rs-matter/matter/src/persist.rs

116 lines
3.3 KiB
Rust

/*
*
* Copyright (c) 2020-2022 Project CHIP Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#[cfg(feature = "std")]
pub use fileio::*;
#[cfg(feature = "std")]
pub mod fileio {
use std::fs;
use std::io::{Read, Write};
use std::path::{Path, PathBuf};
use log::info;
use crate::error::{Error, ErrorCode};
use crate::Matter;
pub struct Psm<'a> {
matter: &'a Matter<'a>,
dir: PathBuf,
buf: [u8; 4096],
}
impl<'a> Psm<'a> {
#[inline(always)]
pub fn new(matter: &'a Matter<'a>, dir: PathBuf) -> Result<Self, Error> {
fs::create_dir_all(&dir)?;
info!("Persisting from/to {}", dir.display());
let mut buf = [0; 4096];
if let Some(data) = Self::load(&dir, "acls", &mut buf)? {
matter.load_acls(data)?;
}
if let Some(data) = Self::load(&dir, "fabrics", &mut buf)? {
matter.load_fabrics(data)?;
}
Ok(Self { matter, dir, buf })
}
pub async fn run(&mut self) -> Result<(), Error> {
loop {
self.matter.wait_changed().await;
if self.matter.is_changed() {
if let Some(data) = self.matter.store_acls(&mut self.buf)? {
Self::store(&self.dir, "acls", data)?;
}
if let Some(data) = self.matter.store_fabrics(&mut self.buf)? {
Self::store(&self.dir, "fabrics", data)?;
}
}
}
}
fn load<'b>(dir: &Path, key: &str, buf: &'b mut [u8]) -> Result<Option<&'b [u8]>, Error> {
let path = dir.join(key);
match fs::File::open(path) {
Ok(mut file) => {
let mut offset = 0;
loop {
if offset == buf.len() {
Err(ErrorCode::NoSpace)?;
}
let len = file.read(&mut buf[offset..])?;
if len == 0 {
break;
}
offset += len;
}
let data = &buf[..offset];
info!("Key {}: loaded {} bytes {:?}", key, data.len(), data);
Ok(Some(data))
}
Err(_) => Ok(None),
}
}
fn store(dir: &Path, key: &str, data: &[u8]) -> Result<(), Error> {
let path = dir.join(key);
let mut file = fs::File::create(path)?;
file.write_all(data)?;
info!("Key {}: stored {} bytes {:?}", key, data.len(), data);
Ok(())
}
}
}