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
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
use std::collections::BTreeSet;
use crate::{parse::Operation, types::Mode, MatchGroup, RefSpecRef};
pub(crate) mod types;
pub use types::{match_lhs, match_rhs, Item, Mapping, Source, SourceRef};
///
pub mod validate;
/// Initialization
impl<'a> MatchGroup<'a> {
/// Take all the fetch ref specs from `specs` get a match group ready.
pub fn from_fetch_specs(specs: impl IntoIterator<Item = RefSpecRef<'a>>) -> Self {
MatchGroup {
specs: specs.into_iter().filter(|s| s.op == Operation::Fetch).collect(),
}
}
/// Take all the push ref specs from `specs` get a match group ready.
pub fn from_push_specs(specs: impl IntoIterator<Item = RefSpecRef<'a>>) -> Self {
MatchGroup {
specs: specs.into_iter().filter(|s| s.op == Operation::Push).collect(),
}
}
}
/// Matching
impl<'spec> MatchGroup<'spec> {
/// Match all `items` against all *fetch* specs present in this group, returning deduplicated mappings from source to destination.
/// `items` are expected to be references on the remote, which will be matched and mapped to obtain their local counterparts,
/// i.e. *left side of refspecs is mapped to their right side*.
/// *Note that this method is correct only for fetch-specs*, even though it also *works for push-specs*.
///
/// Object names are never mapped and always returned as match.
///
/// Note that negative matches are not part of the return value, so they are not observable but will be used to remove mappings.
// TODO: figure out how to deal with push-specs, probably when push is being implemented.
pub fn match_lhs<'item>(
self,
mut items: impl Iterator<Item = Item<'item>> + Clone,
) -> match_lhs::Outcome<'spec, 'item> {
let mut out = Vec::new();
let mut seen = BTreeSet::default();
let mut push_unique = |mapping| {
if seen.insert(calculate_hash(&mapping)) {
out.push(mapping);
}
};
let mut matchers: Vec<Option<Matcher<'_>>> = self
.specs
.iter()
.copied()
.map(Matcher::from)
.enumerate()
.map(|(idx, m)| match m.lhs {
Some(Needle::Object(id)) => {
push_unique(Mapping {
item_index: None,
lhs: SourceRef::ObjectId(id),
rhs: m.rhs.map(Needle::to_bstr),
spec_index: idx,
});
None
}
_ => Some(m),
})
.collect();
let mut has_negation = false;
for (spec_index, (spec, matcher)) in self.specs.iter().zip(matchers.iter_mut()).enumerate() {
if spec.mode == Mode::Negative {
has_negation = true;
continue;
}
for (item_index, item) in items.clone().enumerate() {
let Some(matcher) = matcher else { continue };
let (matched, rhs) = matcher.matches_lhs(item);
if matched {
push_unique(Mapping {
item_index: Some(item_index),
lhs: SourceRef::FullName(item.full_ref_name.into()),
rhs,
spec_index,
});
}
}
}
if let Some(hash_kind) = has_negation.then(|| items.next().map(|i| i.target.kind())).flatten() {
let null_id = hash_kind.null();
for matcher in matchers
.into_iter()
.zip(self.specs.iter())
.filter_map(|(m, spec)| m.and_then(|m| (spec.mode == Mode::Negative).then_some(m)))
{
out.retain(|m| match &m.lhs {
SourceRef::ObjectId(_) => true,
SourceRef::FullName(name) => {
!matcher
.matches_lhs(Item {
full_ref_name: name.as_ref(),
target: &null_id,
object: None,
})
.0
}
});
}
}
match_lhs::Outcome {
group: self,
mappings: out,
}
}
/// Match all `items` against all *fetch* specs present in this group, returning deduplicated mappings from destination to source.
/// `items` are expected to be tracking references in the local clone, which will be matched and reverse-mapped to obtain their remote counterparts,
/// i.e. *right side of refspecs is mapped to their left side*.
/// *Note that this method is correct only for fetch-specs*, even though it also *works for push-specs*.
///
/// Note that negative matches are not part of the return value, so they are not observable but will be used to remove mappings.
// Reverse-mapping is implemented here: https://github.com/git/git/blob/76cf4f61c87855ebf0784b88aaf737d6b09f504b/branch.c#L252
pub fn match_rhs<'item>(
self,
mut items: impl Iterator<Item = Item<'item>> + Clone,
) -> match_rhs::Outcome<'spec, 'item> {
let mut out = Vec::<Mapping<'spec, 'item>>::new();
let mut seen = BTreeSet::default();
let mut push_unique = |mapping| {
if seen.insert(calculate_hash(&mapping)) {
out.push(mapping);
}
};
let mut matchers: Vec<Matcher<'_>> = self.specs.iter().copied().map(Matcher::from).collect();
let mut has_negation = false;
for (spec_index, (spec, matcher)) in self.specs.iter().zip(matchers.iter_mut()).enumerate() {
if spec.mode == Mode::Negative {
has_negation = true;
continue;
}
for (item_index, item) in items.clone().enumerate() {
let (matched, lhs) = matcher.matches_rhs(item);
if let Some(lhs) = lhs.filter(|_| matched) {
push_unique(Mapping {
item_index: Some(item_index),
lhs: SourceRef::FullName(lhs),
rhs: Some(item.full_ref_name.into()),
spec_index,
});
}
}
}
if let Some(hash_kind) = has_negation.then(|| items.next().map(|i| i.target.kind())).flatten() {
let null_id = hash_kind.null();
for matcher in matchers
.into_iter()
.zip(self.specs.iter())
.filter_map(|(m, spec)| (spec.mode == Mode::Negative).then_some(m))
{
out.retain(|m| match &m.lhs {
SourceRef::ObjectId(_) => true,
SourceRef::FullName(name) => {
!matcher
.matches_rhs(Item {
full_ref_name: name.as_ref(),
target: &null_id,
object: None,
})
.0
}
});
}
}
match_rhs::Outcome {
group: self,
mappings: out,
}
}
}
fn calculate_hash<T: std::hash::Hash>(t: &T) -> u64 {
use std::hash::Hasher;
let mut s = std::collections::hash_map::DefaultHasher::new();
t.hash(&mut s);
s.finish()
}
mod util;
use util::{Matcher, Needle};