forgejo/services/repository/files/file.go
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.
2023-02-15 21:37:34 +08:00

140 lines
4.7 KiB
Go

// Copyright 2019 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package files
import (
"context"
"fmt"
"net/url"
"path"
"strings"
"time"
repo_model "code.gitea.io/gitea/models/repo"
user_model "code.gitea.io/gitea/models/user"
"code.gitea.io/gitea/modules/git"
api "code.gitea.io/gitea/modules/structs"
)
// GetFileResponseFromCommit Constructs a FileResponse from a Commit object
func GetFileResponseFromCommit(ctx context.Context, repo *repo_model.Repository, commit *git.Commit, branch, treeName string) (*api.FileResponse, error) {
fileContents, _ := GetContents(ctx, repo, treeName, branch, false) // ok if fails, then will be nil
fileCommitResponse, _ := GetFileCommitResponse(repo, commit) // ok if fails, then will be nil
verification := GetPayloadCommitVerification(ctx, commit)
fileResponse := &api.FileResponse{
Content: fileContents,
Commit: fileCommitResponse,
Verification: verification,
}
return fileResponse, nil
}
// GetFileCommitResponse Constructs a FileCommitResponse from a Commit object
func GetFileCommitResponse(repo *repo_model.Repository, commit *git.Commit) (*api.FileCommitResponse, error) {
if repo == nil {
return nil, fmt.Errorf("repo cannot be nil")
}
if commit == nil {
return nil, fmt.Errorf("commit cannot be nil")
}
commitURL, _ := url.Parse(repo.APIURL() + "/git/commits/" + url.PathEscape(commit.ID.String()))
commitTreeURL, _ := url.Parse(repo.APIURL() + "/git/trees/" + url.PathEscape(commit.Tree.ID.String()))
parents := make([]*api.CommitMeta, commit.ParentCount())
for i := 0; i <= commit.ParentCount(); i++ {
if parent, err := commit.Parent(i); err == nil && parent != nil {
parentCommitURL, _ := url.Parse(repo.APIURL() + "/git/commits/" + url.PathEscape(parent.ID.String()))
parents[i] = &api.CommitMeta{
SHA: parent.ID.String(),
URL: parentCommitURL.String(),
}
}
}
commitHTMLURL, _ := url.Parse(repo.HTMLURL() + "/commit/" + url.PathEscape(commit.ID.String()))
fileCommit := &api.FileCommitResponse{
CommitMeta: api.CommitMeta{
SHA: commit.ID.String(),
URL: commitURL.String(),
},
HTMLURL: commitHTMLURL.String(),
Author: &api.CommitUser{
Identity: api.Identity{
Name: commit.Author.Name,
Email: commit.Author.Email,
},
Date: commit.Author.When.UTC().Format(time.RFC3339),
},
Committer: &api.CommitUser{
Identity: api.Identity{
Name: commit.Committer.Name,
Email: commit.Committer.Email,
},
Date: commit.Committer.When.UTC().Format(time.RFC3339),
},
Message: commit.Message(),
Tree: &api.CommitMeta{
URL: commitTreeURL.String(),
SHA: commit.Tree.ID.String(),
},
Parents: parents,
}
return fileCommit, nil
}
// GetAuthorAndCommitterUsers Gets the author and committer user objects from the IdentityOptions
func GetAuthorAndCommitterUsers(author, committer *IdentityOptions, doer *user_model.User) (authorUser, committerUser *user_model.User) {
// Committer and author are optional. If they are not the doer (not same email address)
// then we use bogus User objects for them to store their FullName and Email.
// If only one of the two are provided, we set both of them to it.
// If neither are provided, both are the doer.
if committer != nil && committer.Email != "" {
if doer != nil && strings.EqualFold(doer.Email, committer.Email) {
committerUser = doer // the committer is the doer, so will use their user object
if committer.Name != "" {
committerUser.FullName = committer.Name
}
} else {
committerUser = &user_model.User{
FullName: committer.Name,
Email: committer.Email,
}
}
}
if author != nil && author.Email != "" {
if doer != nil && strings.EqualFold(doer.Email, author.Email) {
authorUser = doer // the author is the doer, so will use their user object
if authorUser.Name != "" {
authorUser.FullName = author.Name
}
} else {
authorUser = &user_model.User{
FullName: author.Name,
Email: author.Email,
}
}
}
if authorUser == nil {
if committerUser != nil {
authorUser = committerUser // No valid author was given so use the committer
} else if doer != nil {
authorUser = doer // No valid author was given and no valid committer so use the doer
}
}
if committerUser == nil {
committerUser = authorUser // No valid committer so use the author as the committer (was set to a valid user above)
}
return authorUser, committerUser
}
// CleanUploadFileName Trims a filename and returns empty string if it is a .git directory
func CleanUploadFileName(name string) string {
// Rebase the filename
name = strings.Trim(path.Clean("/"+name), "/")
// Git disallows any filenames to have a .git directory in them.
for _, part := range strings.Split(name, "/") {
if strings.ToLower(part) == ".git" {
return ""
}
}
return name
}