// Older versions of Cargo used the single value of the hash of the HEAD commit as a `index_version`.
// This is technically correct but a little too conservative. If a new commit is fetched all cached
// files need to be regenerated even if a particular file was not changed.
- // Cargo now checks the `index_version` in two parts the cache file is considered valid if `index_version`
- // ends with the hash of the HEAD commit OR if it starts with the hash of the file's contents.
- // Cargo writes the cached files with `index_version` = `git_file_hash` + ":" + `git_commit_hash`.
+ // However if an old cargo has written such a file we still know how to read it, as long as we check for that hash value.
+ //
+ // Cargo now uses a hash of the file's contents as provided by git.
fn load(
&mut self,
_root: &Path,
}
// Check if the cache is valid.
let git_commit_hash = self.current_version();
- if let (Some(i), Some(c)) = (index_version, git_commit_hash) {
- if i.ends_with(c.as_str()) {
- return Poll::Ready(Ok(LoadResponse::CacheValid));
- }
+ if index_version.is_some() && index_version == git_commit_hash.as_deref() {
+ // This file was written by an old version of cargo, but it is still up-to-date.
+ return Poll::Ready(Ok(LoadResponse::CacheValid));
}
// Note that the index calls this method and the filesystem is locked
// in the index, so we don't need to worry about an `update_index`
registry: &RemoteRegistry<'_>,
path: &Path,
index_version: Option<&str>,
- git_commit_hash: Option<&str>,
) -> CargoResult<LoadResponse> {
let repo = registry.repo()?;
let tree = registry.tree()?;
let entry = tree.get_path(path);
let entry = entry?;
- let git_file_hash = entry.id().to_string();
+ let git_file_hash = Some(entry.id().to_string());
- if let Some(i) = index_version {
- if i.starts_with(git_file_hash.as_str()) {
- return Ok(LoadResponse::CacheValid);
- }
+ // Check if the cache is valid.
+ if index_version.is_some() && index_version == git_file_hash.as_deref() {
+ return Ok(LoadResponse::CacheValid);
}
let object = entry.to_object(repo)?;
Ok(LoadResponse::Data {
raw_data: blob.content().to_vec(),
- index_version: git_commit_hash.map(|c| git_file_hash + c),
+ index_version: git_file_hash,
})
}
- match load_helper(&self, path, index_version, git_commit_hash.as_deref()) {
+ match load_helper(&self, path, index_version) {
Ok(result) => Poll::Ready(Ok(result)),
Err(_) if !self.updated => {
// If git returns an error and we haven't updated the repo, return