perf: offload network printer socket communication to background thread to prevent POS blocking

models/pos_printer.py

@@ -1,5 +1,6 @@
 import socket
 import logging
+import threading
 from odoo import models, fields, api, _
 
 _logger = logging.getLogger(__name__)
@@ -28,19 +29,24 @@ class PosPrinter(models.Model):
     def print_network_kitchen_receipt(self, printer_id, receipt_data):
         """
         Receives structural receipt_data from POS frontend and sends ESC/POS string to network printer.
-        receipt_data expected format:
-        {
-            'order_name': 'Order 0001',
-            'order_time': '2023-10-01 12:00:00',
-            'lines': [ { 'name': 'Burger', 'qty': 1, 'note': 'No onions' } ],
-            'waiter': 'Mitchell Admin',
-            'table': 'T1'
-        }
+        Optimized to use background threading to prevent blocking the POS transaction/RPC.
         """
         printer = self.browse(printer_id)
         if not printer or not printer.network_printer_ip:
             return {'successful': False, 'message': 'Printer IP not configured'}
 
+        # Start printing in a background thread to avoid POS timeout
+        # We don't need a new cursor here as we've already browsed the printer
+        # and we don't write to the database in the thread.
+        thread = threading.Thread(target=self._threaded_print, args=(printer.network_printer_ip, receipt_data))
+        thread.daemon = True # Ensure thread doesn't block server shutdown
+        thread.start()
+        
+        return {'successful': True, 'message': 'Print job sent to background queue'}
+
+    def _threaded_print(self, ip, receipt_data):
+        """Perform the actual socket communication in the background."""
+        try:
             # Build basic ESC/POS commands
             ESC = b'\x1b'
             GS = b'\x1d'
@@ -87,13 +93,11 @@ class PosPrinter(models.Model):
             data += b"-" * 32 + NEWLINE + NEWLINE + NEWLINE + CUT
 
             # Send to printer
-        try:
             s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-            s.settimeout(3.0)
-            s.connect((printer.network_printer_ip, 9100))
+            s.settimeout(5.0) # Slightly longer timeout for background print
+            s.connect((ip, 9100))
             s.sendall(data)
             s.close()
-            return {'successful': True}
+            _logger.info("Successfully printed to kitchen printer at %s", ip)
         except Exception as e:
-            _logger.error("Failed to print to network ESC/POS printer %s: %s", printer.network_printer_ip, e)
-            return {'successful': False, 'message': str(e)}
+            _logger.error("Background kitchen print failed for IP %s: %s", ip, e)