improve/refactor websocket connections hoping this will fix the undetected disconnections we're seeing.

this commit also remove all the sonic envelope parsing and reintroduces filters in REQ as a slice instead of as a singleton.

why? well, the sonic stuff wasn't really that fast, it was a little bit but only got fast enough once I introduced unsafe conversions between []byte and string and did weird unsafe reuse of []byte in order to save the values of tags, which would definitely cause issues in the future if the caller wasn't aware of it (and even if they were, like myself).

and the filters stuff is because we abandoned the idea of changing NIP-01 to only accept one filter per REQ.

envelopes.go

@@ -13,22 +13,19 @@ import (
 	"github.com/tidwall/gjson"
 )
 
-var UnknownLabel = errors.New("unknown envelope label")
+var (
+	UnknownLabel        = errors.New("unknown envelope label")
+	InvalidJsonEnvelope = errors.New("invalid json envelope")
+)
 
-type MessageParser interface {
-	// ParseMessage parses a message into an Envelope.
-	ParseMessage(string) (Envelope, error)
-}
-
-// Deprecated: use NewMessageParser instead
-func ParseMessage(message string) Envelope {
+func ParseMessage(message string) (Envelope, error) {
 	firstQuote := strings.IndexByte(message, '"')
 	if firstQuote == -1 {
-		return nil
+		return nil, InvalidJsonEnvelope
 	}
 	secondQuote := strings.IndexByte(message[firstQuote+1:], '"')
 	if secondQuote == -1 {
-		return nil
+		return nil, InvalidJsonEnvelope
 	}
 	label := message[firstQuote+1 : firstQuote+1+secondQuote]
 
@@ -56,14 +53,14 @@ func ParseMessage(message string) Envelope {
 		x := CloseEnvelope("")
 		v = &x
 	default:
-		return nil
+		return nil, UnknownLabel
 	}
 
 	if err := v.FromJSON(message); err != nil {
-		return nil
+		return nil, err
 	}
 
-	return v
+	return v, nil
 }
 
 // Envelope is the interface for all nostr message envelopes.
@@ -124,10 +121,14 @@ func (v EventEnvelope) MarshalJSON() ([]byte, error) {
 // ReqEnvelope represents a REQ message.
 type ReqEnvelope struct {
 	SubscriptionID string
-	Filter
+	Filters        []Filter
 }
 
 func (_ ReqEnvelope) Label() string { return "REQ" }
+func (c ReqEnvelope) String() string {
+	v, _ := json.Marshal(c)
+	return string(v)
+}
 
 func (v *ReqEnvelope) FromJSON(data string) error {
 	r := gjson.Parse(data)
@@ -136,8 +137,12 @@ func (v *ReqEnvelope) FromJSON(data string) error {
 		return fmt.Errorf("failed to decode REQ envelope: missing filters")
 	}
 	v.SubscriptionID = string(unsafe.Slice(unsafe.StringData(arr[1].Str), len(arr[1].Str)))
-	if err := easyjson.Unmarshal(unsafe.Slice(unsafe.StringData(arr[2].Raw), len(arr[2].Raw)), &v.Filter); err != nil {
-		return fmt.Errorf("on filter: %w", err)
+
+	v.Filters = make([]Filter, len(arr)-2)
+	for i, filterj := range arr[2:] {
+		if err := easyjson.Unmarshal(unsafe.Slice(unsafe.StringData(filterj.Raw), len(filterj.Raw)), &v.Filters[i]); err != nil {
+			return fmt.Errorf("on filter: %w", err)
+		}
 	}
 
 	return nil
@@ -148,7 +153,7 @@ func (v ReqEnvelope) MarshalJSON() ([]byte, error) {
 	w.RawString(`["REQ","`)
 	w.RawString(v.SubscriptionID)
 	w.RawString(`",`)
-	v.Filter.MarshalEasyJSON(&w)
+	v.Filters[0].MarshalEasyJSON(&w)
 	w.RawString(`]`)
 	return w.BuildBytes()
 }