add ratelimiter model

django_project/gap_api/migrations/0004_apiratelimiter.py

@@ -0,0 +1,26 @@
+# Generated by Django 4.2.7 on 2024-10-30 11:51
+
+from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+        ('gap_api', '0003_location_location_user_locationname'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='APIRateLimiter',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('minute_limit', models.IntegerField()),
+                ('hour_limit', models.IntegerField()),
+                ('day_limit', models.IntegerField()),
+                ('user', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, to=settings.AUTH_USER_MODEL)),
+            ],
+        ),
+    ]

django_project/gap_api/models/__init__.py

@@ -1,3 +1,4 @@
 from gap_api.models.api_request_log import *  # noqa
 from gap_api.models.api_config import *  # noqa
 from gap_api.models.location import *  # noqa
+from gap_api.models.rate_limiter import *  # noqa

django_project/gap_api/models/rate_limiter.py

@@ -0,0 +1,128 @@
+# coding=utf-8
+"""
+Tomorrow Now GAP API.
+
+.. note:: Models for Rate Limiter
+"""
+
+from django.db import models
+from django.conf import settings
+from django.core.cache import cache
+from django.db.models.signals import post_save
+from django.dispatch import receiver
+
+
+class APIRateLimiter(models.Model):
+    """Models that stores GAP API rate limiter."""
+
+    GLOBAL_CACHE_KEY = 'gap-api-ratelimit-global'
+
+    user = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.SET_NULL,
+        null=True,
+        blank=True
+    )
+    minute_limit = models.IntegerField()
+    hour_limit = models.IntegerField()
+    day_limit = models.IntegerField()
+
+    @property
+    def config_name(self):
+        """Return config name."""
+        if self.user:
+            return self.user.username
+        return 'global'
+
+    @property
+    def cache_key(self):
+        """Return cache key for this config."""
+        if self.user:
+            return f'gap-api-ratelimit-{self.user.id}'
+        return APIRateLimiter.GLOBAL_CACHE_KEY
+
+    @property
+    def cache_value(self):
+        """Get dict cache value."""
+        return {
+            'minute': self.minute_limit,
+            'hour': self.hour_limit,
+            'day': self.day_limit
+        }
+
+    def set_cache(self):
+        """Set rate limit to cache."""
+        cache.set(
+            self.cache_key,
+            f'{self.minute_limit}:{self.hour_limit}:{self.day_limit}',
+            timeout=None
+        )
+
+    def clear_cache(self):
+        """Clear cache for this config."""
+        cache.delete(self.cache_key)
+
+    @staticmethod
+    def parse_cache_value(cache_str: str):
+        """Parse cache value."""
+        values = cache_str.split(':')
+        return {
+            'minute': values[0],
+            'hour': values[1],
+            'day': values[2]
+        }
+
+    @staticmethod
+    def get_global_config():
+        """Get global config cache."""
+        config_cache = cache.get(APIRateLimiter.GLOBAL_CACHE_KEY, None)
+        if config_cache:
+            return APIRateLimiter.parse_cache_value(config_cache)
+
+        limit = APIRateLimiter.objects.filter(
+            user=None
+        ).first()
+        if limit:
+            # set to cache
+            limit.set_cache()
+            return limit.cache_value
+
+        return None
+
+    @staticmethod
+    def get_config(user):
+        """Return config for given user."""
+        cache_key = f'gap-api-ratelimit-{user.id}'
+        config_cache = cache.get(cache_key, None)
+
+        if config_cache == 'global':
+            # use global config
+            pass
+        elif config_cache is None:
+            # find from table
+            limit = APIRateLimiter.objects.filter(
+                user=user
+            ).first()
+
+            if limit:
+                # set to cache if found
+                limit.set_cache()
+                return limit.cache_value
+            else:
+                # set to use global config
+                cache.set(cache_key, 'global')
+        else:
+            # parse config for the user
+            return APIRateLimiter.parse_cache_value(config_cache)
+
+        return APIRateLimiter.get_global_config()
+
+
+@receiver(post_save, sender=APIRateLimiter)
+def ratelimiter_post_create(
+        sender, instance: APIRateLimiter, created, *args, **kwargs):
+    """Clear cache after saving the object."""
+    if created:
+        return
+
+    cache.delete(instance.cache_key)