Struct SegmentMut 

pub struct SegmentMut { /* private fields */ }

Mutable view into a region of a memory-mapped file. Holds a reference to the parent map; mutable access is provided on demand.

Examples

use std::sync::Arc;
use mmap_io::{MemoryMappedFile, segment::SegmentMut};

let mmap = Arc::new(MemoryMappedFile::create_rw("data.bin", 1024)?);

// Create a mutable segment for bytes 0-100
let segment = SegmentMut::new(mmap.clone(), 0, 100)?;

// Write data to the segment
segment.write(b"Hello from segment!")?;

Implementations

impl SegmentMut

pub fn new(parent: Arc<MemoryMappedFile>, offset: u64, len: u64) -> Result<Self>

Create a new mutable segment view. Performs bounds checks.

Errors

Returns MmapIoError::OutOfBounds if the segment exceeds file bounds.

pub fn as_slice_mut(&self) -> Result<MappedSliceMut<'_>>

Return a write-capable guard to the underlying bytes for this segment. The guard holds the write lock for the duration of the mutable borrow.

Errors

Returns errors from the underlying MemoryMappedFile::as_slice_mut call.

Note: Bounds are already validated at construction, so as_slice_mut will not perform redundant validation.

pub fn write(&self, data: &[u8]) -> Result<()>

Write bytes into this segment from the provided slice.

Errors

Returns errors from the underlying MemoryMappedFile::update_region call.

pub fn len(&self) -> u64

Length of the segment.

pub fn is_empty(&self) -> bool

Check if the segment is empty.

pub fn offset(&self) -> u64

Offset of the segment in the file.

pub fn parent(&self) -> &MemoryMappedFile

Parent mapping.

Trait Implementations

impl Clone for SegmentMut

fn clone(&self) -> SegmentMut

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SegmentMut

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

Formats the value using the given formatter.