[IMP] base_report_to_printer: Avoid writing on printing printers/jobs if no change

The cron (by default) every minute, updates the printing.printer and
printing.job records from the cups server. The field values rarely
change, so we can prevent many updates in database.

Also, writing on `printing_printer.server_id` triggers another update
on the printing.job records as the model has a stored related field.

base_report_to_printer/__manifest__.py

@@ -7,7 +7,7 @@
 
 {
     "name": "Report to printer",
-    "version": "14.0.1.0.0",
+    "version": "14.0.1.0.1",
     "category": "Generic Modules/Base",
     "author": "Agile Business Group & Domsense, Pegueroles SCP, NaN,"
     " LasLabs, Camptocamp, Odoo Community Association (OCA),"

base_report_to_printer/models/printing_printer.py

@@ -69,7 +69,7 @@ class PrintingPrinter(models.Model):
 
     def _prepare_update_from_cups(self, cups_connection, cups_printer):
         mapping = {3: "available", 4: "printing", 5: "error"}
-        vals = {
+        cups_vals = {
             "name": cups_printer["printer-info"],
             "model": cups_printer.get("printer-make-and-model", False),
             "location": cups_printer.get("printer-location", False),
@@ -77,6 +77,14 @@ class PrintingPrinter(models.Model):
             "status": mapping.get(cups_printer.get("printer-state"), "unknown"),
             "status_message": cups_printer.get("printer-state-message", ""),
         }
+
+        # prevent write if the field didn't change
+        vals = {
+            fieldname: value
+            for fieldname, value in cups_vals.items()
+            if not self or value != self[fieldname]
+        }
+
         printer_uri = cups_printer["printer-uri-supported"]
         printer_system_name = printer_uri[printer_uri.rfind("/") + 1 :]
         ppd_info = cups_connection.getPPD3(printer_system_name)
@@ -96,13 +104,13 @@ class PrintingPrinter(models.Model):
         if not option:
             return vals
 
-        vals["tray_ids"] = []
+        tray_commands = []
         cups_trays = {
             tray_option["choice"]: tray_option["text"] for tray_option in option.choices
         }
 
         # Add new trays
-        vals["tray_ids"].extend(
+        tray_commands.extend(
             [
                 (0, 0, {"name": text, "system_name": choice})
                 for choice, text in cups_trays.items()
@@ -111,7 +119,7 @@ class PrintingPrinter(models.Model):
         )
 
         # Remove deleted trays
-        vals["tray_ids"].extend(
+        tray_commands.extend(
             [
                 (2, tray.id)
                 for tray in self.tray_ids.filtered(
@@ -119,6 +127,8 @@ class PrintingPrinter(models.Model):
                 )
             ]
         )
+        if tray_commands:
+            vals["tray_ids"] = tray_commands
         return vals
 
     def print_document(self, report, content, **print_opts):

base_report_to_printer/models/printing_server.py

@@ -82,11 +82,14 @@ class PrintingServer(models.Model):
                 printer_values = printer._prepare_update_from_cups(
                     connection, printer_info
                 )
-                printer_values.update(system_name=name, server_id=server.id)
+                if server != printer.server_id:
+                    printer_values["server_id"] = server.id
+
                 updated_printers.append(name)
                 if not printer:
+                    printer_values["system_name"] = name
                     printer.create(printer_values)
-                else:
+                elif printer_values:
                     printer.write(printer_values)
 
             # Set printers not found as unavailable
@@ -172,27 +175,30 @@ class PrintingServer(models.Model):
                 jobs = job_obj.with_context(active_test=False).search(
                     [("job_id_cups", "=", cups_job_id), ("server_id", "=", server.id)]
                 )
-                job_values = {
+                cups_job_values = {
                     "name": job_data.get("job-name", ""),
                     "active": True,
-                    "job_id_cups": cups_job_id,
+                    "job_media_progress": job_data.get("job-media-progress", 0),
-                    "job_media_progress": job_data.get("job-media-progress", False),
                     "job_state": mapping.get(job_data.get("job-state"), "unknown"),
                     "job_state_reason": job_data.get("job-state-reasons", ""),
-                    "time_at_creation": fields.Datetime.to_string(
+                    "time_at_creation": datetime.fromtimestamp(
-                        datetime.fromtimestamp(job_data.get("time-at-creation", False))
+                        job_data.get("time-at-creation", 0)
-                    ),
-                    "time_at_processing": job_data.get("time-at-processing", False)
-                    and fields.Datetime.to_string(
-                        datetime.fromtimestamp(
-                            job_data.get("time-at-processing", False)
-                        )
-                    ),
-                    "time_at_completed": job_data.get("time-at-completed", False)
-                    and fields.Datetime.to_string(
-                        datetime.fromtimestamp(job_data.get("time-at-completed", False))
                     ),
                 }
+                if job_data.get("time-at-processing"):
+                    cups_job_values["time_at_processing"] = datetime.fromtimestamp(
+                        job_data["time-at-processing"]
+                    )
+                if job_data.get("time-at-completed"):
+                    cups_job_values["time_at_completed"] = datetime.fromtimestamp(
+                        job_data["time-at-completed"]
+                    )
+
+                job_values = {
+                    fieldname: value
+                    for fieldname, value in cups_job_values.items()
+                    if not jobs or value != jobs[fieldname]
+                }
 
                 # Search for the printer in Odoo
                 printer_uri = job_data["printer-uri"]
@@ -209,12 +215,14 @@ class PrintingServer(models.Model):
                 # discard here if not printer found
                 if not printer:
                     continue
-                job_values["printer_id"] = printer.id
+                if jobs.printer_id != printer:
+                    job_values["printer_id"] = printer.id
 
-                if jobs:
+                if not jobs:
-                    jobs.write(job_values)
+                    job_values["job_id_cups"] = cups_job_id
-                else:
                     job_obj.create(job_values)
+                elif job_values:
+                    jobs.write(job_values)
 
             # Deactive purged jobs
             if which == "all" and first_job_id == -1: