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#![allow(clippy::derive_partial_eq_without_eq)]
// https://github.com/hyperium/tonic/issues/1056
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, PartialEq, Eq, Error)]
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("Invalid Digest length: {0}")]
InvalidDigestLen(usize),
}
/// Checks a Node name for validity as an intermediate node, and returns an
/// error that's generated from the supplied constructor.
///
/// We disallow slashes, null bytes, '.', '..' and the empty string.
fn validate_node_name<E>(name: &str, err: fn(String) -> E) -> Result<(), E> {
if name.is_empty() || name == ".." || name == "." || name.contains('\x00') || name.contains('/')
{
return Err(err(name.to_string()));
}
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()));
}
*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()));
}
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, ValidateDirectoryError::InvalidName)?;
validate_digest(&directory_node.digest)?;
update_if_lt_prev(&mut last_directory_name, 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, ValidateDirectoryError::InvalidName)?;
validate_digest(&file_node.digest)?;
update_if_lt_prev(&mut last_file_name, 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, ValidateDirectoryError::InvalidName)?;
update_if_lt_prev(&mut last_symlink_name, symlink_node.name.as_str())?;
insert_once(&mut seen_names, symlink_node.name.as_str())?;
}
Ok(())
}
}
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