rustdb 0.1.14

SQL database (in development)
Documentation 
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/// Interface for database storage.
pub trait Storage: Send + Sync {
    // Get the current size of the underlying storage.
    fn size(&self) -> u64;
    // Read from the underlying storage.
    fn read(&self, off: u64, bytes: &mut [u8]);
    // Write to the underlying storage.
    fn write(&mut self, off: u64, bytes: &[u8]);
    // Finish write transaction, size is new size of underlying storage.
    fn commit(&mut self, size: u64);
}

use crate::Mutex;
use std::{fs, fs::OpenOptions, io::Read, io::Seek, io::SeekFrom, io::Write};

/// Simple implementation of Storage using std::fs::File.
pub struct SimpleFileStorage {
    pub file: Mutex<fs::File>,
}

impl SimpleFileStorage {
    pub fn new(filename: &str) -> Self {
        Self {
            file: Mutex::new(
                OpenOptions::new()
                    .read(true)
                    .write(true)
                    .create(true)
                    .open(filename)
                    .unwrap(),
            ),
        }
    }
}

impl Storage for SimpleFileStorage {
    fn size(&self) -> u64 {
        let mut f = self.file.lock();
        f.seek(SeekFrom::End(0)).unwrap()
    }
    fn read(&self, off: u64, bytes: &mut [u8]) {
        let mut f = self.file.lock();
        f.seek(SeekFrom::Start(off)).unwrap();
        let _x = f.read_exact(bytes);
    }
    fn write(&mut self, off: u64, bytes: &[u8]) {
        let mut f = self.file.lock();
        f.seek(SeekFrom::Start(off)).unwrap();
        let _x = f.write(bytes);
    }
    fn commit(&mut self, size: u64) {
        let f = self.file.lock();
        f.set_len(size).unwrap();
    }
}