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#![allow(unused_variables)]
use super::{BackendError, Result};
use crate::repository::backend::common::files::LockedFile;
use crate::repository::backend::{
backend_to_object, Backend, BackendObject, Chunk, EncryptedKey, Manifest, SegmentDescriptor,
};
use crate::repository::{ChunkSettings, Key};
use async_trait::async_trait;
use serde_cbor as cbor;
use uuid::Uuid;
use std::fs::{create_dir_all, remove_file, File, OpenOptions};
use std::path::{Path, PathBuf};
use std::sync::Arc;
pub mod index;
pub mod manifest;
pub mod segment;
#[derive(Debug, Clone)]
pub struct MultiFile {
index_handle: index::Index,
manifest_handle: manifest::Manifest,
segment_handle: segment::SegmentHandler,
path: PathBuf,
/// Connection uuid, used for read locks.
uuid: Uuid,
/// Path to readlock for this connection, must be deleted on close
read_lock_path: Arc<PathBuf>,
}
impl MultiFile {
/// Opens a new `MultiFile` backend with default settings
///
/// Subject to change in the near future
///
/// # Errors
///
/// Will error if creating or locking any of the index or manifest files
/// fails (such as if the user does not have permissions for that
/// directory), or if any other I/O error occurs
pub async fn open_defaults(
path: impl AsRef<Path>,
chunk_settings: Option<ChunkSettings>,
key: &Key,
queue_depth: usize,
) -> Result<MultiFile> {
// First, check to see if the global lock exists, and return an error early if it does
let global_lock_path = path.as_ref().join("lock");
if Path::exists(&global_lock_path) {
return Err(BackendError::RepositoryGloballyLocked(format!(
"Global lock for this repository already exists at: {:?}",
global_lock_path
)));
}
// Generate a uuid
let uuid = Uuid::new_v4();
let size_limit = 2_000_000_000;
let segments_per_directory = 100;
// Open up an index connection
let index_handle = index::Index::open(&path, queue_depth)?;
// Open up a manifest connection
let mut manifest_handle =
manifest::Manifest::open(&path, chunk_settings, key, queue_depth)?;
let chunk_settings = if let Some(chunk_settings) = chunk_settings {
chunk_settings
} else {
manifest_handle.chunk_settings().await
};
// Open up a segment handler connection
let segment_handle = segment::SegmentHandler::open(
&path,
size_limit,
segments_per_directory,
chunk_settings,
key.clone(),
queue_depth,
)?;
// Make sure the readlocks directory exists
create_dir_all(path.as_ref().join("readlocks"))?;
// generate a path to our readlock
let read_lock_path = path
.as_ref()
.join("readlocks")
.join(uuid.to_simple().to_string());
// Create the read_lock file
OpenOptions::new()
.create(true)
.write(true)
.open(&read_lock_path)?;
let path = path.as_ref().to_path_buf();
Ok(MultiFile {
index_handle,
manifest_handle,
segment_handle,
path,
uuid,
read_lock_path: Arc::new(read_lock_path),
})
}
/// Reads the encrypted key off the disk
///
/// Does not require that the repository be opened first
///
/// Note: this path is the repository root path, not the key path
///
/// # Errors
///
/// Will error if the key is corrupted or deserialization otherwise fails
pub fn read_key(path: impl AsRef<Path>) -> Result<EncryptedKey> {
let key_path = path.as_ref().join("key");
let file = File::open(&key_path)?;
Ok(cbor::de::from_reader(&file)?)
}
}
#[async_trait]
impl Backend for MultiFile {
type Manifest = manifest::Manifest;
type Index = index::Index;
/// Clones the internal MFManifest
fn get_index(&self) -> Self::Index {
self.index_handle.clone()
}
/// Clones the internal MFIndex
fn get_manifest(&self) -> Self::Manifest {
self.manifest_handle.clone()
}
/// Locks the keyfile and writes the key
///
/// Will return Err if writing the key fails
async fn write_key(&self, key: &EncryptedKey) -> Result<()> {
let key_path = self.path.join("key");
let mut file =
LockedFile::open_read_write(&key_path)?.ok_or(BackendError::FileLockError)?;
Ok(cbor::ser::to_writer(&mut file, key)?)
}
/// Attempts to read the key from the repository
///
/// Returns Err if the key doesn't exist or of another error occurs
async fn read_key(&self) -> Result<EncryptedKey> {
let key_path = self.path.join("key");
let file = File::open(&key_path)?;
Ok(cbor::de::from_reader(&file)?)
}
/// Starts reading a chunk, and returns a oneshot recieve with the result of that process
async fn read_chunk(&mut self, location: SegmentDescriptor) -> Result<Chunk> {
self.segment_handle.read_chunk(location).await
}
/// Starts writing a chunk, and returns a oneshot reciever with the result of that process
async fn write_chunk(&mut self, chunk: Chunk) -> Result<SegmentDescriptor> {
self.segment_handle.write_chunk(chunk).await
}
/// Closes out the index, segment handler, and manifest cleanly, making sure all operations are
/// completed and all drop impls from inside the tasks are called
async fn close(&mut self) {
self.index_handle.close().await;
self.manifest_handle.close().await;
self.segment_handle.close().await;
// Check if the read_lock_file exists and delete it
if self.read_lock_path.exists() {
// FIXME: We ignore this error for now, as this method does not currently return a
// result
let _ = remove_file(self.read_lock_path.as_ref());
}
}
fn get_object_handle(&self) -> BackendObject {
backend_to_object(self.clone())
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::repository::Encryption;
use tempfile::{tempdir, TempDir};
// Utility function, sets up a tempdir and opens a MultiFile Backend
async fn setup(key: &Key) -> (TempDir, MultiFile) {
let tempdir = tempdir().unwrap();
let path = tempdir.path().to_path_buf();
let mf = MultiFile::open_defaults(path, Some(ChunkSettings::lightweight()), key, 4)
.await
.unwrap();
(tempdir, mf)
}
#[test]
fn key_store_load() {
smol::run(async {
let key = Key::random(32);
let (tempdir, mut mf) = setup(&key).await;
// Encrypt the key and store it
let enc_key = EncryptedKey::encrypt(&key, 512, 1, Encryption::new_aes256ctr(), b"");
mf.write_key(&enc_key).await.expect("Unable to write key");
// Load the key back out without unloading
let enc_key = mf
.read_key()
.await
.expect("Unable to read key (before drop)");
// Decrypt it and verify equality
let new_key = enc_key
.decrypt(b"")
.expect("Unable to decrypt key (before drop)");
assert_eq!(key, new_key);
// Drop the backend and try reading it from scratch
mf.close().await;
let enc_key =
MultiFile::read_key(tempdir.path()).expect("Unable to read key (after drop)");
let new_key = enc_key
.decrypt(b"")
.expect("Unable to decrypt key (after drop)");
assert_eq!(key, new_key);
});
}
// Test to make sure that attempting to open a repository respects an existing global lock
#[test]
fn repository_global_lock() {
smol::run(async {
let tempdir = tempdir().unwrap();
let path = tempdir.path().to_path_buf();
let key = Key::random(32);
// Create the lock
OpenOptions::new()
.create(true)
.write(true)
.open(path.join("lock"))
.unwrap();
// Attempt to open the backend
let mf =
MultiFile::open_defaults(path, Some(ChunkSettings::lightweight()), &key, 4).await;
// This should error
assert!(mf.is_err());
// It should also, specifically, be a RepositoryGloballyLocked
assert!(matches!(mf, Err(BackendError::RepositoryGloballyLocked(_))));
});
}
// Tests to make sure that readlocks are created and destroyed properly
#[test]
fn read_lock_create_destroy() {
smol::run(async {
let key = Key::random(32);
let (tempdir, mut mf) = setup(&key).await;
let lock_path: Arc<PathBuf> = mf.read_lock_path.clone();
// the connection is open, assert that the lock exists
assert!(lock_path.exists());
// Close the connection
mf.close().await;
std::mem::drop(mf);
// The connection is now closed, assert that the lock does not exist
assert!(!lock_path.exists());
});
}
}