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//! A cache containing data received from [`Shard`]s.
//!
//! Using the cache allows to avoid REST API requests via the [`http`] module where possible.
//! Issuing too many requests will lead to ratelimits.
//!
//! # Use by Models
//!
//! Most models of Discord objects, such as the [`Message`], [`GuildChannel`], or [`Emoji`], have
//! methods for interacting with that single instance. This feature is only compiled if the `model`
//! feature is enabled. An example of this is [`Guild::edit`], which performs a check to ensure that
//! the current user has the [Manage Guild] permission prior to actually performing the HTTP
//! request. The cache is involved due to the function's use of unlocking the cache and retrieving
//! the permissions of the current user. This is an inexpensive method of being able to access data
//! required by these sugary methods.
//!
//! # Do I need the Cache?
//!
//! If you're asking this, the answer is likely "definitely yes" or "definitely no"; any in-between
//! tends to be "yes". If you are low on RAM, and need to run on only a couple MB, then the answer
//! is "definitely no". If you do not care about RAM and want your bot to be able to access data
//! while needing to hit the REST API as little as possible, then the answer is "yes".
//!
//! [`Shard`]: crate::gateway::Shard
//! [`http`]: crate::http
//! [Manage Guild]: Permissions::MANAGE_GUILD
use std::collections::{HashSet, VecDeque};
use std::hash::Hash;
#[cfg(feature = "temp_cache")]
use std::sync::Arc;
#[cfg(feature = "temp_cache")]
use std::time::Duration;
use dashmap::mapref::entry::Entry;
use dashmap::mapref::one::{MappedRef, Ref};
use dashmap::DashMap;
#[cfg(feature = "temp_cache")]
use mini_moka::sync::Cache as MokaCache;
use parking_lot::RwLock;
use tracing::instrument;
pub use self::cache_update::CacheUpdate;
pub use self::settings::Settings;
use crate::model::prelude::*;
mod cache_update;
mod event;
mod settings;
mod wrappers;
#[cfg(feature = "temp_cache")]
pub(crate) use wrappers::MaybeOwnedArc;
use wrappers::{BuildHasher, MaybeMap, ReadOnlyMapRef};
type MessageCache = DashMap<ChannelId, HashMap<MessageId, Message>, BuildHasher>;
struct NotSend;
enum CacheRefInner<'a, K, V, T> {
#[cfg(feature = "temp_cache")]
Arc(Arc<V>),
DashRef(Ref<'a, K, V, BuildHasher>),
DashMappedRef(MappedRef<'a, K, T, V, BuildHasher>),
ReadGuard(parking_lot::RwLockReadGuard<'a, V>),
}
pub struct CacheRef<'a, K, V, T = ()> {
inner: CacheRefInner<'a, K, V, T>,
phantom: std::marker::PhantomData<*const NotSend>,
}
impl<'a, K, V, T> CacheRef<'a, K, V, T> {
fn new(inner: CacheRefInner<'a, K, V, T>) -> Self {
Self {
inner,
phantom: std::marker::PhantomData,
}
}
#[cfg(feature = "temp_cache")]
fn from_arc(inner: MaybeOwnedArc<V>) -> Self {
Self::new(CacheRefInner::Arc(inner.get_inner()))
}
fn from_ref(inner: Ref<'a, K, V, BuildHasher>) -> Self {
Self::new(CacheRefInner::DashRef(inner))
}
fn from_mapped_ref(inner: MappedRef<'a, K, T, V, BuildHasher>) -> Self {
Self::new(CacheRefInner::DashMappedRef(inner))
}
fn from_guard(inner: parking_lot::RwLockReadGuard<'a, V>) -> Self {
Self::new(CacheRefInner::ReadGuard(inner))
}
}
impl<K: Eq + Hash, V, T> std::ops::Deref for CacheRef<'_, K, V, T> {
type Target = V;
fn deref(&self) -> &Self::Target {
match &self.inner {
#[cfg(feature = "temp_cache")]
CacheRefInner::Arc(inner) => inner,
CacheRefInner::DashRef(inner) => inner.value(),
CacheRefInner::DashMappedRef(inner) => inner.value(),
CacheRefInner::ReadGuard(inner) => inner,
}
}
}
type MappedGuildRef<'a, T> = CacheRef<'a, GuildId, T, Guild>;
pub type UserRef<'a> = CacheRef<'a, UserId, User>;
pub type MemberRef<'a> = MappedGuildRef<'a, Member>;
pub type GuildRef<'a> = CacheRef<'a, GuildId, Guild>;
pub type GuildRoleRef<'a> = MappedGuildRef<'a, Role>;
pub type SettingsRef<'a> = CacheRef<'a, (), Settings>;
pub type CurrentUserRef<'a> = CacheRef<'a, (), CurrentUser>;
pub type GuildChannelRef<'a> = MappedGuildRef<'a, GuildChannel>;
pub type GuildRolesRef<'a> = MappedGuildRef<'a, HashMap<RoleId, Role>>;
pub type GuildChannelsRef<'a> = MappedGuildRef<'a, HashMap<ChannelId, GuildChannel>>;
pub type ChannelMessagesRef<'a> = CacheRef<'a, ChannelId, HashMap<MessageId, Message>>;
pub type MessageRef<'a> = CacheRef<'a, ChannelId, Message, HashMap<MessageId, Message>>;
#[cfg_attr(feature = "typesize", derive(typesize::derive::TypeSize))]
#[derive(Debug)]
pub(crate) struct CachedShardData {
pub total: u32,
pub connected: HashSet<ShardId>,
pub has_sent_shards_ready: bool,
}
/// A cache containing data received from [`Shard`]s.
///
/// Using the cache allows to avoid REST API requests via the [`http`] module where possible.
/// Issuing too many requests will lead to ratelimits.
///
/// This is the list of cached resources and the events that populate them:
/// - channels: [`ChannelCreateEvent`], [`ChannelUpdateEvent`], [`GuildCreateEvent`]
/// - guilds: [`GuildCreateEvent`]
/// - unavailable_guilds: [`ReadyEvent`], [`GuildDeleteEvent`]
/// - users: [`GuildMemberAddEvent`], [`GuildMemberRemoveEvent`], [`GuildMembersChunkEvent`],
/// [`PresenceUpdateEvent`], [`ReadyEvent`]
/// - presences: [`PresenceUpdateEvent`], [`ReadyEvent`]
/// - messages: [`MessageCreateEvent`]
///
/// The documentation of each event contains the required gateway intents.
///
/// [`Shard`]: crate::gateway::Shard
/// [`http`]: crate::http
#[cfg_attr(feature = "typesize", derive(typesize::derive::TypeSize))]
#[derive(Debug)]
#[non_exhaustive]
pub struct Cache {
// Temp cache:
// ---
/// Cache of channels that have been fetched via to_channel.
///
/// The TTL for each value is configured in CacheSettings.
#[cfg(feature = "temp_cache")]
pub(crate) temp_channels: MokaCache<ChannelId, MaybeOwnedArc<GuildChannel>, BuildHasher>,
/// Cache of private channels created via create_dm_channel.
///
/// The TTL for each value is configured in CacheSettings.
#[cfg(feature = "temp_cache")]
pub(crate) temp_private_channels: MokaCache<UserId, MaybeOwnedArc<PrivateChannel>, BuildHasher>,
/// Cache of messages that have been fetched via message.
///
/// The TTL for each value is configured in CacheSettings.
#[cfg(feature = "temp_cache")]
pub(crate) temp_messages: MokaCache<MessageId, MaybeOwnedArc<Message>, BuildHasher>,
/// Cache of users who have been fetched from `to_user`.
///
/// The TTL for each value is configured in CacheSettings.
#[cfg(feature = "temp_cache")]
pub(crate) temp_users: MokaCache<UserId, MaybeOwnedArc<User>, BuildHasher>,
// Channels cache:
/// A map of channel ids to the guilds in which the channel data is stored.
pub(crate) channels: MaybeMap<ChannelId, GuildId>,
// Guilds cache:
// ---
/// A map of guilds with full data available. This includes data like [`Role`]s and [`Emoji`]s
/// that are not available through the REST API.
pub(crate) guilds: MaybeMap<GuildId, Guild>,
/// A list of guilds which are "unavailable".
///
/// Additionally, guilds are always unavailable for bot users when a Ready is received. Guilds
/// are "sent in" over time through the receiving of [`Event::GuildCreate`]s.
pub(crate) unavailable_guilds: MaybeMap<GuildId, ()>,
// Users cache:
// ---
/// A map of users that the current user sees.
///
/// Users are added to - and updated from - this map via the following received events:
///
/// - [`GuildMemberAdd`][`GuildMemberAddEvent`]
/// - [`GuildMemberRemove`][`GuildMemberRemoveEvent`]
/// - [`GuildMembersChunk`][`GuildMembersChunkEvent`]
/// - [`PresenceUpdate`][`PresenceUpdateEvent`]
/// - [`Ready`][`ReadyEvent`]
///
/// Note, however, that users are _not_ removed from the map on removal events such as
/// [`GuildMemberRemove`][`GuildMemberRemoveEvent`], as other structs such as members or
/// recipients may still exist.
pub(crate) users: MaybeMap<UserId, User>,
// Messages cache:
// ---
pub(crate) messages: MessageCache,
/// Queue of message IDs for each channel.
///
/// This is simply a vecdeque so we can keep track of the order of messages inserted into the
/// cache. When a maximum number of messages are in a channel's cache, we can pop the front and
/// remove that ID from the cache.
pub(crate) message_queue: DashMap<ChannelId, VecDeque<MessageId>, BuildHasher>,
// Miscellanous fixed-size data
// ---
/// Information about running shards
pub(crate) shard_data: RwLock<CachedShardData>,
/// The current user "logged in" and for which events are being received for.
///
/// The current user contains information that a regular [`User`] does not, such as whether it
/// is a bot, whether the user is verified, etc.
///
/// Refer to the documentation for [`CurrentUser`] for more information.
pub(crate) user: RwLock<CurrentUser>,
/// The settings for the cache.
settings: RwLock<Settings>,
}
impl Cache {
/// Creates a new cache.
#[inline]
#[must_use]
pub fn new() -> Self {
Self::default()
}
/// Creates a new cache instance with settings applied.
///
/// # Examples
///
/// ```rust
/// use serenity::cache::{Cache, Settings};
///
/// let mut settings = Settings::default();
/// settings.max_messages = 10;
///
/// let cache = Cache::new_with_settings(settings);
/// ```
#[instrument]
pub fn new_with_settings(settings: Settings) -> Self {
#[cfg(feature = "temp_cache")]
fn temp_cache<K, V>(ttl: Duration) -> MokaCache<K, V, BuildHasher>
where
K: Hash + Eq + Send + Sync + 'static,
V: Clone + Send + Sync + 'static,
{
MokaCache::builder().time_to_live(ttl).build_with_hasher(BuildHasher::default())
}
Self {
#[cfg(feature = "temp_cache")]
temp_private_channels: temp_cache(settings.time_to_live),
#[cfg(feature = "temp_cache")]
temp_channels: temp_cache(settings.time_to_live),
#[cfg(feature = "temp_cache")]
temp_messages: temp_cache(settings.time_to_live),
#[cfg(feature = "temp_cache")]
temp_users: temp_cache(settings.time_to_live),
channels: MaybeMap(settings.cache_channels.then(DashMap::default)),
guilds: MaybeMap(settings.cache_guilds.then(DashMap::default)),
unavailable_guilds: MaybeMap(settings.cache_guilds.then(DashMap::default)),
users: MaybeMap(settings.cache_users.then(DashMap::default)),
messages: DashMap::default(),
message_queue: DashMap::default(),
shard_data: RwLock::new(CachedShardData {
total: 1,
connected: HashSet::new(),
has_sent_shards_ready: false,
}),
user: RwLock::new(CurrentUser::default()),
settings: RwLock::new(settings),
}
}
/// Fetches the number of [`Member`]s that have not had data received.
///
/// The important detail to note here is that this is the number of _member_s that have not had
/// data received. A single [`User`] may have multiple associated member objects that have not
/// been received.
///
/// This can be used in combination with [`Shard::chunk_guild`], and can be used to determine
/// how many members have not yet been received.
///
/// ```rust,no_run
/// # use serenity::model::prelude::*;
/// # use serenity::prelude::*;
/// struct Handler;
///
/// #[serenity::async_trait]
/// # #[cfg(feature = "client")]
/// impl EventHandler for Handler {
/// async fn cache_ready(&self, ctx: Context, _: Vec<GuildId>) {
/// println!("{} unknown members", ctx.cache.unknown_members());
/// }
/// }
/// ```
///
/// [`Shard::chunk_guild`]: crate::gateway::Shard::chunk_guild
pub fn unknown_members(&self) -> u64 {
let mut total = 0;
for guild_entry in self.guilds.iter() {
let guild = guild_entry.value();
let members = guild.members.len() as u64;
if guild.member_count > members {
total += guild.member_count - members;
}
}
total
}
/// Fetches a vector of all [`Guild`]s' Ids that are stored in the cache.
///
/// Note that if you are utilizing multiple [`Shard`]s, then the guilds retrieved over all
/// shards are included in this count -- not just the current [`Context`]'s shard, if accessing
/// from one.
///
/// # Examples
///
/// Print all of the Ids of guilds in the Cache:
///
/// ```rust,no_run
/// # use serenity::model::prelude::*;
/// # use serenity::prelude::*;
/// #
/// struct Handler;
///
/// #[serenity::async_trait]
/// impl EventHandler for Handler {
/// async fn ready(&self, context: Context, _: Ready) {
/// let guilds = context.cache.guilds().len();
///
/// println!("Guilds in the Cache: {}", guilds);
/// }
/// }
/// ```
///
/// [`Context`]: crate::client::Context
/// [`Shard`]: crate::gateway::Shard
pub fn guilds(&self) -> Vec<GuildId> {
let unavailable_guilds = self.unavailable_guilds();
let unavailable_guild_ids = unavailable_guilds.iter().map(|i| *i.key());
self.guilds.iter().map(|i| *i.key()).chain(unavailable_guild_ids).collect()
}
/// Retrieves a [`GuildChannel`] from the cache based on the given Id.
#[inline]
#[deprecated = "Use Cache::guild and Guild::channels instead"]
pub fn channel<C: Into<ChannelId>>(&self, id: C) -> Option<GuildChannelRef<'_>> {
self._channel(id.into())
}
fn _channel(&self, id: ChannelId) -> Option<GuildChannelRef<'_>> {
let guild_id = *self.channels.get(&id)?;
let guild_ref = self.guilds.get(&guild_id)?;
let channel = guild_ref.try_map(|g| g.channels.get(&id)).ok();
if let Some(channel) = channel {
return Some(CacheRef::from_mapped_ref(channel));
}
#[cfg(feature = "temp_cache")]
{
if let Some(channel) = self.temp_channels.get(&id) {
return Some(CacheRef::from_arc(channel));
}
}
None
}
/// Get a reference to the cached messages for a channel based on the given `Id`.
///
/// # Examples
///
/// Find all messages by user ID 8 in channel ID 7:
///
/// ```rust,no_run
/// # let cache: serenity::cache::Cache = todo!();
/// let messages_in_channel = cache.channel_messages(7);
/// let messages_by_user = messages_in_channel
/// .as_ref()
/// .map(|msgs| msgs.values().filter(|m| m.author.id == 8).collect::<Vec<_>>());
/// ```
pub fn channel_messages(
&self,
channel_id: impl Into<ChannelId>,
) -> Option<ChannelMessagesRef<'_>> {
self.messages.get(&channel_id.into()).map(CacheRef::from_ref)
}
/// Gets a reference to a guild from the cache based on the given `id`.
///
/// # Examples
///
/// Retrieve a guild from the cache and print its name:
///
/// ```rust,no_run
/// # use serenity::cache::Cache;
/// #
/// # let cache = Cache::default();
/// // assuming the cache is in scope, e.g. via `Context`
/// if let Some(guild) = cache.guild(7) {
/// println!("Guild name: {}", guild.name);
/// };
/// ```
#[inline]
pub fn guild<G: Into<GuildId>>(&self, id: G) -> Option<GuildRef<'_>> {
self._guild(id.into())
}
fn _guild(&self, id: GuildId) -> Option<GuildRef<'_>> {
self.guilds.get(&id).map(CacheRef::from_ref)
}
/// Returns the number of cached guilds.
pub fn guild_count(&self) -> usize {
self.guilds.len()
}
/// Retrieves a [`Guild`]'s member from the cache based on the guild's and user's given Ids.
///
/// # Examples
///
/// Retrieving the member object of the user that posted a message, in a
/// [`EventHandler::message`] context:
///
/// ```rust,no_run
/// # use serenity::cache::Cache;
/// # use serenity::http::Http;
/// # use serenity::model::channel::Message;
/// #
/// # async fn run(http: Http, cache: Cache, message: Message) {
/// #
/// let roles_len = {
/// let channel = match cache.channel(message.channel_id) {
/// Some(channel) => channel,
/// None => {
/// if let Err(why) = message.channel_id.say(http, "Error finding channel data").await {
/// println!("Error sending message: {:?}", why);
/// }
/// return;
/// },
/// };
///
/// cache.member(channel.guild_id, message.author.id).map(|m| m.roles.len())
/// };
///
/// let message_res = if let Some(roles_len) = roles_len {
/// let msg = format!("You have {} roles", roles_len);
/// message.channel_id.say(&http, &msg).await
/// } else {
/// message.channel_id.say(&http, "Error finding member data").await
/// };
///
/// if let Err(why) = message_res {
/// println!("Error sending message: {:?}", why);
/// }
/// # }
/// ```
///
/// [`EventHandler::message`]: crate::client::EventHandler::message
/// [`members`]: crate::model::guild::Guild::members
#[inline]
#[deprecated = "Use Cache::guild and Guild::members instead"]
pub fn member(
&self,
guild_id: impl Into<GuildId>,
user_id: impl Into<UserId>,
) -> Option<MemberRef<'_>> {
self._member(guild_id.into(), user_id.into())
}
fn _member(&self, guild_id: GuildId, user_id: UserId) -> Option<MemberRef<'_>> {
let member = self.guilds.get(&guild_id)?.try_map(|g| g.members.get(&user_id)).ok()?;
Some(CacheRef::from_mapped_ref(member))
}
#[inline]
#[deprecated = "Use Cache::guild and Guild::roles instead"]
pub fn guild_roles(&self, guild_id: impl Into<GuildId>) -> Option<GuildRolesRef<'_>> {
self._guild_roles(guild_id.into())
}
fn _guild_roles(&self, guild_id: GuildId) -> Option<GuildRolesRef<'_>> {
let roles = self.guilds.get(&guild_id)?.map(|g| &g.roles);
Some(CacheRef::from_mapped_ref(roles))
}
/// This method clones and returns all unavailable guilds.
#[inline]
pub fn unavailable_guilds(&self) -> ReadOnlyMapRef<'_, GuildId, ()> {
self.unavailable_guilds.as_read_only()
}
/// This method returns all channels from a guild of with the given `guild_id`.
#[inline]
#[deprecated = "Use Cache::guild and Guild::channels instead"]
pub fn guild_channels(&self, guild_id: impl Into<GuildId>) -> Option<GuildChannelsRef<'_>> {
self._guild_channels(guild_id.into())
}
fn _guild_channels(&self, guild_id: GuildId) -> Option<GuildChannelsRef<'_>> {
let channels = self.guilds.get(&guild_id)?.map(|g| &g.channels);
Some(CacheRef::from_mapped_ref(channels))
}
/// Returns the number of guild channels in the cache.
pub fn guild_channel_count(&self) -> usize {
self.channels.len()
}
/// Returns the number of shards.
#[inline]
pub fn shard_count(&self) -> u32 {
self.shard_data.read().total
}
/// Retrieves a [`Channel`]'s message from the cache based on the channel's and message's given
/// Ids.
///
/// **Note**: This will clone the entire message.
///
/// # Examples
///
/// Retrieving the message object from a channel, in a [`EventHandler::message`] context:
///
/// ```rust,no_run
/// # use serenity::cache::Cache;
/// # use serenity::model::channel::Message;
/// #
/// # fn run(cache: Cache, message: Message) {
/// #
/// match cache.message(message.channel_id, message.id) {
/// Some(m) => assert_eq!(message.content, m.content),
/// None => println!("No message found in cache."),
/// };
/// # }
/// ```
///
/// [`EventHandler::message`]: crate::client::EventHandler::message
#[inline]
pub fn message<C, M>(&self, channel_id: C, message_id: M) -> Option<MessageRef<'_>>
where
C: Into<ChannelId>,
M: Into<MessageId>,
{
self._message(channel_id.into(), message_id.into())
}
fn _message(&self, channel_id: ChannelId, message_id: MessageId) -> Option<MessageRef<'_>> {
#[cfg(feature = "temp_cache")]
if let Some(message) = self.temp_messages.get(&message_id) {
return Some(CacheRef::from_arc(message));
}
let channel_messages = self.messages.get(&channel_id)?;
let message = channel_messages.try_map(|messages| messages.get(&message_id)).ok()?;
Some(CacheRef::from_mapped_ref(message))
}
/// Retrieves a [`Guild`]'s role by their Ids.
///
/// **Note**: This will clone the entire role. Instead, retrieve the guild and retrieve from
/// the guild's [`roles`] map to avoid this.
///
/// # Examples
///
/// Retrieve a role from the cache and print its name:
///
/// ```rust,no_run
/// # use serenity::cache::Cache;
/// #
/// # let cache = Cache::default();
/// // assuming the cache is in scope, e.g. via `Context`
/// if let Some(role) = cache.role(7, 77) {
/// println!("Role with Id 77 is called {}", role.name);
/// };
/// ```
///
/// [`Guild`]: crate::model::guild::Guild
/// [`roles`]: crate::model::guild::Guild::roles
#[inline]
#[deprecated = "Use Cache::guild and Guild::roles instead"]
pub fn role<G, R>(&self, guild_id: G, role_id: R) -> Option<GuildRoleRef<'_>>
where
G: Into<GuildId>,
R: Into<RoleId>,
{
self._role(guild_id.into(), role_id.into())
}
fn _role(&self, guild_id: GuildId, role_id: RoleId) -> Option<GuildRoleRef<'_>> {
let role = self.guilds.get(&guild_id)?.try_map(|g| g.roles.get(&role_id)).ok()?;
Some(CacheRef::from_mapped_ref(role))
}
/// Returns the settings.
///
/// # Examples
///
/// Printing the maximum number of messages in a channel to be cached:
///
/// ```rust
/// use serenity::cache::Cache;
///
/// # fn test() {
/// let mut cache = Cache::new();
/// println!("Max settings: {}", cache.settings().max_messages);
/// # }
/// ```
pub fn settings(&self) -> SettingsRef<'_> {
CacheRef::from_guard(self.settings.read())
}
/// Sets the maximum amount of messages per channel to cache.
///
/// By default, no messages will be cached.
pub fn set_max_messages(&self, max: usize) {
self.settings.write().max_messages = max;
}
/// Retrieves a [`User`] from the cache's [`Self::users`] map, if it exists.
///
/// The only advantage of this method is that you can pass in anything that is indirectly a
/// [`UserId`].
///
/// # Examples
///
/// Retrieve a user from the cache and print their name:
///
/// ```rust,no_run
/// # use serenity::client::Context;
/// #
/// # async fn test(context: &Context) -> Result<(), Box<dyn std::error::Error>> {
/// if let Some(user) = context.cache.user(7) {
/// println!("User with Id 7 is currently named {}", user.name);
/// }
/// # Ok(())
/// # }
/// ```
#[inline]
pub fn user<U: Into<UserId>>(&self, user_id: U) -> Option<UserRef<'_>> {
self._user(user_id.into())
}
#[cfg(feature = "temp_cache")]
fn _user(&self, user_id: UserId) -> Option<UserRef<'_>> {
if let Some(user) = self.users.get(&user_id) {
Some(CacheRef::from_ref(user))
} else {
self.temp_users.get(&user_id).map(CacheRef::from_arc)
}
}
#[cfg(not(feature = "temp_cache"))]
fn _user(&self, user_id: UserId) -> Option<UserRef<'_>> {
self.users.get(&user_id).map(CacheRef::from_ref)
}
/// Clones all users and returns them.
#[inline]
pub fn users(&self) -> ReadOnlyMapRef<'_, UserId, User> {
self.users.as_read_only()
}
/// Returns the amount of cached users.
#[inline]
pub fn user_count(&self) -> usize {
self.users.len()
}
/// This method provides a reference to the user used by the bot.
#[inline]
pub fn current_user(&self) -> CurrentUserRef<'_> {
CacheRef::from_guard(self.user.read())
}
/// Returns a channel category matching the given ID
#[deprecated = "Use Cache::guild, Guild::channels, and GuildChannel::kind"]
pub fn category(&self, channel_id: ChannelId) -> Option<GuildChannelRef<'_>> {
#[allow(deprecated)]
let channel = self.channel(channel_id)?;
if channel.kind == ChannelType::Category {
Some(channel)
} else {
None
}
}
/// Returns the parent category of the given channel ID.
#[deprecated = "Use Cache::guild, Guild::channels, and GuildChannel::parent_id"]
pub fn channel_category_id(&self, channel_id: ChannelId) -> Option<ChannelId> {
#[allow(deprecated)]
self.channel(channel_id)?.parent_id
}
/// Clones all channel categories in the given guild and returns them.
pub fn guild_categories(&self, guild_id: GuildId) -> Option<HashMap<ChannelId, GuildChannel>> {
let guild = self.guilds.get(&guild_id)?;
Some(
guild
.channels
.iter()
.filter(|(_id, channel)| channel.kind == ChannelType::Category)
.map(|(id, channel)| (*id, channel.clone()))
.collect(),
)
}
/// Updates the cache with the update implementation for an event or other custom update
/// implementation.
///
/// Refer to the documentation for [`CacheUpdate`] for more information.
///
/// # Examples
///
/// Refer to the [`CacheUpdate` examples].
///
/// [`CacheUpdate` examples]: CacheUpdate#examples
#[instrument(skip(self, e))]
pub fn update<E: CacheUpdate>(&self, e: &mut E) -> Option<E::Output> {
e.update(self)
}
pub(crate) fn update_user_entry(&self, user: &User) {
if let Some(users) = &self.users.0 {
match users.entry(user.id) {
Entry::Vacant(e) => {
e.insert(user.clone());
},
Entry::Occupied(mut e) => {
e.get_mut().clone_from(user);
},
}
}
}
}
impl Default for Cache {
fn default() -> Self {
Self::new_with_settings(Settings::default())
}
}
#[cfg(test)]
mod test {
use crate::cache::{Cache, CacheUpdate, Settings};
use crate::model::prelude::*;
#[test]
fn test_cache_messages() {
let settings = Settings {
max_messages: 2,
..Default::default()
};
let cache = Cache::new_with_settings(settings);
// Test inserting one message into a channel's message cache.
let mut event = MessageCreateEvent {
message: Message {
id: MessageId::new(3),
guild_id: Some(GuildId::new(1)),
..Default::default()
},
};
// Check that the channel cache doesn't exist.
assert!(!cache.messages.contains_key(&event.message.channel_id));
// Add first message, none because message ID 2 doesn't already exist.
assert!(event.update(&cache).is_none());
// None, it only returns the oldest message if the cache was already full.
assert!(event.update(&cache).is_none());
// Assert there's only 1 message in the channel's message cache.
assert_eq!(cache.messages.get(&event.message.channel_id).unwrap().len(), 1);
// Add a second message, assert that channel message cache length is 2.
event.message.id = MessageId::new(4);
assert!(event.update(&cache).is_none());
assert_eq!(cache.messages.get(&event.message.channel_id).unwrap().len(), 2);
// Add a third message, the first should now be removed.
event.message.id = MessageId::new(5);
assert!(event.update(&cache).is_some());
{
let channel = cache.messages.get(&event.message.channel_id).unwrap();
assert_eq!(channel.len(), 2);
// Check that the first message is now removed.
assert!(!channel.contains_key(&MessageId::new(3)));
}
let channel = GuildChannel {
id: event.message.channel_id,
guild_id: event.message.guild_id.unwrap(),
..Default::default()
};
// Add a channel delete event to the cache, the cached messages for that channel should now
// be gone.
let mut delete = ChannelDeleteEvent {
channel: channel.clone(),
};
assert!(cache.update(&mut delete).is_some());
assert!(!cache.messages.contains_key(&delete.channel.id));
// Test deletion of a guild channel's message cache when a GuildDeleteEvent is received.
let mut guild_create = GuildCreateEvent {
guild: Guild {
id: GuildId::new(1),
channels: HashMap::from([(ChannelId::new(2), channel)]),
..Default::default()
},
};
assert!(cache.update(&mut guild_create).is_none());
assert!(cache.update(&mut event).is_none());
let mut guild_delete = GuildDeleteEvent {
guild: UnavailableGuild {
id: GuildId::new(1),
unavailable: false,
},
};
// The guild existed in the cache, so the cache's guild is returned by the update.
assert!(cache.update(&mut guild_delete).is_some());
// Assert that the channel's message cache no longer exists.
assert!(!cache.messages.contains_key(&ChannelId::new(2)));
}
}