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use skip_locked to skip the locked record

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This commit is contained in:
Ayrat Badykov 2021-06-13 12:26:40 +03:00
parent 27f3e1479f
commit 5824038701
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GPG key ID: 16AE533AB7A3E8C6
1 changed files with 31 additions and 35 deletions
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66
src/postgres.rs
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@ -63,6 +63,7 @@ impl Postgres {
.order(fang_tasks::created_at.asc()) .order(fang_tasks::created_at.asc())
.limit(1) .limit(1)
.for_update() .for_update()
.skip_locked()
.get_result::<Task>(&self.connection) .get_result::<Task>(&self.connection)
{ {
Ok(record) => Some(record), Ok(record) => Some(record),
@ -78,7 +79,7 @@ mod postgres_tests {
use super::Task; use super::Task;
use crate::schema::fang_tasks; use crate::schema::fang_tasks;
use crate::schema::FangTaskState; use crate::schema::FangTaskState;
use chrono::{Duration, Utc}; use chrono::{DateTime, Duration, Utc};
use diesel::connection::Connection; use diesel::connection::Connection;
use diesel::prelude::*; use diesel::prelude::*;
use diesel::result::Error; use diesel::result::Error;
@ -106,23 +107,11 @@ mod postgres_tests {
postgres.connection.test_transaction::<(), Error, _>(|| { postgres.connection.test_transaction::<(), Error, _>(|| {
let timestamp1 = Utc::now() - Duration::hours(40); let timestamp1 = Utc::now() - Duration::hours(40);
let task1 = diesel::insert_into(fang_tasks::table) let task1 = insert_job(serde_json::json!(true), timestamp1, &postgres.connection);
.values(&vec![(
fang_tasks::metadata.eq(serde_json::json!(true)),
fang_tasks::created_at.eq(timestamp1),
)])
.get_result::<Task>(&postgres.connection)
.unwrap();
let timestamp2 = Utc::now() - Duration::hours(20); let timestamp2 = Utc::now() - Duration::hours(20);
diesel::insert_into(fang_tasks::table) insert_job(serde_json::json!(false), timestamp2, &postgres.connection);
.values(&vec![(
fang_tasks::metadata.eq(serde_json::json!(false)),
fang_tasks::created_at.eq(timestamp2),
)])
.get_result::<Task>(&postgres.connection)
.unwrap();
let found_task = postgres.fetch_task().unwrap(); let found_task = postgres.fetch_task().unwrap();
@ -132,37 +121,28 @@ mod postgres_tests {
}); });
} }
// this test ignored because it commits data to the db
#[test] #[test]
#[ignore] #[ignore]
fn fetch_task_locks_the_record() { fn fetch_task_locks_the_record() {
let postgres = Postgres::new(None); let postgres = Postgres::new(None);
let timestamp1 = Utc::now() - Duration::hours(40); let timestamp1 = Utc::now() - Duration::hours(40);
let task1 = diesel::insert_into(fang_tasks::table) let task1 = insert_job(serde_json::json!(true), timestamp1, &postgres.connection);
.values(&vec![(
fang_tasks::metadata.eq(serde_json::json!(true)), let task1_id = task1.id;
fang_tasks::created_at.eq(timestamp1),
)])
.get_result::<Task>(&postgres.connection)
.unwrap();
let timestamp2 = Utc::now() - Duration::hours(20); let timestamp2 = Utc::now() - Duration::hours(20);
let task2 = diesel::insert_into(fang_tasks::table) let task2 = insert_job(serde_json::json!(false), timestamp2, &postgres.connection);
.values(&vec![(
fang_tasks::metadata.eq(serde_json::json!(false)),
fang_tasks::created_at.eq(timestamp2),
)])
.get_result::<Task>(&postgres.connection)
.unwrap();
let thread = std::thread::spawn(move || { let thread = std::thread::spawn(move || {
let postgres = Postgres::new(None); let postgres = Postgres::new(None);
postgres.connection.test_transaction::<(), Error, _>(|| { postgres.connection.transaction::<(), Error, _>(|| {
let found_task = postgres.fetch_task().unwrap(); let found_task = postgres.fetch_task().unwrap();
assert_eq!(found_task.id, task2.id); assert_eq!(found_task.id, task1.id);
std::thread::sleep(std::time::Duration::from_millis(5000)); std::thread::sleep(std::time::Duration::from_millis(5000));
@ -174,12 +154,28 @@ mod postgres_tests {
let found_task = postgres.fetch_task().unwrap(); let found_task = postgres.fetch_task().unwrap();
assert_eq!(found_task.id, task1.id); assert_eq!(found_task.id, task2.id);
let result = thread.join(); let _result = thread.join();
eprintln!("{:?}", result); // returns unlocked record
// assert_eq!(Ok(()), result); let found_task = postgres.fetch_task().unwrap();
assert_eq!(found_task.id, task1_id);
}
fn insert_job(
metadata: serde_json::Value,
timestamp: DateTime<Utc>,
connection: &PgConnection,
) -> Task {
diesel::insert_into(fang_tasks::table)
.values(&vec![(
fang_tasks::metadata.eq(metadata),
fang_tasks::created_at.eq(timestamp),
)])
.get_result::<Task>(connection)
.unwrap()
} }
} }