
    pub index: u32,
    pub change_id: ChangeId,
    pub author: String,
    pub when_ms: u64,
    pub text: Vec<u8>,
}

/// Where a bisect stands.
#[derive(Clone, Debug, PartialEq, Eq)]
pub enum BisectStep {
    /// More `good`/`bad` marks are needed before the search can start.
    NeedMarks { good: usize, bad: usize },
    /// A state is checked out for testing.
    Testing {
        heads: Vec<ChangeHash>,
        remaining: usize,
        steps_left: u32,
    },
    /// The first change whose inclusion makes the state bad.
    Found { culprit: ChangeHash },
    /// Every remaining candidate was skipped.
    Inconclusive { candidates: Vec<ChangeHash> },
}

#[derive(Clone, Debug, Default)]
struct BisectState {
    start: Vec<ChangeHash>,
    good: Vec<ChangeHash>,
    bad: Vec<ChangeHash>,
    candidates: Vec<ChangeHash>,
    lo: usize,
    hi: usize,
    /// The prefix length currently checked out for testing.
    testing: Option<usize>,
    skipped: Vec<usize>,
}

fn hashes_line(v: &[ChangeHash]) -> String {
    v.iter().map(|h| h.to_hex()).collect::<Vec<_>>().join(" ")
}
fn hashes_from(s: &str) -> Vec<ChangeHash> {
    s.split_whitespace()
        .filter_map(ObjectRef::from_hex)
        .collect()
}

impl Repo {
    /// The introducing change, author, and date of every line of `path` in
    /// the working copy's base state (spec §27).
    pub fn blame(&self, path: &str) -> Result<Vec<BlameLine>> {
        let (_, wc) = self.working_copy()?;
        self.blame_heads(path, &wc.deps, "the working copy's base state")
    }

    /// Blame `path` in the state with these heads (hosted repositories).
    pub fn blame_in(&self, path: &str, heads: &[ChangeHash]) -> Result<Vec<BlameLine>> {
        self.blame_heads(path, heads, "that state")
    }

    /// Blame `path` in the state with these heads, building only its graph.
    fn blame_heads(&self, path: &str, heads: &[ChangeHash], what: &str) -> Result<Vec<BlameLine>> {
        let mut state = self.load_state_history(heads)?;
        let tree = state.tree().view();
        if let Some(e) = tree.entries.get(path) {
            self.load_graphs_of(&mut state, &[e.node])?;
        }
        self.blame_state(path, &state, &tree, what)
    }

    /// Blame `path` in a loaded state whose tree view the caller holds; no
    /// file other than `path` is rendered.
    pub fn blame_of(
        &self,
        state: &crate::state::State,
        tree: &crate::tree::TreeView,
        path: &str,
    ) -> Result<Vec<BlameLine>> {
        self.blame_state(path, state, tree, "that state")
    }

    fn blame_state(
        &self,
        path: &str,
        state: &crate::state::State,
        tree: &crate::tree::TreeView,
        what: &str,
    ) -> Result<Vec<BlameLine>> {
        let Some(f) = tree.entries.get(path) else {
            return fail(format!("{path} is not in {what}"));
        };
        if f.kind != crate::objects::NodeKind::File || f.mode.opaque {
            return fail(format!("{path} is not a text file"));
        }
        let mut out = Vec::new();
        for (i, ((hash, index), text)) in state.live_lines(&f.node).into_iter().enumerate() {
            let meta = state.get(&hash);
            let author = match meta {
                Some(m) if !m.author.is_zero() => self
                    .store
                    .get_identity(&m.author)
                    .map(|id| id.name)
                    .unwrap_or_else(|_| m.author.short(12)),
                Some(m) => m
                    .message
                    .lines()
                    .rev()
                    .find_map(|l| l.strip_prefix("Git-Author: "))
                    .map(|a| a.split('<').next().unwrap_or(a).trim().to_string())
                    .unwrap_or_else(|| "unknown".into()),
                None => "unknown".into(),
            };
            out.push(BlameLine {
                line: i + 1,
                hash,
                index,
                change_id: meta.map(|m| m.change_id).unwrap_or(ChangeId([0; 16])),
                author,
                when_ms: meta.map(|m| m.hlc.wall_ms).unwrap_or(0),
                text,
            });
        }
        Ok(out)
    }

    // ------------------------------------------------------------ bisect

    fn bisect_dir(&self) -> PathBuf {
        self.oxy.join("bisect")
    }

    fn bisect_load(&self) -> Result<Option<BisectState>> {
        let dir = self.bisect_dir();
        if !dir.join("start").exists() {
            return Ok(None);
        }
        let read = |name: &str| fs::read_to_string(dir.join(name)).unwrap_or_default();
        let nums: Vec<usize> = read("range")
            .split_whitespace()
            .filter_map(|n| n.parse().ok())
            .collect();
        Ok(Some(BisectState {
            start: hashes_from(&read("start")),
            good: hashes_from(&read("good")),
            bad: hashes_from(&read("bad")),
            candidates: hashes_from(&read("candidates")),
            lo: nums.first().copied().unwrap_or(0),
            hi: nums.get(1).copied().unwrap_or(0),
            testing: nums.get(2).copied().filter(|_| nums.len() > 2),
            skipped: read("skipped")
                .split_whitespace()
                .filter_map(|n| n.parse().ok())
                .collect(),
        }))
    }

    fn bisect_save(&self, st: &BisectState) -> Result<()> {
        let dir = self.bisect_dir();
        fs::create_dir_all(&dir)?;
        write_atomic(&dir.join("start"), hashes_line(&st.start).as_bytes())?;
        write_atomic(&dir.join("good"), hashes_line(&st.good).as_bytes())?;
        write_atomic(&dir.join("bad"), hashes_line(&st.bad).as_bytes())?;
        write_atomic(
            &dir.join("candidates"),
            hashes_line(&st.candidates).as_bytes(),
        )?;
        let mut range = format!("{} {}", st.lo, st.hi);
        if let Some(t) = st.testing {
            range.push_str(&format!(" {t}"));
        }
        write_atomic(&dir.join("range"), range.as_bytes())?;
        write_atomic(
            &dir.join("skipped"),
            st.skipped
                .iter()
                .map(|n| n.to_string())
                .collect::<Vec<_>>()
                .join(" ")
                .as_bytes(),
        )?;
        Ok(())
    }

    /// Begin a bisect: remembers the working copy's base to restore later.
    pub fn bisect_start(&self) -> Result<()> {
        if self.bisect_load()?.is_some() {
            return fail("a bisect is in progress; finish it or run `oxy bisect reset`");
        }
        let (_, wc) = self.working_copy()?;
        let start = self.load_state(&wc.deps)?.maximal(&wc.deps);
        self.bisect_save(&BisectState {
            start,
            ..Default::default()
        })
    }

    pub fn bisect_reset(&self) -> Result<()> {
        let Some(st) = self.bisect_load()? else {
            return fail("no bisect in progress");
        };
        self.checkout(&st.start, false, "oxy bisect reset")?;
        fs::remove_dir_all(self.bisect_dir())?;
        Ok(())
    }

    pub fn bisect_status(&self) -> Result<Option<BisectStep>> {
        let Some(st) = self.bisect_load()? else {
            return Ok(None);
        };
        Ok(Some(self.bisect_step(&st)))
    }

    fn bisect_step(&self, st: &BisectState) -> BisectStep {
        if st.candidates.is_empty() {
            return BisectStep::NeedMarks {
                good: st.good.len(),
                bad: st.bad.len(),
            };
        }
        if st.hi <= st.lo + 1 {
            return BisectStep::Found {
                culprit: st.candidates[st.lo],
            };
        }
        match st.testing {
            Some(_) => {
                let remaining = st.hi - st.lo;
                BisectStep::Testing {
                    heads: self.bisect_heads(st, st.testing.unwrap()),
                    remaining,
                    steps_left: (remaining as f64).log2().ceil() as u32,
                }
            }
            None => BisectStep::Inconclusive {
                candidates: st.candidates[st.lo..st.hi].to_vec(),
            },
        }
    }

    /// `good ∪ candidates[..k]`, as heads.
    fn bisect_heads(&self, st: &BisectState, k: usize) -> Vec<ChangeHash> {
        let mut all = st.good.clone();
        all.extend(st.candidates[..k].iter().copied());
        self.load_state(&all)
            .map(|s| s.maximal(&all))
            .unwrap_or(all)
    }

    /// Check out the midpoint of the open range, skipping indices marked
    /// untestable, and record it as the state under test.
    fn bisect_advance(&self, st: &mut BisectState) -> Result<BisectStep> {
        if st.hi <= st.lo + 1 {
            st.testing = None;
            self.bisect_save(st)?;
            return Ok(BisectStep::Found {
                culprit: st.candidates[st.lo],
            });
        }
        let mid = st.lo + (st.hi - st.lo) / 2;
        // Try mid, then the nearest untried indices on either side.
        let mut order = vec![mid];
        for d in 1..(st.hi - st.lo) {
            if mid + d < st.hi {
                order.push(mid + d);
            }
            if mid > st.lo + d {
                order.push(mid - d);
            }
        }
        let Some(k) = order.into_iter().find(|k| !st.skipped.contains(k)) else {
            st.testing = None;
            self.bisect_save(st)?;
            return Ok(BisectStep::Inconclusive {
                candidates: st.candidates[st.lo..st.hi].to_vec(),
            });
        };
        let heads = self.bisect_heads(st, k);
        self.checkout(
            &heads,
            false,
            &format!("oxy bisect (testing {k} of {})", st.candidates.len()),
        )?;
        st.testing = Some(k);
        self.bisect_save(st)?;
        let remaining = st.hi - st.lo;
        Ok(BisectStep::Testing {
            heads,
            remaining,
            steps_left: (remaining as f64).log2().ceil() as u32,
        })
    }

    /// Mark states good or bad. With `changes`, before the search starts,
    /// they name known-good or known-bad states; without, the state under
    /// test gets the verdict. `None` for `good` means skip (untestable).
    pub fn bisect_mark(&self, good: Option<bool>, changes: &[ChangeHash]) -> Result<BisectStep> {
        let Some(mut st) = self.bisect_load()? else {
            return fail("no bisect in progress; run `oxy bisect start`");
        };
        if !changes.is_empty() {
            if !st.candidates.is_empty() {
                return fail("the search has started; mark the state under test with plain `oxy bisect good|bad`");
            }
            match good {
                Some(true) => st.good.extend(changes.iter().copied()),
                Some(false) => st.bad.extend(changes.iter().copied()),
                None => return fail("skip applies to the state under test"),
            }
            if st.good.is_empty() || st.bad.is_empty() {
                self.bisect_save(&st)?;
                return Ok(BisectStep::NeedMarks {
                    good: st.good.len(),
                    bad: st.bad.len(),
                });
            }
            let good_heads = self.load_state(&st.good)?.maximal(&st.good);
            let bad_heads = self.load_state(&st.bad)?.maximal(&st.bad);
            st.good = good_heads.clone();
            st.bad = bad_heads.clone();
            st.candidates = self.negotiate(&good_heads, &bad_heads)?;
            if st.candidates.is_empty() {
                return fail("the bad state adds nothing to the good state; nothing to bisect");
            }
            st.lo = 0;
            st.hi = st.candidates.len();
            return self.bisect_advance(&mut st);
        }
        let Some(k) = st.testing else {
            return fail("no state is under test; give `oxy bisect good|bad` a change or bookmark to start with");
        };
        match good {
            Some(true) => st.lo = k,
            Some(false) => st.hi = k,
            None => st.skipped.push(k),
        }
        self.bisect_advance(&mut st)
    }

    /// Automate with a command run in the working copy: exit 0 is good, 125
    /// skips, anything else is bad.
    pub fn bisect_run(&self, command: &[String]) -> Result<BisectStep> {
        let Some(st) = self.bisect_load()? else {
            return fail("no bisect in progress; run `oxy bisect start`");
        };
        if st.testing.is_none() {
            return Ok(self.bisect_step(&st));
        }
        loop {
            let status = std::process::Command::new(&command[0])
                .args(&command[1..])
                .current_dir(&self.root)
                .status()
                .map_err(|e| RepoError::Msg(format!("running {}: {e}", command[0])))?;
            let verdict = match status.code() {
                Some(0) => Some(true),
                Some(125) => None,
                _ => Some(false),
            };
            match self.bisect_mark(verdict, &[])? {
                BisectStep::Testing { .. } => continue,
                done => return Ok(done),
            }
        }
    }
}

/// What `oxy describe` reports about the working copy (spec §10.1).
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct Description {
    /// The tag of the base state, or the nearest tag below it.
    pub tag: Option<String>,
    /// Changes in the base state that the tag's state lacks (0: exact).
    pub distance: usize,
    pub bookmark: String,
    /// The base's newest head.
    pub change: ChangeId,
    pub hash: ChangeHash,
    /// Whether the working copy has uncommitted changes.
    pub dirty: bool,
}

impl Description {
    /// `v1.2`, `v1.2-3-8c5ea12a`, or `develop-8c5ea12a`, and `-dirty`.
    pub fn line(&self) -> String {
        let short = self.change.short(8);
        let base = match (&self.tag, self.distance) {
            (Some(t), 0) => t.clone(),
            (Some(t), n) => format!("{t}-{n}-{short}"),
            (None, _) => format!("{}-{short}", self.bookmark),
        };
        if self.dirty {
            format!("{base}-dirty")
        } else {
            base
        }
    }
}

impl Repo {
    /// Name the working copy for builds (`oxy describe`, like `git
    /// describe`): the tag of its base state; else the nearest tag whose
    /// state the base contains, with how many changes it adds and its
    /// newest head; else the bookmark and that head. `dirty` when the
    /// working copy has uncommitted changes.
    pub fn describe_working_copy(&self) -> Result<Description> {
        let snap = self.snapshot_status("oxy describe")?;
        let dirty = !snap.statuses.is_empty();
        let base = snap.base.maximal(&snap.wc.deps);
        let Some(&newest) = base
            .iter()
            .max_by_key(|h| snap.base.get(h).map(|c| (c.hlc, **h)))
        else {
            return fail("the working copy sits on no change yet");
        };
        let Some(change) = snap.base.get(&newest).map(|m| m.change_id) else {
            return fail("the working copy's base is not loaded");
        };
        let mut sorted = base.clone();
        sorted.sort();
        let mut best: Option<(usize, String)> = None;
        for t in self.tags()? {
            if !t.heads.iter().all(|h| snap.base.contains(h)) {
                continue;
            }
            let mut tagged: std::collections::HashSet<ChangeHash> =
                t.heads.iter().copied().collect();
            for h in &t.heads {
                tagged.extend(snap.base.closure(h).iter().copied());
            }
            let mut heads = t.heads.clone();
            heads.sort();
            let distance = if heads == sorted {
                0
            } else {
                snap.base.len().saturating_sub(tagged.len()).max(1)
            };
            if best
                .as_ref()
                .is_none_or(|(d, n)| distance < *d || (distance == *d && t.name < *n))
            {
                best = Some((distance, t.name));
            }
        }
        let (distance, tag) = match best {
            Some((d, t)) => (d, Some(t)),
            None => (0, None),
        };
        Ok(Description {
            tag,
            distance,
            bookmark: self.config.bookmark.clone(),
            change,
            hash: newest,
            dirty,
        })
    }
}

`/`	Search
`g` `c`	Code
`g` `h`	History
`g` `b`	Bookmarks
`g` `t`	Trust
`y`	Permalink to this state (files and trees)
`?`	This sheet

1	//! Inspection (spec §27): blame from atom keys, and bisect over
2	//! dependency-closed prefixes of the candidates between a good and a bad
3	//! state.
4
5	use super::*;
6
7	/// One line of `oxy blame`.
8	#[derive(Clone, Debug)]
9	pub struct BlameLine {
10	pub line: usize,
11	pub hash: ChangeHash,
12	pub index: u32,
13	pub change_id: ChangeId,
14	pub author: String,
15	pub when_ms: u64,
16	pub text: Vec<u8>,
17	}
18
19	/// Where a bisect stands.
20	#[derive(Clone, Debug, PartialEq, Eq)]
21	pub enum BisectStep {
22	/// More `good`/`bad` marks are needed before the search can start.
23	NeedMarks { good: usize, bad: usize },
24	/// A state is checked out for testing.
25	Testing {
26	heads: Vec<ChangeHash>,
27	remaining: usize,
28	steps_left: u32,
29	},
30	/// The first change whose inclusion makes the state bad.
31	Found { culprit: ChangeHash },
32	/// Every remaining candidate was skipped.
33	Inconclusive { candidates: Vec<ChangeHash> },
34	}
35
36	#[derive(Clone, Debug, Default)]
37	struct BisectState {
38	start: Vec<ChangeHash>,
39	good: Vec<ChangeHash>,
40	bad: Vec<ChangeHash>,
41	candidates: Vec<ChangeHash>,
42	lo: usize,
43	hi: usize,
44	/// The prefix length currently checked out for testing.
45	testing: Option<usize>,
46	skipped: Vec<usize>,
47	}
48
49	fn hashes_line(v: &[ChangeHash]) -> String {
50	v.iter().map(\|h\| h.to_hex()).collect::<Vec<_>>().join(" ")
51	}
52	fn hashes_from(s: &str) -> Vec<ChangeHash> {
53	s.split_whitespace()
54	.filter_map(ObjectRef::from_hex)
55	.collect()
56	}
57
58	impl Repo {
59	/// The introducing change, author, and date of every line of `path` in
60	/// the working copy's base state (spec §27).
61	pub fn blame(&self, path: &str) -> Result<Vec<BlameLine>> {
62	let (_, wc) = self.working_copy()?;
63	self.blame_heads(path, &wc.deps, "the working copy's base state")
64	}
65
66	/// Blame `path` in the state with these heads (hosted repositories).
67	pub fn blame_in(&self, path: &str, heads: &[ChangeHash]) -> Result<Vec<BlameLine>> {
68	self.blame_heads(path, heads, "that state")
69	}
70
71	/// Blame `path` in the state with these heads, building only its graph.
72	fn blame_heads(&self, path: &str, heads: &[ChangeHash], what: &str) -> Result<Vec<BlameLine>> {
73	let mut state = self.load_state_history(heads)?;
74	let tree = state.tree().view();
75	if let Some(e) = tree.entries.get(path) {
76	self.load_graphs_of(&mut state, &[e.node])?;
77	}
78	self.blame_state(path, &state, &tree, what)
79	}
80
81	/// Blame `path` in a loaded state whose tree view the caller holds; no
82	/// file other than `path` is rendered.
83	pub fn blame_of(
84	&self,
85	state: &crate::state::State,
86	tree: &crate::tree::TreeView,
87	path: &str,
88	) -> Result<Vec<BlameLine>> {
89	self.blame_state(path, state, tree, "that state")
90	}
91
92	fn blame_state(
93	&self,
94	path: &str,
95	state: &crate::state::State,
96	tree: &crate::tree::TreeView,
97	what: &str,
98	) -> Result<Vec<BlameLine>> {
99	let Some(f) = tree.entries.get(path) else {
100	return fail(format!("{path} is not in {what}"));
101	};
102	if f.kind != crate::objects::NodeKind::File \|\| f.mode.opaque {
103	return fail(format!("{path} is not a text file"));
104	}
105	let mut out = Vec::new();
106	for (i, ((hash, index), text)) in state.live_lines(&f.node).into_iter().enumerate() {
107	let meta = state.get(&hash);
108	let author = match meta {
109	Some(m) if !m.author.is_zero() => self
110	.store
111	.get_identity(&m.author)
112	.map(\|id\| id.name)
113	.unwrap_or_else(\|_\| m.author.short(12)),
114	Some(m) => m
115	.message
116	.lines()
117	.rev()
118	.find_map(\|l\| l.strip_prefix("Git-Author: "))
119	.map(\|a\| a.split('<').next().unwrap_or(a).trim().to_string())
120	.unwrap_or_else(\|\| "unknown".into()),
121	None => "unknown".into(),
122	};
123	out.push(BlameLine {
124	line: i + 1,
125	hash,
126	index,
127	change_id: meta.map(\|m\| m.change_id).unwrap_or(ChangeId([0; 16])),
128	author,
129	when_ms: meta.map(\|m\| m.hlc.wall_ms).unwrap_or(0),
130	text,
131	});
132	}
133	Ok(out)
134	}
135
136	// ------------------------------------------------------------ bisect
137
138	fn bisect_dir(&self) -> PathBuf {
139	self.oxy.join("bisect")
140	}
141
142	fn bisect_load(&self) -> Result<Option<BisectState>> {
143	let dir = self.bisect_dir();
144	if !dir.join("start").exists() {
145	return Ok(None);
146	}
147	let read = \|name: &str\| fs::read_to_string(dir.join(name)).unwrap_or_default();
148	let nums: Vec<usize> = read("range")
149	.split_whitespace()
150	.filter_map(\|n\| n.parse().ok())
151	.collect();
152	Ok(Some(BisectState {
153	start: hashes_from(&read("start")),
154	good: hashes_from(&read("good")),
155	bad: hashes_from(&read("bad")),
156	candidates: hashes_from(&read("candidates")),
157	lo: nums.first().copied().unwrap_or(0),
158	hi: nums.get(1).copied().unwrap_or(0),
159	testing: nums.get(2).copied().filter(\|_\| nums.len() > 2),
160	skipped: read("skipped")
161	.split_whitespace()
162	.filter_map(\|n\| n.parse().ok())
163	.collect(),
164	}))
165	}
166
167	fn bisect_save(&self, st: &BisectState) -> Result<()> {
168	let dir = self.bisect_dir();
169	fs::create_dir_all(&dir)?;
170	write_atomic(&dir.join("start"), hashes_line(&st.start).as_bytes())?;
171	write_atomic(&dir.join("good"), hashes_line(&st.good).as_bytes())?;
172	write_atomic(&dir.join("bad"), hashes_line(&st.bad).as_bytes())?;
173	write_atomic(
174	&dir.join("candidates"),
175	hashes_line(&st.candidates).as_bytes(),
176	)?;
177	let mut range = format!("{} {}", st.lo, st.hi);
178	if let Some(t) = st.testing {
179	range.push_str(&format!(" {t}"));
180	}
181	write_atomic(&dir.join("range"), range.as_bytes())?;
182	write_atomic(
183	&dir.join("skipped"),
184	st.skipped
185	.iter()
186	.map(\|n\| n.to_string())
187	.collect::<Vec<_>>()
188	.join(" ")
189	.as_bytes(),
190	)?;
191	Ok(())
192	}
193
194	/// Begin a bisect: remembers the working copy's base to restore later.
195	pub fn bisect_start(&self) -> Result<()> {
196	if self.bisect_load()?.is_some() {
197	return fail("a bisect is in progress; finish it or run `oxy bisect reset`");
198	}
199	let (_, wc) = self.working_copy()?;
200	let start = self.load_state(&wc.deps)?.maximal(&wc.deps);
201	self.bisect_save(&BisectState {
202	start,
203	..Default::default()
204	})
205	}
206
207	pub fn bisect_reset(&self) -> Result<()> {
208	let Some(st) = self.bisect_load()? else {
209	return fail("no bisect in progress");
210	};
211	self.checkout(&st.start, false, "oxy bisect reset")?;
212	fs::remove_dir_all(self.bisect_dir())?;
213	Ok(())
214	}
215
216	pub fn bisect_status(&self) -> Result<Option<BisectStep>> {
217	let Some(st) = self.bisect_load()? else {
218	return Ok(None);
219	};
220	Ok(Some(self.bisect_step(&st)))
221	}
222
223	fn bisect_step(&self, st: &BisectState) -> BisectStep {
224	if st.candidates.is_empty() {
225	return BisectStep::NeedMarks {
226	good: st.good.len(),
227	bad: st.bad.len(),
228	};
229	}
230	if st.hi <= st.lo + 1 {
231	return BisectStep::Found {
232	culprit: st.candidates[st.lo],
233	};
234	}
235	match st.testing {
236	Some(_) => {
237	let remaining = st.hi - st.lo;
238	BisectStep::Testing {
239	heads: self.bisect_heads(st, st.testing.unwrap()),
240	remaining,
241	steps_left: (remaining as f64).log2().ceil() as u32,
242	}
243	}
244	None => BisectStep::Inconclusive {
245	candidates: st.candidates[st.lo..st.hi].to_vec(),
246	},
247	}
248	}
249
250	/// `good ∪ candidates[..k]`, as heads.
251	fn bisect_heads(&self, st: &BisectState, k: usize) -> Vec<ChangeHash> {
252	let mut all = st.good.clone();
253	all.extend(st.candidates[..k].iter().copied());
254	self.load_state(&all)
255	.map(\|s\| s.maximal(&all))
256	.unwrap_or(all)
257	}
258
259	/// Check out the midpoint of the open range, skipping indices marked
260	/// untestable, and record it as the state under test.
261	fn bisect_advance(&self, st: &mut BisectState) -> Result<BisectStep> {
262	if st.hi <= st.lo + 1 {
263	st.testing = None;
264	self.bisect_save(st)?;
265	return Ok(BisectStep::Found {
266	culprit: st.candidates[st.lo],
267	});
268	}
269	let mid = st.lo + (st.hi - st.lo) / 2;
270	// Try mid, then the nearest untried indices on either side.
271	let mut order = vec![mid];
272	for d in 1..(st.hi - st.lo) {
273	if mid + d < st.hi {
274	order.push(mid + d);
275	}
276	if mid > st.lo + d {
277	order.push(mid - d);
278	}
279	}
280	let Some(k) = order.into_iter().find(\|k\| !st.skipped.contains(k)) else {
281	st.testing = None;
282	self.bisect_save(st)?;
283	return Ok(BisectStep::Inconclusive {
284	candidates: st.candidates[st.lo..st.hi].to_vec(),
285	});
286	};
287	let heads = self.bisect_heads(st, k);
288	self.checkout(
289	&heads,
290	false,
291	&format!("oxy bisect (testing {k} of {})", st.candidates.len()),
292	)?;
293	st.testing = Some(k);
294	self.bisect_save(st)?;
295	let remaining = st.hi - st.lo;
296	Ok(BisectStep::Testing {
297	heads,
298	remaining,
299	steps_left: (remaining as f64).log2().ceil() as u32,
300	})
301	}
302
303	/// Mark states good or bad. With `changes`, before the search starts,
304	/// they name known-good or known-bad states; without, the state under
305	/// test gets the verdict. `None` for `good` means skip (untestable).
306	pub fn bisect_mark(&self, good: Option<bool>, changes: &[ChangeHash]) -> Result<BisectStep> {
307	let Some(mut st) = self.bisect_load()? else {
308	return fail("no bisect in progress; run `oxy bisect start`");
309	};
310	if !changes.is_empty() {
311	if !st.candidates.is_empty() {
312	return fail("the search has started; mark the state under test with plain `oxy bisect good\|bad`");
313	}
314	match good {
315	Some(true) => st.good.extend(changes.iter().copied()),
316	Some(false) => st.bad.extend(changes.iter().copied()),
317	None => return fail("skip applies to the state under test"),
318	}
319	if st.good.is_empty() \|\| st.bad.is_empty() {
320	self.bisect_save(&st)?;
321	return Ok(BisectStep::NeedMarks {
322	good: st.good.len(),
323	bad: st.bad.len(),
324	});
325	}
326	let good_heads = self.load_state(&st.good)?.maximal(&st.good);
327	let bad_heads = self.load_state(&st.bad)?.maximal(&st.bad);
328	st.good = good_heads.clone();
329	st.bad = bad_heads.clone();
330	st.candidates = self.negotiate(&good_heads, &bad_heads)?;
331	if st.candidates.is_empty() {
332	return fail("the bad state adds nothing to the good state; nothing to bisect");
333	}
334	st.lo = 0;
335	st.hi = st.candidates.len();
336	return self.bisect_advance(&mut st);
337	}
338	let Some(k) = st.testing else {
339	return fail("no state is under test; give `oxy bisect good\|bad` a change or bookmark to start with");
340	};
341	match good {
342	Some(true) => st.lo = k,
343	Some(false) => st.hi = k,
344	None => st.skipped.push(k),
345	}
346	self.bisect_advance(&mut st)
347	}
348
349	/// Automate with a command run in the working copy: exit 0 is good, 125
350	/// skips, anything else is bad.
351	pub fn bisect_run(&self, command: &[String]) -> Result<BisectStep> {
352	let Some(st) = self.bisect_load()? else {
353	return fail("no bisect in progress; run `oxy bisect start`");
354	};
355	if st.testing.is_none() {
356	return Ok(self.bisect_step(&st));
357	}
358	loop {
359	let status = std::process::Command::new(&command[0])
360	.args(&command[1..])
361	.current_dir(&self.root)
362	.status()
363	.map_err(\|e\| RepoError::Msg(format!("running {}: {e}", command[0])))?;
364	let verdict = match status.code() {
365	Some(0) => Some(true),
366	Some(125) => None,
367	_ => Some(false),
368	};
369	match self.bisect_mark(verdict, &[])? {
370	BisectStep::Testing { .. } => continue,
371	done => return Ok(done),
372	}
373	}
374	}
375	}
376
377	/// What `oxy describe` reports about the working copy (spec §10.1).
378	#[derive(Clone, Debug, PartialEq, Eq)]
379	pub struct Description {
380	/// The tag of the base state, or the nearest tag below it.
381	pub tag: Option<String>,
382	/// Changes in the base state that the tag's state lacks (0: exact).
383	pub distance: usize,
384	pub bookmark: String,
385	/// The base's newest head.
386	pub change: ChangeId,
387	pub hash: ChangeHash,
388	/// Whether the working copy has uncommitted changes.
389	pub dirty: bool,
390	}
391
392	impl Description {
393	/// `v1.2`, `v1.2-3-8c5ea12a`, or `develop-8c5ea12a`, and `-dirty`.
394	pub fn line(&self) -> String {
395	let short = self.change.short(8);
396	let base = match (&self.tag, self.distance) {
397	(Some(t), 0) => t.clone(),
398	(Some(t), n) => format!("{t}-{n}-{short}"),
399	(None, _) => format!("{}-{short}", self.bookmark),
400	};
401	if self.dirty {
402	format!("{base}-dirty")
403	} else {
404	base
405	}
406	}
407	}
408
409	impl Repo {
410	/// Name the working copy for builds (`oxy describe`, like `git
411	/// describe`): the tag of its base state; else the nearest tag whose
412	/// state the base contains, with how many changes it adds and its
413	/// newest head; else the bookmark and that head. `dirty` when the
414	/// working copy has uncommitted changes.
415	pub fn describe_working_copy(&self) -> Result<Description> {
416	let snap = self.snapshot_status("oxy describe")?;
417	let dirty = !snap.statuses.is_empty();
418	let base = snap.base.maximal(&snap.wc.deps);
419	let Some(&newest) = base
420	.iter()
421	.max_by_key(\|h\| snap.base.get(h).map(\|c\| (c.hlc, **h)))
422	else {
423	return fail("the working copy sits on no change yet");
424	};
425	let Some(change) = snap.base.get(&newest).map(\|m\| m.change_id) else {
426	return fail("the working copy's base is not loaded");
427	};
428	let mut sorted = base.clone();
429	sorted.sort();
430	let mut best: Option<(usize, String)> = None;
431	for t in self.tags()? {
432	if !t.heads.iter().all(\|h\| snap.base.contains(h)) {
433	continue;
434	}
435	let mut tagged: std::collections::HashSet<ChangeHash> =
436	t.heads.iter().copied().collect();
437	for h in &t.heads {
438	tagged.extend(snap.base.closure(h).iter().copied());
439	}
440	let mut heads = t.heads.clone();
441	heads.sort();
442	let distance = if heads == sorted {
443	0
444	} else {
445	snap.base.len().saturating_sub(tagged.len()).max(1)
446	};
447	if best
448	.as_ref()
449	.is_none_or(\|(d, n)\| distance < d \|\| (distance == d && t.name < *n))
450	{
451	best = Some((distance, t.name));
452	}
453	}
454	let (distance, tag) = match best {
455	Some((d, t)) => (d, Some(t)),
456	None => (0, None),
457	};
458	Ok(Description {
459	tag,
460	distance,
461	bookmark: self.config.bookmark.clone(),
462	change,
463	hash: newest,
464	dirty,
465	})
466	}
467	}

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