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
|
use gix_object::bstr::BString;
use crate::{
transaction::{Change, LogChange, PreviousValue, RefEdit, RefLog, Target},
PartialNameRef,
};
/// An extension trait to perform commonly used operations on edits across different ref stores.
pub trait RefEditsExt<T>
where
T: std::borrow::Borrow<RefEdit> + std::borrow::BorrowMut<RefEdit>,
{
/// Return true if each ref `name` has exactly one `edit` across multiple ref edits
fn assure_one_name_has_one_edit(&self) -> Result<(), BString>;
/// Split all symbolic refs into updates for the symbolic ref as well as all their referents if the `deref` flag is enabled.
///
/// Note no action is performed if deref isn't specified.
fn extend_with_splits_of_symbolic_refs(
&mut self,
find: impl FnMut(&PartialNameRef) -> Option<Target>,
make_entry: impl FnMut(usize, RefEdit) -> T,
) -> Result<(), std::io::Error>;
/// All processing steps in one and in the correct order.
///
/// Users call this to assure derefs are honored and duplicate checks are done.
fn pre_process(
&mut self,
find: impl FnMut(&PartialNameRef) -> Option<Target>,
make_entry: impl FnMut(usize, RefEdit) -> T,
) -> Result<(), std::io::Error> {
self.extend_with_splits_of_symbolic_refs(find, make_entry)?;
self.assure_one_name_has_one_edit().map_err(|name| {
std::io::Error::new(
std::io::ErrorKind::AlreadyExists,
format!("A reference named '{name}' has multiple edits"),
)
})
}
}
impl<E> RefEditsExt<E> for Vec<E>
where
E: std::borrow::Borrow<RefEdit> + std::borrow::BorrowMut<RefEdit>,
{
fn assure_one_name_has_one_edit(&self) -> Result<(), BString> {
let mut names: Vec<_> = self.iter().map(|e| &e.borrow().name).collect();
names.sort();
match names.windows(2).find(|v| v[0] == v[1]) {
Some(name) => Err(name[0].as_bstr().to_owned()),
None => Ok(()),
}
}
fn extend_with_splits_of_symbolic_refs(
&mut self,
mut find: impl FnMut(&PartialNameRef) -> Option<Target>,
mut make_entry: impl FnMut(usize, RefEdit) -> E,
) -> Result<(), std::io::Error> {
let mut new_edits = Vec::new();
let mut first = 0;
let mut round = 1;
loop {
for (eid, edit) in self[first..].iter_mut().enumerate().map(|(eid, v)| (eid + first, v)) {
let edit = edit.borrow_mut();
if !edit.deref {
continue;
};
// we can't tell what happened and we are here because it's a non-existing ref or an invalid one.
// In any case, we don't want the following algorithms to try dereffing it and assume they deal with
// broken refs gracefully.
edit.deref = false;
if let Some(Target::Symbolic(referent)) = find(edit.name.as_ref().as_partial_name()) {
new_edits.push(make_entry(
eid,
match &mut edit.change {
Change::Delete {
expected: previous,
log: mode,
} => {
let current_mode = *mode;
*mode = RefLog::Only;
RefEdit {
change: Change::Delete {
expected: previous.clone(),
log: current_mode,
},
name: referent,
deref: true,
}
}
Change::Update { log, expected, new } => {
let current = std::mem::replace(
log,
LogChange {
message: log.message.clone(),
mode: RefLog::Only,
force_create_reflog: log.force_create_reflog,
},
);
let next = std::mem::replace(expected, PreviousValue::Any);
RefEdit {
change: Change::Update {
expected: next,
new: new.clone(),
log: current,
},
name: referent,
deref: true,
}
}
},
));
}
}
if new_edits.is_empty() {
break Ok(());
}
if round == 5 {
break Err(std::io::Error::new(
std::io::ErrorKind::WouldBlock,
format!("Could not follow all splits after {round} rounds, assuming reference cycle"),
));
}
round += 1;
first = self.len();
self.append(&mut new_edits);
}
}
}
|
