Implement single-owner reconciliation modes

internal/publish/execute.go

@@ -12,6 +12,7 @@ import (
 )
 
 func Execute(ctx context.Context, req Request, plan Plan) error {
+	plan.Reconciliation = normalizeReconciliation(plan.Reconciliation)
 	switch plan.Action {
 	case ActionSkipSame, ActionSkipDestinationNewer:
 		return nil
@@ -24,11 +25,13 @@ func Execute(ctx context.Context, req Request, plan Plan) error {
 		if plan.ExistingState == nil {
 			return fmt.Errorf("replace requires existing destination state")
 		}
-		if err := req.DestinationBackend.DeleteManagedBundle(ctx, req.DestinationBundlePath, stateOutputManagedPaths(plan.ExistingState.Outputs), storage.DeleteOptions{IgnoreMissing: true, PruneEmptyDirs: true}); err != nil {
-			return err
-		}
-		if err := ensureDestinationEmpty(ctx, req.DestinationBackend, req.DestinationBundlePath); err != nil {
-			return err
+		if plan.Reconciliation.Mode == config.ReconciliationModeReplace {
+			if err := req.DestinationBackend.DeleteManagedBundle(ctx, req.DestinationBundlePath, state.ManagedOutputPaths(*plan.ExistingState), storage.DeleteOptions{IgnoreMissing: true, PruneEmptyDirs: true}); err != nil {
+				return err
+			}
+			if err := ensureDestinationEmpty(ctx, req.DestinationBackend, req.DestinationBundlePath); err != nil {
+				return err
+			}
 		}
 	}
 	if plan.Action == ActionForceReplace {
@@ -39,10 +42,20 @@ func Execute(ctx context.Context, req Request, plan Plan) error {
 			return err
 		}
 	}
+	if usesMergeRetention(plan) {
+		if err := ensureMergeOutputPaths(ctx, req.DestinationBackend, req.DestinationBundlePath, plan); err != nil {
+			return err
+		}
+	}
 
 	writtenOutputs := make([]Output, 0, len(plan.Outputs))
+	newOutputs := make([]Output, 0, len(plan.Outputs))
 	cleanup := func() {
-		_ = req.DestinationBackend.DeleteManagedBundle(ctx, req.DestinationBundlePath, ManagedOutputPaths(writtenOutputs), storage.DeleteOptions{IgnoreMissing: true, PruneEmptyDirs: true})
+		outputs := writtenOutputs
+		if usesMergeRetention(plan) {
+			outputs = newOutputs
+		}
+		_ = req.DestinationBackend.DeleteManagedBundle(ctx, req.DestinationBundlePath, ManagedOutputPaths(outputs), storage.DeleteOptions{IgnoreMissing: true, PruneEmptyDirs: true})
 	}
 	for _, output := range plan.Outputs {
 		destinationPath, err := storage.Join(req.DestinationBundlePath, output.DestinationPath)
@@ -63,19 +76,26 @@ func Execute(ctx context.Context, req Request, plan Plan) error {
 				return err
 			}
 		}
-		if _, err := req.DestinationBackend.WriteFile(ctx, destinationPath, data, storage.WriteOptions{Overwrite: false, PreferAtomic: true}); err != nil {
+		managed := outputManagedByExistingState(output, plan.ExistingState)
+		if _, err := req.DestinationBackend.WriteFile(ctx, destinationPath, data, storage.WriteOptions{Overwrite: managed && usesMergeRetention(plan), PreferAtomic: true}); err != nil {
 			cleanup()
 			return err
 		}
 		writtenOutputs = append(writtenOutputs, output)
+		if !managed {
+			newOutputs = append(newOutputs, output)
+		}
 	}
 
 	now := time.Now().UTC()
 	createdAt := now
-	existingOutputs := []state.OutputFile(nil)
 	if plan.ExistingState != nil {
 		createdAt = plan.ExistingState.CreatedAt
-		existingOutputs = plan.ExistingState.Outputs
+	}
+	stateOutputs, err := stateOutputsForPlan(plan, now)
+	if err != nil {
+		cleanup()
+		return err
 	}
 	destinationState := state.DistributorState{
 		SchemaVersion:      state.SchemaVersion,
@@ -86,9 +106,9 @@ func Execute(ctx context.Context, req Request, plan Plan) error {
 		CreatedAt:          createdAt,
 		UpdatedAt:          now,
 		State:              state.StatePolicy{Mode: state.StateModeSingleOwner},
-		Reconciliation:     state.ReconciliationPolicy{Mode: config.ReconciliationModeReplace},
+		Reconciliation:     state.ReconciliationPolicy{Mode: plan.Reconciliation.Mode},
 		Source:             state.SourceState{Manifest: req.SourceBundle.Manifest},
-		Outputs:            state.ProjectOutputs(StateOutputProjections(plan.Outputs), existingOutputs, now),
+		Outputs:            stateOutputs,
 	}
 	if plan.PrimaryURL != "" {
 		destinationState.Links = &state.LinkState{PrimaryURL: plan.PrimaryURL}
@@ -108,9 +128,51 @@ func Execute(ctx context.Context, req Request, plan Plan) error {
 		cleanup()
 		return err
 	}
-	if _, err := req.DestinationBackend.WriteFile(ctx, statePath, data, storage.WriteOptions{Overwrite: false, PreferAtomic: true}); err != nil {
+	if _, err := req.DestinationBackend.WriteFile(ctx, statePath, data, storage.WriteOptions{Overwrite: plan.ExistingState != nil, PreferAtomic: true}); err != nil {
 		cleanup()
 		return err
 	}
 	return nil
 }
+
+func ensureMergeOutputPaths(ctx context.Context, backend storage.Backend, bundlePath string, plan Plan) error {
+	for _, output := range plan.Outputs {
+		if outputManagedByExistingState(output, plan.ExistingState) {
+			continue
+		}
+		destinationPath, err := storage.Join(bundlePath, output.DestinationPath)
+		if err != nil {
+			return err
+		}
+		if _, err := backend.Stat(ctx, destinationPath); err == nil {
+			return fmt.Errorf("merge output path %s exists but is not managed by destination state", storage.DisplayPath(output.DestinationPath))
+		} else if !storage.IsNotFound(err) {
+			return err
+		}
+	}
+	return nil
+}
+
+func outputManagedByExistingState(output Output, existing *state.DistributorState) bool {
+	if existing == nil {
+		return false
+	}
+	_, ok := state.FindOutputByPath(existing.Outputs, output.DestinationPath)
+	return ok
+}
+
+func stateOutputsForPlan(plan Plan, now time.Time) ([]state.OutputFile, error) {
+	existingOutputs := []state.OutputFile(nil)
+	if plan.ExistingState != nil {
+		existingOutputs = plan.ExistingState.Outputs
+	}
+	planned := state.ProjectOutputs(StateOutputProjections(plan.Outputs), existingOutputs, now)
+	if !usesMergeRetention(plan) || plan.ExistingState == nil {
+		return planned, nil
+	}
+	return state.MergeOutputFiles(plan.ExistingState.Outputs, planned)
+}
+
+func usesMergeRetention(plan Plan) bool {
+	return plan.Reconciliation.Mode == config.ReconciliationModeMerge && plan.Action == ActionReplaceOlder
+}