FileMetadata

datafusion_execution::cache::cache_manager

Trait FileMetadata 

Source 
pub trait FileMetadata:
    Any
    + Send
    + Sync {
    // Required methods
    fn as_any(&self) -> &dyn Any;
    fn memory_size(&self) -> usize;
    fn extra_info(&self) -> HashMap<String, String>;
}
Expand description

Generic file-embedded metadata used with FileMetadataCache.

For example, Parquet footers and page metadata can be represented using this trait.

See crate::runtime_env::RuntimeEnv for more details

Required Methods§

Source

fn as_any(&self) -> &dyn Any

Returns the file metadata as Any so that it can be downcast to a specific implementation.

Source

fn memory_size(&self) -> usize

Returns the size of the metadata in bytes.

Source

fn extra_info(&self) -> HashMap<String, String>

Returns extra information about this entry (used by FileMetadataCache::list_entries).

Implementors§