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
use gix_error::{ErrorExt, ExnResult, Message, ResultExt, message};
use crate::{
Target,
store_impl::file::{Transaction, transaction::PackedRefs},
transaction::{Change, LogChange, RefEdit, RefLog},
};
impl Transaction<'_, '_> {
/// Make all [prepared][Transaction::prepare()] permanent and return the performed edits which represent the current
/// state of the affected refs in the ref store in that instant. Please note that the obtained edits may have been
/// adjusted to contain more dependent edits or additional information.
/// `committer` is used in the reflog and only if the reflog is actually written, which is why it is optional. Please note
/// that if `None` is passed and the reflog needs to be written, the operation will be aborted late and a few refs may have been
/// successfully committed already, making clear the non-atomic nature of multi-file edits.
///
/// On error the transaction may have been performed partially, depending on the nature of the error, and no attempt to roll back
/// partial changes is made.
///
/// In this stage, we perform the following operations:
///
/// * update the ref log
/// * move updated refs into place
/// * delete reflogs and empty parent directories
/// * delete packed refs
/// * delete their corresponding reference (if applicable)
/// along with empty parent directories
///
/// Note that transactions will be prepared automatically as needed.
/// Per-reference failures include [metadata](gix_error::Exn::metadata()) `reference` (bytes), the affected name.
/// A missing reflog identity is identifiable as [`file::log::create_or_update::MissingCommitter`](crate::file::log::create_or_update::MissingCommitter).
pub fn commit<'a>(self, committer: impl Into<Option<gix_actor::SignatureRef<'a>>>) -> ExnResult<Vec<RefEdit>> {
self.commit_inner(committer.into())
}
/// Per-reference failures include [metadata](gix_error::Exn::metadata()) `reference` (bytes), the affected name.
fn commit_inner(self, committer: Option<gix_actor::SignatureRef<'_>>) -> ExnResult<Vec<RefEdit>> {
let mut updates = self.updates.expect("BUG: must call prepare before commit");
let delete_loose_refs = matches!(
self.packed_refs,
PackedRefs::DeletionsAndNonSymbolicUpdatesRemoveLooseSourceReference(_)
);
// Perform updates first so live commits remain referenced
for change in &mut updates {
assert!(!change.update.deref, "Deref mode is turned into splits and turned off");
match &change.update.change {
// reflog first, then reference
Change::Update { log, new, expected } => {
let lock = change.lock.take();
let (update_ref, update_reflog) = match log.mode {
RefLog::Only => (false, true),
RefLog::AndReference => (true, true),
};
if update_reflog {
let log_update = match new {
Target::Symbolic(_) => {
// Special HACK: no reflog for symref changes as there is no OID involved which the reflog needs.
// Unless, the ref is new and we can obtain a peeled id
// identified by the expectation of what could be there, as is the case when cloning.
match expected {
PreviousValue::ExistingMustMatch(Target::Object(oid)) => {
Some((Some(gix_hash::ObjectId::null(oid.kind())), oid))
}
_ => None,
}
}
Target::Object(new_oid) => {
let previous = match expected {
// Here, this means that the ref already existed, and that it will receive (even transitively)
// the given value
PreviousValue::MustExistAndMatch(Target::Object(oid)) => Some(oid.to_owned()),
_ => None,
}
.or(change.leaf_referent_previous_oid);
Some((previous, new_oid))
}
};
if let Some((previous, new_oid)) = log_update {
let do_update = previous.as_ref() != Some(new_oid);
if do_update {
self.store
.reflog_create_or_append(
change.update.name.as_ref(),
previous,
new_oid,
committer,
log.message.as_ref(),
log.force_create_reflog,
)
.or_raise_erased(|| {
Message::new("Could not update reflog")
.with("reference", change.update.name.as_bstr())
})?;
}
}
}
// Don't do anything else while keeping the lock after potentially updating the reflog.
// We delay deletion of the reference and dropping the lock to after the packed-refs were
// safely written.
if delete_loose_refs && matches!(new, Target::Object(_)) {
change.lock = lock;
continue;
}
if update_ref && let Some(Err(err)) = lock.map(gix_lock::Marker::commit) {
// TODO: when Kind::IsADirectory becomes stable, use that.
let err = if err.instance.resource_path().is_dir() {
gix_tempfile::remove_dir::empty_depth_first(err.instance.resource_path())
.map_err(std::io::Error::other)
.and_then(|_| err.instance.commit().map_err(|err| err.error))
.err()
} else {
Some(err.error)
};
if let Some(err) = err {
return Err(err
.and_raise(Message::new("Could not commit reference").with("reference", change.name()))
.erased());
}
}
}
Change::Delete { .. } => {}
}
}
for change in &mut updates {
let (reflog_root, relative_name) = self.store.reflog_base_and_relative_path(change.update.name.as_ref());
match &change.update.change {
Change::Update { .. } => {}
Change::Delete { .. } => {
// Reflog deletion happens first in case it fails a ref without log is less terrible than
// a log without a reference.
let reflog_path = reflog_root.join(relative_name);
if let Err(err) = std::fs::remove_file(&reflog_path) {
if err.kind() != std::io::ErrorKind::NotFound {
return Err(err
.and_raise(Message::new("Could not delete reflog").with("reference", change.name()))
.erased());
}
} else {
gix_tempfile::remove_dir::empty_upward_until_boundary(
reflog_path.parent().expect("never without parent"),
&reflog_root,
)
.ok();
}
}
}
}
if let Some(t) = self.packed_transaction {
t.commit()
.or_raise_erased(|| message("Could not commit packed-ref transaction"))?;
// Always refresh ourselves right away to avoid races. We ignore errors as there may be many reasons this fails, and it's not
// critical to be done here. In other words, the pack may be refreshed at a later time and then it might work.
self.store.force_refresh_packed_buffer().ok();
}
for change in &mut updates {
let take_lock_and_delete = match &change.update.change {
Change::Update {
log: LogChange { mode, .. },
new,
..
} => delete_loose_refs && *mode == RefLog::AndReference && matches!(new, Target::Object(_)),
Change::Delete { log: mode, .. } => *mode == RefLog::AndReference,
};
if take_lock_and_delete {
let lock = change.lock.take();
let reference_path = self.store.reference_path(change.update.name.as_ref());
if let Err(err) = std::fs::remove_file(reference_path)
&& err.kind() != std::io::ErrorKind::NotFound
{
return Err(err
.and_raise(Message::new("Could not delete reference").with("reference", change.name()))
.erased());
}
drop(lock);
}
}
Ok(updates.into_iter().map(|edit| edit.update).collect())
}
}
use crate::transaction::PreviousValue;