bring in khatru and eventstore.

khatru/responding.go

@@ -0,0 +1,119 @@
+package khatru
+
+import (
+	"context"
+	"errors"
+	"sync"
+
+	"github.com/nbd-wtf/go-nostr"
+	"github.com/nbd-wtf/go-nostr/nip45/hyperloglog"
+)
+
+func (rl *Relay) handleRequest(ctx context.Context, id string, eose *sync.WaitGroup, ws *WebSocket, filter nostr.Filter) error {
+	defer eose.Done()
+
+	// overwrite the filter (for example, to eliminate some kinds or
+	// that we know we don't support)
+	for _, ovw := range rl.OverwriteFilter {
+		ovw(ctx, &filter)
+	}
+
+	if filter.LimitZero {
+		// don't do any queries, just subscribe to future events
+		return nil
+	}
+
+	// then check if we'll reject this filter (we apply this after overwriting
+	// because we may, for example, remove some things from the incoming filters
+	// that we know we don't support, and then if the end result is an empty
+	// filter we can just reject it)
+	for _, reject := range rl.RejectFilter {
+		if reject, msg := reject(ctx, filter); reject {
+			return errors.New(nostr.NormalizeOKMessage(msg, "blocked"))
+		}
+	}
+
+	// run the functions to query events (generally just one,
+	// but we might be fetching stuff from multiple places)
+	eose.Add(len(rl.QueryEvents))
+	for _, query := range rl.QueryEvents {
+		ch, err := query(ctx, filter)
+		if err != nil {
+			ws.WriteJSON(nostr.NoticeEnvelope(err.Error()))
+			eose.Done()
+			continue
+		} else if ch == nil {
+			eose.Done()
+			continue
+		}
+
+		go func(ch chan *nostr.Event) {
+			for event := range ch {
+				for _, ovw := range rl.OverwriteResponseEvent {
+					ovw(ctx, event)
+				}
+				ws.WriteJSON(nostr.EventEnvelope{SubscriptionID: &id, Event: *event})
+			}
+			eose.Done()
+		}(ch)
+	}
+
+	return nil
+}
+
+func (rl *Relay) handleCountRequest(ctx context.Context, ws *WebSocket, filter nostr.Filter) int64 {
+	// check if we'll reject this filter
+	for _, reject := range rl.RejectCountFilter {
+		if rejecting, msg := reject(ctx, filter); rejecting {
+			ws.WriteJSON(nostr.NoticeEnvelope(msg))
+			return 0
+		}
+	}
+
+	// run the functions to count (generally it will be just one)
+	var subtotal int64 = 0
+	for _, count := range rl.CountEvents {
+		res, err := count(ctx, filter)
+		if err != nil {
+			ws.WriteJSON(nostr.NoticeEnvelope(err.Error()))
+		}
+		subtotal += res
+	}
+
+	return subtotal
+}
+
+func (rl *Relay) handleCountRequestWithHLL(
+	ctx context.Context,
+	ws *WebSocket,
+	filter nostr.Filter,
+	offset int,
+) (int64, *hyperloglog.HyperLogLog) {
+	// check if we'll reject this filter
+	for _, reject := range rl.RejectCountFilter {
+		if rejecting, msg := reject(ctx, filter); rejecting {
+			ws.WriteJSON(nostr.NoticeEnvelope(msg))
+			return 0, nil
+		}
+	}
+
+	// run the functions to count (generally it will be just one)
+	var subtotal int64 = 0
+	var hll *hyperloglog.HyperLogLog
+	for _, countHLL := range rl.CountEventsHLL {
+		res, fhll, err := countHLL(ctx, filter, offset)
+		if err != nil {
+			ws.WriteJSON(nostr.NoticeEnvelope(err.Error()))
+		}
+		subtotal += res
+		if fhll != nil {
+			if hll == nil {
+				hll = fhll
+			} else {
+				hll.Merge(fhll)
+			}
+		}
+	}
+
+	return subtotal, hll
+}