Struct CacheReader 

pub struct CacheReader<Fs: Filesystem> { /* private fields */ }

Read-only handle to the cache tree rooted at <workspace_root>/.haz/cache, parameterised over a Filesystem backend.

Pairs with crate::CacheWriter: a writer wraps a reader and adds the mutating operations under the stricter haz_vfs::WritableFilesystem bound. Consumers that only need to consult the cache (e.g. haz cache info per AUX-018, the cache-introspection step of haz why per AUX-014) take a CacheReader and gain a compile-time guarantee that no write can sneak in.

Implementations

impl<Fs: Filesystem> CacheReader<Fs>

pub fn info(&self) -> Result<CacheInfoReport, CacheInfoError>

Walk the cache root and classify every entry per AUX-019.

Idempotent on an absent cache root: when <workspace_root>/.haz/cache does not exist, returns the default-zero report rather than an error.

Errors

Returns CacheInfoError::Io wrapping the underlying FsError when any filesystem read fails. Manifest parse failures and schema mismatches are NOT errors: those entries fold into the CacheInfoReport::corrupt_entries count.

impl<Fs: Filesystem> CacheReader<Fs>

pub fn lookup(&self, key: &CacheKey) -> Option<Manifest>

Look up the cache entry for key.

Returns Some(Manifest) on a hit (every consistency check from CACHE-016 passed), or None on any miss. Miss reasons enumerated by CACHE-016:

1. manifest file absent or unreadable;
2. manifest JSON malformed, contains unknown fields, or uses an unknown hash_function value;
3. manifest’s chapter_revision does not match crate::CHAPTER_REVISION;
4. manifest’s hash_function does not match the cache’s active haz_domain::settings::cache::HashAlgo;
5. any output blob the manifest references is missing, not a regular file, or has a size different from the manifest’s recorded size;
6. the captured stdout or stderr stream is missing, not a regular file, or has a size different from the manifest’s recorded stdout_len / stderr_len.

pub fn lookup_status( &self, key: &CacheKey, ) -> Result<CacheLookupStatus, CacheLookupError>

Introspecting variant of Self::lookup for AUX-015 step 11.

Performs the same per-entry checks as Self::lookup but discriminates the outcome into the four spec-named sub-states. Reuses the same blob / stream verification (CACHE-015 step 4 / 5), so a hit here is observationally equivalent to a hit from Self::lookup.

Errors

Returns CacheLookupError::Io wrapping the underlying FsError for filesystem errors that are NOT a “missing entry” shape (those collapse into the CacheLookupStatus::MissNoEntry / CacheLookupStatus::MissCorruptEntry variants).

impl<Fs: Filesystem> CacheReader<Fs>

pub fn new(fs: Fs, workspace_root: &Path, hash_algo: HashAlgo) -> Self

Construct a CacheReader handle for the workspace rooted at workspace_root. The cache root is derived as <workspace_root>/.haz/cache via layout::cache_root.

hash_algo is the active hash function for this cache session and is used by lookup to reject entries that were written under a different algorithm (CACHE-016 step 3).

pub fn workspace_root(&self) -> &Path

The absolute path to the workspace root. Restoration (CACHE-019) needs this to map workspace-anchored /foo/bar paths recorded in the manifest into real filesystem paths.

pub fn cache_root(&self) -> &Path

The absolute path to the cache root, <workspace_root>/.haz/cache.

pub fn hash_algo(&self) -> HashAlgo

The hash function this CacheReader was constructed with.

pub fn fs(&self) -> &Fs

Borrow the underlying filesystem handle.

Trait Implementations

impl<Fs: Clone + Filesystem> Clone for CacheReader<Fs>

fn clone(&self) -> CacheReader<Fs>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<Fs: Debug + Filesystem> Debug for CacheReader<Fs>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.