From 2ad188201bee633c583a926000771f6e90c93d4d Mon Sep 17 00:00:00 2001
From: Xavier-Do <xdo@odoo.com>
Date: Fri, 31 Mar 2023 17:05:27 +0200
Subject: [PATCH] [IMP] runbot_merge: speedup frontend page

The mergebot page become a bit slow with the years, it is time to make
small optimisation to speed up thinks a little.

Note: all changes where applied modifying the views or adding index by
hand. There is still room for improvement but it would need more in
depth refactoring, mainly adding specialized computed fields to
enable a better batching.

The first issue was using branch.staging_ids

    branch.staging_ids.sorted(lambda s: s.staged_at, reverse=True)[:6]

The number of staging_ids is increasing and prefetching + sorting all
of them is slow.

The proposed solution is to replace it by a search, not ideal, a
specialized compute field may be a good idea, but this is a quick fix
that can be done editing a view.

    branch.env['runbot_merge.stagings'].search([('target', '=', branch.id)],order='staged_at desc', limit=6)

Other changes are just index on critical columns.

Before changes, /runbot_merge page takes ~5s to load
After changes,  /runbot_merge page takes ~1s to load

Small note: note 100% sure that runbot_merge.batch.target was useful
---
 runbot_merge/models/pull_requests.py | 10 +++++-----
 runbot_merge/views/templates.xml     |  2 +-
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/runbot_merge/models/pull_requests.py b/runbot_merge/models/pull_requests.py
index 549d673a..b7490aa9 100644
--- a/runbot_merge/models/pull_requests.py
+++ b/runbot_merge/models/pull_requests.py
@@ -1722,7 +1722,7 @@ class Commit(models.Model):
 class Stagings(models.Model):
     _name = _description = 'runbot_merge.stagings'
 
-    target = fields.Many2one('runbot_merge.branch', required=True)
+    target = fields.Many2one('runbot_merge.branch', required=True, index=True)
 
     batch_ids = fields.One2many(
         'runbot_merge.batch', 'staging_id',
@@ -1737,7 +1737,7 @@ class Stagings(models.Model):
     ], default='pending')
     active = fields.Boolean(default=True)
 
-    staged_at = fields.Datetime(default=fields.Datetime.now)
+    staged_at = fields.Datetime(default=fields.Datetime.now, index=True)
     timeout_limit = fields.Datetime(store=True, compute='_compute_timeout_limit')
     reason = fields.Text("Reason for final state (if any)")
 
@@ -2127,9 +2127,9 @@ class Batch(models.Model):
     """
     _name = _description = 'runbot_merge.batch'
 
-    target = fields.Many2one('runbot_merge.branch', required=True)
-    staging_id = fields.Many2one('runbot_merge.stagings')
-    split_id = fields.Many2one('runbot_merge.split')
+    target = fields.Many2one('runbot_merge.branch', required=True, index=True)
+    staging_id = fields.Many2one('runbot_merge.stagings', index=True)
+    split_id = fields.Many2one('runbot_merge.split', index=True)
 
     prs = fields.Many2many('runbot_merge.pull_requests')
 
diff --git a/runbot_merge/views/templates.xml b/runbot_merge/views/templates.xml
index 5059005e..73e8e883 100644
--- a/runbot_merge/views/templates.xml
+++ b/runbot_merge/views/templates.xml
@@ -154,7 +154,7 @@
     <template id="stagings" name="mergebot branch stagings">
         <t t-set="repo_statuses" t-value="branch.project_id.repo_ids.having_branch(branch).status_ids"/>
         <ul class="list-unstyled stagings">
-            <t t-foreach="branch.staging_ids.sorted(lambda s: s.staged_at, reverse=True)[:6]" t-as="staging">
+            <t t-foreach="branch.env['runbot_merge.stagings'].search([('target', '=', branch.id)], order='staged_at desc', limit=6)" t-as="staging">
                 <t t-set="success" t-value="staging.state == 'success'"/>
                 <t t-set="failure" t-value="staging.state == 'failure'"/>
                 <t t-set="pending" t-value="staging.active and (not staging.state or staging.state == 'pending')"/>