Struct rustdb::atomfile::AtomicFile

pub struct AtomicFile {
    pub map: Mutex<BTreeMap<u64, DataSlice>>,
    pub stg: Box<dyn Storage>,
    pub upd: Box<dyn Storage>,
}

AtomicFile makes sure that database updates are all-or-nothing. Keeps a list of outstanding writes which have not yet been written to the underlying file.

Fields

map: Mutex<BTreeMap<u64, DataSlice>>

Map of existing outstanding writes. Note the key is the file address of the last byte written.

stg: Box<dyn Storage>

upd: Box<dyn Storage>

Implementations

impl AtomicFile

pub fn new(stg: Box<dyn Storage>, upd: Box<dyn Storage>) -> Self

Construct a new AtomicFle. stg is the main underlying storage, upd is temporary storage for updates during commit.

Trait Implementations

impl Storage for AtomicFile

fn commit(&self, size: u64)

Finish write transaction, size is new size of underlying storage.

fn size(&self) -> u64

Get the size of the underlying storage. Note : this is valid initially and after a commit but is no updated by write operations.

fn read(&self, start: u64, data: &mut [u8])

Read data from storage.

fn write_data(&self, start: u64, data: Data, off: usize, len: usize)

Write Data slice to storage.

fn write(&self, start: u64, data: &[u8])

Write byte slice to storage.

fn write_vec(&self, start: u64, data: Vec<u8>)

Write byte Vec to storage.

fn write_u64(&self, start: u64, value: u64)

Write u64 to storage.

fn read_u64(&self, start: u64) -> u64

Read u64 from storage.