optimizing badger cache, won a 10-15% improvement in most benchmarks

pkg/dgraph/delete.go

@@ -0,0 +1,190 @@
+package dgraph
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/dgraph-io/dgo/v230/protos/api"
+	"next.orly.dev/pkg/database/indexes/types"
+	"next.orly.dev/pkg/encoders/event"
+	"next.orly.dev/pkg/encoders/hex"
+)
+
+// DeleteEvent deletes an event by its ID
+func (d *D) DeleteEvent(c context.Context, eid []byte) error {
+	idStr := hex.Enc(eid)
+
+	// Find the event's UID
+	query := fmt.Sprintf(`{
+		event(func: eq(event.id, %q)) {
+			uid
+		}
+	}`, idStr)
+
+	resp, err := d.Query(c, query)
+	if err != nil {
+		return fmt.Errorf("failed to find event for deletion: %w", err)
+	}
+
+	// Parse UID
+	var result struct {
+		Event []struct {
+			UID string `json:"uid"`
+		} `json:"event"`
+	}
+
+	if err = unmarshalJSON(resp.Json, &result); err != nil {
+		return err
+	}
+
+	if len(result.Event) == 0 {
+		return nil // Event doesn't exist
+	}
+
+	// Delete the event node
+	mutation := &api.Mutation{
+		DelNquads: []byte(fmt.Sprintf("<%s> * * .", result.Event[0].UID)),
+		CommitNow: true,
+	}
+
+	if _, err = d.Mutate(c, mutation); err != nil {
+		return fmt.Errorf("failed to delete event: %w", err)
+	}
+
+	return nil
+}
+
+// DeleteEventBySerial deletes an event by its serial number
+func (d *D) DeleteEventBySerial(c context.Context, ser *types.Uint40, ev *event.E) error {
+	serial := ser.Get()
+
+	// Find the event's UID
+	query := fmt.Sprintf(`{
+		event(func: eq(event.serial, %d)) {
+			uid
+		}
+	}`, serial)
+
+	resp, err := d.Query(c, query)
+	if err != nil {
+		return fmt.Errorf("failed to find event for deletion: %w", err)
+	}
+
+	// Parse UID
+	var result struct {
+		Event []struct {
+			UID string `json:"uid"`
+		} `json:"event"`
+	}
+
+	if err = unmarshalJSON(resp.Json, &result); err != nil {
+		return err
+	}
+
+	if len(result.Event) == 0 {
+		return nil // Event doesn't exist
+	}
+
+	// Delete the event node
+	mutation := &api.Mutation{
+		DelNquads: []byte(fmt.Sprintf("<%s> * * .", result.Event[0].UID)),
+		CommitNow: true,
+	}
+
+	if _, err = d.Mutate(c, mutation); err != nil {
+		return fmt.Errorf("failed to delete event: %w", err)
+	}
+
+	return nil
+}
+
+// DeleteExpired removes events that have passed their expiration time
+func (d *D) DeleteExpired() {
+	// Query for events with expiration tags
+	// This is a stub - full implementation would:
+	// 1. Find events with "expiration" tag
+	// 2. Check if current time > expiration time
+	// 3. Delete those events
+}
+
+// ProcessDelete processes a kind 5 deletion event
+func (d *D) ProcessDelete(ev *event.E, admins [][]byte) (err error) {
+	if ev.Kind != 5 {
+		return fmt.Errorf("event is not a deletion event (kind 5)")
+	}
+
+	// Extract event IDs to delete from tags
+	for _, tag := range *ev.Tags {
+		if len(tag.T) >= 2 && string(tag.T[0]) == "e" {
+			eventID := tag.T[1]
+
+			// Verify the deletion is authorized (author must match or be admin)
+			if err = d.CheckForDeleted(ev, admins); err != nil {
+				continue
+			}
+
+			// Delete the event
+			if err = d.DeleteEvent(context.Background(), eventID); err != nil {
+				// Log error but continue with other deletions
+				d.Logger.Errorf("failed to delete event %s: %v", hex.Enc(eventID), err)
+			}
+		}
+	}
+
+	return nil
+}
+
+// CheckForDeleted checks if an event has been deleted
+func (d *D) CheckForDeleted(ev *event.E, admins [][]byte) (err error) {
+	// Query for delete events (kind 5) that reference this event
+	evID := hex.Enc(ev.ID[:])
+
+	query := fmt.Sprintf(`{
+		deletes(func: eq(event.kind, 5)) @filter(eq(event.pubkey, %q)) {
+			uid
+			event.pubkey
+			references @filter(eq(event.id, %q)) {
+				event.id
+			}
+		}
+	}`, hex.Enc(ev.Pubkey), evID)
+
+	resp, err := d.Query(context.Background(), query)
+	if err != nil {
+		return fmt.Errorf("failed to check for deletions: %w", err)
+	}
+
+	var result struct {
+		Deletes []struct {
+			UID        string `json:"uid"`
+			Pubkey     string `json:"event.pubkey"`
+			References []struct {
+				ID string `json:"event.id"`
+			} `json:"references"`
+		} `json:"deletes"`
+	}
+
+	if err = unmarshalJSON(resp.Json, &result); err != nil {
+		return err
+	}
+
+	// Check if any delete events reference this event
+	for _, del := range result.Deletes {
+		if len(del.References) > 0 {
+			// Check if deletion is from the author or an admin
+			delPubkey, _ := hex.Dec(del.Pubkey)
+			if string(delPubkey) == string(ev.Pubkey) {
+				return fmt.Errorf("event has been deleted by author")
+			}
+
+			// Check admins
+			for _, admin := range admins {
+				if string(delPubkey) == string(admin) {
+					return fmt.Errorf("event has been deleted by admin")
+				}
+			}
+		}
+	}
+
+	return nil
+}