Struct MemStore 

pub struct MemStore {
    inner: Arc<Mutex<MemInner>>,
    lock: Arc<(Mutex<bool>, Condvar)>,
    capacity: u64,
}

Fields

inner: Arc<Mutex<MemInner>>

lock: Arc<(Mutex<bool>, Condvar)>

capacity: u64

Implementations

impl MemStore

pub fn new(capacity: u64) -> MemStore

fn inner(&self) -> MutexGuard<'_, MemInner>

pub fn crash(&self)

A power loss: the log keeps exactly what the last sync covered; a write after it is gone, as if never made.

pub fn tear_next_write(&self, keep: usize)

pub fn tear_write_containing(&self, needle: &str)

Tear the next log write that contains needle (e.g. "Checking", to tear the record of that state).

pub fn torn(&self) -> bool

Whether an injected tear has happened.

pub fn fail_next_checkpoint(&self)

pub fn set_enospc(&self, on: bool)

Trait Implementations

impl Clone for MemStore

fn clone(&self) -> MemStore

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MemStore

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

Formats the value using the given formatter.

impl Store for MemStore

type Guard = MemGuard

Held while a journal handle reads-then-appends; serializes all handles (across processes for FileStore). Released on drop.

fn lock(&self) -> Result<MemGuard>

fn capacity(&self) -> u64

fn read_at(&self, off: u64, len: usize) -> Result<Vec<u8>>

Up to len bytes at off; shorter at the end of the preallocation.

fn write_at(&self, off: u64, bytes: &[u8]) -> Result<()>

fn sync(&self) -> Result<()>

fn read_checkpoint(&self) -> Result<Option<Vec<u8>>>

fn write_checkpoint(&self, bytes: &[u8]) -> Result<()>

Atomic: either the old checkpoint or the complete new one survives.

fn read_sentinel(&self) -> Result<Option<Vec<u8>>>

fn write_sentinel(&self, bytes: &[u8]) -> Result<()>

fn fence(&self, txn: TxnId) -> Result<Option<u64>>

The epoch backends fence on. Written before the journal’s Takeover record.

fn set_fence(&self, txn: TxnId, epoch: u64) -> Result<()>

fn create_fence(&self, txn: TxnId, epoch: u64) -> Result<()>

A new transaction’s fence, created exclusively (§9 step 4, C5): fails with AlreadyExists if anything is already there for this id.

fn forget_fences<F: Fn(TxnId) -> bool>(&self, keep: F) -> Result<Vec<TxnId>>

Removes the fence of every transaction keep rejects; returns them. A transaction without a fence is never admitted, so this only narrows.