Struct MemoryMap 

pub struct MemoryMap { /* private fields */ }

A memory-mapped file as an array of u64.

This interface is highly unsafe. The file remains open until the MemoryMap is dropped. Memory-mapped structures should implement the MemoryMapped trait.

Examples

use simple_sds_sbwt::serialize::{MemoryMap, MappingMode, Serialize};
use simple_sds_sbwt::serialize;
use std::fs;

let v: Vec<u64> = vec![123, 456];
let filename = serialize::temp_file_name("memory-map");
serialize::serialize_to(&v, &filename);

let map = MemoryMap::new(&filename, MappingMode::ReadOnly).unwrap();
assert_eq!(map.mode(), MappingMode::ReadOnly);
assert_eq!(map.len(), 3);
unsafe {
    let slice: &[u64] = map.as_ref();
    assert_eq!(slice[0], 2);
    assert_eq!(slice[1], 123);
    assert_eq!(slice[2], 456);
}

drop(map);
fs::remove_file(&filename).unwrap();

Implementations

impl MemoryMap

pub fn new<P: AsRef<Path>>(filename: P, mode: MappingMode) -> Result<MemoryMap>

Returns a memory map for the specified file in the given mode.

Arguments

• filename: Name of the file.
• mode: Memory mapping mode.

Errors

The call may fail for a number of reasons, including:

• File filename does not exist.
• The file cannot be opened for writing with mode MappingMode::Mutable.
• The size of the file is not a multiple of 8 bytes.
• Memory mapping the file fails.

pub fn filename(&self) -> &Path

Returns the name of the memory mapped file.

pub fn mode(&self) -> MappingMode

Returns the memory mapping mode for the file.

pub unsafe fn as_mut_slice(&mut self) -> &mut [u64]

Returns a mutable slice corresponding to the file.

Safety

Behavior is undefined if the file was opened with mode MappingMode::ReadOnly.

pub fn len(&self) -> usize

Returns the length of the memory-mapped file.

pub fn is_empty(&self) -> bool

Returns true if the file is empty.

Trait Implementations

impl AsRef<[u64]> for MemoryMap

Available on non-target_family=wasm only.

fn as_ref(&self) -> &[u64]

Converts this type into a shared reference of the (usually inferred) input type.

impl Debug for MemoryMap

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

Formats the value using the given formatter.

impl Drop for MemoryMap

Available on non-target_family=wasm only.

fn drop(&mut self)

Executes the destructor for this type.