# Changelog

All notable changes to this project will be documented in this file.

The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and this project
adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).


## Unreleased

### Added

### Changed

### Fixed


## 0.6.3

### Fixed
- Update dependencies to fix security vulnerabilities affecting the following crates and versions:
  - `linked-hash-map < 0.5.3`
  - `nix < 0.20.2`
  - `regex < 1.5.5`


## 0.6.2

### Added
- Add `--ignore-uncommitted-changes` flag to optionally ignore uncommitted changes.


## 0.6.1

### Fixed
- Fix detection of uncommitted changes on inputs within submodules.


## 0.6.0

### Changed
- Take uncommitted changes into account when computing which commit last changed a path
  (technically: the *required object* in `cache::Cache::required_object`).  This means artifact
  lookups will now always miss in the cache if one of its inputs has uncommitted changes.


## 0.5.0

### Changed
- Separate cached outputs not only by the required commit but also by the artifact name.
  Previously, the outputs of all artifacts were stored under a directory named after the required
  commit.  Thus, if the required commit was identical for two artifacts that had an identical output
  path, the outputs would collide in the cache, leading to false positive lookups or retrievals or
  overwrites on insertion.  With this change, the outputs of each artifact are stored under a
  directory named after the artifact within the directory of the required commit, thereby preventing
  these collisions.  A different way of thinking about this change is that the cache is now indexed
  by the required commit *and* the artifact name.


## 0.4.4

### Changed
- `cache::Cache`: The pattern in Pattern Artifacts now matches three characters (`-`, `.`, and `+`)
  in addition to word characters (i.e., alphanumerics and underscore `_`).  As the pattern now
  matches non-greedily, original behavior if a pattern does not contain one of the three characters
  but the string after the pattern does is preserved.

### Fixed
- `cache::Cache`:
  - The pattern in Pattern Artifacts now matches non-greedily.
  - Fix documentation of outputs of Pattern Artifacts.


## 0.4.3

### Changed
- `cache::Cache::cached_object` now returns `None` as soon as the intersection set of candidate
  objects for the outputs is empty.  Before, that function computed the candidates of all outputs
  before computing the intersection.
- `cache::Cache` now caches the fact that a path does or does not change between two objects.  This
  drastically reduces the number of `git diff` invocations.
- `git::Repo` now caches ancestry relations among objects.  This drastically reduces the number of
  `git rev-list` invocations.


## 0.4.2

### Fixed
- `cache::Cache::find_candidates` now also includes descendants when the ancestor itself is a
  candidate.


## 0.4.1

### Fixed
- `fs::copy` now also overwrites symlinks.


## 0.4.0

### Changed
- `fs::copy` no longer follows and resolves symlinks.  As a result, symlinks are now inserted and
  retrieved verbatim from the build artifact cache.  Additionally, it is now possible to cache
  artifacts with circular or nonexistent symlink targets.


## 0.3.1

### Fixed
- `git::Repo::oldest_common_descendant_on_current_branch`: Add missing intersection of descendants.


## 0.3.0

### Added
- Add support for Pattern Artifacts, which allows one Artifact definition to match many actual
  artifacts; see the [documentation of `cache::Artifacts`][PatternArtifacts] for details.
- `git::Object`: Implement `PartialOrd`.
- `git::Repo`:
  - Add `oldest_object` method as counterpart of `youngest_object`.
  - Add `oldest_common_descendant_on_current_branch` method to determine the oldest common
    descendant of a set of objects on the current branch.

### Changed
- `cache::Cache`: `artifacts` field is now private.  Get an individual artifact by name using the
  `artifact` method.  Getting all artifact definitions is no longer possible outside `Cache`.
- `git::Repo`:
  - `youngest_object` method now returns a `Result` instead of an `Option` and no longer panics if
    any two given `objects` are incomparable.
  - `youngest_object` method now takes a `HashSet` as `objects` argument, because the `objects` are
    unordered.

### Fixed
- `cache::Cache::required_object`: Fix required object resolution when merges are involved.


## 0.2.2

### Fixed

- `git::Repo::last_commit_on_path`: Return `None` when Git log for given path is empty.
- `cache::Cache::required_object`: Return `None` when required object for at least one input is
  not known.


## 0.2.1

### Fixed
- Implicitly add path of manifest to inputs of all artifacts.


## 0.2.0

### Added
- Add `lookup` command to determine whether an artifact is cached without copying the outputs.


## 0.1.1

### Fixed
- README: Add missing 'POSIX advisory record locks' URL.


## 0.1.0

Initial release.


[PatternArtifacts]: https://docs.rs/memora/latest/memora/cache/type.Artifact.html#PatternArtifacts