Struct MmapFilePusher 

pub struct MmapFilePusher { /* private fields */ }

File pusher using memory-mapped I/O for zero-copy writes.

Delegates writes to the OS via MmapMut. The file size is fixed at construction time via file.set_len(size). On flush, if sync_all is true an fsync is performed; otherwise an async flush is issued.

Implementations

impl MmapFilePusher

pub async fn new(file: &File, size: u64, sync_all: bool) -> Result<Self>

Errors

1. Returns an error if fs::set_len fails.
2. Returns an error if MmapMut::map_mut fails.

Trait Implementations

impl Debug for MmapFilePusher

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

Formats the value using the given formatter.

impl Pusher for MmapFilePusher

fn flush(&mut self) -> Result<(), Self::Error>

Data is already in the shared mapping, visible to any other reader.

Only sync_all forces the dirty pages out; otherwise this is a no-op so the writeback is left to the OS instead of blocking the download on msync/FlushViewOfFile. The mapping keeps the pages reachable until the pusher is dropped, so the data is never lost.

type Error = Error

Error produced while pushing.

fn set_listener(&mut self, cb: ProgressListener)

Install a callback that fires whenever a chunk has been successfully pushed to its destination.

fn push( &mut self, range: &ProgressEntry, bytes: Bytes, ) -> Result<(), (Self::Error, Bytes)>

Write content covering the given range to the destination.