forgejo/modules/test/context_tests.go
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

133 lines
3.7 KiB
Go

// Copyright 2017 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package test
import (
scontext "context"
"io"
"net/http"
"net/http/httptest"
"net/url"
"testing"
access_model "code.gitea.io/gitea/models/perm/access"
repo_model "code.gitea.io/gitea/models/repo"
"code.gitea.io/gitea/models/unittest"
user_model "code.gitea.io/gitea/models/user"
"code.gitea.io/gitea/modules/context"
"code.gitea.io/gitea/modules/git"
"code.gitea.io/gitea/modules/templates"
"code.gitea.io/gitea/modules/translation"
"code.gitea.io/gitea/modules/web/middleware"
chi "github.com/go-chi/chi/v5"
"github.com/stretchr/testify/assert"
)
// MockContext mock context for unit tests
// TODO: move this function to other packages, because it depends on "models" package
func MockContext(t *testing.T, path string) *context.Context {
resp := &mockResponseWriter{}
ctx := context.Context{
Render: &mockRender{},
Data: make(middleware.ContextData),
Flash: &middleware.Flash{
Values: make(url.Values),
},
Resp: context.NewResponse(resp),
Locale: &translation.MockLocale{},
}
defer ctx.Close()
requestURL, err := url.Parse(path)
assert.NoError(t, err)
req := &http.Request{
URL: requestURL,
Form: url.Values{},
}
chiCtx := chi.NewRouteContext()
req = req.WithContext(scontext.WithValue(req.Context(), chi.RouteCtxKey, chiCtx))
ctx.Req = context.WithContext(req, &ctx)
return &ctx
}
// LoadRepo load a repo into a test context.
func LoadRepo(t *testing.T, ctx *context.Context, repoID int64) {
ctx.Repo = &context.Repository{}
ctx.Repo.Repository = unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: repoID})
var err error
ctx.Repo.Owner, err = user_model.GetUserByID(ctx, ctx.Repo.Repository.OwnerID)
assert.NoError(t, err)
ctx.Repo.RepoLink = ctx.Repo.Repository.Link()
ctx.Repo.Permission, err = access_model.GetUserRepoPermission(ctx, ctx.Repo.Repository, ctx.Doer)
assert.NoError(t, err)
}
// LoadRepoCommit loads a repo's commit into a test context.
func LoadRepoCommit(t *testing.T, ctx *context.Context) {
gitRepo, err := git.OpenRepository(ctx, ctx.Repo.Repository.RepoPath())
assert.NoError(t, err)
defer gitRepo.Close()
branch, err := gitRepo.GetHEADBranch()
assert.NoError(t, err)
assert.NotNil(t, branch)
if branch != nil {
ctx.Repo.Commit, err = gitRepo.GetBranchCommit(branch.Name)
assert.NoError(t, err)
}
}
// LoadUser load a user into a test context.
func LoadUser(t *testing.T, ctx *context.Context, userID int64) {
ctx.Doer = unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: userID})
}
// LoadGitRepo load a git repo into a test context. Requires that ctx.Repo has
// already been populated.
func LoadGitRepo(t *testing.T, ctx *context.Context) {
assert.NoError(t, ctx.Repo.Repository.LoadOwner(ctx))
var err error
ctx.Repo.GitRepo, err = git.OpenRepository(ctx, ctx.Repo.Repository.RepoPath())
assert.NoError(t, err)
}
type mockResponseWriter struct {
httptest.ResponseRecorder
size int
}
func (rw *mockResponseWriter) Write(b []byte) (int, error) {
rw.size += len(b)
return rw.ResponseRecorder.Write(b)
}
func (rw *mockResponseWriter) Status() int {
return rw.ResponseRecorder.Code
}
func (rw *mockResponseWriter) Written() bool {
return rw.ResponseRecorder.Code > 0
}
func (rw *mockResponseWriter) Size() int {
return rw.size
}
func (rw *mockResponseWriter) Push(target string, opts *http.PushOptions) error {
return nil
}
type mockRender struct{}
func (tr *mockRender) TemplateLookup(tmpl string) (templates.TemplateExecutor, error) {
return nil, nil
}
func (tr *mockRender) HTML(w io.Writer, status int, _ string, _ interface{}) error {
if resp, ok := w.(http.ResponseWriter); ok {
resp.WriteHeader(status)
}
return nil
}