OXYGENHUB
# 1a3b62032ed9 oxygen / crates / oxy-core / src / repo / prompt.rs
17.3 KiB · Rust · last changed Git import: shared graphs, deterministic node ids; quieter status 1 month ago source blame history raw
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//! Fast, side-effect-free status for shell prompts.
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//!
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//! Every snapshot and checkout writes a manifest of the working copy as it
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//! was last seen: `size`, `mtime`, and BLAKE3 of each file. `quick_status`
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//! walks the working copy and compares against that manifest, reading a
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//! file's content only when its size or mtime changed, and records no
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//! operation. Ahead/behind counts come from walking the store between the
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//! local bookmark and its `origin` tracking state.
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use super::*;
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use std::time::UNIX_EPOCH;
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#[derive(Debug, Clone, Default, PartialEq, Eq)]
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pub struct PromptInfo {
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    pub bookmark: String,
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    /// Working-copy ChangeId prefix.
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    pub change_id: String,
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    pub heads: usize,
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    pub dirty: bool,
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    pub conflicted: bool,
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    /// Changes local `main` has that `origin/main` lacks, when tracking exists.
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    pub ahead: Option<usize>,
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    pub behind: Option<usize>,
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}
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impl PromptInfo {
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    /// The glyph for the working copy's state: `‼` conflicted, `✎` dirty,
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    /// `✔` clean.
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    pub fn state_glyph(&self) -> &'static str {
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        if self.conflicted {
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            "‼"
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        } else if self.dirty {
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            "✎"
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        } else {
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            "✔"
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        }
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    }
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    /// The ANSI colour (SGR parameter) for the state: red, yellow, or cyan.
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    pub fn state_color(&self) -> u8 {
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        if self.conflicted {
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            31
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        } else if self.dirty {
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            33
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        } else {
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            36
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        }
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    }
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    /// `format` wrapped in the state colour. `guard` is `("\\[", "\\]")` for
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    /// bash prompts, `("%{", "%}")` for zsh, or empty for raw output.
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    pub fn format_colored(&self, fmt: &str, guard: (&str, &str)) -> String {
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        format!(
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            "{}\x1b[{}m{}{}{}\x1b[0m{}",
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            guard.0,
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            self.state_color(),
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            guard.1,
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            self.format(fmt),
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            guard.0,
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            guard.1
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        )
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    }
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    /// Expand `%b` bookmark, `%c` change id, `%h` heads, `%d` dirty marker
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    /// (`*`), `%x` conflict marker (`!`), `%a`/`%B` ahead/behind counts
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    /// (empty when unknown), `%A`/`%D` `+n`/`-n` when non-zero, `%s` the
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    /// state glyph, `%U`/`%O` `↑n`/`↓n` when non-zero, `%i` the repository
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    /// icon, `%%` percent.
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    pub fn format(&self, fmt: &str) -> String {
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        let mut out = String::new();
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        let mut chars = fmt.chars();
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        while let Some(c) = chars.next() {
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            if c != '%' {
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                out.push(c);
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                continue;
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            }
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            match chars.next() {
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                Some('b') => out.push_str(&self.bookmark),
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                Some('c') => out.push_str(&self.change_id),
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                Some('h') => out.push_str(&self.heads.to_string()),
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                Some('d') => {
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                    if self.dirty {
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                        out.push('*');
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                    }
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                }
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                Some('x') => {
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                    if self.conflicted {
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                        out.push('!');
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                    }
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                }
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                Some('a') => out.push_str(&self.ahead.map(|n| n.to_string()).unwrap_or_default()),
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                Some('B') => out.push_str(&self.behind.map(|n| n.to_string()).unwrap_or_default()),
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                Some('A') => {
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                    if let Some(n) = self.ahead.filter(|n| *n > 0) {
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                        out.push_str(&format!("+{n}"));
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                    }
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                }
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                Some('D') => {
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                    if let Some(n) = self.behind.filter(|n| *n > 0) {
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                        out.push_str(&format!("-{n}"));
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                    }
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                }
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                Some('s') => out.push_str(self.state_glyph()),
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                Some('U') => {
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                    if let Some(n) = self.ahead.filter(|n| *n > 0) {
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                        out.push_str(&format!("↑{n}"));
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                    }
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                }
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                Some('O') => {
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                    if let Some(n) = self.behind.filter(|n| *n > 0) {
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                        out.push_str(&format!("↓{n}"));
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                    }
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                }
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                Some('i') => out.push_str(ICON),
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                Some('%') => out.push('%'),
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                Some(other) => {
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                    out.push('%');
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                    out.push(other);
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                }
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                None => out.push('%'),
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            }
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        }
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        out
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    }
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}
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/// Path → (size, mtime in nanoseconds, BLAKE3 hex) as last seen.
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/// One manifest entry: the file's stat, its content hash, and the stored
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/// blob for an opaque file.
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#[derive(Clone, Debug)]
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pub(crate) struct ManifestEntry {
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    pub size: u64,
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    pub mtime_ns: u128,
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    pub hash: String,
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    pub blob: Option<ObjectRef>,
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    /// The graph key (`State::graph_key`) of the base file this text file
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    /// was found equal to, rendered, byte for byte.
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    pub graph: Option<String>,
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}
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#[derive(Clone, Debug, Default)]
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pub(crate) struct Manifest {
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    /// When the manifest was written, for the racy-stat guard.
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    pub written_ns: u128,
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    pub entries: BTreeMap<String, ManifestEntry>,
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}
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pub(crate) fn mtime_ns(m: &fs::Metadata) -> u128 {
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    m.modified()
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        .ok()
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        .and_then(|t| t.duration_since(UNIX_EPOCH).ok())
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        .map(|d| d.as_nanos())
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        .unwrap_or(0)
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}
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pub const DEFAULT_PROMPT_FORMAT: &str = "%b %c%d%x%A%D";
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/// The repository icon for `%i` (an atom, for oxygen).
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pub const ICON: &str = "⚛";
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/// A format with glyphs: icon, bookmark, change id, state, ahead/behind.
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pub const GLYPH_PROMPT_FORMAT: &str = "%i %b %c %s%U%O";
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/// One manifest line per file: size, mtime in nanoseconds, hash, blob ref
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/// or `-`, graph key or `-`, path.
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fn manifest_line(
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    path: &str,
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    size: u64,
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    mtime_ns: u128,
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    hash: &str,
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    blob: Option<ObjectRef>,
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    graph: Option<&str>,
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) -> String {
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    format!(
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        "{size}\t{mtime_ns}\t{hash}\t{}\t{}\t{path}\n",
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        blob.map(|b| b.to_hex()).unwrap_or_else(|| "-".into()),
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        graph.unwrap_or("-")
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    )
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}
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impl Repo {
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    pub(crate) fn manifest_path(&self) -> PathBuf {
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        self.oxy
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            .join("workspaces")
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            .join(self.workspace.to_hex())
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            .join("manifest")
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    }
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    /// Record the working copy as it is now (after a snapshot, commit, or
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    /// checkout), with header lines saying whether the base state is
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    /// conflicted and whether the working-copy change holds uncommitted work.
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    pub(crate) fn write_manifest(&self, conflicted: bool, uncommitted: bool) -> Result<()> {
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        let entries = self.walk_working_copy()?;
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        self.write_manifest_entries(conflicted, uncommitted, &entries, &HashMap::new())
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    }
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    /// Write the manifest from entries already walked; `blobs` names the
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    /// stored blob of each opaque path so the next walk can skip reading it.
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    pub(crate) fn write_manifest_entries(
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        &self,
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        conflicted: bool,
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        uncommitted: bool,
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        entries: &BTreeMap<String, FsEntry>,
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        blobs: &HashMap<String, ObjectRef>,
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    ) -> Result<()> {
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        let written = std::time::SystemTime::now()
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            .duration_since(UNIX_EPOCH)
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            .map(|d| d.as_nanos())
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            .unwrap_or(0);
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        let head = format!(
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            "# conflicted={}\n# uncommitted={}\n",
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            conflicted as u8, uncommitted as u8
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        );
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        let mut body = String::new();
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        let mut newest_ns: u128 = 0;
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        for (path, e) in entries {
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            let full = self.root.join(path);
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            let (size, mtime_ns) = match fs::symlink_metadata(&full) {
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                Ok(m) => (m.len(), mtime_ns(&m)),
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                Err(_) => (e.content.len() as u64, 0),
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            };
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            let hash = match &e.content_hash {
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                Some(h) => h.clone(),
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                None => blake3::hash(&e.content).to_hex().to_string(),
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            };
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            let blob = blobs.get(path).copied().or(e.blob);
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            newest_ns = newest_ns.max(mtime_ns);
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            body.push_str(&manifest_line(
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                path,
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                size,
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                mtime_ns,
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                &hash,
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                blob,
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                e.graph_key.as_deref(),
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            ));
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        }
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        let p = self.manifest_path();
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        // Leave an unchanged manifest alone when its stamp already trusts
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        // every entry (none is within the racy window): rewriting it would
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        // change nothing but the file, which editors watching the tree
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        // (and subrepos inside it) take as a change.
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        if let Ok(old) = fs::read_to_string(&p) {
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            let old_written: Option<u128> = old.lines().find_map(|l| {
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                l.strip_prefix("# written=")
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                    .and_then(|v| v.trim().parse().ok())
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            });
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            let old_rest: String = old
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                .lines()
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                .filter(|l| !l.starts_with("# written="))
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                .map(|l| format!("{l}\n"))
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                .collect();
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            if let Some(w) = old_written {
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                if old_rest == format!("{head}{body}") && newest_ns + 2_000_000_000 < w {
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                    return Ok(());
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                }
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            }
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        }
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        let text = format!("{head}# written={written}\n{body}");
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        fs::create_dir_all(p.parent().unwrap())?;
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        write_atomic(&p, text.as_bytes())
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    }
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    /// Change only the header flags of the current manifest (after a commit
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    /// the files are as the snapshot left them).
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    pub(crate) fn rewrite_manifest_flags(&self, conflicted: bool, uncommitted: bool) -> Result<()> {
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        let p = self.manifest_path();
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        let text = match fs::read_to_string(&p) {
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            Ok(t) => t,
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            Err(_) => return self.write_manifest(conflicted, uncommitted),
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        };
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        let mut out = String::with_capacity(text.len());
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        for line in text.lines() {
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            if line.starts_with("# conflicted=") {
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                out.push_str(&format!("# conflicted={}\n", conflicted as u8));
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            } else if line.starts_with("# uncommitted=") {
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                out.push_str(&format!("# uncommitted={}\n", uncommitted as u8));
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            } else {
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                out.push_str(line);
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                out.push('\n');
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            }
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        }
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        write_atomic(&p, out.as_bytes())
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    }
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    /// Forget the manifest after an operation that changed the working-copy
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    /// change without a snapshot (undo, rewrites); the prompt shows blank
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    /// markers until the next snapshot.
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    pub(crate) fn drop_manifest(&self) {
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        let _ = fs::remove_file(self.manifest_path());
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    }
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    pub(crate) fn read_manifest(&self) -> Result<Option<(bool, bool, Manifest)>> {
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        let text = match fs::read_to_string(self.manifest_path()) {
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            Ok(t) => t,
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            Err(e) if e.kind() == std::io::ErrorKind::NotFound => return Ok(None),
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            Err(e) => return Err(e.into()),
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        };
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        let mut out = Manifest::default();
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        let mut conflicted = false;
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        let mut uncommitted = false;
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        for line in text.lines() {
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            if let Some(v) = line.strip_prefix("# conflicted=") {
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                conflicted = v.trim() == "1";
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                continue;
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            }
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            if let Some(v) = line.strip_prefix("# uncommitted=") {
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                uncommitted = v.trim() == "1";
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                continue;
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            }
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            if let Some(v) = line.strip_prefix("# written=") {
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                out.written_ns = v.trim().parse().unwrap_or(u128::MAX);
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                continue;
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            }
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            let f: Vec<&str> = line.splitn(6, '\t').collect();
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            if f.len() == 6 {
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                out.entries.insert(
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                    f[5].to_string(),
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                    ManifestEntry {
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                        size: f[0].parse().unwrap_or(0),
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                        mtime_ns: f[1].parse().unwrap_or(0),
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                        hash: f[2].to_string(),
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                        blob: ObjectRef::from_hex(f[3]),
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                        graph: (f[4] != "-").then(|| f[4].to_string()),
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                    },
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                );
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            }
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        }
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        Ok(Some((conflicted, uncommitted, out)))
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    }
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    /// Whether the working copy differs from the last manifest. Without a
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    /// manifest the answer is `None`.
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    pub fn quick_dirty(&self) -> Result<Option<bool>> {
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        let Some((_, uncommitted, manifest)) = self.read_manifest()? else {
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            return Ok(None);
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        };
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        if uncommitted {
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            return Ok(Some(true));
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        }
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        let mut seen = 0usize;
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        let nested = std::sync::Arc::new(std::sync::Mutex::new(Vec::new()));
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        let wb = self.walker(&nested);
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        for entry in wb.build() {
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            let Ok(entry) = entry else { continue };
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            let Some(ft) = entry.file_type() else {
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                continue;
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            };
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            if ft.is_dir() {
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                continue;
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            }
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            let rel: String = entry
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                .path()
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                .strip_prefix(&self.root)
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                .unwrap()
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                .components()
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                .map(|c| c.as_os_str().to_string_lossy().to_string())
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                .collect::<Vec<_>>()
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                .join("/");
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            if !self.in_scope(&rel) {
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                continue;
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            }
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            let Some(me) = manifest.entries.get(&rel) else {
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                return Ok(Some(true));
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            };
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            seen += 1;
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            let m = fs::symlink_metadata(entry.path())?;
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            let now_mtime = mtime_ns(&m);
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            if ft.is_symlink() {
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                let target = fs::read_link(entry.path())?;
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                if blake3::hash(target.to_string_lossy().as_bytes())
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                    .to_hex()
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                    .as_str()
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                    != me.hash
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                {
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                    return Ok(Some(true));
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                }
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                continue;
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            }
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            if m.len() != me.size {
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                return Ok(Some(true));
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            }
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            if now_mtime != me.mtime_ns
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                && blake3::hash(&fs::read(entry.path())?).to_hex().as_str() != me.hash
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            {
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                return Ok(Some(true));
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            }
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        }
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        if seen == manifest.entries.len() {
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            return Ok(Some(false));
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        }
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        // Manifest entries the walk skipped: tracked files that ignore rules
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        // hide. They count as present when still on disk and unchanged.
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        for (rel, me) in &manifest.entries {
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            let path = self.root.join(rel);
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            let Ok(m) = fs::symlink_metadata(&path) else {
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                return Ok(Some(true));
395
            };
396
            if m.file_type().is_symlink() {
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                continue;
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            }
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            if m.len() != me.size
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                || (mtime_ns(&m) != me.mtime_ns
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                    && blake3::hash(&fs::read(&path)?).to_hex().as_str() != me.hash)
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            {
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                return Ok(Some(true));
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            }
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        }
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        Ok(Some(false))
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    }
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    /// Prompt information without recording anything.
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    pub fn quick_status(&self) -> Result<PromptInfo> {
411
        let view = self.view()?;
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        let bookmark = self.config.bookmark.clone();
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        let heads = self.heads_of(&view, &bookmark)?;
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        let wc_hash = view.workspaces.get(&self.workspace).copied();
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        let change_id = match wc_hash {
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            Some(h) => self.store.get_change(&h)?.change_id.short(8),
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            None => String::new(),
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        };
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        // Conflictedness was recorded by the last snapshot; without a
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        // manifest (never snapshotted) both flags are unknown and shown clear.
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        let manifest = self.read_manifest()?;
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        let conflicted = manifest.as_ref().map(|(c, _, _)| *c).unwrap_or(false);
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        let dirty = self.quick_dirty()?.unwrap_or(false);
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        let (ahead, behind) = match view.remotes.get("origin").and_then(|b| b.get(&bookmark)) {
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            Some(st) => {
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                let remote_heads = self.store.get_state(st)?.heads;
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                let ahead = self.negotiate(&remote_heads, &heads).map(|v| v.len()).ok();
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                let behind = self.negotiate(&heads, &remote_heads).map(|v| v.len()).ok();
429
                (ahead, behind)
430
            }
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            None => (None, None),
432
        };
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        Ok(PromptInfo {
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            bookmark,
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            change_id,
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            heads: heads.len(),
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            dirty,
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            conflicted,
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            ahead,
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            behind,
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        })
442
    }
443
}
444
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#[cfg(test)]
446
mod tests {
447
    use super::*;
448
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    #[test]
450
    fn placeholders_and_glyphs() {
451
        let clean = PromptInfo {
452
            bookmark: "main".into(),
453
            change_id: "658990aa".into(),
454
            heads: 1,
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            dirty: false,
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            conflicted: false,
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            ahead: Some(0),
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            behind: None,
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        };
460
        assert_eq!(clean.format(DEFAULT_PROMPT_FORMAT), "main 658990aa");
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        assert_eq!(clean.format(GLYPH_PROMPT_FORMAT), "⚛ main 658990aa ✔");
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        let busy = PromptInfo {
463
            dirty: true,
464
            ahead: Some(2),
465
            behind: Some(3),
466
            ..clean.clone()
467
        };
468
        assert_eq!(busy.format(DEFAULT_PROMPT_FORMAT), "main 658990aa*+2-3");
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        assert_eq!(busy.format(GLYPH_PROMPT_FORMAT), "⚛ main 658990aa ✎↑2↓3");
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        let bad = PromptInfo {
471
            conflicted: true,
472
            ..busy.clone()
473
        };
474
        assert_eq!(bad.format("%s%x%d %h %a/%B %%"), "‼!* 1 2/3 %");
475
        assert_eq!(bad.state_color(), 31);
476
        assert_eq!(
477
            busy.format_colored("%b", ("\\[", "\\]")),
478
            "\\[\x1b[33m\\]main\\[\x1b[0m\\]"
479
        );
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        assert_eq!(clean.format_colored("%b", ("", "")), "\x1b[36mmain\x1b[0m");
481
        assert_eq!(clean.format("%q"), "%q");
482
    }
483
}