Trait raft_engine::internals::PipeLog
source · [−]pub trait PipeLog: Sized {
fn read_bytes(&self, handle: FileBlockHandle) -> Result<Vec<u8>>;
fn append<T: ReactiveBytes + ?Sized>(
&self,
queue: LogQueue,
bytes: &mut T
) -> Result<FileBlockHandle>;
fn sync(&self, queue: LogQueue) -> Result<()>;
fn file_span(&self, queue: LogQueue) -> (FileSeq, FileSeq);
fn total_size(&self, queue: LogQueue) -> usize;
fn rotate(&self, queue: LogQueue) -> Result<()>;
fn purge_to(&self, file_id: FileId) -> Result<usize>;
fn file_at(&self, queue: LogQueue, position: f64) -> FileSeq { ... }
}Expand description
A PipeLog serves reads and writes over multiple queues of log files.
Safety
The pipe will panic if it encounters an unrecoverable failure. Otherwise the operations on it should be atomic, i.e. failed operation will not affect other ones, and user can still use it afterwards without breaking consistency.
Required Methods
sourcefn read_bytes(&self, handle: FileBlockHandle) -> Result<Vec<u8>>
fn read_bytes(&self, handle: FileBlockHandle) -> Result<Vec<u8>>
Reads some bytes from the specified position.
sourcefn append<T: ReactiveBytes + ?Sized>(
&self,
queue: LogQueue,
bytes: &mut T
) -> Result<FileBlockHandle>
fn append<T: ReactiveBytes + ?Sized>(
&self,
queue: LogQueue,
bytes: &mut T
) -> Result<FileBlockHandle>
Appends some bytes to the specified log queue. Returns file position of the written bytes.
Synchronizes all buffered writes.
This operation might incurs a great latency overhead. It’s advised to call it once every batch of writes.
Returns the smallest and largest file sequence number, still in use, of the specified log queue.
sourcefn total_size(&self, queue: LogQueue) -> usize
fn total_size(&self, queue: LogQueue) -> usize
Returns total size of the specified log queue.
Rotates a new log file for the specified log queue.
Implementation should be atomic under error conditions but not necessarily panic-safe.