Struct simple_wal::LogFile

pub struct LogFile { /* fields omitted */ }

A write-ahead-log.

Implementations

impl LogFile

pub fn first_entry<'l>(&'l mut self) -> Result<LogEntry<'l>, LogError>

The first entry in the log

pub fn seek<'l>(&'l mut self, to_index: u64) -> Result<LogEntry<'l>, LogError>

Seek to the given entry in the log

pub fn first_index(&self) -> u64

Returns the index/sequence number of the first entry in the log

pub fn last_index(&self) -> u64

Returns the index/sequence number of the last entry in the log

pub fn iter<'s, R: RangeBounds<u64>>(
    &'s mut self,
    range: R
) -> Result<LogIterator<'s>, LogError>

Iterate through the log

pub fn write<R: AsMut<[u8]>>(&mut self, entry: &mut R) -> Result<()>

Write the given log entry to the end of the log

pub fn flush(&mut self) -> Result<()>

Flush writes to disk

pub fn open<P: AsRef<Path>>(path: P) -> Result<LogFile, LogError>

Open the log. Takes out an advisory lock.

This is O(n): we have to iterate to the end of the log in order to clean interrupted writes and determine the length of the log

pub fn compact(&mut self, new_start_index: u64) -> Result<(), LogError>

Compact the log, removing entries older than new_start_index.

This is done by copying all entries >= new_start_index to a temporary file, than overriding the old log file once the copy is complete.

Before compacting, the log is flushed.

pub fn restart(&mut self, starting_index: u64) -> Result<(), LogError>

Clear all entries in the write-ahead-log and restart at the given index.