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Diffstat (limited to 'vendor/gix-diff/src/blob/mod.rs')
-rw-r--r-- | vendor/gix-diff/src/blob/mod.rs | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/vendor/gix-diff/src/blob/mod.rs b/vendor/gix-diff/src/blob/mod.rs new file mode 100644 index 000000000..0c76c2d91 --- /dev/null +++ b/vendor/gix-diff/src/blob/mod.rs @@ -0,0 +1,133 @@ +//! For using text diffs, please have a look at the [`imara-diff` documentation](https://docs.rs/imara-diff), +//! maintained by [Pascal Kuthe](https://github.com/pascalkuthe). +use std::{collections::HashMap, path::PathBuf}; + +use bstr::BString; +pub use imara_diff::*; + +/// +pub mod pipeline; + +/// +pub mod platform; + +/// Information about the diff performed to detect similarity. +#[derive(Debug, Default, Clone, Copy, PartialEq, PartialOrd)] +pub struct DiffLineStats { + /// The amount of lines to remove from the source to get to the destination. + pub removals: u32, + /// The amount of lines to add to the source to get to the destination. + pub insertions: u32, + /// The amount of lines of the previous state, in the source. + pub before: u32, + /// The amount of lines of the new state, in the destination. + pub after: u32, + /// A range from 0 to 1.0, where 1.0 is a perfect match and 0.5 is a similarity of 50%. + /// Similarity is the ratio between all lines in the previous blob and the current blob, + /// calculated as `(old_lines_count - new_lines_count) as f32 / old_lines_count.max(new_lines_count) as f32`. + pub similarity: f32, +} + +/// A way to classify a resource suitable for diffing. +#[derive(Copy, Clone, Debug, Ord, PartialOrd, Eq, PartialEq, Hash)] +pub enum ResourceKind { + /// The source of a rewrite, rename or copy operation, or generally the old version of a resource. + OldOrSource, + /// The destination of a rewrite, rename or copy operation, or generally the new version of a resource. + NewOrDestination, +} + +/// A set of values to define how to diff something that is associated with it using `git-attributes`, relevant for regular files. +/// +/// Some values are related to diffing, some are related to conversions. +#[derive(Default, Debug, Clone, PartialEq, Eq)] +pub struct Driver { + /// The name of the driver, as referred to by `[diff "name"]` in the git configuration. + pub name: BString, + /// The command to execute to perform the diff entirely like `<command> old-file old-hex old-mode new-file new-hex new-mode`. + /// + /// Please note that we don't make this call ourselves, but use it to determine that we should not run the our standard + /// built-in algorithm but bail instead as the output of such a program isn't standardized. + pub command: Option<BString>, + /// The per-driver algorithm to use. + pub algorithm: Option<Algorithm>, + /// The external filter program to call like `<binary_to_text_command> /path/to/blob` which outputs a textual version of the provided + /// binary file. + /// Note that it's invoked with a shell if arguments are given. + /// Further, if present, it will always be executed, whether `is_binary` is set or not. + pub binary_to_text_command: Option<BString>, + /// `Some(true)` if this driver deals with binary files, which means that a `binary_to_text_command` should be used to convert binary + /// into a textual representation. + /// Without such a command, anything that is considered binary is not diffed, but only the size of its data is made available. + /// If `Some(false)`, it won't be considered binary, and the its data will not be sampled for the null-byte either. + /// Leaving it to `None` means binary detection is automatic, and is based on the presence of the `0` byte in the first 8kB of the buffer. + pub is_binary: Option<bool>, +} + +/// A conversion pipeline to take an object or path from what's stored in `git` to what can be diffed, while +/// following the guidance of git-attributes at the respective path to learn if diffing should happen or if +/// the content is considered binary. +/// +/// There are two different conversion flows, where the target of the flow is a buffer with diffable content: +// TODO: update this with information about possible directions. +/// +/// * `worktree on disk` -> `text conversion` +/// * `object` -> `worktree-filters` -> `text conversion` +#[derive(Clone)] +pub struct Pipeline { + /// A way to read data directly from the worktree. + pub roots: pipeline::WorktreeRoots, + /// A pipeline to convert objects from what's stored in `git` to its worktree version. + pub worktree_filter: gix_filter::Pipeline, + /// Options affecting the way we read files. + pub options: pipeline::Options, + /// Drivers to help customize the conversion behaviour depending on the location of items. + drivers: Vec<Driver>, + /// Pre-configured attributes to obtain additional diff-related information. + attrs: gix_filter::attributes::search::Outcome, + /// A buffer to manipulate paths + path: PathBuf, +} + +/// A utility for performing a diff of two blobs, including flexible conversions, conversion-caching +/// acquisition of diff information. +/// Note that this instance will not call external filters as their output can't be known programmatically, +/// but it allows to prepare their input if the caller wishes to perform this task. +/// +/// Optimized for NxM lookups with built-in caching. +#[derive(Clone)] +pub struct Platform { + /// The old version of a diff-able blob, if set. + old: Option<platform::CacheKey>, + /// The new version of a diff-able blob, if set. + new: Option<platform::CacheKey>, + + /// Options to alter how diffs should be performed. + pub options: platform::Options, + /// A way to convert objects into a diff-able format. + pub filter: Pipeline, + /// A way to access .gitattributes + pub attr_stack: gix_worktree::Stack, + + /// The way we convert resources into diffable states. + filter_mode: pipeline::Mode, + /// A continuously growing cache keeping ready-for-diff blobs by their path in the worktree, + /// as that is what affects their final diff-able state. + /// + /// That way, expensive rewrite-checks with NxM matrix checks would be as fast as possible, + /// avoiding duplicate work. + diff_cache: HashMap<platform::CacheKey, platform::CacheValue>, +} + +mod impls { + use crate::blob::ResourceKind; + + impl std::fmt::Display for ResourceKind { + fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { + f.write_str(match self { + ResourceKind::OldOrSource => "old", + ResourceKind::NewOrDestination => "new", + }) + } + } +} |