lemmy/crates/db_schema/src/traits.rs
Dessalines d075acce43
Make all single-fetch database calls return an Option. (#4617)
- Diesel ordinarily throws an error when no results are returned for a
  single fetch, which is a bit confusing. This PR ensures that the
  missing value cases are all caught, and wrapped with new LemmyErrors,
  rather than diesel errors.
- Fixes #4601
2024-04-16 14:48:15 +02:00

199 lines
5.2 KiB
Rust

use crate::{
diesel::OptionalExtension,
newtypes::{CommunityId, DbUrl, PersonId},
utils::{get_conn, DbPool},
};
use diesel::{
associations::HasTable,
dsl,
query_builder::{DeleteStatement, IntoUpdateTarget},
query_dsl::methods::{FindDsl, LimitDsl},
result::Error,
Table,
};
use diesel_async::{
methods::{ExecuteDsl, LoadQuery},
AsyncPgConnection,
RunQueryDsl,
};
/// Returned by `diesel::delete`
pub type Delete<T> = DeleteStatement<<T as HasTable>::Table, <T as IntoUpdateTarget>::WhereClause>;
/// Returned by `Self::table().find(id)`
pub type Find<T> = dsl::Find<<T as HasTable>::Table, <T as Crud>::IdType>;
pub type PrimaryKey<T> = <<T as HasTable>::Table as Table>::PrimaryKey;
// Trying to create default implementations for `create` and `update` results in a lifetime mess and weird compile errors.
// https://github.com/rust-lang/rust/issues/102211
#[async_trait]
pub trait Crud: HasTable + Sized
where
Self::Table: FindDsl<Self::IdType>,
Find<Self>: LimitDsl + IntoUpdateTarget + Send,
Delete<Find<Self>>: ExecuteDsl<AsyncPgConnection> + Send + 'static,
// Used by `RunQueryDsl::first`
dsl::Limit<Find<Self>>: LoadQuery<'static, AsyncPgConnection, Self> + Send + 'static,
{
type InsertForm;
type UpdateForm;
type IdType: Send;
async fn create(pool: &mut DbPool<'_>, form: &Self::InsertForm) -> Result<Self, Error>;
async fn read(pool: &mut DbPool<'_>, id: Self::IdType) -> Result<Option<Self>, Error> {
let query: Find<Self> = Self::table().find(id);
let conn = &mut *get_conn(pool).await?;
query.first(conn).await.optional()
}
/// when you want to null out a column, you have to send Some(None)), since sending None means you just don't want to update that column.
async fn update(
pool: &mut DbPool<'_>,
id: Self::IdType,
form: &Self::UpdateForm,
) -> Result<Self, Error>;
async fn delete(pool: &mut DbPool<'_>, id: Self::IdType) -> Result<usize, Error> {
let query: Delete<Find<Self>> = diesel::delete(Self::table().find(id));
let conn = &mut *get_conn(pool).await?;
query.execute(conn).await
}
}
#[async_trait]
pub trait Followable {
type Form;
async fn follow(pool: &mut DbPool<'_>, form: &Self::Form) -> Result<Self, Error>
where
Self: Sized;
async fn follow_accepted(
pool: &mut DbPool<'_>,
community_id: CommunityId,
person_id: PersonId,
) -> Result<Self, Error>
where
Self: Sized;
async fn unfollow(pool: &mut DbPool<'_>, form: &Self::Form) -> Result<usize, Error>
where
Self: Sized;
}
#[async_trait]
pub trait Joinable {
type Form;
async fn join(pool: &mut DbPool<'_>, form: &Self::Form) -> Result<Self, Error>
where
Self: Sized;
async fn leave(pool: &mut DbPool<'_>, form: &Self::Form) -> Result<usize, Error>
where
Self: Sized;
}
#[async_trait]
pub trait Likeable {
type Form;
type IdType;
async fn like(pool: &mut DbPool<'_>, form: &Self::Form) -> Result<Self, Error>
where
Self: Sized;
async fn remove(
pool: &mut DbPool<'_>,
person_id: PersonId,
item_id: Self::IdType,
) -> Result<usize, Error>
where
Self: Sized;
}
#[async_trait]
pub trait Bannable {
type Form;
async fn ban(pool: &mut DbPool<'_>, form: &Self::Form) -> Result<Self, Error>
where
Self: Sized;
async fn unban(pool: &mut DbPool<'_>, form: &Self::Form) -> Result<usize, Error>
where
Self: Sized;
}
#[async_trait]
pub trait Saveable {
type Form;
async fn save(pool: &mut DbPool<'_>, form: &Self::Form) -> Result<Self, Error>
where
Self: Sized;
async fn unsave(pool: &mut DbPool<'_>, form: &Self::Form) -> Result<usize, Error>
where
Self: Sized;
}
#[async_trait]
pub trait Blockable {
type Form;
async fn block(pool: &mut DbPool<'_>, form: &Self::Form) -> Result<Self, Error>
where
Self: Sized;
async fn unblock(pool: &mut DbPool<'_>, form: &Self::Form) -> Result<usize, Error>
where
Self: Sized;
}
#[async_trait]
pub trait Reportable {
type Form;
type IdType;
type ObjectIdType;
async fn report(pool: &mut DbPool<'_>, form: &Self::Form) -> Result<Self, Error>
where
Self: Sized;
async fn resolve(
pool: &mut DbPool<'_>,
report_id: Self::IdType,
resolver_id: PersonId,
) -> Result<usize, Error>
where
Self: Sized;
async fn resolve_all_for_object(
pool: &mut DbPool<'_>,
comment_id_: Self::ObjectIdType,
by_resolver_id: PersonId,
) -> Result<usize, Error>
where
Self: Sized;
async fn unresolve(
pool: &mut DbPool<'_>,
report_id: Self::IdType,
resolver_id: PersonId,
) -> Result<usize, Error>
where
Self: Sized;
}
#[async_trait]
pub trait ApubActor {
async fn read_from_apub_id(
pool: &mut DbPool<'_>,
object_id: &DbUrl,
) -> Result<Option<Self>, Error>
where
Self: Sized;
/// - actor_name is the name of the community or user to read.
/// - include_deleted, if true, will return communities or users that were deleted/removed
async fn read_from_name(
pool: &mut DbPool<'_>,
actor_name: &str,
include_deleted: bool,
) -> Result<Option<Self>, Error>
where
Self: Sized;
async fn read_from_name_and_domain(
pool: &mut DbPool<'_>,
actor_name: &str,
protocol_domain: &str,
) -> Result<Option<Self>, Error>
where
Self: Sized;
}