Struct Cache 

pub struct Cache {
    pub(super) root: PathBuf,
    index: Index,
    pub(super) state: IndexState,
}

Fields

root: PathBuf

index: Index

state: IndexState

Implementations

impl Cache

pub fn open(root: impl Into<PathBuf>) -> Cache

An index that is missing or cannot be read opens as an empty cache and leaves the payloads on disk; index_state says which happened.

pub fn index_state(&self) -> IndexState

pub fn root(&self) -> &Path

pub fn get(&self, key: &str) -> Option<&CachedPackage>

pub fn entries(&self) -> Vec<CachedPackage>

Every entry whose payload is still on disk, so nothing missing is offered as downloaded.

pub(super) fn names(&self, sha256: &str) -> bool

Whether an index entry names this payload.

pub(super) fn known_digests(&self) -> BTreeSet<&str>

pub fn insert(&mut self, package: CachedPackage) -> Result<()>

Saves at once, so an interrupted run keeps the download that just finished.

pub fn remove(&mut self, key: &str) -> Result<()>

pub fn save(&mut self) -> Result<()>

A temp file renamed over the old index, which std::fs::rename replaces in one step, so a crash never leaves the cache without one.

impl Cache

pub fn payload_path(&self, sha256: &str) -> PathBuf

Where a payload with this digest lives, whether or not it is there.

pub fn has_payload(&self, sha256: &str) -> bool

The index can outlive its file, so an install asks this rather than trusting the index.

pub fn holds(&self, key: &str) -> bool

Whether key’s payload is here to install, not merely named by the index.

pub fn orphans(&self) -> Vec<PathBuf>

Payloads no index entry refers to, for the I9 sweep, and none unless the index was really read, or a damaged index would condemn the whole cache.

pub fn sweep(&self, in_use: Option<&[String]>) -> Swept

Deletes what a killed download left half-written, and, given in_use (the digests the ledger and the restore points need), every payload neither it nor the index names; None deletes no payload, for when what is needed is unknown, and so does an index that was not read.