forgejo/modules
wxiaoguang 6f9c278559
Rewrite queue (#24505)
# ⚠️ Breaking

Many deprecated queue config options are removed (actually, they should
have been removed in 1.18/1.19).

If you see the fatal message when starting Gitea: "Please update your
app.ini to remove deprecated config options", please follow the error
messages to remove these options from your app.ini.

Example:

```
2023/05/06 19:39:22 [E] Removed queue option: `[indexer].ISSUE_INDEXER_QUEUE_TYPE`. Use new options in `[queue.issue_indexer]`
2023/05/06 19:39:22 [E] Removed queue option: `[indexer].UPDATE_BUFFER_LEN`. Use new options in `[queue.issue_indexer]`
2023/05/06 19:39:22 [F] Please update your app.ini to remove deprecated config options
```

Many options in `[queue]` are are dropped, including:
`WRAP_IF_NECESSARY`, `MAX_ATTEMPTS`, `TIMEOUT`, `WORKERS`,
`BLOCK_TIMEOUT`, `BOOST_TIMEOUT`, `BOOST_WORKERS`, they can be removed
from app.ini.

# The problem

The old queue package has some legacy problems:

* complexity: I doubt few people could tell how it works.
* maintainability: Too many channels and mutex/cond are mixed together,
too many different structs/interfaces depends each other.
* stability: due to the complexity & maintainability, sometimes there
are strange bugs and difficult to debug, and some code doesn't have test
(indeed some code is difficult to test because a lot of things are mixed
together).
* general applicability: although it is called "queue", its behavior is
not a well-known queue.
* scalability: it doesn't seem easy to make it work with a cluster
without breaking its behaviors.

It came from some very old code to "avoid breaking", however, its
technical debt is too heavy now. It's a good time to introduce a better
"queue" package.

# The new queue package

It keeps using old config and concept as much as possible.

* It only contains two major kinds of concepts:
    * The "base queue": channel, levelqueue, redis
* They have the same abstraction, the same interface, and they are
tested by the same testing code.
* The "WokerPoolQueue", it uses the "base queue" to provide "worker
pool" function, calls the "handler" to process the data in the base
queue.
* The new code doesn't do "PushBack"
* Think about a queue with many workers, the "PushBack" can't guarantee
the order for re-queued unhandled items, so in new code it just does
"normal push"
* The new code doesn't do "pause/resume"
* The "pause/resume" was designed to handle some handler's failure: eg:
document indexer (elasticsearch) is down
* If a queue is paused for long time, either the producers blocks or the
new items are dropped.
* The new code doesn't do such "pause/resume" trick, it's not a common
queue's behavior and it doesn't help much.
* If there are unhandled items, the "push" function just blocks for a
few seconds and then re-queue them and retry.
* The new code doesn't do "worker booster"
* Gitea's queue's handlers are light functions, the cost is only the
go-routine, so it doesn't make sense to "boost" them.
* The new code only use "max worker number" to limit the concurrent
workers.
* The new "Push" never blocks forever
* Instead of creating more and more blocking goroutines, return an error
is more friendly to the server and to the end user.

There are more details in code comments: eg: the "Flush" problem, the
strange "code.index" hanging problem, the "immediate" queue problem.

Almost ready for review.

TODO:

* [x] add some necessary comments during review
* [x] add some more tests if necessary
* [x] update documents and config options
* [x] test max worker / active worker
* [x] re-run the CI tasks to see whether any test is flaky
* [x] improve the `handleOldLengthConfiguration` to provide more
friendly messages
* [x] fine tune default config values (eg: length?)

## Code coverage:

![image](https://user-images.githubusercontent.com/2114189/236620635-55576955-f95d-4810-b12f-879026a3afdf.png)
2023-05-08 19:49:59 +08:00
..
actions show workflow config error on file view also (#24267) 2023-04-22 22:16:54 -04:00
activitypub Add Chef package registry (#22554) 2023-02-06 09:49:21 +08:00
analyze Implement FSFE REUSE for golang files (#21840) 2022-11-27 18:20:29 +00:00
assetfs Use a general approach to access custom/static/builtin assets (#24022) 2023-04-12 18:16:45 +08:00
auth Use a general approach to access custom/static/builtin assets (#24022) 2023-04-12 18:16:45 +08:00
avatar Allow webp images as avatars (#24248) 2023-04-21 13:15:49 -04:00
base Use a general Eval function for expressions in templates. (#23927) 2023-04-07 21:25:49 +08:00
cache Update redis library to support redis v7 (#24114) 2023-04-13 18:41:04 -04:00
charset Update go tool dependencies, restructure lint targets (#24239) 2023-04-22 14:53:00 -04:00
container Implement FSFE REUSE for golang files (#21840) 2022-11-27 18:20:29 +00:00
context Split "modules/context.go" to separate files (#24569) 2023-05-08 17:36:54 +08:00
csv Refactor locale number (#24134) 2023-04-17 11:37:23 +08:00
doctor Merge setting.InitXXX into one function with options (#24389) 2023-05-04 11:55:35 +08:00
emoji Fix unstable emoji sort (#22346) 2023-01-05 13:58:51 +02:00
eventsource Move convert package to services (#22264) 2022-12-29 10:57:15 +08:00
generate Implement FSFE REUSE for golang files (#21840) 2022-11-27 18:20:29 +00:00
git Pass 'not' to commit count (#24473) 2023-05-08 07:10:53 +00:00
gitgraph Add context cache as a request level cache (#22294) 2023-02-15 21:37:34 +08:00
graceful Remove most path-based golangci exclusions (#24214) 2023-04-19 22:08:01 -04:00
hcaptcha Consume hcaptcha and pwn deps (#22610) 2023-01-29 09:49:51 -06:00
highlight test_env: hardcode major go version in use (#23464) 2023-03-14 16:09:01 -04:00
hostmatcher Implement FSFE REUSE for golang files (#21840) 2022-11-27 18:20:29 +00:00
html Implement FSFE REUSE for golang files (#21840) 2022-11-27 18:20:29 +00:00
httpcache Set X-Gitea-Debug header once (#23361) 2023-03-08 15:40:04 -05:00
httplib Refactor internal API for git commands, use meaningful messages instead of "Internal Server Error" (#23687) 2023-03-29 14:32:26 +08:00
indexer Rewrite queue (#24505) 2023-05-08 19:49:59 +08:00
issue/template Allow issue templates to not render title (#22589) 2023-01-26 22:45:49 -06:00
json Update gitea-vet to check FSFE REUSE (#22004) 2022-12-02 22:14:57 +08:00
label Make label templates have consistent behavior and priority (#23749) 2023-04-10 16:44:02 +08:00
lfs Use more specific test methods (#24265) 2023-04-22 17:56:27 -04:00
log Enable forbidigo linter (#24278) 2023-04-24 05:50:58 -04:00
markup Merge setting.InitXXX into one function with options (#24389) 2023-05-04 11:55:35 +08:00
mcaptcha Implement FSFE REUSE for golang files (#21840) 2022-11-27 18:20:29 +00:00
metrics include build info in Prometheus metrics (#22819) 2023-02-08 19:54:01 +02:00
migration Scoped labels (#22585) 2023-02-18 21:17:39 +02:00
mirror Rewrite queue (#24505) 2023-05-08 19:49:59 +08:00
nosql Update redis library to support redis v7 (#24114) 2023-04-13 18:41:04 -04:00
notification Rewrite queue (#24505) 2023-05-08 19:49:59 +08:00
options Use a general approach to access custom/static/builtin assets (#24022) 2023-04-12 18:16:45 +08:00
packages Add RPM registry (#23380) 2023-05-05 20:33:37 +00:00
paginator Use more specific test methods (#24265) 2023-04-22 17:56:27 -04:00
pprof Implement FSFE REUSE for golang files (#21840) 2022-11-27 18:20:29 +00:00
private Fix incorrect internal response type (#24173) 2023-04-17 23:10:40 -04:00
process Improve trace logging for pulls and processes (#22633) 2023-02-03 18:11:48 -05:00
proxy Use proxy for pull mirror (#22771) 2023-02-11 08:39:50 +08:00
proxyprotocol Implement FSFE REUSE for golang files (#21840) 2022-11-27 18:20:29 +00:00
public Use a general approach to access custom/static/builtin assets (#24022) 2023-04-12 18:16:45 +08:00
queue Rewrite queue (#24505) 2023-05-08 19:49:59 +08:00
recaptcha Implement FSFE REUSE for golang files (#21840) 2022-11-27 18:20:29 +00:00
references Use correct captured group range when parsing cross-reference (#22672) 2023-01-31 10:08:05 +01:00
regexplru Implement FSFE REUSE for golang files (#21840) 2022-11-27 18:20:29 +00:00
repository Replace placeholders in licenses (#24354) 2023-05-05 13:46:17 +00:00
secret Improve decryption failure message (#24573) 2023-05-07 19:29:43 +08:00
session Update redis library to support redis v7 (#24114) 2023-04-13 18:41:04 -04:00
setting Rewrite queue (#24505) 2023-05-08 19:49:59 +08:00
sitemap Fix sitemap (#22272) 2022-12-30 23:31:00 +08:00
ssh Implement FSFE REUSE for golang files (#21840) 2022-11-27 18:20:29 +00:00
storage Use more specific test methods (#24265) 2023-04-22 17:56:27 -04:00
structs Add API for gitignore templates (#22783) 2023-04-27 11:51:20 +08:00
svg Use a general approach to access custom/static/builtin assets (#24022) 2023-04-12 18:16:45 +08:00
sync Implement FSFE REUSE for golang files (#21840) 2022-11-27 18:20:29 +00:00
system Implement FSFE REUSE for golang files (#21840) 2022-11-27 18:20:29 +00:00
templates Simplify template helper functions (#24570) 2023-05-07 09:49:46 +00:00
test Rewrite queue (#24505) 2023-05-08 19:49:59 +08:00
testlogger Rewrite queue (#24505) 2023-05-08 19:49:59 +08:00
timeutil Fix incorrect webhook time and use relative-time to display it (#24477) 2023-05-03 19:53:43 -04:00
translation Make repo size style matches others (commits/branches/tags) (#24408) 2023-04-28 17:23:19 -04:00
turnstile Add new captcha: cloudflare turnstile (#22369) 2023-02-05 15:29:03 +08:00
typesniffer Do not recognize text files as audio (#23355) 2023-03-07 22:40:41 -05:00
updatechecker Implement FSFE REUSE for golang files (#21840) 2022-11-27 18:20:29 +00:00
upload Implement FSFE REUSE for golang files (#21840) 2022-11-27 18:20:29 +00:00
uri Implement FSFE REUSE for golang files (#21840) 2022-11-27 18:20:29 +00:00
user Implement FSFE REUSE for golang files (#21840) 2022-11-27 18:20:29 +00:00
util Rewrite queue (#24505) 2023-05-08 19:49:59 +08:00
validation Map OIDC groups to Orgs/Teams (#21441) 2023-02-08 14:44:42 +08:00
web Improve template system and panic recovery (#24461) 2023-05-04 14:36:34 +08:00
webhook Restructure webhook module (#22256) 2023-01-01 23:23:15 +08:00