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
|
use std::collections::HashSet;
use thiserror::Error;
use prost::Message;
tonic::include_proto!("tvix.store.v1");
/// Errors that can occur during the validation of Directory messages.
#[derive(Debug, Error, PartialEq)]
pub enum ValidateDirectoryError {
/// Elements are not in sorted order
#[error("{0} is not sorted")]
WrongSorting(String),
/// Multiple elements with the same name encountered
#[error("{0} is a duplicate name")]
DuplicateName(String),
/// Invalid name encountered
#[error("Invalid name in {0}")]
InvalidName(String),
/// Invalid digest length encountered
#[error("Ivalid Digest length: {0}")]
InvalidDigestLen(usize),
}
/// Checks a name for validity.
/// We disallow slashes, null bytes, '.', '..' and the empty string.
/// Depending on the context, a [DirectoryNode], [FileNode] or [SymlinkNode]
/// message with an empty string as name is allowed, but they don't occur
/// inside a Directory message.
fn validate_node_name(name: &str) -> Result<(), ValidateDirectoryError> {
if name == "" || name == ".." || name == "." || name.contains("\x00") || name.contains("/") {
return Err(ValidateDirectoryError::InvalidName(
name.to_string().clone(),
));
}
Ok(())
}
/// Checks a digest for validity.
/// Digests are 32 bytes long, as we store blake3 digests.
fn validate_digest(digest: &Vec<u8>) -> Result<(), ValidateDirectoryError> {
if digest.len() != 32 {
return Err(ValidateDirectoryError::InvalidDigestLen(digest.len()));
}
Ok(())
}
/// Accepts a name, and a mutable reference to the previous name.
/// If the passed name is larger than the previous one, the reference is updated.
/// If it's not, an error is returned.
fn update_if_lt_prev<'set, 'n>(
prev_name: &'set mut &'n str,
name: &'n str,
) -> Result<(), ValidateDirectoryError> {
if *name < **prev_name {
return Err(ValidateDirectoryError::WrongSorting(
name.to_string().clone(),
));
}
*prev_name = name;
Ok(())
}
/// Inserts the given name into a HashSet if it's not already in there.
/// If it is, an error is returned.
fn insert_once<'n>(
seen_names: &mut HashSet<&'n str>,
name: &'n str,
) -> Result<(), ValidateDirectoryError> {
if seen_names.get(name).is_some() {
return Err(ValidateDirectoryError::DuplicateName(
name.to_string().clone(),
));
}
seen_names.insert(name);
Ok(())
}
impl Directory {
// The size of a directory is the number of all regular and symlink elements,
// the number of directory elements, and their size fields.
pub fn size(&self) -> u32 {
self.files.len() as u32
+ self.symlinks.len() as u32
+ self
.directories
.iter()
.fold(0, |acc: u32, e| (acc + 1 + e.size) as u32)
}
pub fn digest(&self) -> Vec<u8> {
let mut hasher = blake3::Hasher::new();
hasher.update(&self.encode_to_vec()).finalize().as_bytes()[..].to_vec()
}
/// validate checks the directory for invalid data, such as:
/// - violations of name restrictions
/// - invalid digest lengths
/// - not properly sorted lists
/// - duplicate names in the three lists
pub fn validate(&self) -> Result<(), ValidateDirectoryError> {
let mut seen_names: HashSet<&str> = HashSet::new();
let mut last_directory_name: &str = "";
let mut last_file_name: &str = "";
let mut last_symlink_name: &str = "";
// check directories
for directory_node in &self.directories {
validate_node_name(&directory_node.name)?;
validate_digest(&directory_node.digest)?;
update_if_lt_prev(&mut last_directory_name, &mut directory_node.name.as_str())?;
insert_once(&mut seen_names, &directory_node.name.as_str())?;
}
// check files
for file_node in &self.files {
validate_node_name(&file_node.name)?;
validate_digest(&file_node.digest)?;
update_if_lt_prev(&mut last_file_name, &mut file_node.name.as_str())?;
insert_once(&mut seen_names, &file_node.name.as_str())?;
}
// check symlinks
for symlink_node in &self.symlinks {
validate_node_name(&symlink_node.name)?;
update_if_lt_prev(&mut last_symlink_name, &mut symlink_node.name.as_str())?;
insert_once(&mut seen_names, &symlink_node.name.as_str())?;
}
Ok(())
}
}
|
