view rust/hg-core/src/copy_tracing/tests.rs @ 47347:73ddcedeaadf

dirstate-tree: Change status() results to not borrow DirstateMap The `status` function takes a `&'tree mut DirstateMap<'on_disk>` parameter. `'on_disk` borrows a read-only byte buffer with the contents of the `.hg/dirstate` file. `DirstateMap` internally uses represents file paths as `std::borrow::Cow<'on_disk, HgPath>`, which borrows the byte buffer when possible and allocates an owned string if not, such as for files added to the dirstate after it was loaded from disk. Previously the return type of of `status` has a `'tree`?lifetime, meaning it could borrow all paths from the `DirstateMap`. With this changeset, that lifetime is changed to `'on_disk` meaning that only paths from the byte buffer can be borrowed, and paths allocated by `DirstateMap` must be copied. Usually most paths are in the byte buffer, and most paths are not part of the return value of `status`, so the number of extra copies should be small. This change will enable `status` to mutate the `DirstateMap` after it has finished constructing its return value. Previously such mutation would be prevented by possible on-going borrows. Differential Revision: https://phab.mercurial-scm.org/D10824
author Simon Sapin <simon.sapin@octobus.net>
date Fri, 28 May 2021 20:07:27 +0200
parents fa21633af201
children 750409505286
line wrap: on
line source

use super::*;

/// Unit tests for:
///
/// ```ignore
/// fn compare_value(
///     current_merge: Revision,
///     merge_case_for_dest: impl Fn() -> MergeCase,
///     src_minor: &CopySource,
///     src_major: &CopySource,
/// ) -> (MergePick, /* overwrite: */ bool)
///  ```
#[test]
fn test_compare_value() {
    // The `compare_value!` macro calls the `compare_value` function with
    // arguments given in pseudo-syntax:
    //
    // * For `merge_case_for_dest` it takes a plain `MergeCase` value instead
    //   of a closure.
    // * `CopySource` values are represented as `(rev, path, overwritten)`
    //   tuples of type `(Revision, Option<PathToken>, OrdSet<Revision>)`.
    // * `PathToken` is an integer not read by `compare_value`. It only checks
    //   for `Some(_)` indicating a file copy v.s. `None` for a file deletion.
    // * `OrdSet<Revision>` is represented as a Python-like set literal.

    use MergeCase::*;
    use MergePick::*;

    assert_eq!(
        compare_value!(1, Normal, (1, None, { 1 }), (1, None, { 1 })),
        (Any, false)
    );
}

/// Unit tests for:
///
/// ```ignore
/// fn merge_copies_dict(
///     path_map: &TwoWayPathMap, // Not visible in test cases
///     current_merge: Revision,
///     minor: InternalPathCopies,
///     major: InternalPathCopies,
///     get_merge_case: impl Fn(&HgPath) -> MergeCase + Copy,
/// ) -> InternalPathCopies
/// ```
#[test]
fn test_merge_copies_dict() {
    // The `merge_copies_dict!` macro calls the `merge_copies_dict` function
    // with arguments given in pseudo-syntax:
    //
    // * `TwoWayPathMap` and path tokenization are implicitly taken care of.
    //   All paths are given as string literals.
    // * Key-value maps are represented with `{key1 => value1, key2 => value2}`
    //   pseudo-syntax.
    // * `InternalPathCopies` is a map of copy destination path keys to
    //   `CopySource` values.
    //   - `CopySource` is represented as a `(rev, source_path, overwritten)`
    //     tuple of type `(Revision, Option<Path>, OrdSet<Revision>)`.
    //   - Unlike in `test_compare_value`, source paths are string literals.
    //   - `OrdSet<Revision>` is again represented as a Python-like set
    //     literal.
    // * `get_merge_case` is represented as a map of copy destination path to
    //   `MergeCase`. The default for paths not in the map is
    //   `MergeCase::Normal`.
    //
    // `internal_path_copies!` creates an `InternalPathCopies` value with the
    // same pseudo-syntax as in `merge_copies_dict!`.

    use MergeCase::*;

    assert_eq!(
        merge_copies_dict!(
            1,
            {"foo" => (1, None, {})},
            {},
            {"foo" => Merged}
        ),
        internal_path_copies!("foo" => (1, None, {}))
    );
}

/// Unit tests for:
///
/// ```ignore
/// impl CombineChangesetCopies {
///     fn new(children_count: HashMap<Revision, usize>) -> Self
///
///     // Called repeatedly:
///     fn add_revision_inner<'a>(
///         &mut self,
///         rev: Revision,
///         p1: Revision,
///         p2: Revision,
///         copy_actions: impl Iterator<Item = Action<'a>>,
///         get_merge_case: impl Fn(&HgPath) -> MergeCase + Copy,
///     )
///
///     fn finish(mut self, target_rev: Revision) -> PathCopies
/// }
/// ```
#[test]
fn test_combine_changeset_copies() {
    // `combine_changeset_copies!` creates a `CombineChangesetCopies` with
    // `new`, then calls `add_revision_inner` repeatedly, then calls `finish`
    // for its return value.
    //
    // All paths given as string literals.
    //
    // * Key-value maps are represented with `{key1 => value1, key2 => value2}`
    //   pseudo-syntax.
    // * `children_count` is a map of revision numbers to count of children in
    //   the DAG. It includes all revisions that should be considered by the
    //   algorithm.
    // * Calls to `add_revision_inner` are represented as an array of anonymous
    //   structs with named fields, one pseudo-struct per call.
    //
    // `path_copies!` creates a `PathCopies` value, a map of copy destination
    // keys to copy source values. Note: the arrows for map literal syntax
    // point **backwards** compared to the logical direction of copy!

    use crate::NULL_REVISION as NULL;
    use Action::*;
    use MergeCase::*;

    assert_eq!(
        combine_changeset_copies!(
            { 1 => 1, 2 => 1 },
            [
                { rev: 1, p1: NULL, p2: NULL, actions: [], merge_cases: {}, },
                { rev: 2, p1: NULL, p2: NULL, actions: [], merge_cases: {}, },
                {
                    rev: 3, p1: 1, p2: 2,
                    actions: [CopiedFromP1("destination.txt", "source.txt")],
                    merge_cases: {"destination.txt" => Merged},
                },
            ],
            3,
        ),
        path_copies!("destination.txt" => "source.txt")
    );
}