Struct PageFileOptions 

pub struct PageFileOptions { /* private fields */ }

Options for opening a PageFile.

Build with PageFileOptions::new, adjust, then open. The defaults are a 4 KiB page size, Direct I/O enabled, and create-if-absent.

Examples

use page_db::{PageFileOptions, PageSize};

let file = PageFileOptions::new()
    .page_size(PageSize::new(8192)?)
    .direct_io(false)          // buffered, e.g. on a filesystem without O_DIRECT
    .open(&path)?;
assert_eq!(file.page_size(), 8192);

Implementations

impl PageFileOptions

pub fn new() -> Self

Start from the defaults: 4 KiB pages, Direct I/O on, create-if-absent.

pub fn page_size(self, page_size: PageSize) -> Self

Set the page size. Every page in the file is this size; it is fixed for the life of the file and the caller is responsible for reopening with the same size.

pub fn direct_io(self, enabled: bool) -> Self

Enable or disable Direct I/O (cache-bypass).

Direct I/O is the default and the point of this crate. Disable it for a filesystem that does not support it (some network and overlay filesystems reject O_DIRECT); durability via PageFile::sync is unaffected, only the page cache is.

pub fn create(self, create: bool) -> Self

Create the file if it does not exist (the default). When false, opening a missing file is an error.

pub fn open<P: AsRef<Path>>(self, path: P) -> PageResult<PageFile>

Open the page file at path with these options.

Errors

Returns PageError::Io if the file cannot be opened (including a filesystem that rejects Direct I/O, surfaced as the OS error).

Trait Implementations

impl Clone for PageFileOptions

fn clone(&self) -> PageFileOptions

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PageFileOptions

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

Formats the value using the given formatter.

impl Default for PageFileOptions

fn default() -> Self

Returns the “default value” for a type.