Module factory 

The factory execution context and its product.

When get_or_set must produce a value, it hands the factory a FactoryContext. Through it the factory can:

• read the previously-cached stale value and its ETag/LastModified (conditional refresh);
• adapt the entry options for the value it is about to produce (adaptive caching) via FactoryContext::options_mut;
• signal one of three outcomes: a new value (FactoryContext::value / FactoryContext::modified), “nothing changed, reuse the stale value” (FactoryContext::not_modified), or failure (FactoryContext::fail).

The factory returns Result<FactoryProduct<V>, FactoryError>; an Err drives the fail-safe path.

Structs

FactoryContext

Context passed to a factory, carrying stale-value information and the mutable options for the value being produced.

FactoryProduct

The value (and metadata) a factory produced, ready to be cached.

ModifiedBuilder

Builder for a modified factory result with conditional-refresh metadata.