Optimize buffer allocation logic in event encoding to reduce GC pressure and improve performance.

pkg/encoders/event/event.go

@@ -112,6 +112,22 @@ func (ev *E) Marshal(dst []byte) (b []byte) {
 	b = append(b, '"')
 	b = append(b, jId...)
 	b = append(b, `":"`...)
+	// it can happen the slice has insufficient capacity to hold the content AND
+	// the signature at this point, because the signature encoder must have
+	// sufficient capacity pre-allocated as it does not append to the buffer.
+	// unlike every other encoding function up to this point. This also ensures
+	// that since the bufpool defaults to 1kb, most events won't have a
+	// re-allocation required, but if they do, it will be this next one, and it
+	// integrates properly with the buffer pool, reducing GC pressure and
+	// avoiding new heap allocations.
+	if cap(b) < len(b)+len(ev.Content)+7+256+2 {
+		b2 := make([]byte, len(b)+len(ev.Content)*2+7+256+2)
+		copy(b2, b)
+		b2 = b2[:len(b)]
+		// return the old buffer to the pool for reuse.
+		bufpool.PutBytes(b)
+		b = b2
+	}
 	b = b[:len(b)+2*sha256.Size]
 	xhex.Encode(b[len(b)-2*sha256.Size:], ev.ID)
 	b = append(b, `","`...)
@@ -136,22 +152,6 @@ func (ev *E) Marshal(dst []byte) (b []byte) {
 	b = append(b, `,"`...)
 	b = append(b, jContent...)
 	b = append(b, `":"`...)
-	// it can happen the slice has insufficient capacity to hold the content AND
-	// the signature at this point, because the signature encoder must have
-	// sufficient capacity pre-allocated as it does not append to the buffer.
-	// unlike every other encoding function up to this point. This also ensures
-	// that since the bufpool defaults to 1kb, most events won't have a
-	// re-allocation required, but if they do, it will be this next one, and it
-	// integrates properly with the buffer pool, reducing GC pressure and
-	// avoiding new heap allocations.
-	if cap(b) < len(b)+len(ev.Content)+7+256+2 {
-		b2 := make([]byte, len(b)+len(ev.Content)*2+7+256+2)
-		copy(b2, b)
-		b2 = b2[:len(b)]
-		// return the old buffer to the pool for reuse.
-		bufpool.PutBytes(b)
-		b = b2
-	}
 	b = text.NostrEscape(b, ev.Content)
 	b = append(b, `","`...)
 	b = append(b, jSig...)