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gitea/routers/web/repo
Lunny Xiao bd820aa9c5
Add context cache as a request level cache (#22294)
To avoid duplicated load of the same data in an HTTP request, we can set
a context cache to do that. i.e. Some pages may load a user from a
database with the same id in different areas on the same page. But the
code is hidden in two different deep logic. How should we share the
user? As a result of this PR, now if both entry functions accept
`context.Context` as the first parameter and we just need to refactor
`GetUserByID` to reuse the user from the context cache. Then it will not
be loaded twice on an HTTP request.

But of course, sometimes we would like to reload an object from the
database, that's why `RemoveContextData` is also exposed.

The core context cache is here. It defines a new context
```go
type cacheContext struct {
	ctx  context.Context
	data map[any]map[any]any
        lock sync.RWMutex
}

var cacheContextKey = struct{}{}

func WithCacheContext(ctx context.Context) context.Context {
	return context.WithValue(ctx, cacheContextKey, &cacheContext{
		ctx:  ctx,
		data: make(map[any]map[any]any),
	})
}
```

Then you can use the below 4 methods to read/write/del the data within
the same context.

```go
func GetContextData(ctx context.Context, tp, key any) any
func SetContextData(ctx context.Context, tp, key, value any)
func RemoveContextData(ctx context.Context, tp, key any)
func GetWithContextCache[T any](ctx context.Context, cacheGroupKey string, cacheTargetID any, f func() (T, error)) (T, error)
```

Then let's take a look at how `system.GetString` implement it.

```go
func GetSetting(ctx context.Context, key string) (string, error) {
	return cache.GetWithContextCache(ctx, contextCacheKey, key, func() (string, error) {
		return cache.GetString(genSettingCacheKey(key), func() (string, error) {
			res, err := GetSettingNoCache(ctx, key)
			if err != nil {
				return "", err
			}
			return res.SettingValue, nil
		})
	})
}
```

First, it will check if context data include the setting object with the
key. If not, it will query from the global cache which may be memory or
a Redis cache. If not, it will get the object from the database. In the
end, if the object gets from the global cache or database, it will be
set into the context cache.

An object stored in the context cache will only be destroyed after the
context disappeared.
2 years ago
..
actions Fix improper HTMLURL usages in Go code (#22839) 2 years ago
activity.go Implement FSFE REUSE for golang files (#21840) 2 years ago
attachment.go Add API management for issue/pull and comment attachments (#21783) 2 years ago
blame.go Add context cache as a request level cache (#22294) 2 years ago
branch.go Supports wildcard protected branch (#20825) 2 years ago
cherry_pick.go Rename almost all Ctx functions (#22071) 2 years ago
commit.go Add context cache as a request level cache (#22294) 2 years ago
compare.go Pull Requests: setting to allow edits by maintainers by default, tweak UI (#22862) 2 years ago
download.go Use context parameter in models/git (#22367) 2 years ago
editor.go Rename almost all Ctx functions (#22071) 2 years ago
editor_test.go Implement FSFE REUSE for golang files (#21840) 2 years ago
find.go Implement FSFE REUSE for golang files (#21840) 2 years ago
http.go Refactor legacy strange git operations (#22756) 2 years ago
http_test.go Implement FSFE REUSE for golang files (#21840) 2 years ago
issue.go Add context cache as a request level cache (#22294) 2 years ago
issue_content_history.go Move helpers to be prefixed with `gt-` (#22879) 2 years ago
issue_dependency.go Fix improper HTMLURL usages in Go code (#22839) 2 years ago
issue_label.go Map OIDC groups to Orgs/Teams (#21441) 2 years ago
issue_label_test.go Implement FSFE REUSE for golang files (#21840) 2 years ago
issue_lock.go Fix improper HTMLURL usages in Go code (#22839) 2 years ago
issue_stopwatch.go Fix improper HTMLURL usages in Go code (#22839) 2 years ago
issue_test.go Implement FSFE REUSE for golang files (#21840) 2 years ago
issue_timetrack.go Fix improper HTMLURL usages in Go code (#22839) 2 years ago
issue_watch.go Fix improper HTMLURL usages in Go code (#22839) 2 years ago
lfs.go Refactor git command package to improve security and maintainability (#22678) 2 years ago
main_test.go Implement FSFE REUSE for golang files (#21840) 2 years ago
middlewares.go Implement FSFE REUSE for golang files (#21840) 2 years ago
migrate.go Implement FSFE REUSE for golang files (#21840) 2 years ago
milestone.go Rename almost all Ctx functions (#22071) 2 years ago
packages.go Use dynamic package type list (#22263) 2 years ago
patch.go Rename almost all Ctx functions (#22071) 2 years ago
projects.go Preview images for Issue cards in Project Board view (#22112) 2 years ago
projects_test.go Implement FSFE REUSE for golang files (#21840) 2 years ago
pull.go Use link in UI which returned a relative url but not html_url which contains an absolute url (#21986) 2 years ago
pull_review.go Fix improper HTMLURL usages in Go code (#22839) 2 years ago
release.go Fix improper HTMLURL usages in Go code (#22839) 2 years ago
release_test.go Implement FSFE REUSE for golang files (#21840) 2 years ago
render.go Implement FSFE REUSE for golang files (#21840) 2 years ago
repo.go Fix improper HTMLURL usages in Go code (#22839) 2 years ago
runners.go Implement actions (#21937) 2 years ago
search.go Fix improper HTMLURL usages in Go code (#22839) 2 years ago
setting.go Pull Requests: setting to allow edits by maintainers by default, tweak UI (#22862) 2 years ago
setting_protected_branch.go Add main landmark to templates and adjust titles (#22670) 2 years ago
setting_secrets.go Add user secrets (#22191) 2 years ago
settings_test.go Implement FSFE REUSE for golang files (#21840) 2 years ago
tag.go Add main landmark to templates and adjust titles (#22670) 2 years ago
topic.go Implement FSFE REUSE for golang files (#21840) 2 years ago
treelist.go Implement FSFE REUSE for golang files (#21840) 2 years ago
view.go Add context cache as a request level cache (#22294) 2 years ago
view_test.go Implement FSFE REUSE for golang files (#21840) 2 years ago
webhook.go Add context cache as a request level cache (#22294) 2 years ago
wiki.go Use context parameter in models/git (#22367) 2 years ago
wiki_test.go Implement FSFE REUSE for golang files (#21840) 2 years ago