jobqueue: Introduce jobqueue backed by a postgres database

Co-authored-by: sanne <sanne.raymaekers@gmail.com>

vendor/github.com/jackc/pgproto3/v2/copy_data.go

@@ -0,0 +1,44 @@
+package pgproto3
+
+import (
+	"encoding/hex"
+	"encoding/json"
+
+	"github.com/jackc/pgio"
+)
+
+type CopyData struct {
+	Data []byte
+}
+
+// Backend identifies this message as sendable by the PostgreSQL backend.
+func (*CopyData) Backend() {}
+
+// Frontend identifies this message as sendable by a PostgreSQL frontend.
+func (*CopyData) Frontend() {}
+
+// Decode decodes src into dst. src must contain the complete message with the exception of the initial 1 byte message
+// type identifier and 4 byte message length.
+func (dst *CopyData) Decode(src []byte) error {
+	dst.Data = src
+	return nil
+}
+
+// Encode encodes src into dst. dst will include the 1 byte message type identifier and the 4 byte message length.
+func (src *CopyData) Encode(dst []byte) []byte {
+	dst = append(dst, 'd')
+	dst = pgio.AppendInt32(dst, int32(4+len(src.Data)))
+	dst = append(dst, src.Data...)
+	return dst
+}
+
+// MarshalJSON implements encoding/json.Marshaler.
+func (src CopyData) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		Type string
+		Data string
+	}{
+		Type: "CopyData",
+		Data: hex.EncodeToString(src.Data),
+	})
+}