Don't use subselect in `DeleteIssuesByRepoID` (#27332)

Part of https://codeberg.org/forgejo/discussions/issues/61

This is workaround for a bug in MariaDB

diff --git a/models/issues/issue_update.go b/models/issues/issue_update.go
index c01cb859e265ce4cd545729d9212c72e90132137..b258dc882cb2c87183ee2485c58b74c3a4d226b6 100644 (file)
--- a/models/issues/issue_update.go
+++ b/models/issues/issue_update.go
@@ -685,85 +685,100 @@ func UpdateReactionsMigrationsByType(ctx context.Context, gitServiceType api.Git
 
 // DeleteIssuesByRepoID deletes issues by repositories id
 func DeleteIssuesByRepoID(ctx context.Context, repoID int64) (attachmentPaths []string, err error) {
-       deleteCond := builder.Select("id").From("issue").Where(builder.Eq{"issue.repo_id": repoID})
-
+       // MariaDB has a performance bug: https://jira.mariadb.org/browse/MDEV-16289
+       // so here it uses "DELETE ... WHERE IN" with pre-queried IDs.
        sess := db.GetEngine(ctx)
-       // Delete content histories
-       if _, err = sess.In("issue_id", deleteCond).
-               Delete(&ContentHistory{}); err != nil {
-               return nil, err
-       }
 
-       // Delete comments and attachments
-       if _, err = sess.In("issue_id", deleteCond).
-               Delete(&Comment{}); err != nil {
-               return nil, err
-       }
+       for {
+               issueIDs := make([]int64, 0, db.DefaultMaxInSize)
 
-       // Dependencies for issues in this repository
-       if _, err = sess.In("issue_id", deleteCond).
-               Delete(&IssueDependency{}); err != nil {
-               return nil, err
-       }
+               err := sess.Table(&Issue{}).Where("repo_id = ?", repoID).OrderBy("id").Limit(db.DefaultMaxInSize).Cols("id").Find(&issueIDs)
+               if err != nil {
+                       return nil, err
+               }
 
-       // Delete dependencies for issues in other repositories
-       if _, err = sess.In("dependency_id", deleteCond).
-               Delete(&IssueDependency{}); err != nil {
-               return nil, err
-       }
+               if len(issueIDs) == 0 {
+                       break
+               }
 
-       if _, err = sess.In("issue_id", deleteCond).
-               Delete(&IssueUser{}); err != nil {
-               return nil, err
-       }
+               // Delete content histories
+               _, err = sess.In("issue_id", issueIDs).Delete(&ContentHistory{})
+               if err != nil {
+                       return nil, err
+               }
 
-       if _, err = sess.In("issue_id", deleteCond).
-               Delete(&Reaction{}); err != nil {
-               return nil, err
-       }
+               // Delete comments and attachments
+               _, err = sess.In("issue_id", issueIDs).Delete(&Comment{})
+               if err != nil {
+                       return nil, err
+               }
 
-       if _, err = sess.In("issue_id", deleteCond).
-               Delete(&IssueWatch{}); err != nil {
-               return nil, err
-       }
+               // Dependencies for issues in this repository
+               _, err = sess.In("issue_id", issueIDs).Delete(&IssueDependency{})
+               if err != nil {
+                       return nil, err
+               }
 
-       if _, err = sess.In("issue_id", deleteCond).
-               Delete(&Stopwatch{}); err != nil {
-               return nil, err
-       }
+               // Delete dependencies for issues in other repositories
+               _, err = sess.In("dependency_id", issueIDs).Delete(&IssueDependency{})
+               if err != nil {
+                       return nil, err
+               }
 
-       if _, err = sess.In("issue_id", deleteCond).
-               Delete(&TrackedTime{}); err != nil {
-               return nil, err
-       }
+               _, err = sess.In("issue_id", issueIDs).Delete(&IssueUser{})
+               if err != nil {
+                       return nil, err
+               }
 
-       if _, err = sess.In("issue_id", deleteCond).
-               Delete(&project_model.ProjectIssue{}); err != nil {
-               return nil, err
-       }
+               _, err = sess.In("issue_id", issueIDs).Delete(&Reaction{})
+               if err != nil {
+                       return nil, err
+               }
 
-       if _, err = sess.In("dependent_issue_id", deleteCond).
-               Delete(&Comment{}); err != nil {
-               return nil, err
-       }
+               _, err = sess.In("issue_id", issueIDs).Delete(&IssueWatch{})
+               if err != nil {
+                       return nil, err
+               }
 
-       var attachments []*repo_model.Attachment
-       if err = sess.In("issue_id", deleteCond).
-               Find(&attachments); err != nil {
-               return nil, err
-       }
+               _, err = sess.In("issue_id", issueIDs).Delete(&Stopwatch{})
+               if err != nil {
+                       return nil, err
+               }
 
-       for j := range attachments {
-               attachmentPaths = append(attachmentPaths, attachments[j].RelativePath())
-       }
+               _, err = sess.In("issue_id", issueIDs).Delete(&TrackedTime{})
+               if err != nil {
+                       return nil, err
+               }
 
-       if _, err = sess.In("issue_id", deleteCond).
-               Delete(&repo_model.Attachment{}); err != nil {
-               return nil, err
-       }
+               _, err = sess.In("issue_id", issueIDs).Delete(&project_model.ProjectIssue{})
+               if err != nil {
+                       return nil, err
+               }
 
-       if _, err = db.DeleteByBean(ctx, &Issue{RepoID: repoID}); err != nil {
-               return nil, err
+               _, err = sess.In("dependent_issue_id", issueIDs).Delete(&Comment{})
+               if err != nil {
+                       return nil, err
+               }
+
+               var attachments []*repo_model.Attachment
+               err = sess.In("issue_id", issueIDs).Find(&attachments)
+               if err != nil {
+                       return nil, err
+               }
+
+               for j := range attachments {
+                       attachmentPaths = append(attachmentPaths, attachments[j].RelativePath())
+               }
+
+               _, err = sess.In("issue_id", issueIDs).Delete(&repo_model.Attachment{})
+               if err != nil {
+                       return nil, err
+               }
+
+               _, err = sess.In("id", issueIDs).Delete(&Issue{})
+               if err != nil {
+                       return nil, err
+               }
        }
 
        return attachmentPaths, err