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gitea/routers/api/v1/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
..
blob.go Implement FSFE REUSE for golang files (#21840) 2 years ago
branch.go Add context cache as a request level cache (#22294) 2 years ago
collaborators.go Add context cache as a request level cache (#22294) 2 years ago
commits.go Add context cache as a request level cache (#22294) 2 years ago
file.go Use context parameter in models/git (#22367) 2 years ago
fork.go Map OIDC groups to Orgs/Teams (#21441) 2 years ago
git_hook.go Move `convert` package to services (#22264) 2 years ago
git_ref.go Implement FSFE REUSE for golang files (#21840) 2 years ago
hook.go Add context cache as a request level cache (#22294) 2 years ago
hook_test.go Implement FSFE REUSE for golang files (#21840) 2 years ago
issue.go Webhooks: for issue close/reopen action, add commit ID that caused it (#22583) 2 years ago
issue_attachment.go Move `convert` package to services (#22264) 2 years ago
issue_comment.go Add context cache as a request level cache (#22294) 2 years ago
issue_comment_attachment.go Move `convert` package to services (#22264) 2 years ago
issue_label.go Move `convert` package to services (#22264) 2 years ago
issue_reaction.go Add context cache as a request level cache (#22294) 2 years ago
issue_stopwatch.go Move `convert` package to services (#22264) 2 years ago
issue_subscription.go Add context cache as a request level cache (#22294) 2 years ago
issue_tracked_time.go Move `convert` package to services (#22264) 2 years ago
key.go Move `convert` package to services (#22264) 2 years ago
label.go Move `convert` package to services (#22264) 2 years ago
language.go Implement FSFE REUSE for golang files (#21840) 2 years ago
main_test.go Implement FSFE REUSE for golang files (#21840) 2 years ago
migrate.go Move `convert` package to services (#22264) 2 years ago
milestone.go Move `convert` package to services (#22264) 2 years ago
mirror.go Add `sync_on_commit` option for push mirrors api (#22271) 2 years ago
notes.go Add context cache as a request level cache (#22294) 2 years ago
patch.go Implement FSFE REUSE for golang files (#21840) 2 years ago
pull.go Add context cache as a request level cache (#22294) 2 years ago
pull_review.go Add context cache as a request level cache (#22294) 2 years ago
release.go Add context cache as a request level cache (#22294) 2 years ago
release_attachment.go Add context cache as a request level cache (#22294) 2 years ago
release_tags.go Add context cache as a request level cache (#22294) 2 years ago
repo.go Pull Requests: setting to allow edits by maintainers by default, tweak UI (#22862) 2 years ago
repo_test.go Implement FSFE REUSE for golang files (#21840) 2 years ago
star.go Add context cache as a request level cache (#22294) 2 years ago
status.go Use context parameter in models/git (#22367) 2 years ago
subscriber.go Add context cache as a request level cache (#22294) 2 years ago
tag.go Add context cache as a request level cache (#22294) 2 years ago
teams.go Add context cache as a request level cache (#22294) 2 years ago
topic.go Move `convert` package to services (#22264) 2 years ago
transfer.go Add context cache as a request level cache (#22294) 2 years ago
tree.go Implement FSFE REUSE for golang files (#21840) 2 years ago
wiki.go Move `convert` package to services (#22264) 2 years ago