gix_index/entry/mode.rs
1use crate::entry::Mode;
2
3impl Mode {
4 /// Return `true` if this is a sparse entry, as it points to a directory which usually isn't what an 'unsparse' index tracks.
5 pub fn is_sparse(&self) -> bool {
6 *self == Self::DIR
7 }
8
9 /// Return `true` if this is a submodule entry.
10 pub fn is_submodule(&self) -> bool {
11 *self == Self::DIR | Self::SYMLINK
12 }
13
14 /// Convert this instance to a tree's entry mode, or return `None` if for some
15 /// and unexpected reason the bitflags don't resemble any known entry-mode.
16 pub fn to_tree_entry_mode(&self) -> Option<gix_object::tree::EntryMode> {
17 gix_object::tree::EntryMode::try_from(self.bits()).ok()
18 }
19
20 /// Compares this mode to the file system version ([`std::fs::symlink_metadata`])
21 /// and returns the change needed to update this mode to match the file.
22 ///
23 /// * if `has_symlinks` is false symlink entries will simply check if there
24 /// is a normal file on disk
25 /// * if `executable_bit` is false the executable bit will not be compared
26 /// `Change::ExecutableBit` will never be generated
27 ///
28 /// If there is a type change then we will use whatever information is
29 /// present on the FS. Specifically if `has_symlinks` is false we will
30 /// never generate `Change::TypeChange { new_mode: Mode::SYMLINK }`. and
31 /// if `executable_bit` is false we will never generate `Change::TypeChange
32 /// { new_mode: Mode::FILE_EXECUTABLE }` (all files are assumed to be not
33 /// executable). That means that unstaging and staging files can be a lossy
34 /// operation on such file systems.
35 ///
36 /// If a directory replaced a normal file/symlink we assume that the
37 /// directory is a submodule. Normal (non-submodule) directories would
38 /// cause a file to be deleted from the index and should be handled before
39 /// calling this function.
40 ///
41 /// If the stat information belongs to something other than a normal file/
42 /// directory (like a socket) we just return an identity change (non-files
43 /// can not be committed to git).
44 pub fn change_to_match_fs(
45 self,
46 stat: &crate::fs::Metadata,
47 has_symlinks: bool,
48 executable_bit: bool,
49 ) -> Option<Change> {
50 match self {
51 Mode::FILE if !stat.is_file() => (),
52 Mode::SYMLINK if has_symlinks && !stat.is_symlink() => (),
53 Mode::SYMLINK if !has_symlinks && !stat.is_file() => (),
54 Mode::COMMIT | Mode::DIR if !stat.is_dir() => (),
55 Mode::FILE if executable_bit && stat.is_executable() => return Some(Change::ExecutableBit),
56 Mode::FILE_EXECUTABLE if executable_bit && !stat.is_executable() => return Some(Change::ExecutableBit),
57 _ => return None,
58 };
59 let new_mode = if stat.is_dir() {
60 Mode::COMMIT
61 } else if executable_bit && stat.is_executable() {
62 Mode::FILE_EXECUTABLE
63 } else if has_symlinks && stat.is_symlink() {
64 Mode::SYMLINK
65 } else {
66 Mode::FILE
67 };
68 Some(Change::Type { new_mode })
69 }
70}
71
72impl From<gix_object::tree::EntryMode> for Mode {
73 fn from(value: gix_object::tree::EntryMode) -> Self {
74 Self::from_bits_truncate(u32::from(value.0))
75 }
76}
77
78/// A change of a [`Mode`].
79#[derive(Debug, Copy, Clone, PartialEq, Eq)]
80pub enum Change {
81 /// The type of mode changed, like symlink => file.
82 Type {
83 /// The mode representing the new index type.
84 new_mode: Mode,
85 },
86 /// The executable permission of this file has changed.
87 ExecutableBit,
88}
89
90impl Change {
91 /// Applies this change to `mode` and returns the changed one.
92 pub fn apply(self, mode: Mode) -> Mode {
93 match self {
94 Change::Type { new_mode } => new_mode,
95 Change::ExecutableBit => match mode {
96 Mode::FILE => Mode::FILE_EXECUTABLE,
97 Mode::FILE_EXECUTABLE => Mode::FILE,
98 _ => unreachable!("invalid mode change: can't flip executable bit of {mode:?}"),
99 },
100 }
101 }
102}