Add deadlines to git network ops and lock merges per project

internal/agents/mergein.go

@@ -8,6 +8,7 @@ import (
 	"log/slog"
 	"slices"
 	"strings"
+	"sync"
 	"unicode/utf8"
 
 	"g.fc.run/misc/byre/internal/api"
@@ -65,10 +66,11 @@ func (m *Manager) Merge(ctx context.Context, task api.Task, project api.Project,
 		return api.Task{}, err
 	}
 
-	m.mergeMu.Lock()
-	defer m.mergeMu.Unlock()
+	pm := m.projectMerge(project.Id)
+	pm.mu.Lock()
+	defer pm.mu.Unlock()
 
-	if m.mergeHolders[project.Id] == task.Id {
+	if pm.holder == task.Id {
 		return api.Task{}, fmt.Errorf("%w: task %s is already merging", ErrConflict, task.Id)
 	}
 	if title != task.MergeTitle {
@@ -79,9 +81,9 @@ func (m *Manager) Merge(ctx context.Context, task api.Task, project api.Project,
 		task.MergeTitle = title
 	}
 
-	switch m.mergeHolders[project.Id] {
+	switch pm.holder {
 	case "":
-		err := m.startMerge(ctx, task, project, user)
+		err := m.startMerge(ctx, pm, task, project, user)
 		if err != nil {
 			return api.Task{}, err
 		}
@@ -97,8 +99,24 @@ func (m *Manager) Merge(ctx context.Context, task api.Task, project api.Project,
 	return m.store.GetTask(ctx, task.Id)
 }
 
-func (m *Manager) startMerge(ctx context.Context, task api.Task, project api.Project, user api.User) error {
-	err := git.FetchFastForward(project.RepoPath, project.DefaultBranch)
+type projectMerge struct {
+	mu     sync.Mutex
+	holder string
+}
+
+func (m *Manager) projectMerge(projectID string) *projectMerge {
+	m.mergeMu.Lock()
+	defer m.mergeMu.Unlock()
+	pm := m.merges[projectID]
+	if pm == nil {
+		pm = &projectMerge{}
+		m.merges[projectID] = pm
+	}
+	return pm
+}
+
+func (m *Manager) startMerge(ctx context.Context, pm *projectMerge, task api.Task, project api.Project, user api.User) error {
+	err := git.FetchFastForward(ctx, project.RepoPath, project.DefaultBranch)
 	if err != nil {
 		return err
 	}
@@ -110,13 +128,13 @@ func (m *Manager) startMerge(ctx context.Context, task api.Task, project api.Pro
 	if err != nil {
 		return err
 	}
-	m.mergeHolders[project.Id] = task.Id
+	pm.holder = task.Id
 
 	prompt := mergeInPrompt(project.DefaultBranch) + fmt.Sprintf(" When this turn ends, byre squashes this branch onto %s and pushes it; if you stop, call stop_merge first so it doesn't. ", project.DefaultBranch) + summaryRequest
 	_, err = m.sendMergeIn(ctx, task, user, prompt)
 	if err != nil {
 		m.takeMerge(task.Id)
-		delete(m.mergeHolders, project.Id)
+		pm.holder = ""
 	}
 	return err
 }
@@ -127,10 +145,11 @@ func (m *Manager) recoverMerges(ctx context.Context) error {
 		return err
 	}
 
-	m.mergeMu.Lock()
-	defer m.mergeMu.Unlock()
 	for _, t := range merging {
-		m.mergeHolders[t.ProjectId] = t.Id
+		pm := m.projectMerge(t.ProjectId)
+		pm.mu.Lock()
+		pm.holder = t.Id
+		pm.mu.Unlock()
 	}
 	return nil
 }
@@ -177,7 +196,7 @@ func (m *Manager) resumeFinalizing(ctx context.Context, f store.FinalizingMerge)
 		return errors.New("nothing was pushed. Merge again to retry")
 	}
 
-	landed, err := pushLanded(project, f.Commit)
+	landed, err := pushLanded(ctx, project, f.Commit)
 	if err != nil {
 		return err
 	}
@@ -187,9 +206,9 @@ func (m *Manager) resumeFinalizing(ctx context.Context, f store.FinalizingMerge)
 	return m.closePushed(ctx, f.Task, project, f.Commit, f.Notes, f.By)
 }
 
-func pushLanded(project api.Project, commit string) (bool, error) {
+func pushLanded(ctx context.Context, project api.Project, commit string) (bool, error) {
 	target := git.Remote + "/" + project.DefaultBranch
-	err := git.Fetch(project.RepoPath)
+	err := git.Fetch(ctx, project.RepoPath)
 	if err != nil {
 		return false, &unfinishedMergeError{fmt.Errorf("checking whether %s reached %s failed: %w", commit, target, err)}
 	}
@@ -231,22 +250,24 @@ func (m *Manager) abandonMerge(taskID, projectID string) {
 }
 
 func (m *Manager) releaseMerge(projectID, taskID string) {
-	m.mergeMu.Lock()
-	defer m.mergeMu.Unlock()
-	if m.mergeHolders[projectID] == taskID {
-		delete(m.mergeHolders, projectID)
+	pm := m.projectMerge(projectID)
+	pm.mu.Lock()
+	defer pm.mu.Unlock()
+	if pm.holder == taskID {
+		pm.holder = ""
 	}
-	m.startNextMerge(projectID)
+	m.startNextMerge(pm, projectID)
 }
 
 func (m *Manager) nextMerge(projectID string) {
-	m.mergeMu.Lock()
-	defer m.mergeMu.Unlock()
-	m.startNextMerge(projectID)
+	pm := m.projectMerge(projectID)
+	pm.mu.Lock()
+	defer pm.mu.Unlock()
+	m.startNextMerge(pm, projectID)
 }
 
-func (m *Manager) startNextMerge(projectID string) {
-	if m.mergeHolders[projectID] != "" {
+func (m *Manager) startNextMerge(pm *projectMerge, projectID string) {
+	if pm.holder != "" {
 		return
 	}
 
@@ -278,7 +299,7 @@ func (m *Manager) startNextMerge(projectID string) {
 			continue
 		}
 
-		err = m.startHeldMerge(ctx, task, login)
+		err = m.startHeldMerge(ctx, pm, task, login)
 		if err == nil {
 			slog.Info("started held merge", "task", task.Id, "by", login)
 			return
@@ -288,7 +309,7 @@ func (m *Manager) startNextMerge(projectID string) {
 	}
 }
 
-func (m *Manager) startHeldMerge(ctx context.Context, task api.Task, login string) error {
+func (m *Manager) startHeldMerge(ctx context.Context, pm *projectMerge, task api.Task, login string) error {
 	project, err := m.store.GetProject(ctx, task.ProjectId)
 	if err != nil {
 		return err
@@ -300,7 +321,7 @@ func (m *Manager) startHeldMerge(ctx context.Context, task api.Task, login strin
 	if user.GitName == "" || user.GitEmail == "" {
 		return ErrNoGitIdentity
 	}
-	return m.startMerge(ctx, task, project, user)
+	return m.startMerge(ctx, pm, task, project, user)
 }
 
 func (m *Manager) fileTaskError(ctx context.Context, task api.Task, sessions []api.AgentSession, msg string) {
@@ -396,12 +417,12 @@ func (m *Manager) squashAndClose(ctx context.Context, taskID, login string) erro
 	if err != nil {
 		return err
 	}
-	err = git.Push(project.RepoPath, commit, project.DefaultBranch, notes)
+	err = git.Push(ctx, project.RepoPath, commit, project.DefaultBranch, notes)
 	if errors.Is(err, git.ErrRemoteMoved) {
 		return err
 	}
 	if err != nil {
-		landed, lerr := pushLanded(project, commit)
+		landed, lerr := pushLanded(ctx, project, commit)
 		if lerr != nil {
 			return &unfinishedMergeError{fmt.Errorf("%w, and %w", err, errors.Unwrap(lerr))}
 		}