Crate rabuf

Expand description

The Buffer for random access file.

When you read and write a file, this read and write in Chunk units and reduce IO operation.

Features

random access
Chunk units os io operation
reduce os io operation
support small size access accel.
minimum support rustc 1.56.1 (59eed8a2a 2021-11-01)

Examples

Write, Seek, Read

use rabuf::BufFile;
use std::fs::OpenOptions;
use std::io::{Read, Seek, SeekFrom, Write};

std::fs::create_dir_all("target/tmp").unwrap();

let path = "target/tmp/doc_test_1";
let bw = b"ABCEDFG\nhijklmn\n";

let f = OpenOptions::new().create(true)
    .read(true).write(true).open(path).unwrap();
let mut bf = BufFile::new("tes", f).unwrap();
bf.write_all(bw).unwrap();

bf.seek(SeekFrom::Start(0)).unwrap();

let mut br = vec![0u8; bw.len()];
bf.read_exact(&mut br).unwrap();
assert_eq!(&br, bw);

Write, Close, Open, Read

use rabuf::BufFile;
use std::fs::OpenOptions;
use std::io::{Read, Seek, SeekFrom, Write};

std::fs::create_dir_all("target/tmp").unwrap();
let path = "target/tmp/doc_test_2";

let bw = b"abcdefg\nHIJKLMN\n";
{
    let f = OpenOptions::new().create(true)
        .read(true).write(true).open(path).unwrap();
    let mut bf = BufFile::new("tes", f).unwrap();
    bf.write_all(bw).unwrap();
}
{
    let f = OpenOptions::new().create(true)
        .read(true).write(true).open(path).unwrap();
    let mut bf = BufFile::new("tes", f).unwrap();
    let mut br = vec![0u8; bw.len()];
    bf.read_exact(&mut br).unwrap();
    assert_eq!(&br, bw);
}