rust/hg-core/src/revset.rs

blackbox: add milliseconds to blackbox logs by default

The current second granularity is often not specific enough to
determine whether an hg command is happening before or after some
other event.

Given that starting a process takes on the order of 1ms (well, for
native processes. It's quite a bit more for python processes),
microseconds seems like unnecessary noise.

This also lines up behavior with the rust version, where we already
switched to millisecond precision.

Differential Revision: https://phab.mercurial-scm.org/D12005

//! The revset query language
//!
//! <https://www.mercurial-scm.org/repo/hg/help/revsets>

use crate::errors::HgError;
use crate::repo::Repo;
use crate::revlog::revlog::{Revlog, RevlogError};
use crate::revlog::NodePrefix;
use crate::revlog::{Revision, NULL_REVISION, WORKING_DIRECTORY_HEX};
use crate::Node;

/// Resolve a query string into a single revision.
///
/// Only some of the revset language is implemented yet.
pub fn resolve_single(
    input: &str,
    repo: &Repo,
) -> Result<Revision, RevlogError> {
    let changelog = repo.changelog()?;

    match input {
        "." => {
            let p1 = repo.dirstate_parents()?.p1;
            return Ok(changelog.revlog.rev_from_node(p1.into())?);
        }
        "null" => return Ok(NULL_REVISION),
        _ => {}
    }

    match resolve_rev_number_or_hex_prefix(input, &changelog.revlog) {
        Err(RevlogError::InvalidRevision) => {
            // TODO: support for the rest of the language here.
            let msg = format!("cannot parse revset '{}'", input);
            Err(HgError::unsupported(msg).into())
        }
        result => return result,
    }
}

/// Resolve the small subset of the language suitable for revlogs other than
/// the changelog, such as in `hg debugdata --manifest` CLI argument.
///
/// * A non-negative decimal integer for a revision number, or
/// * An hexadecimal string, for the unique node ID that starts with this
///   prefix
pub fn resolve_rev_number_or_hex_prefix(
    input: &str,
    revlog: &Revlog,
) -> Result<Revision, RevlogError> {
    // The Python equivalent of this is part of `revsymbol` in
    // `mercurial/scmutil.py`

    if let Ok(integer) = input.parse::<i32>() {
        if integer.to_string() == input
            && integer >= 0
            && revlog.has_rev(integer)
        {
            return Ok(integer);
        }
    }
    if let Ok(prefix) = NodePrefix::from_hex(input) {
        if prefix.is_prefix_of(&Node::from_hex(WORKING_DIRECTORY_HEX).unwrap())
        {
            return Err(RevlogError::WDirUnsupported);
        }
        return revlog.rev_from_node(prefix);
    }
    Err(RevlogError::InvalidRevision)
}