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Impl: Ref::refind()

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This commit is contained in:
Matthias Beyer 2016-06-25 16:55:49 +02:00
parent cc8048ea24
commit 757d69f41a
1 changed files with 46 additions and 3 deletions
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49
libimagref/src/reference.rs
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@ -384,15 +384,58 @@ impl<'a> Ref<'a> {
/// Re-find a referenced file
///
/// This function tries to re-find a ref by searching all directories in `search_roots` recursively
/// for a file which matches the hash of the Ref `ref`.
/// for a file which matches the hash of the Ref.
///
/// If `search_roots` is `None`, it starts at the filesystem root `/`.
///
/// If the target cannot be found, this yields a RefTargetDoesNotExist error kind.
///
/// # Warning
///
/// This option causes heavy I/O as it recursively searches the Filesystem.
pub fn refind(&self, search_roots: Option<Vec<PathBuf>>) -> Option<PathBuf> {
unimplemented!()
pub fn refind(&self, search_roots: Option<Vec<PathBuf>>) -> Result<PathBuf> {
use itertools::Itertools;
use walkdir::WalkDir;
self.get_stored_hash()
.and_then(|stored_hash| {
search_roots
.unwrap_or(vec![PathBuf::from("/")])
.into_iter()
.map(|root| {
WalkDir::new(root)
.follow_links(false)
.into_iter()
.map(|entry| {
entry
.map_err(Box::new)
.map_err(|e| REK::IOError.into_error_with_cause(e))
.and_then(|entry| {
let pb = PathBuf::from(entry.path());
File::open(entry.path())
.map_err(Box::new)
.map_err(|e| REK::IOError.into_error_with_cause(e))
.map(|f| (pb, f))
})
.map(|(path, mut file)| (path, hash_file_contents(&mut file)))
.map(|(path, hash)| {
if hash == stored_hash {
Some(path)
} else {
None
}
})
.map_err(Box::new)
.map_err(|e| REK::IOError.into_error_with_cause(e))
})
.filter_map(|e| e.ok())
.filter_map(|e| e)
.next()
})
.flatten()
.next()
.ok_or(REK::RefTargetDoesNotExist.into_error())
})
}
}