Send pending updates when a new slot is received

Author: tompntn

pc/manager.cpp

@@ -746,6 +746,12 @@ void manager::on_response( rpc::get_slot *res )
   if (
     has_status( PC_PYTH_RPC_CONNECTED )
   ) {
+    
+      // New slot received, so flush all pending updates for all active users
+      for( user *uptr = olist_.first(); uptr; uptr = uptr->get_next() ) {
+        uptr->send_pending_upds();
+      }
+
     if ( sub_ ) {
       sub_->on_slot_publish( this );
     }

pc/user.cpp

@@ -11,6 +11,7 @@
 #define PC_JSON_UNKNOWN_SYMBOL  -32000
 #define PC_JSON_MISSING_PERMS   -32001
 #define PC_JSON_NOT_READY       -32002
+#define PC_BATCH_SEND_FAILED    -32010
 
 using namespace pc;
 
@@ -326,6 +327,19 @@ void user::parse_get_product( uint32_t tok, uint32_t itok )
   add_tail( itok );
 }
 
+void user::send_pending_upds()
+{
+  if ( pending_vec_.empty() ) {
+    return;
+  }
+
+  if ( !price::send( pending_vec_.data(), pending_vec_.size()) ) {
+    add_error( 0, PC_BATCH_SEND_FAILED, "batch send failed - please check the pyth logs" );
+  }
+
+  pending_vec_.clear();
+}
+
 void user::parse_get_all_products( uint32_t itok )
 {
   add_header();

pc/user.hpp

@@ -43,6 +43,9 @@ namespace pc
     // symbol price schedule callback
     void on_response( price_sched *, uint64_t ) override;
 
+    // send all pending updates
+    void send_pending_upds();
+
   private:
 
     // http-only request parsing