Fix#31327
This is a quick patch to fix the bug.
Some parameters are using 0, some are using -1. I think it needs a
refactor to keep consistent. But that will be another PR.
(cherry picked from commit e4abaff7ffbbc5acd3aa668a9c458fbdf76f9573)
This updates the mapping definition of the elasticsearch issue indexer backend to use `long` instead of `integer`s wherever the go type is a `int64`. Without it larger instances could run into an issue.
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/3982
Reviewed-by: Earl Warren <earl-warren@noreply.codeberg.org>
Co-authored-by: Mai-Lapyst <mai-lapyst@noreply.codeberg.org>
Co-committed-by: Mai-Lapyst <mai-lapyst@noreply.codeberg.org>
This PR split the `Board` into two parts. One is the struct has been
renamed to `Column` and the second we have a `Template Type`.
But to make it easier to review, this PR will not change the database
schemas, they are just renames. The database schema changes could be in
future PRs.
---------
Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: yp05327 <576951401@qq.com>
(cherry picked from commit 98751108b11dc748cc99230ca0fc1acfdf2c8929)
Conflicts:
docs/content/administration/config-cheat-sheet.en-us.md
docs/content/index.en-us.md
docs/content/installation/comparison.en-us.md
docs/content/usage/permissions.en-us.md
non existent files
options/locale/locale_en-US.ini
routers/web/web.go
templates/repo/header.tmpl
templates/repo/settings/options.tmpl
trivial context conflicts
More about codespell: https://github.com/codespell-project/codespell .
I personally introduced it to dozens if not hundreds of projects already and so far only positive feedback.
```
❯ grep lint-spell Makefile
@echo " - lint-spell lint spelling"
@echo " - lint-spell-fix lint spelling and fix issues"
lint: lint-frontend lint-backend lint-spell
lint-fix: lint-frontend-fix lint-backend-fix lint-spell-fix
.PHONY: lint-spell
lint-spell: lint-codespell
.PHONY: lint-spell-fix
lint-spell-fix: lint-codespell-fix
❯ git grep lint- -- .forgejo/
.forgejo/workflows/testing.yml: - run: make --always-make -j$(nproc) lint-backend checks-backend # ensure the "go-licenses" make target runs
.forgejo/workflows/testing.yml: - run: make lint-frontend
```
so how would you like me to invoke `lint-codespell` on CI? (without that would be IMHO very suboptimal and let typos sneak in)
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/3270
Reviewed-by: Earl Warren <earl-warren@noreply.codeberg.org>
Co-authored-by: Yaroslav Halchenko <debian@onerussian.com>
Co-committed-by: Yaroslav Halchenko <debian@onerussian.com>
Should resolve#30642.
Before this commit, we were treating an empty `?sort=` query parameter
as the correct sorting type (which is to sort issues in descending order
by their created UNIX time). But when we perform `sort=latest`, we did
not include this as a type so we would sort by the most recently updated
when reaching the `default` switch statement block.
This commit fixes this by considering the empty string, "latest", and
just any other string that is not mentioned in the switch statement as
sorting by newest.
(cherry picked from commit 9b7af4340c36d3e1888788499d16f83feeb1601b)
Noteable additions:
- `redefines-builtin-id` forbid variable names that shadow go builtins
- `empty-lines` remove unnecessary empty lines that `gofumpt` does not
remove for some reason
- `superfluous-else` eliminate more superfluous `else` branches
Rules are also sorted alphabetically and I cleaned up various parts of
`.golangci.yml`.
(cherry picked from commit 74f0c84fa4245a20ce6fb87dac1faf2aeeded2a2)
Conflicts:
.golangci.yml
apply the linter recommendations to Forgejo code as well
This PR uses `db.ListOptions` instead of `Paginor` to make the code
simpler.
And it also fixed the performance problem when viewing /pulls or
/issues. Before the counting in fact will also do the search.
---------
Co-authored-by: Jason Song <i@wolfogre.com>
Co-authored-by: silverwind <me@silverwind.io>
(cherry picked from commit 3f26fe2fa2c7141c9e622297e50a70f3e0003e4d)
also bleve did match on fuzzy search and the other way around. this also fix that bug.
(cherry picked from commit b9c57fb78e8e0d80d786d8e1da433b6c7ebf2f1c)
Conflicts:
tests/integration/repo_search_test.go
simple conflict resolution in the tests
(cherry picked from commit f8ab9dafb7a173a35e9308f8f784735b0f822439)
Conflicts:
routers/web/repo/fork.go
trivial context conflict, the file does not exist in Forgejo
meilisearch does not have an search option to contorl fuzzynes per query
right now:
- https://github.com/meilisearch/meilisearch/issues/1192
- https://github.com/orgs/meilisearch/discussions/377
- https://github.com/meilisearch/meilisearch/discussions/1096
so we have to create a workaround by post-filter the search result in
gitea until this is addressed.
For future works I added an option in backend only atm, to enable
fuzzynes for issue indexer too.
And also refactored the code so the fuzzy option is equal in logic to
code indexer
---
*Sponsored by Kithara Software GmbH*
Conflicts:
routers/web/repo/search.go
trivial context confict s/isMatch/isFuzzy/
just some refactoring bits towards replacing **util.OptionalBool** with
**optional.Option[bool]**
---------
Co-authored-by: KN4CK3R <admin@oldschoolhack.me>
(cherry picked from commit f6656181e4a07d6c415927220efa2077d509f7c6)
Conflicts:
models/repo/repo_list_test.go
trivial shared fixture count conflicts
Fix#14459
The following users can add/remove review requests of a PR
- the poster of the PR
- the owner or collaborators of the repository
- members with read permission on the pull requests unit
(cherry picked from commit c42083a33950be6ee9f822c6d0de3c3a79d1f51b)
Conflicts:
models/repo/repo_list_test.go
tests/integration/api_nodeinfo_test.go
tests/integration/api_repo_test.go
shared fixture counts
(cherry picked from commit a1381d9146fba42cb97d72d38525fa3e721bfb03)
(cherry picked from commit 74714e0246)
(cherry picked from commit 7749dbfe66)
(cherry picked from commit 4379249711)
(cherry picked from commit a69f55bebf)
(cherry picked from commit 24dd5fbfdb)
(cherry picked from commit dda856d6b8)
(cherry picked from commit bc14f4fa97)
(cherry picked from commit 78fef4f137)
(cherry picked from commit 69e013cc51)
(cherry picked from commit f173c6a273)
(cherry picked from commit 92f9d02547)
(cherry picked from commit c99d51e665)
(cherry picked from commit aa0650fd2b)
(cherry picked from commit 0a8ef91302)
(cherry picked from commit 7b54fe01c2)
(cherry picked from commit 0e154f366f)
(cherry picked from commit 02d88ee16d)
(cherry picked from commit 411924e017)
(cherry picked from commit f4e9ca6db5)
(cherry picked from commit cd80126a23)
(cherry picked from commit da626702f9)
(cherry picked from commit 4b81d0bd04)
(cherry picked from commit 53ac260669)
(cherry picked from commit 984081f08d)
(cherry picked from commit 1c39bae3ec)
It will fix#28268 .
<img width="1313" alt="image"
src="https://github.com/go-gitea/gitea/assets/9418365/cb1e07d5-7a12-4691-a054-8278ba255bfc">
<img width="1318" alt="image"
src="https://github.com/go-gitea/gitea/assets/9418365/4fd60820-97f1-4c2c-a233-d3671a5039e9">
## ⚠️ BREAKING ⚠️
But need to give up some features:
<img width="1312" alt="image"
src="https://github.com/go-gitea/gitea/assets/9418365/281c0d51-0e7d-473f-bbed-216e2f645610">
However, such abandonment may fix#28055 .
## Backgroud
When the user switches the dashboard context to an org, it means they
want to search issues in the repos that belong to the org. However, when
they switch to themselves, it means all repos they can access because
they may have created an issue in a public repo that they don't own.
<img width="286" alt="image"
src="https://github.com/go-gitea/gitea/assets/9418365/182dcd5b-1c20-4725-93af-96e8dfae5b97">
It's a confusing design. Think about this: What does "In your
repositories" mean when the user switches to an org? Repos belong to the
user or the org?
Whatever, it has been broken by #26012 and its following PRs. After the
PR, it searches for issues in repos that the dashboard context user owns
or has been explicitly granted access to, so it causes #28268.
## How to fix it
It's not really difficult to fix it. Just extend the repo scope to
search issues when the dashboard context user is the doer. Since the
user may create issues or be mentioned in any public repo, we can just
set `AllPublic` to true, which is already supported by indexers. The DB
condition will also support it in this PR.
But the real difficulty is how to count the search results grouped by
repos. It's something like "search issues with this keyword and those
filters, and return the total number and the top results. **Then, group
all of them by repo and return the counts of each group.**"
<img width="314" alt="image"
src="https://github.com/go-gitea/gitea/assets/9418365/5206eb20-f8f5-49b9-b45a-1be2fcf679f4">
Before #26012, it was being done in the DB, but it caused the results to
be incomplete (see the description of #26012).
And to keep this, #26012 implement it in an inefficient way, just count
the issues by repo one by one, so it cannot work when `AllPublic` is
true because it's almost impossible to do this for all public repos.
1bfcdeef4c/modules/indexer/issues/indexer.go (L318-L338)
## Give up unnecessary features
We may can resovle `TODO: use "group by" of the indexer engines to
implement it`, I'm sure it can be done with Elasticsearch, but IIRC,
Bleve and Meilisearch don't support "group by".
And the real question is, does it worth it? Why should we need to know
the counts grouped by repos?
Let me show you my search dashboard on gitea.com.
<img width="1304" alt="image"
src="https://github.com/go-gitea/gitea/assets/9418365/2bca2d46-6c71-4de1-94cb-0c9af27c62ff">
I never think the long repo list helps anything.
And if we agree to abandon it, things will be much easier. That is this
PR.
## TODO
I know it's important to filter by repos when searching issues. However,
it shouldn't be the way we have it now. It could be implemented like
this.
<img width="1316" alt="image"
src="https://github.com/go-gitea/gitea/assets/9418365/99ee5f21-cbb5-4dfe-914d-cb796cb79fbe">
The indexers support it well now, but it requires some frontend work,
which I'm not good at. So, I think someone could help do that in another
PR and merge this one to fix the bug first.
Or please block this PR and help to complete it.
Finally, "Switch dashboard context" is also a design that needs
improvement. In my opinion, it can be accomplished by adding filtering
conditions instead of "switching".
Previously only the first term had to be matched. That default
Meilisearch behavior makes sense for e.g. some kind of autocomplete to
find and select a single result. But for filtering issues it means you
can't narrow down results by adding more terms.
This is also more consistent with other indexers and GitHub.
---
Reference:
https://www.meilisearch.com/docs/reference/api/search#matching-strategy
See https://github.com/go-gitea/gitea/pull/27718#issuecomment-1773743014
. Add a test to ensure its behavior.
Why this test uses `ProjectBoardID=0`? Because in `SearchOptions`,
`ProjectBoardID=0` means what it is. But in `IssueOptions`,
`ProjectBoardID=0` means there is no condition, and
`ProjectBoardID=db.NoConditionID` means the board ID = 0.
It's really confusing. Probably it's better to separate the db search
engine and the other issue search code. It's really two different
systems. As far as I can see, `IssueOptions` is not necessary for most
of the code, which has very simple issue search conditions.
1. remove unused function `MoveIssueAcrossProjectBoards`
2. extract the project board condition into a function
3. use db.NoCondition instead of -1. (BTW, the usage of db.NoCondition
is too confusing. Is there any way to avoid that?)
4. remove the unnecessary comment since the ctx refactor is completed.
5. Change `b.ID != 0` to `b.ID > 0`. It's more intuitive but I think
they're the same since board ID can't be negative.
This PR removed `unittest.MainTest` the second parameter
`TestOptions.GiteaRoot`. Now it detects the root directory by current
working directory.
---------
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
As described in the title.
Some points:
1. Why need those tests?
Because `buildIssueOverview` is not well tested, there are several
continuous bugs in the issue overview webpage.
2. Why in indexer_test.go?
It's hard to put those tests in `./modules/indexer/issue/db/db_test.go`
because those tests need 'real' data in db mocked by fixtures instead of
random data in `./modules/indexer/issue/internal/tests`. When using
'real' data(`unittest.PrepareTestDatabase`), `InitIssueIndexer` and the
package `init()` function of `indexer` are required to init indexer.
3. Why only db?
The other three indexer engines are well tested by random data and it's
okay to also test them with 'real' data in db mocked by fixtures. Any
follow-up PR is welcome.
4. Those tests are really basic, any more complicated tests are welcome.
5. I think it's also necessary to add tests in `TestAPISearchIssues`
in`api_test_issue.go` and `TestIssues` in `home_test.go`
Since the issue indexer has been refactored, the issue overview webpage
is built by the `buildIssueOverview` function and underlying
`indexer.Search` function and `GetIssueStats` instead of
`GetUserIssueStats`. So the function is no longer used.
I moved the relevant tests to `indexer_test.go` and since the search
option changed from `IssueOptions` to `SearchOptions`, most of the tests
are useless now.
We need more tests about the db indexer because those tests are highly
connected with the issue overview webpage and now this page has several
bugs.
Any advice about those test cases is appreciated.
---------
Co-authored-by: CaiCandong <50507092+CaiCandong@users.noreply.github.com>
This PR has multiple parts, and I didn't split them because
it's not easy to test them separately since they are all about the
dashboard page for issues.
1. Support counting issues via indexer to fix#26361
2. Fix repo selection so it also fixes#26653
3. Keep keywords in filter links.
The first two are regressions of #26012.
After:
https://github.com/go-gitea/gitea/assets/9418365/71dfea7e-d9e2-42b6-851a-cc081435c946
Thanks to @CaiCandong for helping with some tests.
Fix#24662.
Replace #24822 and #25708 (although it has been merged)
## Background
In the past, Gitea supported issue searching with a keyword and
conditions in a less efficient way. It worked by searching for issues
with the keyword and obtaining limited IDs (as it is heavy to get all)
on the indexer (bleve/elasticsearch/meilisearch), and then querying with
conditions on the database to find a subset of the found IDs. This is
why the results could be incomplete.
To solve this issue, we need to store all fields that could be used as
conditions in the indexer and support both keyword and additional
conditions when searching with the indexer.
## Major changes
- Redefine `IndexerData` to include all fields that could be used as
filter conditions.
- Refactor `Search(ctx context.Context, kw string, repoIDs []int64,
limit, start int, state string)` to `Search(ctx context.Context, options
*SearchOptions)`, so it supports more conditions now.
- Change the data type stored in `issueIndexerQueue`. Use
`IndexerMetadata` instead of `IndexerData` in case the data has been
updated while it is in the queue. This also reduces the storage size of
the queue.
- Enhance searching with Bleve/Elasticsearch/Meilisearch, make them
fully support `SearchOptions`. Also, update the data versions.
- Keep most logic of database indexer, but remove
`issues.SearchIssueIDsByKeyword` in `models` to avoid confusion where is
the entry point to search issues.
- Start a Meilisearch instance to test it in unit tests.
- Add unit tests with almost full coverage to test
Bleve/Elasticsearch/Meilisearch indexer.
---------
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
A couple of notes:
* Future changes should refactor arguments into a struct
* This filtering only is supported by meilisearch right now
* Issue index number is bumped which will cause a re-index
Fix regression of #5363 (so long ago).
The old code definded a document mapping for `issueIndexerDocType`, and
assigned it to `BleveIndexerData` as its type. (`BleveIndexerData` has
been renamed to `IndexerData` in #25174, but nothing more.) But the old
code never used `BleveIndexerData`, it wrote the index with an anonymous
struct type. Nonetheless, bleve would use the default auto-mapping for
struct it didn't know, so the indexer still worked. This means the
custom document mapping was always dead code.
The custom document mapping is not useless, it can reduce index storage,
this PR brings it back and disable default mapping to prevent it from
happening again. Since `IndexerData`(`BleveIndexerData`) has JSON tags,
and bleve uses them first, so we should use `repo_id` as the field name
instead of `RepoID`.
I did a test to compare the storage size before and after this, with
about 3k real comments that were migrated from some public repos.
Before:
```text
[ 160] .
├── [ 42] index_meta.json
├── [ 13] rupture_meta.json
└── [ 128] store
├── [6.9M] 00000000005d.zap
└── [256K] root.bolt
```
After:
```text
[ 160] .
├── [ 42] index_meta.json
├── [ 13] rupture_meta.json
└── [ 128] store
├── [3.5M] 000000000065.zap
└── [256K] root.bolt
```
It saves about half the storage space.
---------
Co-authored-by: Giteabot <teabot@gitea.io>
Refactor `modules/indexer` to make it more maintainable. And it can be
easier to support more features. I'm trying to solve some of issue
searching, this is a precursor to making functional changes.
Current supported engines and the index versions:
| engines | issues | code |
| - | - | - |
| db | Just a wrapper for database queries, doesn't need version | - |
| bleve | The version of index is **2** | The version of index is **6**
|
| elasticsearch | The old index has no version, will be treated as
version **0** in this PR | The version of index is **1** |
| meilisearch | The old index has no version, will be treated as version
**0** in this PR | - |
## Changes
### Split
Splited it into mutiple packages
```text
indexer
├── internal
│ ├── bleve
│ ├── db
│ ├── elasticsearch
│ └── meilisearch
├── code
│ ├── bleve
│ ├── elasticsearch
│ └── internal
└── issues
├── bleve
├── db
├── elasticsearch
├── internal
└── meilisearch
```
- `indexer/interanal`: Internal shared package for indexer.
- `indexer/interanal/[engine]`: Internal shared package for each engine
(bleve/db/elasticsearch/meilisearch).
- `indexer/code`: Implementations for code indexer.
- `indexer/code/internal`: Internal shared package for code indexer.
- `indexer/code/[engine]`: Implementation via each engine for code
indexer.
- `indexer/issues`: Implementations for issues indexer.
### Deduplication
- Combine `Init/Ping/Close` for code indexer and issues indexer.
- ~Combine `issues.indexerHolder` and `code.wrappedIndexer` to
`internal.IndexHolder`.~ Remove it, use dummy indexer instead when the
indexer is not ready.
- Duplicate two copies of creating ES clients.
- Duplicate two copies of `indexerID()`.
### Enhancement
- [x] Support index version for elasticsearch issues indexer, the old
index without version will be treated as version 0.
- [x] Fix spell of `elastic_search/ElasticSearch`, it should be
`Elasticsearch`.
- [x] Improve versioning of ES index. We don't need `Aliases`:
- Gitea does't need aliases for "Zero Downtime" because it never delete
old indexes.
- The old code of issues indexer uses the orignal name to create issue
index, so it's tricky to convert it to an alias.
- [x] Support index version for meilisearch issues indexer, the old
index without version will be treated as version 0.
- [x] Do "ping" only when `Ping` has been called, don't ping
periodically and cache the status.
- [x] Support the context parameter whenever possible.
- [x] Fix outdated example config.
- [x] Give up the requeue logic of issues indexer: When indexing fails,
call Ping to check if it was caused by the engine being unavailable, and
only requeue the task if the engine is unavailable.
- It is fragile and tricky, could cause data losing (It did happen when
I was doing some tests for this PR). And it works for ES only.
- Just always requeue the failed task, if it caused by bad data, it's a
bug of Gitea which should be fixed.
---------
Co-authored-by: Giteabot <teabot@gitea.io>
Before there was a "graceful function": RunWithShutdownFns, it's mainly
for some modules which doesn't support context.
The old queue system doesn't work well with context, so the old queues
need it.
After the queue refactoring, the new queue works with context well, so,
use Golang context as much as possible, the `RunWithShutdownFns` could
be removed (replaced by RunWithCancel for context cancel mechanism), the
related code could be simplified.
This PR also fixes some legacy queue-init problems, eg:
* typo : archiver: "unable to create codes indexer queue" => "unable to
create repo-archive queue"
* no nil check for failed queues, which causes unfriendly panic
After this PR, many goroutines could have better display name:
## ⚠️ Breaking
The `log.<mode>.<logger>` style config has been dropped. If you used it,
please check the new config manual & app.example.ini to make your
instance output logs as expected.
Although many legacy options still work, it's encouraged to upgrade to
the new options.
The SMTP logger is deleted because SMTP is not suitable to collect logs.
If you have manually configured Gitea log options, please confirm the
logger system works as expected after upgrading.
## Description
Close#12082 and maybe more log-related issues, resolve some related
FIXMEs in old code (which seems unfixable before)
Just like rewriting queue #24505 : make code maintainable, clear legacy
bugs, and add the ability to support more writers (eg: JSON, structured
log)
There is a new document (with examples): `logging-config.en-us.md`
This PR is safer than the queue rewriting, because it's just for
logging, it won't break other logic.
## The old problems
The logging system is quite old and difficult to maintain:
* Unclear concepts: Logger, NamedLogger, MultiChannelledLogger,
SubLogger, EventLogger, WriterLogger etc
* Some code is diffuclt to konw whether it is right:
`log.DelNamedLogger("console")` vs `log.DelNamedLogger(log.DEFAULT)` vs
`log.DelLogger("console")`
* The old system heavily depends on ini config system, it's difficult to
create new logger for different purpose, and it's very fragile.
* The "color" trick is difficult to use and read, many colors are
unnecessary, and in the future structured log could help
* It's difficult to add other log formats, eg: JSON format
* The log outputer doesn't have full control of its goroutine, it's
difficult to make outputer have advanced behaviors
* The logs could be lost in some cases: eg: no Fatal error when using
CLI.
* Config options are passed by JSON, which is quite fragile.
* INI package makes the KEY in `[log]` section visible in `[log.sub1]`
and `[log.sub1.subA]`, this behavior is quite fragile and would cause
more unclear problems, and there is no strong requirement to support
`log.<mode>.<logger>` syntax.
## The new design
See `logger.go` for documents.
## Screenshot
<details>
</details>
## TODO
* [x] add some new tests
* [x] fix some tests
* [x] test some sub-commands (manually ....)
---------
Co-authored-by: Jason Song <i@wolfogre.com>
Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: Giteabot <teabot@gitea.io>
This PR
- [x] Move some functions from `issues.go` to `issue_stats.go` and
`issue_label.go`
- [x] Remove duplicated issue options `UserIssueStatsOption` to keep
only one `IssuesOptions`
# ⚠️ 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:
