path: root/examples/demo1.rs

use async_trait::async_trait;
use libc::off_t;
use nix::fcntl::{fallocate, open, openat, FallocateFlags, OFlag};
use nix::sys::{
    stat::Mode,
    uio::{pread, pwrite},
};
use nix::unistd::{close, ftruncate, mkdir, unlinkat, UnlinkatFlags};
use rand::{seq::SliceRandom, Rng};
use std::os::unix::io::RawFd;

use growthring::wal::{
    WALBytes, WALFile, WALLoader, WALPos, WALRingId, WALStore, WALWriter,
};

struct WALFileTest {
    filename: String,
    fd: RawFd,
}

impl WALFileTest {
    fn new(rootfd: RawFd, filename: &str) -> Result<Self, ()> {
        openat(
            rootfd,
            filename,
            OFlag::O_CREAT | OFlag::O_RDWR,
            Mode::S_IRUSR | Mode::S_IWUSR,
        )
        .and_then(|fd| {
            let filename = filename.to_string();
            Ok(WALFileTest { filename, fd })
        })
        .or_else(|_| Err(()))
    }
}

impl Drop for WALFileTest {
    fn drop(&mut self) {
        close(self.fd).unwrap();
    }
}

#[async_trait(?Send)]
impl WALFile for WALFileTest {
    async fn allocate(&self, offset: WALPos, length: usize) -> Result<(), ()> {
        println!(
            "{}.allocate(offset=0x{:x}, end=0x{:x})",
            self.filename,
            offset,
            offset + length as u64
        );
        fallocate(
            self.fd,