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
|
//! This module implements logic required for persisting known paths
//! during an evaluation.
//!
//! Tvix needs to be able to keep track of each Nix store path that it
//! knows about during the scope of a single evaluation and its
//! related builds.
//!
//! This data is required to scan derivation inputs for the build
//! references (the "build closure") that they make use of.
//!
//! Please see //tvix/eval/docs/build-references.md for more
//! information.
use crate::refscan::ReferenceScanner;
use std::{
collections::{hash_map, BTreeSet, HashMap},
ops::Index,
};
#[derive(Debug, PartialEq)]
pub enum PathType {
/// A literal derivation (`.drv`-file), and the *names* of its outputs.
Derivation { output_names: BTreeSet<String> },
/// An output of a derivation, its name, and the path of its derivation.
Output { name: String, derivation: String },
/// A plain store path (e.g. source files copied to the store).
Plain,
}
#[derive(Debug, Default)]
pub struct KnownPaths {
/// All known paths, and their associated [`PathType`].
paths: HashMap<String, PathType>,
/// All known replacement strings for derivations.
///
/// Keys are derivation paths, values are the opaque replacement
/// strings.
replacements: HashMap<String, String>,
}
impl Index<&str> for KnownPaths {
type Output = PathType;
fn index(&self, index: &str) -> &Self::Output {
&self.paths[index]
}
}
impl KnownPaths {
fn insert_path(&mut self, path: String, path_type: PathType) {
match self.paths.entry(path) {
hash_map::Entry::Vacant(entry) => {
entry.insert(path_type);
}
hash_map::Entry::Occupied(mut entry) => {
match (path_type, entry.get_mut()) {
// These variant combinations require no "merging action".
(PathType::Plain, PathType::Plain) => (),
(PathType::Output { .. }, PathType::Output { .. }) => (),
(
PathType::Derivation { output_names: new },
PathType::Derivation {
output_names: ref mut old,
},
) => {
old.extend(new);
}
_ => panic!("path '{}' inserted twice with different types", entry.key()),
};
}
};
}
/// Mark a plain path as known.
pub fn plain<S: ToString>(&mut self, path: S) {
self.insert_path(path.to_string(), PathType::Plain);
}
/// Mark a derivation as known.
pub fn drv<P: ToString, O: ToString>(&mut self, path: P, outputs: &[O]) {
self.insert_path(
path.to_string(),
PathType::Derivation {
output_names: outputs.into_iter().map(ToString::to_string).collect(),
},
);
}
/// Mark a derivation output path as known.
pub fn output<P: ToString, N: ToString, D: ToString>(
&mut self,
output_path: P,
name: N,
drv_path: D,
) {
self.insert_path(
output_path.to_string(),
PathType::Output {
name: name.to_string(),
derivation: drv_path.to_string(),
},
);
}
/// Create a reference scanner from the current set of known paths.
pub fn reference_scanner(&self) -> ReferenceScanner {
let candidates = self.paths.keys().map(Clone::clone).collect();
ReferenceScanner::new(candidates)
}
/// Fetch the opaque "replacement string" for a given derivation path.
pub fn get_replacement_string(&self, drv: &str) -> String {
// TODO: we rely on an invariant that things *should* have
// been calculated if we get this far.
self.replacements[drv].clone()
}
pub fn add_replacement_string<D: ToString>(&mut self, drv: D, replacement_str: &str) {
let old = self
.replacements
.insert(drv.to_string(), replacement_str.to_owned());
#[cfg(debug_assertions)]
{
if let Some(old) = old {
debug_assert!(
old == replacement_str,
"replacement string for a given derivation should always match"
);
}
}
}
}
|
