Struct MmapDirectory 

pub struct MmapDirectory { /* private fields */ }

Memory-mapped directory for efficient access to large index files

Uses memory-mapped files to avoid loading entire files into memory. The OS manages paging, making this ideal for indices larger than RAM.

Benefits:

• Files are not fully loaded into memory
• OS handles caching and paging automatically
• Multiple processes can share the same mapped pages
• Efficient random access patterns

Note: Write operations still use regular file I/O.

Implementations

impl MmapDirectory

pub fn new(root: impl AsRef<Path>) -> Self

Create a new MmapDirectory rooted at the given path

pub fn clear_cache(&self)

Clear the mmap cache (useful after writes)

Trait Implementations

impl Clone for MmapDirectory

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Directory for MmapDirectory

fn exists<'life0, 'life1, 'async_trait>( &'life0 self, path: &'life1 Path, ) -> Pin<Box<dyn Future<Output = Result<bool>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Check if a file exists

fn file_size<'life0, 'life1, 'async_trait>( &'life0 self, path: &'life1 Path, ) -> Pin<Box<dyn Future<Output = Result<u64>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Get file size

fn open_read<'life0, 'life1, 'async_trait>( &'life0 self, path: &'life1 Path, ) -> Pin<Box<dyn Future<Output = Result<FileSlice>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Open a file for reading, returns a FileSlice (loads entire file)

fn read_range<'life0, 'life1, 'async_trait>( &'life0 self, path: &'life1 Path, range: Range<u64>, ) -> Pin<Box<dyn Future<Output = Result<OwnedBytes>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Read a specific byte range from a file (optimized for network)

fn list_files<'life0, 'life1, 'async_trait>( &'life0 self, prefix: &'life1 Path, ) -> Pin<Box<dyn Future<Output = Result<Vec<PathBuf>>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

List files in directory

fn open_lazy<'life0, 'life1, 'async_trait>( &'life0 self, path: &'life1 Path, ) -> Pin<Box<dyn Future<Output = Result<LazyFileHandle>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Open a lazy file handle that fetches ranges on demand This is more efficient for large files over network

impl DirectoryWriter for MmapDirectory

fn write<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, path: &'life1 Path, data: &'life2 [u8], ) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

Create/overwrite a file with data

fn delete<'life0, 'life1, 'async_trait>( &'life0 self, path: &'life1 Path, ) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Delete a file

fn rename<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, from: &'life1 Path, to: &'life2 Path, ) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

Atomic rename

fn sync<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Sync all pending writes