Remove maps containing channels.

The old implementation of the github bridge used maps to store several
channels holding data obtained from the Github API. Removing the maps and
simply packing data and channels together in a struct and passing it
through one single channel makes the program simpler in terms of
concurrency and, additionally, enables the garbage collector to free the
memory gradually without any additional provisions.

1 files changed, 20 insertions, 15 deletions

diff --git a/bridge/github/import.go b/bridge/github/import.go
index 09a39586..d492488b 100644
--- a/bridge/github/import.go
+++ b/bridge/github/import.go
@@ -56,9 +56,12 @@ func (gi *githubImporter) ImportAll(ctx context.Context, repo *cache.RepoCache,
 		defer close(gi.out)
 
 		// Loop over all matching issues
-		for issue := range gi.mediator.Issues() {
+		for bundle := range gi.mediator.Issues() {
+			issue := bundle.issue
+			issueEdits := bundle.issueEdits
+			timelineBundles := bundle.timelineBundles
 			// create issue
-			b, err := gi.ensureIssue(ctx, repo, &issue)
+			b, err := gi.ensureIssue(ctx, repo, &issue, issueEdits)
 			if err != nil {
 				err := fmt.Errorf("issue creation: %v", err)
 				out <- core.NewImportError(err, "")
@@ -66,8 +69,10 @@ func (gi *githubImporter) ImportAll(ctx context.Context, repo *cache.RepoCache,
 			}
 
 			// loop over timeline items
-			for item := range gi.mediator.TimelineItems(&issue) {
-				err := gi.ensureTimelineItem(ctx, repo, b, item)
+			for bundle := range timelineBundles {
+				item := bundle.timelineItem
+				edits := bundle.userContentEdits
+				err := gi.ensureTimelineItem(ctx, repo, b, &item, edits)
 				if err != nil {
 					err = fmt.Errorf("timeline item creation: %v", err)
 					out <- core.NewImportError(err, "")
@@ -93,7 +98,7 @@ func (gi *githubImporter) ImportAll(ctx context.Context, repo *cache.RepoCache,
 	return out, nil
 }
 
-func (gi *githubImporter) ensureIssue(ctx context.Context, repo *cache.RepoCache, issue *issue) (*cache.BugCache, error) {
+func (gi *githubImporter) ensureIssue(ctx context.Context, repo *cache.RepoCache, issue *issue, issueEdits <-chan userContentEdit) (*cache.BugCache, error) {
 	author, err := gi.ensurePerson(ctx, repo, issue.Author)
 	if err != nil {
 		return nil, err
@@ -110,7 +115,7 @@ func (gi *githubImporter) ensureIssue(ctx context.Context, repo *cache.RepoCache
 
 	// get first issue edit
 	// if it exists, then it holds the bug creation
-	firstEdit, hasEdit := <-gi.mediator.IssueEdits(issue)
+	firstEdit, hasEdit := <-issueEdits
 
 	// At Github there exist issues with seemingly empty titles. An example is
 	// https://github.com/NixOS/nixpkgs/issues/72730 .
@@ -157,7 +162,7 @@ func (gi *githubImporter) ensureIssue(ctx context.Context, repo *cache.RepoCache
 		return nil, fmt.Errorf("finding or creating issue")
 	}
 	// process remaining issue edits, if they exist
-	for edit := range gi.mediator.IssueEdits(issue) {
+	for edit := range issueEdits {
 		// other edits will be added as CommentEdit operations
 		target, err := b.ResolveOperationWithMetadata(metaKeyGithubId, parseId(issue.Id))
 		if err == cache.ErrNoMatchingOp {
@@ -169,7 +174,7 @@ func (gi *githubImporter) ensureIssue(ctx context.Context, repo *cache.RepoCache
 			return nil, err
 		}
 
-		err = gi.ensureCommentEdit(ctx, repo, b, target, edit)
+		err = gi.ensureCommentEdit(ctx, repo, b, target, &edit)
 		if err != nil {
 			return nil, err
 		}
@@ -177,11 +182,11 @@ func (gi *githubImporter) ensureIssue(ctx context.Context, repo *cache.RepoCache
 	return b, nil
 }
 
-func (gi *githubImporter) ensureTimelineItem(ctx context.Context, repo *cache.RepoCache, b *cache.BugCache, item timelineItem) error {
+func (gi *githubImporter) ensureTimelineItem(ctx context.Context, repo *cache.RepoCache, b *cache.BugCache, item *timelineItem, commentEdits <-chan userContentEdit) error {
 
 	switch item.Typename {
 	case "IssueComment":
-		err := gi.ensureComment(ctx, repo, b, &item.IssueComment)
+		err := gi.ensureComment(ctx, repo, b, &item.IssueComment, commentEdits)
 		if err != nil {
 			return fmt.Errorf("timeline comment creation: %v", err)
 		}
@@ -340,7 +345,7 @@ func (gi *githubImporter) ensureTimelineItem(ctx context.Context, repo *cache.Re
 	return nil
 }
 
-func (gi *githubImporter) ensureComment(ctx context.Context, repo *cache.RepoCache, b *cache.BugCache, comment *issueComment) error {
+func (gi *githubImporter) ensureComment(ctx context.Context, repo *cache.RepoCache, b *cache.BugCache, comment *issueComment, commentEdits <-chan userContentEdit) error {
 	author, err := gi.ensurePerson(ctx, repo, comment.Author)
 	if err != nil {
 		return err
@@ -351,7 +356,7 @@ func (gi *githubImporter) ensureComment(ctx context.Context, repo *cache.RepoCac
 		// real error
 		return err
 	}
-	firstEdit, hasEdit := <-gi.mediator.CommentEdits(comment)
+	firstEdit, hasEdit := <-commentEdits
 	if err == cache.ErrNoMatchingOp {
 		var textInput string
 		if hasEdit {
@@ -388,14 +393,14 @@ func (gi *githubImporter) ensureComment(ctx context.Context, repo *cache.RepoCac
 		return fmt.Errorf("finding or creating issue comment")
 	}
 	// process remaining comment edits, if they exist
-	for edit := range gi.mediator.CommentEdits(comment) {
+	for edit := range commentEdits {
 		// ensure editor identity
 		_, err := gi.ensurePerson(ctx, repo, edit.Editor)
 		if err != nil {
 			return err
 		}
 
-		err = gi.ensureCommentEdit(ctx, repo, b, targetOpID, edit)
+		err = gi.ensureCommentEdit(ctx, repo, b, targetOpID, &edit)
 		if err != nil {
 			return err
 		}
@@ -403,7 +408,7 @@ func (gi *githubImporter) ensureComment(ctx context.Context, repo *cache.RepoCac
 	return nil
 }
 
-func (gi *githubImporter) ensureCommentEdit(ctx context.Context, repo *cache.RepoCache, b *cache.BugCache, target entity.Id, edit userContentEdit) error {
+func (gi *githubImporter) ensureCommentEdit(ctx context.Context, repo *cache.RepoCache, b *cache.BugCache, target entity.Id, edit *userContentEdit) error {
 	_, err := b.ResolveOperationWithMetadata(metaKeyGithubId, parseId(edit.Id))
 	if err == nil {
 		return nil