pub const M000002_MIGRATION: &[&str] = &[
r#"
alter table :ARCHIMEDES_SCHEMA.jobs add column key text unique check(length(key) > 0);
"#,
r#"
alter table :ARCHIMEDES_SCHEMA.jobs add locked_at timestamptz;
"#,
r#"
alter table :ARCHIMEDES_SCHEMA.jobs add locked_by text;
"#,
r#"
update :ARCHIMEDES_SCHEMA.jobs
set locked_at = q.locked_at, locked_by = q.locked_by
from :ARCHIMEDES_SCHEMA.job_queues q
where q.queue_name = jobs.queue_name
and q.locked_at is not null;
"#,
r#"
drop function if exists :ARCHIMEDES_SCHEMA.add_job(
identifier text,
payload json,
queue_name text,
run_at timestamptz,
max_attempts int
);
"#,
r#"
create function :ARCHIMEDES_SCHEMA.add_job(
identifier text,
payload json = '{}',
queue_name text = null,
run_at timestamptz = now(),
max_attempts int = 25,
job_key text = null
) returns :ARCHIMEDES_SCHEMA.jobs as $$
declare
v_job :ARCHIMEDES_SCHEMA.jobs;
begin
if job_key is not null then
-- Upsert job
insert into :ARCHIMEDES_SCHEMA.jobs (task_identifier, payload, queue_name, run_at, max_attempts, key)
values(
identifier,
payload,
queue_name,
run_at,
max_attempts,
job_key
)
on conflict (key) do update set
-- update all job details other than queue_name, which we want to keep
-- the same unless explicitly provided
task_identifier=excluded.task_identifier,
payload=excluded.payload,
queue_name=coalesce(add_job.queue_name, jobs.queue_name),
max_attempts=excluded.max_attempts,
run_at=excluded.run_at,
-- always reset error/retry state
attempts=0,
last_error=null
where jobs.locked_at is null
returning *
into v_job;
-- If upsert succeeded (insert or update), return early
if not (v_job is null) then
return v_job;
end if;
-- Upsert failed -> there must be an existing job that is locked. Remove
-- existing key to allow a new one to be inserted, and prevent any
-- subsequent retries by bumping attempts to the max allowed.
update :ARCHIMEDES_SCHEMA.jobs
set
key = null,
attempts = jobs.max_attempts
where key = job_key;
end if;
-- insert the new job. Assume no conflicts due to the update above
insert into :ARCHIMEDES_SCHEMA.jobs(task_identifier, payload, queue_name, run_at, max_attempts, key)
values(
identifier,
payload,
queue_name,
run_at,
max_attempts,
job_key
)
returning *
into v_job;
return v_job;
end;
$$ language plpgsql volatile;
"#,
r#"
create function :ARCHIMEDES_SCHEMA.remove_job(
job_key text
) returns :ARCHIMEDES_SCHEMA.jobs as $$
delete from :ARCHIMEDES_SCHEMA.jobs
where key = job_key
and locked_at is null
returning *;
$$ language sql strict volatile;
"#,
r#"
create or replace function :ARCHIMEDES_SCHEMA.get_job(worker_id text, task_identifiers text[] = null, job_expiry interval = interval '4 hours') returns :ARCHIMEDES_SCHEMA.jobs as $$
declare
v_job_id bigint;
v_queue_name text;
v_row :ARCHIMEDES_SCHEMA.jobs;
v_now timestamptz = now();
begin
if worker_id is null or length(worker_id) < 10 then
raise exception 'invalid worker id';
end if;
select job_queues.queue_name, jobs.id into v_queue_name, v_job_id
from :ARCHIMEDES_SCHEMA.jobs
inner join :ARCHIMEDES_SCHEMA.job_queues using (queue_name)
where (job_queues.locked_at is null or job_queues.locked_at < (v_now - job_expiry))
and run_at <= v_now
and attempts < max_attempts
and (task_identifiers is null or task_identifier = any(task_identifiers))
order by priority asc, run_at asc, id asc
limit 1
for update of job_queues
skip locked;
if v_queue_name is null then
return null;
end if;
update :ARCHIMEDES_SCHEMA.job_queues
set
locked_by = worker_id,
locked_at = v_now
where job_queues.queue_name = v_queue_name;
update :ARCHIMEDES_SCHEMA.jobs
set
attempts = attempts + 1,
locked_by = worker_id,
locked_at = v_now
where id = v_job_id
returning * into v_row;
return v_row;
end;
$$ language plpgsql volatile;
"#,
r#"
create or replace function :ARCHIMEDES_SCHEMA.fail_job(worker_id text, job_id bigint, error_message text) returns :ARCHIMEDES_SCHEMA.jobs as $$
declare
v_row :ARCHIMEDES_SCHEMA.jobs;
begin
update :ARCHIMEDES_SCHEMA.jobs
set
last_error = error_message,
run_at = greatest(now(), run_at) + (exp(least(attempts, 10))::text || ' seconds')::interval,
locked_by = null,
locked_at = null
where id = job_id and locked_by = worker_id
returning * into v_row;
update :ARCHIMEDES_SCHEMA.job_queues
set locked_by = null, locked_at = null
where queue_name = v_row.queue_name and locked_by = worker_id;
return v_row;
end;
$$ language plpgsql volatile strict;
"#,
];