meli/melib/src/backends.rs
Manos Pitsidianakis 5761f854e2
melib: Add FolderPermissions
permissions() method on BackendFolder and SetPermissions in
FolderOperation enum.
2019-11-11 00:47:23 +02:00

401 lines
10 KiB
Rust

/*
* meli - backends module
*
* Copyright 2017 Manos Pitsidianakis
*
* This file is part of meli.
*
* meli is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* meli is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with meli. If not, see <http://www.gnu.org/licenses/>.
*/
#[cfg(feature = "imap_backend")]
pub mod imap;
#[cfg(feature = "maildir_backend")]
pub mod maildir;
#[cfg(feature = "mbox_backend")]
pub mod mbox;
#[cfg(feature = "imap_backend")]
pub use self::imap::ImapType;
use crate::async_workers::*;
use crate::conf::AccountSettings;
use crate::error::{MeliError, Result};
#[cfg(feature = "maildir_backend")]
use self::maildir::MaildirType;
#[cfg(feature = "mbox_backend")]
use self::mbox::MboxType;
use super::email::{Envelope, EnvelopeHash, Flag};
use std::any::Any;
use std::fmt;
use std::fmt::Debug;
use std::ops::Deref;
use fnv::FnvHashMap;
use std;
pub type BackendCreator =
Box<dyn Fn(&AccountSettings, Box<dyn Fn(&str) -> bool + Send + Sync>) -> Box<dyn MailBackend>>;
/// A hashmap containing all available mail backends.
/// An abstraction over any available backends.
pub struct Backends {
map: FnvHashMap<std::string::String, Box<dyn Fn() -> BackendCreator>>,
}
impl Default for Backends {
fn default() -> Self {
Backends::new()
}
}
impl Backends {
pub fn new() -> Self {
let mut b = Backends {
map: FnvHashMap::with_capacity_and_hasher(1, Default::default()),
};
#[cfg(feature = "maildir_backend")]
{
b.register(
"maildir".to_string(),
Box::new(|| Box::new(|f, i| Box::new(MaildirType::new(f, i)))),
);
}
#[cfg(feature = "mbox_backend")]
{
b.register(
"mbox".to_string(),
Box::new(|| Box::new(|f, i| Box::new(MboxType::new(f, i)))),
);
}
#[cfg(feature = "imap_backend")]
{
b.register(
"imap".to_string(),
Box::new(|| Box::new(|f, i| Box::new(ImapType::new(f, i)))),
);
}
b
}
pub fn get(&self, key: &str) -> BackendCreator {
if !self.map.contains_key(key) {
panic!("{} is not a valid mail backend", key);
}
self.map[key]()
}
pub fn register(&mut self, key: String, backend: Box<dyn Fn() -> BackendCreator>) {
if self.map.contains_key(&key) {
panic!("{} is an already registered backend", key);
}
self.map.insert(key, backend);
}
}
#[derive(Debug)]
pub enum RefreshEventKind {
Update(EnvelopeHash, Box<Envelope>),
/// Rename(old_hash, new_hash)
Rename(EnvelopeHash, EnvelopeHash),
Create(Box<Envelope>),
Remove(EnvelopeHash),
Rescan,
Failure(MeliError),
}
#[derive(Debug)]
pub struct RefreshEvent {
hash: FolderHash,
kind: RefreshEventKind,
}
impl RefreshEvent {
pub fn hash(&self) -> FolderHash {
self.hash
}
pub fn kind(self) -> RefreshEventKind {
/* consumes self! */
self.kind
}
}
/// A `RefreshEventConsumer` is a boxed closure that must be used to consume a `RefreshEvent` and
/// send it to a UI provided channel. We need this level of abstraction to provide an interface for
/// all users of mailbox refresh events.
pub struct RefreshEventConsumer(Box<dyn Fn(RefreshEvent) -> () + Send + Sync>);
impl RefreshEventConsumer {
pub fn new(b: Box<dyn Fn(RefreshEvent) -> () + Send + Sync>) -> Self {
RefreshEventConsumer(b)
}
pub fn send(&self, r: RefreshEvent) {
self.0(r);
}
}
pub struct NotifyFn(Box<dyn Fn(FolderHash) -> () + Send + Sync>);
impl fmt::Debug for NotifyFn {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "NotifyFn Box")
}
}
impl From<Box<dyn Fn(FolderHash) -> () + Send + Sync>> for NotifyFn {
fn from(kind: Box<dyn Fn(FolderHash) -> () + Send + Sync>) -> Self {
NotifyFn(kind)
}
}
impl NotifyFn {
pub fn new(b: Box<dyn Fn(FolderHash) -> () + Send + Sync>) -> Self {
NotifyFn(b)
}
pub fn notify(&self, f: FolderHash) {
self.0(f);
}
}
#[derive(Debug, PartialEq, Eq, Hash, Clone)]
pub enum FolderOperation {
Create,
Delete,
Subscribe,
Unsubscribe,
Rename(NewFolderName),
SetPermissions(FolderPermissions),
}
type NewFolderName = String;
pub trait MailBackend: ::std::fmt::Debug + Send + Sync {
fn is_online(&self) -> bool;
fn get(&mut self, folder: &Folder) -> Async<Result<Vec<Envelope>>>;
fn watch(
&self,
sender: RefreshEventConsumer,
work_context: WorkContext,
) -> Result<std::thread::ThreadId>;
fn folders(&self) -> FnvHashMap<FolderHash, Folder>;
fn operation(&self, hash: EnvelopeHash) -> Box<dyn BackendOp>;
fn save(&self, bytes: &[u8], folder: &str, flags: Option<Flag>) -> Result<()>;
fn folder_operation(&mut self, _path: &str, _op: FolderOperation) -> Result<()> {
Ok(())
}
fn as_any(&self) -> &dyn Any;
}
/// A `BackendOp` manages common operations for the various mail backends. They only live for the
/// duration of the operation. They are generated by the `operation` method of `Mailbackend` trait.
///
/// # Motivation
///
/// We need a way to do various operations on individual mails regardless of what backend they come
/// from (eg local or imap).
///
/// # Creation
/// ```no_run
/// /* Create operation from Backend */
///
/// let op = backend.operation(message.hash(), mailbox.folder.hash());
/// ```
///
/// # Example
/// ```
/// use melib::mailbox::backends::{BackendOp};
/// use melib::Result;
/// use melib::{Envelope, Flag};
///
/// #[derive(Debug)]
/// struct FooOp {}
///
/// impl BackendOp for FooOp {
/// fn description(&self) -> String {
/// "Foobar".to_string()
/// }
/// fn as_bytes(&mut self) -> Result<&[u8]> {
/// unimplemented!()
/// }
/// fn fetch_headers(&mut self) -> Result<&[u8]> {
/// unimplemented!()
/// }
/// fn fetch_body(&mut self) -> Result<&[u8]> {
/// unimplemented!()
/// }
/// fn fetch_flags(&self) -> Flag {
/// unimplemented!()
/// }
/// }
///
/// let operation = Box::new(FooOp {});
/// assert_eq!("Foobar", &operation.description());
/// ```
pub trait BackendOp: ::std::fmt::Debug + ::std::marker::Send {
fn description(&self) -> String;
fn as_bytes(&mut self) -> Result<&[u8]>;
//fn delete(&self) -> ();
//fn copy(&self
fn fetch_headers(&mut self) -> Result<&[u8]>;
fn fetch_body(&mut self) -> Result<&[u8]>;
fn fetch_flags(&self) -> Flag;
fn set_flag(&mut self, envelope: &mut Envelope, flag: Flag) -> Result<()>;
}
/// Wrapper for BackendOps that are to be set read-only.
///
/// Warning: Backend implementations may still cause side-effects (for example IMAP can set the
/// Seen flag when fetching an envelope)
#[derive(Debug)]
pub struct ReadOnlyOp {
op: Box<dyn BackendOp>,
}
impl ReadOnlyOp {
pub fn new(op: Box<dyn BackendOp>) -> Box<dyn BackendOp> {
Box::new(ReadOnlyOp { op })
}
}
impl BackendOp for ReadOnlyOp {
fn description(&self) -> String {
format!("read-only: {}", self.op.description())
}
fn as_bytes(&mut self) -> Result<&[u8]> {
self.op.as_bytes()
}
fn fetch_headers(&mut self) -> Result<&[u8]> {
self.op.fetch_headers()
}
fn fetch_body(&mut self) -> Result<&[u8]> {
self.op.fetch_body()
}
fn fetch_flags(&self) -> Flag {
self.op.fetch_flags()
}
fn set_flag(&mut self, _envelope: &mut Envelope, _flag: Flag) -> Result<()> {
Err(MeliError::new("read-only set."))
}
}
#[derive(Debug, Copy, Hash, Eq, Clone, Serialize, Deserialize, PartialEq)]
pub enum SpecialUseMailbox {
Normal,
Inbox,
Archive,
Drafts,
Flagged,
Junk,
Sent,
Trash,
}
pub trait BackendFolder: Debug {
fn hash(&self) -> FolderHash;
fn name(&self) -> &str;
/// Path of folder within the mailbox hierarchy, with `/` as separator.
fn path(&self) -> &str;
fn change_name(&mut self, new_name: &str);
fn clone(&self) -> Folder;
fn children(&self) -> &Vec<FolderHash>;
fn parent(&self) -> Option<FolderHash>;
fn permissions(&self) -> FolderPermissions;
}
#[derive(Debug)]
struct DummyFolder {
v: Vec<FolderHash>,
}
impl BackendFolder for DummyFolder {
fn hash(&self) -> FolderHash {
0
}
fn name(&self) -> &str {
""
}
fn path(&self) -> &str {
""
}
fn change_name(&mut self, _s: &str) {}
fn clone(&self) -> Folder {
folder_default()
}
fn children(&self) -> &Vec<FolderHash> {
&self.v
}
fn parent(&self) -> Option<FolderHash> {
None
}
fn permissions(&self) -> FolderPermissions {
FolderPermissions::default()
}
}
pub fn folder_default() -> Folder {
Box::new(DummyFolder {
v: Vec::with_capacity(0),
})
}
pub type FolderHash = u64;
pub type Folder = Box<dyn BackendFolder + Send + Sync>;
impl Clone for Folder {
fn clone(&self) -> Self {
BackendFolder::clone(self.deref())
}
}
impl Default for Folder {
fn default() -> Self {
folder_default()
}
}
#[derive(Debug, PartialEq, Eq, Hash, Clone, Copy)]
pub struct FolderPermissions {
pub create_messages: bool,
pub remove_messages: bool,
pub set_flags: bool,
pub create_child: bool,
pub rename_messages: bool,
pub delete_messages: bool,
pub delete_mailbox: bool,
pub change_permissions: bool,
}
impl Default for FolderPermissions {
fn default() -> Self {
FolderPermissions {
create_messages: false,
remove_messages: false,
set_flags: false,
create_child: false,
rename_messages: false,
delete_messages: false,
delete_mailbox: false,
change_permissions: false,
}
}
}