datafusion_execution/cache/
mod.rs

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16// under the License.
17
18pub mod cache_manager;
19pub mod cache_unit;
20pub mod lru_queue;
21
22mod file_metadata_cache;
23mod list_files_cache;
24
25pub use file_metadata_cache::DefaultFilesMetadataCache;
26pub use list_files_cache::DefaultListFilesCache;
27pub use list_files_cache::TableScopedPath;
28
29/// A trait that can be implemented to provide custom cache behavior for the caches managed by
30/// [`cache_manager::CacheManager`].
31///
32/// Implementations must handle their own locking via internal mutability, as methods do not
33/// take mutable references and may be accessed by multiple concurrent queries.
34pub trait CacheAccessor<K, V>: Send + Sync {
35    // Extra info but not part of the cache key or cache value.
36    type Extra: Clone;
37
38    /// Get value from cache.
39    fn get(&self, k: &K) -> Option<V>;
40    /// Get value from cache.
41    fn get_with_extra(&self, k: &K, e: &Self::Extra) -> Option<V>;
42    /// Put value into cache. Returns the old value associated with the key if there was one.
43    fn put(&self, key: &K, value: V) -> Option<V>;
44    /// Put value into cache. Returns the old value associated with the key if there was one.
45    fn put_with_extra(&self, key: &K, value: V, e: &Self::Extra) -> Option<V>;
46    /// Remove an entry from the cache, returning value if they existed in the map.
47    fn remove(&self, k: &K) -> Option<V>;
48    /// Check if the cache contains a specific key.
49    fn contains_key(&self, k: &K) -> bool;
50    /// Fetch the total number of cache entries.
51    fn len(&self) -> usize;
52    /// Check if the Cache collection is empty or not.
53    fn is_empty(&self) -> bool {
54        self.len() == 0
55    }
56    /// Remove all entries from the cache.
57    fn clear(&self);
58    /// Return the cache name.
59    fn name(&self) -> String;
60}