Crate nano_wal 

A concurrent Write-Ahead Log (WAL) with CAS-based segment rotation and coalesced preadv reads.

Features

• Lock-free segment rotation via ArcSwap + CAS
• Concurrent reads via dup’d file descriptors (preadv)
• Coalesced batch reads for minimal syscalls
• Clock-aligned segment expiration windows
• Vectored writes (writev) for batch appends

Examples

use nano_wal::{Wal, WalOptions};
use std::time::Duration;

let options = WalOptions {
    retention: Duration::from_secs(3600),
    segment_duration: Duration::from_secs(600),
};
let wal = Wal::new("/tmp/my_wal", "stream-0", options).unwrap();

let now_ms = 1711234567890i64;
let entry = wal.append(None, b"hello world", now_ms, false).unwrap();

Structs

Bytes

Re-exported for callers who need to hold segment read fds. A cheaply cloneable and sliceable chunk of contiguous memory.

CleanupResult

DeletedSegment

EntryRef

EntryRef returned from append operations.

ReadDescriptor

Descriptor for a single record to be read from a segment.

Record

A parsed record read from the WAL.

Segment

A single WAL segment file with concurrent read/write support.

Wal

WalOptions

WriteEntry

A single entry for batch append operations.

Enums

WalError

Functions

read_batch

Read a batch of records, coalescing contiguous reads on the same fd into single preadv syscalls.

Type Aliases

Result