forgejo-federation/services/repository/files/patch.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

193 lines
5.4 KiB
Go

// Copyright 2021 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package files
import (
"context"
"fmt"
"strings"
"code.gitea.io/gitea/models"
git_model "code.gitea.io/gitea/models/git"
repo_model "code.gitea.io/gitea/models/repo"
user_model "code.gitea.io/gitea/models/user"
"code.gitea.io/gitea/modules/git"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/structs"
asymkey_service "code.gitea.io/gitea/services/asymkey"
)
// ApplyDiffPatchOptions holds the repository diff patch update options
type ApplyDiffPatchOptions struct {
LastCommitID string
OldBranch string
NewBranch string
Message string
Content string
SHA string
Author *IdentityOptions
Committer *IdentityOptions
Dates *CommitDateOptions
Signoff bool
}
// Validate validates the provided options
func (opts *ApplyDiffPatchOptions) Validate(ctx context.Context, repo *repo_model.Repository, doer *user_model.User) error {
// If no branch name is set, assume master
if opts.OldBranch == "" {
opts.OldBranch = repo.DefaultBranch
}
if opts.NewBranch == "" {
opts.NewBranch = opts.OldBranch
}
gitRepo, closer, err := git.RepositoryFromContextOrOpen(ctx, repo.RepoPath())
if err != nil {
return err
}
defer closer.Close()
// oldBranch must exist for this operation
if _, err := gitRepo.GetBranch(opts.OldBranch); err != nil {
return err
}
// A NewBranch can be specified for the patch to be applied to.
// Check to make sure the branch does not already exist, otherwise we can't proceed.
// If we aren't branching to a new branch, make sure user can commit to the given branch
if opts.NewBranch != opts.OldBranch {
existingBranch, err := gitRepo.GetBranch(opts.NewBranch)
if existingBranch != nil {
return models.ErrBranchAlreadyExists{
BranchName: opts.NewBranch,
}
}
if err != nil && !git.IsErrBranchNotExist(err) {
return err
}
} else {
protectedBranch, err := git_model.GetFirstMatchProtectedBranchRule(ctx, repo.ID, opts.OldBranch)
if err != nil {
return err
}
if protectedBranch != nil {
protectedBranch.Repo = repo
if !protectedBranch.CanUserPush(ctx, doer) {
return models.ErrUserCannotCommit{
UserName: doer.LowerName,
}
}
}
if protectedBranch != nil && protectedBranch.RequireSignedCommits {
_, _, _, err := asymkey_service.SignCRUDAction(ctx, repo.RepoPath(), doer, repo.RepoPath(), opts.OldBranch)
if err != nil {
if !asymkey_service.IsErrWontSign(err) {
return err
}
return models.ErrUserCannotCommit{
UserName: doer.LowerName,
}
}
}
}
return nil
}
// ApplyDiffPatch applies a patch to the given repository
func ApplyDiffPatch(ctx context.Context, repo *repo_model.Repository, doer *user_model.User, opts *ApplyDiffPatchOptions) (*structs.FileResponse, error) {
if err := opts.Validate(ctx, repo, doer); err != nil {
return nil, err
}
message := strings.TrimSpace(opts.Message)
author, committer := GetAuthorAndCommitterUsers(opts.Author, opts.Committer, doer)
t, err := NewTemporaryUploadRepository(ctx, repo)
if err != nil {
log.Error("%v", err)
}
defer t.Close()
if err := t.Clone(opts.OldBranch); err != nil {
return nil, err
}
if err := t.SetDefaultIndex(); err != nil {
return nil, err
}
// Get the commit of the original branch
commit, err := t.GetBranchCommit(opts.OldBranch)
if err != nil {
return nil, err // Couldn't get a commit for the branch
}
// Assigned LastCommitID in opts if it hasn't been set
if opts.LastCommitID == "" {
opts.LastCommitID = commit.ID.String()
} else {
lastCommitID, err := t.gitRepo.ConvertToSHA1(opts.LastCommitID)
if err != nil {
return nil, fmt.Errorf("ApplyPatch: Invalid last commit ID: %w", err)
}
opts.LastCommitID = lastCommitID.String()
if commit.ID.String() != opts.LastCommitID {
return nil, models.ErrCommitIDDoesNotMatch{
GivenCommitID: opts.LastCommitID,
CurrentCommitID: opts.LastCommitID,
}
}
}
stdout := &strings.Builder{}
stderr := &strings.Builder{}
cmdApply := git.NewCommand(ctx, "apply", "--index", "--recount", "--cached", "--ignore-whitespace", "--whitespace=fix", "--binary")
if git.CheckGitVersionAtLeast("2.32") == nil {
cmdApply.AddArguments("-3")
}
if err := cmdApply.Run(&git.RunOpts{
Dir: t.basePath,
Stdout: stdout,
Stderr: stderr,
Stdin: strings.NewReader(opts.Content),
}); err != nil {
return nil, fmt.Errorf("Error: Stdout: %s\nStderr: %s\nErr: %w", stdout.String(), stderr.String(), err)
}
// Now write the tree
treeHash, err := t.WriteTree()
if err != nil {
return nil, err
}
// Now commit the tree
var commitHash string
if opts.Dates != nil {
commitHash, err = t.CommitTreeWithDate("HEAD", author, committer, treeHash, message, opts.Signoff, opts.Dates.Author, opts.Dates.Committer)
} else {
commitHash, err = t.CommitTree("HEAD", author, committer, treeHash, message, opts.Signoff)
}
if err != nil {
return nil, err
}
// Then push this tree to NewBranch
if err := t.Push(doer, commitHash, opts.NewBranch); err != nil {
return nil, err
}
commit, err = t.GetCommit(commitHash)
if err != nil {
return nil, err
}
fileCommitResponse, _ := GetFileCommitResponse(repo, commit) // ok if fails, then will be nil
verification := GetPayloadCommitVerification(ctx, commit)
fileResponse := &structs.FileResponse{
Commit: fileCommitResponse,
Verification: verification,
}
return fileResponse, nil
}