gix-diff 0.28.1

Calculate differences between various git objects
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157

use gix_hash::ObjectId;
use gix_object::{
    bstr::{BStr, BString, ByteSlice, ByteVec},
    tree,
};

use crate::tree::{visit, Recorder};

/// Describe how to track the location of a change.
#[derive(Debug, Clone, Copy, Eq, PartialEq)]
pub enum Location {
    /// Track the entire path, relative to the repository.
    Path,
    /// Keep only the file-name as location, which may be enough for some calculations.
    ///
    /// This is less expensive than tracking the entire `Path`.
    FileName,
}

/// A Change as observed by a call to [`visit(…)`][visit::Visit::visit()], enhanced with the path affected by the change.
/// Its similar to [visit::Change] but includes the path that changed.
#[derive(Clone, Debug, PartialEq, Eq)]
#[allow(missing_docs)]
pub enum Change {
    Addition {
        entry_mode: tree::EntryMode,
        oid: ObjectId,
        path: BString,
    },
    Deletion {
        entry_mode: tree::EntryMode,
        oid: ObjectId,
        path: BString,
    },
    Modification {
        previous_entry_mode: tree::EntryMode,
        previous_oid: ObjectId,

        entry_mode: tree::EntryMode,
        oid: ObjectId,

        path: BString,
    },
}

impl Default for Recorder {
    fn default() -> Self {
        Recorder {
            path_deque: Default::default(),
            path: Default::default(),
            location: Some(Location::Path),
            records: vec![],
        }
    }
}

/// Builder
impl Recorder {
    /// Obtain a copy of the currently tracked, full path of the entry.
    pub fn track_location(mut self, location: Option<Location>) -> Self {
        self.location = location;
        self
    }
}

/// Access
impl Recorder {
    /// Obtain a copy of the currently tracked, full path of the entry.
    pub fn path_clone(&self) -> BString {
        self.path.clone()
    }

    /// Return the currently set path.
    pub fn path(&self) -> &BStr {
        self.path.as_ref()
    }
}

impl Recorder {
    fn pop_element(&mut self) {
        if let Some(pos) = self.path.rfind_byte(b'/') {
            self.path.resize(pos, 0);
        } else {
            self.path.clear();
        }
    }

    fn push_element(&mut self, name: &BStr) {
        if !self.path.is_empty() {
            self.path.push(b'/');
        }
        self.path.push_str(name);
    }
}

impl visit::Visit for Recorder {
    fn pop_front_tracked_path_and_set_current(&mut self) {
        if let Some(Location::Path) = self.location {
            self.path = self.path_deque.pop_front().expect("every parent is set only once");
        }
    }

    fn push_back_tracked_path_component(&mut self, component: &BStr) {
        if let Some(Location::Path) = self.location {
            self.push_element(component);
            self.path_deque.push_back(self.path.clone());
        }
    }

    fn push_path_component(&mut self, component: &BStr) {
        match self.location {
            None => {}
            Some(Location::Path) => {
                self.push_element(component);
            }
            Some(Location::FileName) => {
                self.path.clear();
                self.path.extend_from_slice(component);
            }
        }
    }

    fn pop_path_component(&mut self) {
        if let Some(Location::Path) = self.location {
            self.pop_element();
        }
    }

    fn visit(&mut self, change: visit::Change) -> visit::Action {
        use visit::Change::*;
        self.records.push(match change {
            Deletion { entry_mode, oid } => Change::Deletion {
                entry_mode,
                oid,
                path: self.path_clone(),
            },
            Addition { entry_mode, oid } => Change::Addition {
                entry_mode,
                oid,
                path: self.path_clone(),
            },
            Modification {
                previous_entry_mode,
                previous_oid,
                entry_mode,
                oid,
            } => Change::Modification {
                previous_entry_mode,
                previous_oid,
                entry_mode,
                oid,
                path: self.path_clone(),
            },
        });
        visit::Action::Continue
    }
}