From c2fb000b976d490e6741938f1e880be9e5d7f7cb Mon Sep 17 00:00:00 2001 From: Christoph Berg Date: Fri, 16 Oct 2026 18:59:41 +0200 Subject: [PATCH v14 09/12] Store the badge image md5 in the database badge_image() reads imagedata out of TOAST and computes its md5 on every request, including when all it has to do is answer If-None-Match with a 304. Add a Badge.imagehash generated column holding the md5 of imagedata, empty when there is no image, so a revalidation can be answered from this alone. The column is used the same way as SecurityPatch.cvenumber: the database keeps it current, so nothing has to backfill it and no code path can forget to update it. The following commits add the migration and make badge_image() use it. --- pgweb/contributors/models.py | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/pgweb/contributors/models.py b/pgweb/contributors/models.py index d3bd8eef..bf8f8b62 100644 --- a/pgweb/contributors/models.py +++ b/pgweb/contributors/models.py @@ -3,7 +3,7 @@ import re from django.core.exceptions import ValidationError from django.db import models -from django.db.models import Case, When +from django.db.models import Case, F, Func, Value, When from django.db.models.functions import Length from django.db.models.lookups import GreaterThan from django.contrib.auth.models import User @@ -112,6 +112,19 @@ class Badge(TwostateModerateModel): description = models.TextField(null=True, blank=True, help_text='What did the people do who contributed here?') url = models.URLField(max_length=100, null=True, blank=True, verbose_name='Contribution URL', help_text='URL for this contribution, e.g. the conference homepage. (Leave blank when there is no URL.)') imagedata = ImageBinaryField(max_length=1000000, resolution=(150, 150), auto_scale=False, blank=True, null=True, verbose_name="Image", help_text="Square image, must be 150x150. JPEG or PNG, up to 1 MB. When left blank, the PostgreSQL logo will be used.") + imagehash = models.GeneratedField( + # md5 of the image, computed and stored by the database, so badge_image() + # can answer If-None-Match from this alone, without reading imagedata out + # of TOAST and hashing it on every request. Empty when there is no image. + expression=Case( + When(GreaterThan(Length('imagedata'), 0), + then=Func(F('imagedata'), function='MD5', output_field=models.TextField())), + default=Value(''), + output_field=models.TextField(), + ), + output_field=models.TextField(), + db_persist=True, + ) contact = models.CharField(max_length=100, null=True, blank=True, verbose_name='Contact address', help_text='Contact address (email, URL, other) for people who want to be added as badge holder') holders = models.ManyToManyField(User, through="Badgeholder", through_fields=("badge", "user"), blank=True) -- 2.53.0