1use std::{
2 hash::{Hash, Hasher},
3 path::{Path, PathBuf},
4 sync::Arc,
5};
6
7use crate::paths::SanitizedPath;
8use itertools::Itertools;
9use serde::{Deserialize, Serialize};
10
11/// A list of absolute paths, with an associated display order.
12///
13/// Two `PathList` values are considered equal if they contain the same paths,
14/// regardless of the order in which those paths were originally provided.
15///
16/// The paths can be retrieved in the original order using `ordered_paths()`.
17#[derive(Default, Debug, Clone)]
18pub struct PathList {
19 /// The paths, in lexicographic order.
20 paths: Arc<[PathBuf]>,
21 /// The order in which the paths were provided.
22 ///
23 /// See `ordered_paths()` for a way to get the paths in the original order.
24 order: Arc<[usize]>,
25}
26
27impl PartialEq for PathList {
28 fn eq(&self, other: &Self) -> bool {
29 self.paths == other.paths
30 }
31}
32
33impl Eq for PathList {}
34
35impl Hash for PathList {
36 fn hash<H: Hasher>(&self, state: &mut H) {
37 self.paths.hash(state);
38 }
39}
40
41#[derive(Debug, Serialize, Deserialize)]
42pub struct SerializedPathList {
43 pub paths: String,
44 pub order: String,
45}
46
47impl PathList {
48 pub fn new<P: AsRef<Path>>(paths: &[P]) -> Self {
49 let mut indexed_paths: Vec<(usize, PathBuf)> = paths
50 .iter()
51 .enumerate()
52 .map(|(ix, path)| (ix, SanitizedPath::new(path).into()))
53 .collect();
54 indexed_paths.sort_by(|(_, a), (_, b)| a.cmp(b));
55 let order = indexed_paths.iter().map(|e| e.0).collect::<Vec<_>>().into();
56 let paths = indexed_paths
57 .into_iter()
58 .map(|e| e.1)
59 .collect::<Vec<_>>()
60 .into();
61 Self { order, paths }
62 }
63
64 pub fn is_empty(&self) -> bool {
65 self.paths.is_empty()
66 }
67
68 /// Get the paths in lexicographic order.
69 pub fn paths(&self) -> &[PathBuf] {
70 self.paths.as_ref()
71 }
72
73 /// Get the order in which the paths were provided.
74 pub fn order(&self) -> &[usize] {
75 self.order.as_ref()
76 }
77
78 /// Get the paths in the original order.
79 pub fn ordered_paths(&self) -> impl Iterator<Item = &PathBuf> {
80 self.order
81 .iter()
82 .zip(self.paths.iter())
83 .sorted_by_key(|(i, _)| **i)
84 .map(|(_, path)| path)
85 }
86
87 pub fn is_lexicographically_ordered(&self) -> bool {
88 self.order.iter().enumerate().all(|(i, &j)| i == j)
89 }
90
91 pub fn deserialize(serialized: &SerializedPathList) -> Self {
92 let mut paths: Vec<PathBuf> = if serialized.paths.is_empty() {
93 Vec::new()
94 } else {
95 serialized.paths.split('\n').map(PathBuf::from).collect()
96 };
97
98 let mut order: Vec<usize> = serialized
99 .order
100 .split(',')
101 .filter_map(|s| s.parse().ok())
102 .collect();
103
104 if !paths.is_sorted() || order.len() != paths.len() {
105 order = (0..paths.len()).collect();
106 paths.sort();
107 }
108
109 Self {
110 paths: paths.into(),
111 order: order.into(),
112 }
113 }
114
115 pub fn serialize(&self) -> SerializedPathList {
116 use std::fmt::Write as _;
117
118 let mut paths = String::new();
119 for path in self.paths.iter() {
120 if !paths.is_empty() {
121 paths.push('\n');
122 }
123 paths.push_str(&path.to_string_lossy());
124 }
125
126 let mut order = String::new();
127 for ix in self.order.iter() {
128 if !order.is_empty() {
129 order.push(',');
130 }
131 write!(&mut order, "{}", *ix).unwrap();
132 }
133 SerializedPathList { paths, order }
134 }
135}
136
137#[cfg(test)]
138mod tests {
139 use super::*;
140
141 #[test]
142 fn test_path_list() {
143 let list1 = PathList::new(&["a/d", "a/c"]);
144 let list2 = PathList::new(&["a/c", "a/d"]);
145
146 assert_eq!(list1.paths(), list2.paths(), "paths differ");
147 assert_eq!(list1.order(), &[1, 0], "list1 order incorrect");
148 assert_eq!(list2.order(), &[0, 1], "list2 order incorrect");
149
150 // Same paths in different order are equal (order is display-only).
151 assert_eq!(
152 list1, list2,
153 "same paths with different order should be equal"
154 );
155
156 let list1_deserialized = PathList::deserialize(&list1.serialize());
157 assert_eq!(list1_deserialized, list1, "list1 deserialization failed");
158
159 let list2_deserialized = PathList::deserialize(&list2.serialize());
160 assert_eq!(list2_deserialized, list2, "list2 deserialization failed");
161
162 assert_eq!(
163 list1.ordered_paths().collect_array().unwrap(),
164 [&PathBuf::from("a/d"), &PathBuf::from("a/c")],
165 "list1 ordered paths incorrect"
166 );
167 assert_eq!(
168 list2.ordered_paths().collect_array().unwrap(),
169 [&PathBuf::from("a/c"), &PathBuf::from("a/d")],
170 "list2 ordered paths incorrect"
171 );
172 }
173
174 #[test]
175 fn test_path_list_ordering() {
176 let list = PathList::new(&["b", "a", "c"]);
177 assert_eq!(
178 list.paths(),
179 &[PathBuf::from("a"), PathBuf::from("b"), PathBuf::from("c")]
180 );
181 assert_eq!(list.order(), &[1, 0, 2]);
182 assert!(!list.is_lexicographically_ordered());
183
184 let serialized = list.serialize();
185 let deserialized = PathList::deserialize(&serialized);
186 assert_eq!(deserialized, list);
187
188 assert_eq!(
189 deserialized.ordered_paths().collect_array().unwrap(),
190 [
191 &PathBuf::from("b"),
192 &PathBuf::from("a"),
193 &PathBuf::from("c")
194 ]
195 );
196
197 let list = PathList::new(&["b", "c", "a"]);
198 assert_eq!(
199 list.paths(),
200 &[PathBuf::from("a"), PathBuf::from("b"), PathBuf::from("c")]
201 );
202 assert_eq!(list.order(), &[2, 0, 1]);
203 assert!(!list.is_lexicographically_ordered());
204
205 let serialized = list.serialize();
206 let deserialized = PathList::deserialize(&serialized);
207 assert_eq!(deserialized, list);
208
209 assert_eq!(
210 deserialized.ordered_paths().collect_array().unwrap(),
211 [
212 &PathBuf::from("b"),
213 &PathBuf::from("c"),
214 &PathBuf::from("a"),
215 ]
216 );
217 }
218}