Struct MemMapCfg 

pub struct MemMapCfg {
    pub module_id: u8,
    pub path: PathBuf,
    pub version: u32,
    pub initial_t: usize,
    pub sync_interval: Option<Duration>,
    pub page_size: Option<PageSize>,
}

Configurations for MemMap

Example

use frozen_core::memmap::MemMapCfg;
use std::time::Duration;

let cfg = MemMapCfg {
    module_id: 1,
    path: std::path::PathBuf::from("test.db"),
    version: 1,
    initial_t: 512,
    sync_interval: Some(Duration::from_millis(0x64)),
    page_size: None,
};

assert_eq!(cfg.version, 1);
assert_eq!(cfg.initial_t, 512);
assert_eq!(cfg.sync_interval, Some(Duration::from_millis(0x64)));
assert_eq!(cfg.page_size, None);

Fields

module_id: u8

Identifier used while error propagation

path: PathBuf

Base path for/of the file

Notes

• The caller must make sure that the path represents a file and all the parent directories included in the path do exist
• The actual file created on disk is derived by appending the version to the base file name (e.g. data.bin with version 1 becomes data_1.bin)

version: u32

Schema or layout version of the underlying memory-mapped file

Because the binary layout on disk is constructed according to the initial type T and structural parameters, MemMap strictly requires type invariants across a file’s lifetime

When an application evolves its data structures or migrates T, incrementing version ensures a new versioned backing file (<name>_<ver>) is created on disk without corrupting or clashing with previously persisted data

initial_t: usize

Number of T elements to pre-allocate on fs when MemMap is initialized

Initial file length will be core::mem::size_of::<T>() * initial_t (bytes)

sync_interval: Option<Duration>

Optional interval for the background sync thread

If Some(duration), a background worker thread is spawned which flushes dirty mapped pages at this interval; and if None, background sync is disabled and durability advances via manual sync or forced tickets

page_size: Option<PageSize>

Configured page size unit for file allocation and growth

Must be a power of 2 and at least 4096 bytes (PageSize::K4). If None, defaults to the platform/host page size ([PlatformMemMap::page_size()]).

Trait Implementations

impl Clone for MemMapCfg

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MemMapCfg

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

Formats the value using the given formatter.