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.

18 files changed, 40 insertions, 40 deletions

diff --git a/routers/api/v1/repo/branch.go b/routers/api/v1/repo/branch.go
index eacec6a609..8acaeaffb4 100644
--- a/routers/api/v1/repo/branch.go
+++ b/routers/api/v1/repo/branch.go
@@ -76,7 +76,7 @@ func GetBranch(ctx *context.APIContext) {
 		return
 	}
 
-	br, err := convert.ToBranch(ctx.Repo.Repository, branch, c, branchProtection, ctx.Doer, ctx.Repo.IsAdmin())
+	br, err := convert.ToBranch(ctx, ctx.Repo.Repository, branch, c, branchProtection, ctx.Doer, ctx.Repo.IsAdmin())
 	if err != nil {
 		ctx.Error(http.StatusInternalServerError, "convert.ToBranch", err)
 		return
@@ -212,7 +212,7 @@ func CreateBranch(ctx *context.APIContext) {
 		return
 	}
 
-	br, err := convert.ToBranch(ctx.Repo.Repository, branch, commit, branchProtection, ctx.Doer, ctx.Repo.IsAdmin())
+	br, err := convert.ToBranch(ctx, ctx.Repo.Repository, branch, commit, branchProtection, ctx.Doer, ctx.Repo.IsAdmin())
 	if err != nil {
 		ctx.Error(http.StatusInternalServerError, "convert.ToBranch", err)
 		return
@@ -284,7 +284,7 @@ func ListBranches(ctx *context.APIContext) {
 			}
 
 			branchProtection := rules.GetFirstMatched(branches[i].Name)
-			apiBranch, err := convert.ToBranch(ctx.Repo.Repository, branches[i], c, branchProtection, ctx.Doer, ctx.Repo.IsAdmin())
+			apiBranch, err := convert.ToBranch(ctx, ctx.Repo.Repository, branches[i], c, branchProtection, ctx.Doer, ctx.Repo.IsAdmin())
 			if err != nil {
 				ctx.Error(http.StatusInternalServerError, "convert.ToBranch", err)
 				return
diff --git a/routers/api/v1/repo/collaborators.go b/routers/api/v1/repo/collaborators.go
index 293778420b..942d4c799f 100644
--- a/routers/api/v1/repo/collaborators.go
+++ b/routers/api/v1/repo/collaborators.go
@@ -65,7 +65,7 @@ func ListCollaborators(ctx *context.APIContext) {
 
 	users := make([]*api.User, len(collaborators))
 	for i, collaborator := range collaborators {
-		users[i] = convert.ToUser(collaborator.User, ctx.Doer)
+		users[i] = convert.ToUser(ctx, collaborator.User, ctx.Doer)
 	}
 
 	ctx.SetTotalCountHeader(count)
@@ -287,7 +287,7 @@ func GetRepoPermissions(ctx *context.APIContext) {
 		return
 	}
 
-	ctx.JSON(http.StatusOK, convert.ToUserAndPermission(collaborator, ctx.ContextUser, permission.AccessMode))
+	ctx.JSON(http.StatusOK, convert.ToUserAndPermission(ctx, collaborator, ctx.ContextUser, permission.AccessMode))
 }
 
 // GetReviewers return all users that can be requested to review in this repo
@@ -317,7 +317,7 @@ func GetReviewers(ctx *context.APIContext) {
 		ctx.Error(http.StatusInternalServerError, "ListCollaborators", err)
 		return
 	}
-	ctx.JSON(http.StatusOK, convert.ToUsers(ctx.Doer, reviewers))
+	ctx.JSON(http.StatusOK, convert.ToUsers(ctx, ctx.Doer, reviewers))
 }
 
 // GetAssignees return all users that have write access and can be assigned to issues
@@ -347,5 +347,5 @@ func GetAssignees(ctx *context.APIContext) {
 		ctx.Error(http.StatusInternalServerError, "ListCollaborators", err)
 		return
 	}
-	ctx.JSON(http.StatusOK, convert.ToUsers(ctx.Doer, assignees))
+	ctx.JSON(http.StatusOK, convert.ToUsers(ctx, ctx.Doer, assignees))
 }
diff --git a/routers/api/v1/repo/commits.go b/routers/api/v1/repo/commits.go
index 68a92ca2a8..22b013e7dc 100644
--- a/routers/api/v1/repo/commits.go
+++ b/routers/api/v1/repo/commits.go
@@ -69,7 +69,7 @@ func getCommit(ctx *context.APIContext, identifier string) {
 		return
 	}
 
-	json, err := convert.ToCommit(ctx.Repo.Repository, ctx.Repo.GitRepo, commit, nil, true)
+	json, err := convert.ToCommit(ctx, ctx.Repo.Repository, ctx.Repo.GitRepo, commit, nil, true)
 	if err != nil {
 		ctx.Error(http.StatusInternalServerError, "toCommit", err)
 		return
@@ -217,7 +217,7 @@ func GetAllCommits(ctx *context.APIContext) {
 
 	for i, commit := range commits {
 		// Create json struct
-		apiCommits[i], err = convert.ToCommit(ctx.Repo.Repository, ctx.Repo.GitRepo, commit, userCache, stat)
+		apiCommits[i], err = convert.ToCommit(ctx, ctx.Repo.Repository, ctx.Repo.GitRepo, commit, userCache, stat)
 		if err != nil {
 			ctx.Error(http.StatusInternalServerError, "toCommit", err)
 			return
diff --git a/routers/api/v1/repo/hook.go b/routers/api/v1/repo/hook.go
index 100a28d7f6..fd54d1f740 100644
--- a/routers/api/v1/repo/hook.go
+++ b/routers/api/v1/repo/hook.go
@@ -174,7 +174,7 @@ func TestHook(ctx *context.APIContext) {
 		return
 	}
 
-	commit := convert.ToPayloadCommit(ctx.Repo.Repository, ctx.Repo.Commit)
+	commit := convert.ToPayloadCommit(ctx, ctx.Repo.Repository, ctx.Repo.Commit)
 
 	commitID := ctx.Repo.Commit.ID.String()
 	if err := webhook_service.PrepareWebhook(ctx, hook, webhook_module.HookEventPush, &api.PushPayload{
@@ -186,8 +186,8 @@ func TestHook(ctx *context.APIContext) {
 		TotalCommits: 1,
 		HeadCommit:   commit,
 		Repo:         convert.ToRepo(ctx, ctx.Repo.Repository, perm.AccessModeNone),
-		Pusher:       convert.ToUserWithAccessMode(ctx.Doer, perm.AccessModeNone),
-		Sender:       convert.ToUserWithAccessMode(ctx.Doer, perm.AccessModeNone),
+		Pusher:       convert.ToUserWithAccessMode(ctx, ctx.Doer, perm.AccessModeNone),
+		Sender:       convert.ToUserWithAccessMode(ctx, ctx.Doer, perm.AccessModeNone),
 	}); err != nil {
 		ctx.Error(http.StatusInternalServerError, "PrepareWebhook: ", err)
 		return
diff --git a/routers/api/v1/repo/issue_comment.go b/routers/api/v1/repo/issue_comment.go
index 40c92998d1..3d14343d47 100644
--- a/routers/api/v1/repo/issue_comment.go
+++ b/routers/api/v1/repo/issue_comment.go
@@ -103,7 +103,7 @@ func ListIssueComments(ctx *context.APIContext) {
 	apiComments := make([]*api.Comment, len(comments))
 	for i, comment := range comments {
 		comment.Issue = issue
-		apiComments[i] = convert.ToComment(comments[i])
+		apiComments[i] = convert.ToComment(ctx, comments[i])
 	}
 
 	ctx.SetTotalCountHeader(totalCount)
@@ -308,7 +308,7 @@ func ListRepoIssueComments(ctx *context.APIContext) {
 		return
 	}
 	for i := range comments {
-		apiComments[i] = convert.ToComment(comments[i])
+		apiComments[i] = convert.ToComment(ctx, comments[i])
 	}
 
 	ctx.SetTotalCountHeader(totalCount)
@@ -368,7 +368,7 @@ func CreateIssueComment(ctx *context.APIContext) {
 		return
 	}
 
-	ctx.JSON(http.StatusCreated, convert.ToComment(comment))
+	ctx.JSON(http.StatusCreated, convert.ToComment(ctx, comment))
 }
 
 // GetIssueComment Get a comment by ID
@@ -436,7 +436,7 @@ func GetIssueComment(ctx *context.APIContext) {
 		return
 	}
 
-	ctx.JSON(http.StatusOK, convert.ToComment(comment))
+	ctx.JSON(http.StatusOK, convert.ToComment(ctx, comment))
 }
 
 // EditIssueComment modify a comment of an issue
@@ -561,7 +561,7 @@ func editIssueComment(ctx *context.APIContext, form api.EditIssueCommentOption)
 		return
 	}
 
-	ctx.JSON(http.StatusOK, convert.ToComment(comment))
+	ctx.JSON(http.StatusOK, convert.ToComment(ctx, comment))
 }
 
 // DeleteIssueComment delete a comment from an issue
diff --git a/routers/api/v1/repo/issue_reaction.go b/routers/api/v1/repo/issue_reaction.go
index 1b998a5354..921f6e53f9 100644
--- a/routers/api/v1/repo/issue_reaction.go
+++ b/routers/api/v1/repo/issue_reaction.go
@@ -80,7 +80,7 @@ func GetIssueCommentReactions(ctx *context.APIContext) {
 	var result []api.Reaction
 	for _, r := range reactions {
 		result = append(result, api.Reaction{
-			User:     convert.ToUser(r.User, ctx.Doer),
+			User:     convert.ToUser(ctx, r.User, ctx.Doer),
 			Reaction: r.Type,
 			Created:  r.CreatedUnix.AsTime(),
 		})
@@ -202,7 +202,7 @@ func changeIssueCommentReaction(ctx *context.APIContext, form api.EditReactionOp
 				ctx.Error(http.StatusForbidden, err.Error(), err)
 			} else if issues_model.IsErrReactionAlreadyExist(err) {
 				ctx.JSON(http.StatusOK, api.Reaction{
-					User:     convert.ToUser(ctx.Doer, ctx.Doer),
+					User:     convert.ToUser(ctx, ctx.Doer, ctx.Doer),
 					Reaction: reaction.Type,
 					Created:  reaction.CreatedUnix.AsTime(),
 				})
@@ -213,7 +213,7 @@ func changeIssueCommentReaction(ctx *context.APIContext, form api.EditReactionOp
 		}
 
 		ctx.JSON(http.StatusCreated, api.Reaction{
-			User:     convert.ToUser(ctx.Doer, ctx.Doer),
+			User:     convert.ToUser(ctx, ctx.Doer, ctx.Doer),
 			Reaction: reaction.Type,
 			Created:  reaction.CreatedUnix.AsTime(),
 		})
@@ -298,7 +298,7 @@ func GetIssueReactions(ctx *context.APIContext) {
 	var result []api.Reaction
 	for _, r := range reactions {
 		result = append(result, api.Reaction{
-			User:     convert.ToUser(r.User, ctx.Doer),
+			User:     convert.ToUser(ctx, r.User, ctx.Doer),
 			Reaction: r.Type,
 			Created:  r.CreatedUnix.AsTime(),
 		})
@@ -412,7 +412,7 @@ func changeIssueReaction(ctx *context.APIContext, form api.EditReactionOption, i
 				ctx.Error(http.StatusForbidden, err.Error(), err)
 			} else if issues_model.IsErrReactionAlreadyExist(err) {
 				ctx.JSON(http.StatusOK, api.Reaction{
-					User:     convert.ToUser(ctx.Doer, ctx.Doer),
+					User:     convert.ToUser(ctx, ctx.Doer, ctx.Doer),
 					Reaction: reaction.Type,
 					Created:  reaction.CreatedUnix.AsTime(),
 				})
@@ -423,7 +423,7 @@ func changeIssueReaction(ctx *context.APIContext, form api.EditReactionOption, i
 		}
 
 		ctx.JSON(http.StatusCreated, api.Reaction{
-			User:     convert.ToUser(ctx.Doer, ctx.Doer),
+			User:     convert.ToUser(ctx, ctx.Doer, ctx.Doer),
 			Reaction: reaction.Type,
 			Created:  reaction.CreatedUnix.AsTime(),
 		})
diff --git a/routers/api/v1/repo/issue_subscription.go b/routers/api/v1/repo/issue_subscription.go
index 6d22c82652..107119eb08 100644
--- a/routers/api/v1/repo/issue_subscription.go
+++ b/routers/api/v1/repo/issue_subscription.go
@@ -280,7 +280,7 @@ func GetIssueSubscribers(ctx *context.APIContext) {
 	}
 	apiUsers := make([]*api.User, 0, len(users))
 	for _, v := range users {
-		apiUsers = append(apiUsers, convert.ToUser(v, ctx.Doer))
+		apiUsers = append(apiUsers, convert.ToUser(ctx, v, ctx.Doer))
 	}
 
 	count, err := issues_model.CountIssueWatchers(ctx, issue.ID)
diff --git a/routers/api/v1/repo/notes.go b/routers/api/v1/repo/notes.go
index 8eaa503ff7..2d1f3291f8 100644
--- a/routers/api/v1/repo/notes.go
+++ b/routers/api/v1/repo/notes.go
@@ -68,7 +68,7 @@ func getNote(ctx *context.APIContext, identifier string) {
 		return
 	}
 
-	cmt, err := convert.ToCommit(ctx.Repo.Repository, ctx.Repo.GitRepo, note.Commit, nil, true)
+	cmt, err := convert.ToCommit(ctx, ctx.Repo.Repository, ctx.Repo.GitRepo, note.Commit, nil, true)
 	if err != nil {
 		ctx.Error(http.StatusInternalServerError, "ToCommit", err)
 		return
diff --git a/routers/api/v1/repo/pull.go b/routers/api/v1/repo/pull.go
index 8164b38694..7005725cf6 100644
--- a/routers/api/v1/repo/pull.go
+++ b/routers/api/v1/repo/pull.go
@@ -1311,7 +1311,7 @@ func GetPullRequestCommits(ctx *context.APIContext) {
 
 	apiCommits := make([]*api.Commit, 0, end-start)
 	for i := start; i < end; i++ {
-		apiCommit, err := convert.ToCommit(ctx.Repo.Repository, baseGitRepo, commits[i], userCache, true)
+		apiCommit, err := convert.ToCommit(ctx, ctx.Repo.Repository, baseGitRepo, commits[i], userCache, true)
 		if err != nil {
 			ctx.ServerError("toCommit", err)
 			return
diff --git a/routers/api/v1/repo/pull_review.go b/routers/api/v1/repo/pull_review.go
index 96dc1fc2de..f6acaa780a 100644
--- a/routers/api/v1/repo/pull_review.go
+++ b/routers/api/v1/repo/pull_review.go
@@ -673,7 +673,7 @@ func apiReviewRequest(ctx *context.APIContext, opts api.PullReviewRequestOptions
 	for _, r := range opts.Reviewers {
 		var reviewer *user_model.User
 		if strings.Contains(r, "@") {
-			reviewer, err = user_model.GetUserByEmail(r)
+			reviewer, err = user_model.GetUserByEmail(ctx, r)
 		} else {
 			reviewer, err = user_model.GetUserByName(ctx, r)
 		}
diff --git a/routers/api/v1/repo/release.go b/routers/api/v1/repo/release.go
index c01e66150f..e9693dd053 100644
--- a/routers/api/v1/repo/release.go
+++ b/routers/api/v1/repo/release.go
@@ -64,7 +64,7 @@ func GetRelease(ctx *context.APIContext) {
 		ctx.Error(http.StatusInternalServerError, "LoadAttributes", err)
 		return
 	}
-	ctx.JSON(http.StatusOK, convert.ToRelease(release))
+	ctx.JSON(http.StatusOK, convert.ToRelease(ctx, release))
 }
 
 // GetLatestRelease gets the most recent non-prerelease, non-draft release of a repository, sorted by created_at
@@ -105,7 +105,7 @@ func GetLatestRelease(ctx *context.APIContext) {
 		ctx.Error(http.StatusInternalServerError, "LoadAttributes", err)
 		return
 	}
-	ctx.JSON(http.StatusOK, convert.ToRelease(release))
+	ctx.JSON(http.StatusOK, convert.ToRelease(ctx, release))
 }
 
 // ListReleases list a repository's releases
@@ -174,7 +174,7 @@ func ListReleases(ctx *context.APIContext) {
 			ctx.Error(http.StatusInternalServerError, "LoadAttributes", err)
 			return
 		}
-		rels[i] = convert.ToRelease(release)
+		rels[i] = convert.ToRelease(ctx, release)
 	}
 
 	filteredCount, err := repo_model.CountReleasesByRepoID(ctx.Repo.Repository.ID, opts)
@@ -272,7 +272,7 @@ func CreateRelease(ctx *context.APIContext) {
 			return
 		}
 	}
-	ctx.JSON(http.StatusCreated, convert.ToRelease(rel))
+	ctx.JSON(http.StatusCreated, convert.ToRelease(ctx, rel))
 }
 
 // EditRelease edit a release
@@ -357,7 +357,7 @@ func EditRelease(ctx *context.APIContext) {
 		ctx.Error(http.StatusInternalServerError, "LoadAttributes", err)
 		return
 	}
-	ctx.JSON(http.StatusOK, convert.ToRelease(rel))
+	ctx.JSON(http.StatusOK, convert.ToRelease(ctx, rel))
 }
 
 // DeleteRelease delete a release from a repository
diff --git a/routers/api/v1/repo/release_attachment.go b/routers/api/v1/repo/release_attachment.go
index 5aaea693c0..597578aac5 100644
--- a/routers/api/v1/repo/release_attachment.go
+++ b/routers/api/v1/repo/release_attachment.go
@@ -117,7 +117,7 @@ func ListReleaseAttachments(ctx *context.APIContext) {
 		ctx.Error(http.StatusInternalServerError, "LoadAttributes", err)
 		return
 	}
-	ctx.JSON(http.StatusOK, convert.ToRelease(release).Attachments)
+	ctx.JSON(http.StatusOK, convert.ToRelease(ctx, release).Attachments)
 }
 
 // CreateReleaseAttachment creates an attachment and saves the given file
diff --git a/routers/api/v1/repo/release_tags.go b/routers/api/v1/repo/release_tags.go
index 7cc846fdc4..051ee8f22e 100644
--- a/routers/api/v1/repo/release_tags.go
+++ b/routers/api/v1/repo/release_tags.go
@@ -63,7 +63,7 @@ func GetReleaseByTag(ctx *context.APIContext) {
 		ctx.Error(http.StatusInternalServerError, "LoadAttributes", err)
 		return
 	}
-	ctx.JSON(http.StatusOK, convert.ToRelease(release))
+	ctx.JSON(http.StatusOK, convert.ToRelease(ctx, release))
 }
 
 // DeleteReleaseByTag delete a release from a repository by tag name
diff --git a/routers/api/v1/repo/star.go b/routers/api/v1/repo/star.go
index c7b2eb01ff..e4cf0ffab6 100644
--- a/routers/api/v1/repo/star.go
+++ b/routers/api/v1/repo/star.go
@@ -50,7 +50,7 @@ func ListStargazers(ctx *context.APIContext) {
 	}
 	users := make([]*api.User, len(stargazers))
 	for i, stargazer := range stargazers {
-		users[i] = convert.ToUser(stargazer, ctx.Doer)
+		users[i] = convert.ToUser(ctx, stargazer, ctx.Doer)
 	}
 
 	ctx.SetTotalCountHeader(int64(ctx.Repo.Repository.NumStars))
diff --git a/routers/api/v1/repo/subscriber.go b/routers/api/v1/repo/subscriber.go
index 6cd369898e..613fbee409 100644
--- a/routers/api/v1/repo/subscriber.go
+++ b/routers/api/v1/repo/subscriber.go
@@ -50,7 +50,7 @@ func ListSubscribers(ctx *context.APIContext) {
 	}
 	users := make([]*api.User, len(subscribers))
 	for i, subscriber := range subscribers {
-		users[i] = convert.ToUser(subscriber, ctx.Doer)
+		users[i] = convert.ToUser(ctx, subscriber, ctx.Doer)
 	}
 
 	ctx.SetTotalCountHeader(int64(ctx.Repo.Repository.NumWatches))
diff --git a/routers/api/v1/repo/tag.go b/routers/api/v1/repo/tag.go
index cb65e2b651..b28b6b0b91 100644
--- a/routers/api/v1/repo/tag.go
+++ b/routers/api/v1/repo/tag.go
@@ -107,7 +107,7 @@ func GetAnnotatedTag(ctx *context.APIContext) {
 		if err != nil {
 			ctx.Error(http.StatusBadRequest, "GetAnnotatedTag", err)
 		}
-		ctx.JSON(http.StatusOK, convert.ToAnnotatedTag(ctx.Repo.Repository, tag, commit))
+		ctx.JSON(http.StatusOK, convert.ToAnnotatedTag(ctx, ctx.Repo.Repository, tag, commit))
 	}
 }
 
diff --git a/routers/api/v1/repo/teams.go b/routers/api/v1/repo/teams.go
index eafe4236ec..01292f18d8 100644
--- a/routers/api/v1/repo/teams.go
+++ b/routers/api/v1/repo/teams.go
@@ -47,7 +47,7 @@ func ListTeams(ctx *context.APIContext) {
 		return
 	}
 
-	apiTeams, err := convert.ToTeams(teams, false)
+	apiTeams, err := convert.ToTeams(ctx, teams, false)
 	if err != nil {
 		ctx.InternalServerError(err)
 		return
@@ -98,7 +98,7 @@ func IsTeam(ctx *context.APIContext) {
 	}
 
 	if models.HasRepository(team, ctx.Repo.Repository.ID) {
-		apiTeam, err := convert.ToTeam(team)
+		apiTeam, err := convert.ToTeam(ctx, team)
 		if err != nil {
 			ctx.InternalServerError(err)
 			return
diff --git a/routers/api/v1/repo/transfer.go b/routers/api/v1/repo/transfer.go
index aec398da7a..ded8edd41c 100644
--- a/routers/api/v1/repo/transfer.go
+++ b/routers/api/v1/repo/transfer.go
@@ -81,7 +81,7 @@ func Transfer(ctx *context.APIContext) {
 			return
 		}
 
-		org := convert.ToOrganization(organization.OrgFromUser(newOwner))
+		org := convert.ToOrganization(ctx, organization.OrgFromUser(newOwner))
 		for _, tID := range *opts.TeamIDs {
 			team, err := organization.GetTeamByID(ctx, tID)
 			if err != nil {