1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612
// Copyright 2023-2024 Hugo Osvaldo Barrera
//
// SPDX-License-Identifier: EUPL-1.2
//! Traits and common implementations shared by different storages.
//!
//! When writing code that should deal with different storage implementations, these traits should
//! be used as input / outputs, rather than concrete per-store types.
//!
//! See [`Storage`] as an entry point to this module.
use std::num::NonZeroUsize;
use async_trait::async_trait;
use libdav::{
names::{self},
PropertyName,
};
use tokio::sync::mpsc::Receiver;
use crate::{
disco::Discovery, util::replace_uid, watch::Event, CollectionId, Error, ErrorKind, Etag, Href,
Result,
};
/// A storage is the highest level abstraction where items can be stored. It can be a remote CalDav
/// account, a local filesystem, etc.
///
/// Each storage may contain one or more **collections** (e.g.: calendars or address books).
///
/// The specific type of item that a storage can hold is defined by the `I` generic parameter.
/// E.g.: a CalDav storage can hold icalendar items. Only items with the same kind of item can be
/// synchronised with each other (e.g.: it it nos possible to synchronise `Storage<VcardItem>` with
/// `Storage<IcsItem>`
///
/// # Note for implementors
///
/// The auto-generated documentation for this trait is rather hard to read due to the usage of
/// [`#[async_trait]`](mod@async_trait) macro. You might want to consider clicking on the
/// `source` link and reading the documentation from the raw code for this trait.
#[async_trait]
pub trait Storage<I: Item>: Sync + Send {
// TODO: Some calendar instances only allow a single item type (e.g.: events but not todos).
/// Checks that the storage works. This includes validating credentials, and reachability.
///
/// # Errors
///
/// Returns an error if the storage is not reachable and usable.
async fn check(&self) -> Result<()>;
/// Finds existing collections for this storage.
async fn discover_collections(&self) -> Result<Discovery>;
/// Creates a new collection with a specified `href`.
async fn create_collection(&self, href: &str) -> Result<Collection>;
/// Deletes an existing collection.
///
/// A collection must be empty for deletion to succeed.
async fn destroy_collection(&self, href: &str) -> Result<()>;
/// List all properties of a collection.
async fn list_properties(
&self,
collection_href: &str,
) -> Result<Vec<ListedProperty<I::Property>>>;
/// Returns the value of a property for a given collection.
async fn get_property(&self, href: &str, property: I::Property) -> Result<Option<String>>;
/// Sets the value of a property for a given collection.
async fn set_property(&self, href: &str, property: I::Property, value: &str) -> Result<()>;
/// Unsets a property for a given collection.
async fn unset_property(&self, href: &str, property: I::Property) -> Result<()>;
/// Enumerates items in a given collection.
async fn list_items(&self, collection_href: &str) -> Result<Vec<ItemRef>>;
/// Fetches a single item from given collection.
///
/// Storages never cache data locally. For reading items in bulk, prefer
/// [`Storage::get_many_items`].
async fn get_item(&self, href: &str) -> Result<(I, Etag)>;
/// Fetches multiple items.
///
/// Similar to [`Storage::get_item`], but optimised to minimise the amount of IO required.
/// Duplicate `href`s are ignored.
///
/// All requested items MUST belong to the same collection.
///
/// # Note for implementers
///
/// The default implementation is usually not optimal, and implementations of this trait should
/// override it.
async fn get_many_items(&self, hrefs: &[&str]) -> Result<Vec<FetchedItem<I>>> {
let mut items = Vec::with_capacity(hrefs.len());
for href in hrefs {
let item = self.get_item(href).await?;
items.push(FetchedItem {
href: (*href).to_owned(),
item: item.0,
etag: item.1,
});
}
Ok(items)
}
/// Fetch all items from a given collection.
///
/// # Note for implementors
///
/// The default implementation is usually not optimal, and implementations of this trait should
/// override it.
async fn get_all_items(&self, collection: &str) -> Result<Vec<FetchedItem<I>>> {
let item_refs = self.list_items(collection).await?;
let mut items = Vec::with_capacity(item_refs.len());
for item_ref in item_refs {
let item = self.get_item(&item_ref.href).await?;
items.push(FetchedItem {
href: item_ref.href,
item: item.0,
etag: item.1,
});
}
Ok(items)
}
/// Saves a new item into a given collection
async fn add_item(&self, collection: &str, item: &I) -> Result<ItemRef>;
/// Updates the contents of an existing item.
async fn update_item(&self, href: &str, etag: &Etag, item: &I) -> Result<Etag>;
/// Deletes an existing item.
async fn delete_item(&self, href: &str, etag: &Etag) -> Result<()>;
/// Return the id for a collection with the given `href`.
///
/// The id for a given Collection must never change. Usually this is based off the last
/// component of the href, but may be different for storages where this does not make sense.
///
/// # Errors
///
/// This functions returns an `Err` variant if the provided `collection` is invalid.
fn collection_id(&self, collection_href: &str) -> Result<CollectionId>;
/// Return the `href` for a collection that is expected to have `id`.
///
/// Creating a collection under `href` SHOULD result in the collection being available via
/// discovery with the provided `id`.
///
/// # Errors
///
/// Returns an error if no collection can exist such that it is available via discovery AND its
/// `CollectionId` matches the input.
fn href_for_collection_id(&self, id: &CollectionId) -> Result<Href>;
/// Monitor the storage for changes.
///
/// Returns the [`Receiver`] of a channel which receives [`Event`] instances when changes are
/// detected.
///
/// # Errors
///
/// The default implementation returns [`ErrorKind::Unsupported`].
async fn monitor(&self, bufsize: NonZeroUsize) -> Result<Receiver<Event>> {
let _ = bufsize;
return Err(Error::new(
ErrorKind::Unsupported,
"Storage implementation does not currently support monitoring.",
));
}
}
/// A collection may, for example, be an address book or a calendar.
///
/// The type of items contained is restricted by the underlying implementation. Collections contain
/// zero or more items (e.g.: an address book contains events). Each item is addressed by its own
/// [`Href`].
///
/// This type wraps around the `href` for a collection on a given storage. Using the same
/// `Collection` instance across different storages is disallowed.
#[derive(Debug)]
pub struct Collection {
href: Href,
}
impl Collection {
/// The path to this collection inside the storage.
///
/// Href should not change over time, so should be associated with an immutable property of the
/// collection (e.g.: a relative URL path, or a directory's filename).
///
/// The exact meaning of this value is storage-specific, but should be remain consistent with a
/// storage.
#[must_use]
pub fn href(&self) -> &Href {
&self.href
}
#[must_use]
pub fn into_href(self) -> Href {
self.href
}
pub(crate) fn new(href: String) -> Collection {
Collection { href }
}
}
/// A reference to an [`Item`] inside a collection.
#[derive(PartialEq, Debug, Clone)]
pub struct ItemRef {
pub href: Href,
pub etag: Etag,
}
/// Properties for storage collections or items.
///
/// See [`Item::Property`].
pub trait Property:
Sync + Send + Clone + std::fmt::Debug + std::hash::Hash + PartialEq + Eq
{
fn name(&self) -> String;
}
/// A type of item that is contained in a [`Storage`].
///
/// A `Storage` can contain items of a concrete type described by implementations of this trait.
/// This trait defines how to extract the basic information that is required to synchronise
/// storages. Additional parsing is out of scope here and should be done by inspecting the raw data
/// inside an item via [`Item::as_str`].
pub trait Item: Sync + Send + std::fmt::Debug
where
Self: From<String>,
{
/// Property types supported by storages.
///
/// Generally, this type should be an `enum` with each known property represented as a
/// different variant.
///
/// These were known as "metadata" in the original vdirsyncer implementation.
///
/// See also [`Storage::get_property`] and [`Storage::set_property`].
type Property: Property;
/// Parse the item and return a unique identifier for it.
///
/// The `uid` does not change when the item is modified. The `uid` remains the same when the
/// item is copied across storages and storage types.
#[must_use]
fn uid(&self) -> Option<String>;
/// Return the hash of this item, usually normalised.
///
/// Implementations SHOULD normalise content before hashing to ensure that two semantically
/// equivalent items return the same hash.
///
/// This value is used as a fallback when a storage backend doesn't provide [`Etag`] values, or
/// when an item's [`Item::uid`] returns `None`.
#[must_use]
fn hash(&self) -> String;
/// A unique identifier for this item. Is either the UID (if any), or the hash of its contents.
#[must_use]
fn ident(&self) -> String;
/// Returns a new copy of this Item with the supplied UID.
#[must_use]
fn with_uid(&self, new_uid: &str) -> Self;
#[must_use]
/// Returns the raw contents of this item.
fn as_str(&self) -> &str;
}
/// Immutable wrapper around a `VCALENDAR` or `VCARD`.
///
/// Note that this is not a proper validating parser for icalendar or vcard; it's a very simple
/// one with the sole purpose of extracing a UID. Proper parsing of components is out of scope,
/// since supporting potentially invalid items is required.
#[derive(Debug)]
pub struct IcsItem {
raw: String,
}
/// Properties supported for calendars.
///
/// This is strongly based on the properties supported by `CalDav`.
#[non_exhaustive]
#[derive(Debug, Clone, Hash, PartialEq, Eq)]
pub enum CalendarProperty {
/// A colour to be used when displaying this collection.
///
/// Graphical interfaces may use this for the collection itself or its items.
Colour,
/// A user-friendly name for a collection.
///
/// It is recommended to show this name in user interfaces.
DisplayName,
Description,
Order,
}
impl CalendarProperty {
#[must_use]
pub fn dav_propname(&self) -> &PropertyName<'_, '_> {
match self {
CalendarProperty::Colour => &names::CALENDAR_COLOUR,
CalendarProperty::DisplayName => &names::DISPLAY_NAME,
CalendarProperty::Description => &names::CALENDAR_DESCRIPTION,
CalendarProperty::Order => &names::CALENDAR_ORDER,
}
}
}
impl Property for CalendarProperty {
fn name(&self) -> String {
match self {
CalendarProperty::DisplayName => "displayname".into(),
CalendarProperty::Colour => "color".into(),
CalendarProperty::Description => "description".into(),
CalendarProperty::Order => "order".into(),
}
}
}
impl Item for IcsItem {
/// Calendar properties defined by `CalDav`.
type Property = CalendarProperty;
/// Returns the contents of the `UID` property, if defined.
#[must_use]
fn uid(&self) -> Option<String> {
uid(&self.raw)
}
/// Returns the hash of the normalised content.
#[must_use]
fn hash(&self) -> String {
crate::util::hash(&self.raw)
}
/// A unique identifier for this item. Is either the UID (if any), or the hash of its contents.
#[must_use]
fn ident(&self) -> String {
self.uid().unwrap_or_else(|| self.hash())
}
/// Returns a new copy of this Item with the supplied UID.
#[must_use]
fn with_uid(&self, new_uid: &str) -> Self {
IcsItem::from(replace_uid(&self.raw, new_uid))
}
#[inline]
#[must_use]
/// Returns the raw contents of this item.
fn as_str(&self) -> &str {
&self.raw
}
}
impl From<String> for IcsItem {
/// Create a new `IcsItem`, normalising newlines into `\r\n`.
fn from(value: String) -> Self {
let mut lines = value
.split_terminator('\n')
.map(|line| line.trim_end_matches('\r'));
let mut raw = lines
.next()
.expect("split line yields at least one item")
.to_string();
for line in lines {
raw.push_str("\r\n");
raw.push_str(line);
}
IcsItem { raw }
}
}
fn uid(raw: &str) -> Option<String> {
let mut lines = raw.split_terminator("\r\n");
let mut uid = lines
.find_map(|line| line.strip_prefix("UID:"))
.map(String::from)?;
// If the following lines start with a space or tab, they're a continuation of the UID.
// See: https://www.rfc-editor.org/rfc/rfc5545#section-3.1
lines
.map_while(|line| line.strip_prefix(' ').or_else(|| line.strip_prefix('\t')))
.for_each(|part| uid.push_str(part));
Some(uid)
}
#[cfg(test)]
mod tests {
// Note: Some of these examples are NOT valid vcards.
// pimsync is expected to handle invalid input gracefully and sync it as-is,
// so this is not really a problem.
use crate::base::{IcsItem, Item, Storage};
#[test]
fn test_single_line_uid() {
let raw = ["BEGIN:VCARD", "UID:hello", "END:VCARD"].join("\r\n");
let item = IcsItem::from(raw);
assert_eq!(item.uid(), Some(String::from("hello")));
assert_eq!(item.ident(), String::from("hello"));
let raw = ["BEGIN:VCARD", "UID:hel", "lo", "END:VCARD"].join("\r\n");
let item = IcsItem::from(raw);
assert_eq!(item.uid(), Some(String::from("hel")));
assert_eq!(item.ident(), String::from("hel"));
let raw = [
"BEGIN:VCARD",
"UID:hello",
"REV:20210307T195614Z\tthere",
"END:VCARD",
]
.join("\r\n");
let item = IcsItem::from(raw);
assert_eq!(item.uid(), Some(String::from("hello")));
assert_eq!(item.ident(), String::from("hello"));
}
#[test]
fn test_missing_carrige_return() {
// Same as above, but missing \r.
let raw = ["BEGIN:VCARD", "UID:hello", "END:VCARD"].join("\n");
let item = IcsItem::from(raw);
assert_eq!(item.uid(), Some(String::from("hello")));
assert_eq!(item.ident(), String::from("hello"));
let raw = ["BEGIN:VCARD", "UID:hel", "lo", "END:VCARD"].join("\n");
let item = IcsItem::from(raw);
assert_eq!(item.uid(), Some(String::from("hel")));
assert_eq!(item.ident(), String::from("hel"));
let raw = [
"BEGIN:VCARD",
"UID:hello",
"REV:20210307T195614Z\tthere",
"END:VCARD",
]
.join("\r\n");
let item = IcsItem::from(raw);
assert_eq!(item.uid(), Some(String::from("hello")));
assert_eq!(item.ident(), String::from("hello"));
}
#[test]
fn test_multi_line_uid() {
let raw = ["BEGIN:VCARD", "UID:hello", "\tthere", "END:VCARD"].join("\r\n");
let item = IcsItem::from(raw);
assert_eq!(item.uid(), Some(String::from("hellothere")));
assert_eq!(item.ident(), String::from("hellothere"));
let raw = [
"BEGIN:VCARD",
"UID:hello",
"\tthere",
"REV:20210307T195614Z",
"\tnope",
"END:VCARD",
]
.join("\r\n");
let item = IcsItem::from(raw);
assert_eq!(item.uid(), Some(String::from("hellothere")));
assert_eq!(item.ident(), String::from("hellothere"));
}
#[test]
fn test_missing_uid() {
let raw = [
"BEGIN:VCARD",
"UIDX:hello",
"REV:20210307T195614Z\tthere",
"END:VCARD",
]
.join("\r\n");
let item = IcsItem::from(raw);
assert_eq!(item.uid(), None);
assert_eq!(item.ident(), item.hash());
}
#[test]
fn test_storage_is_object_safe() {
#[allow(dead_code)]
fn dummy(_: Box<dyn Storage<IcsItem>>) {}
}
#[test]
fn test_with_uid() {
let raw = ["BEGIN:VCARD", "UID:hello", "END:VCARD"].join("\r\n");
let item = IcsItem::from(raw);
let item2 = item.with_uid("goodbye");
assert_eq!(item2.uid(), Some(String::from("goodbye")));
assert_eq!(item2.ident(), String::from("goodbye"));
}
#[test]
fn test_with_uid_without_uid() {
let raw = ["BEGIN:VCARD", "SUMMARY:hello", "END:VCARD"].join("\r\n");
let item = IcsItem::from(raw);
let item2 = item.with_uid("goodbye");
assert_eq!(item2.uid(), None);
}
}
/// Immutable wrapper around a `VCARD`.
///
/// Note that this is not a proper validating parser for vcard; it's a very simple one with the
/// sole purpose of extracing a UID. Proper parsing of components is out of scope, since we want to
/// enable operating on potentially invalid items too.
#[derive(Debug)]
pub struct VcardItem {
raw: String,
}
/// Properties supported for address books.
///
/// This is strongly based on the properties supported by `CardDav`.
#[non_exhaustive]
#[derive(Debug, Clone, Hash, PartialEq, Eq)]
pub enum AddressBookProperty {
DisplayName,
Description,
}
impl AddressBookProperty {
#[must_use]
pub fn dav_propname(&self) -> &PropertyName<'_, '_> {
match self {
AddressBookProperty::DisplayName => &names::DISPLAY_NAME,
AddressBookProperty::Description => &names::ADDRESSBOOK_DESCRIPTION,
}
}
}
impl Property for AddressBookProperty {
fn name(&self) -> String {
match self {
AddressBookProperty::DisplayName => "displayname".into(),
AddressBookProperty::Description => "description".into(),
}
}
}
impl Item for VcardItem {
type Property = AddressBookProperty;
/// Returns a unique identifier for this item.
///
/// The UID does not change when the item is modified. The UID must remain the same when the
/// item is copied across storages and storage types.
#[must_use]
fn uid(&self) -> Option<String> {
uid(&self.raw)
}
/// Returns the hash of the normalised content.
#[must_use]
fn hash(&self) -> String {
crate::util::hash(&self.raw)
}
/// A unique identifier for this item. Is either the UID (if any), or the hash of its contents.
#[must_use]
fn ident(&self) -> String {
self.uid().unwrap_or_else(|| self.hash())
}
/// Returns a new copy of this Item with the supplied UID.
#[must_use]
fn with_uid(&self, new_uid: &str) -> Self {
VcardItem::from(replace_uid(&self.raw, new_uid))
}
#[inline]
#[must_use]
/// Returns the raw contents of this item.
fn as_str(&self) -> &str {
&self.raw
}
}
impl From<String> for VcardItem {
fn from(value: String) -> Self {
VcardItem { raw: value }
}
}
/// An item plus metadata returned when fetching it.
pub struct FetchedItem<I: Item> {
/// See [`Href`]
pub href: Href,
/// The actual content of this item. See [`Item`].
pub item: I,
/// See [`Etag`]
pub etag: Etag,
}
pub struct ListedProperty<P: Property> {
pub property: P,
pub value: String,
}