Struct InMemoryFeedCache 

pub struct InMemoryFeedCache { /* private fields */ }

What: Provide a small deterministic in-memory implementation of FeedCache.

Inputs:

• Constructed with InMemoryFeedCache::new and a maximum entry count.

Output:

• A thread-safe cache suitable for short-lived applications and tests.

Details:

• This implementation has no time-to-live policy; use a caller-provided cache when persistence or expiration is required.
• On capacity pressure it removes the lexically first key, keeping eviction deterministic without adding an AUR-coupled cache dependency.

Implementations

impl InMemoryFeedCache

pub fn new(capacity: usize) -> Result<Self>

What: Create an empty in-memory feed cache with an explicit capacity.

Inputs:

• capacity: Maximum number of feed payloads that may be retained.

Output:

• A ready-to-use cache, or InvalidInput when capacity is zero.

Details:

• The explicit non-zero bound prevents unbounded cache construction and keeps memory ownership visible to callers.

Errors

Returns ArchToolkitError::InvalidInput when capacity is zero.

Trait Implementations

impl Debug for InMemoryFeedCache

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

Formats the value using the given formatter.

impl FeedCache for InMemoryFeedCache

fn get(&self, key: &str) -> Result<Option<String>>

What: Return a cloned payload for the requested feed key.

Inputs:

• key: Feed cache key to look up.

Output:

• The stored payload when present, otherwise None.

Details:

• Recovers the in-memory cache after a poisoned mutex because payloads are independent values and the map remains usable.

fn put(&self, key: &str, value: &str) -> Result<()>

What: Store a payload and evict deterministically when full.

Inputs:

• key: Feed cache key to write.
• value: Raw successful feed payload.

Output:

• Ok(()) after the in-memory map is updated.

Details:

• Updating an existing key does not evict another entry.
• A new key evicts the lexically first existing key only at capacity.