Synchronize and cache Generic Camera still image fetching (#105821)

tests/components/generic/test_camera.py

@@ -1,9 +1,11 @@
 """The tests for generic camera component."""
 import asyncio
+from datetime import timedelta
 from http import HTTPStatus
 from unittest.mock import patch
 
 import aiohttp
+from freezegun.api import FrozenDateTimeFactory
 import httpx
 import pytest
 import respx
@@ -49,6 +51,7 @@ async def test_fetching_url(
                 "username": "user",
                 "password": "pass",
                 "authentication": "basic",
+                "framerate": 20,
             }
         },
     )
@@ -63,10 +66,87 @@ async def test_fetching_url(
     body = await resp.read()
     assert body == fakeimgbytes_png
 
+    # sleep .1 seconds to make cached image expire
+    await asyncio.sleep(0.1)
+
     resp = await client.get("/api/camera_proxy/camera.config_test")
     assert respx.calls.call_count == 2
 
 
+@respx.mock
+async def test_image_caching(
+    hass: HomeAssistant,
+    hass_client: ClientSessionGenerator,
+    freezer: FrozenDateTimeFactory,
+    fakeimgbytes_png,
+) -> None:
+    """Test that the image is cached and not fetched more often than the framerate indicates."""
+    respx.get("http://example.com").respond(stream=fakeimgbytes_png)
+
+    framerate = 5
+    await async_setup_component(
+        hass,
+        "camera",
+        {
+            "camera": {
+                "name": "config_test",
+                "platform": "generic",
+                "still_image_url": "http://example.com",
+                "username": "user",
+                "password": "pass",
+                "authentication": "basic",
+                "framerate": framerate,
+            }
+        },
+    )
+    await hass.async_block_till_done()
+
+    client = await hass_client()
+
+    resp = await client.get("/api/camera_proxy/camera.config_test")
+    assert resp.status == HTTPStatus.OK
+    body = await resp.read()
+    assert body == fakeimgbytes_png
+
+    resp = await client.get("/api/camera_proxy/camera.config_test")
+    assert resp.status == HTTPStatus.OK
+    body = await resp.read()
+    assert body == fakeimgbytes_png
+
+    # time is frozen, image should have come from cache
+    assert respx.calls.call_count == 1
+
+    # advance time by 150ms
+    freezer.tick(timedelta(seconds=0.150))
+
+    resp = await client.get("/api/camera_proxy/camera.config_test")
+    assert resp.status == HTTPStatus.OK
+    body = await resp.read()
+    assert body == fakeimgbytes_png
+
+    # Only 150ms have passed, image should still have come from cache
+    assert respx.calls.call_count == 1
+
+    # advance time by another 150ms
+    freezer.tick(timedelta(seconds=0.150))
+
+    resp = await client.get("/api/camera_proxy/camera.config_test")
+    assert resp.status == HTTPStatus.OK
+    body = await resp.read()
+    assert body == fakeimgbytes_png
+
+    # 300ms have passed, now we should have fetched a new image
+    assert respx.calls.call_count == 2
+
+    resp = await client.get("/api/camera_proxy/camera.config_test")
+    assert resp.status == HTTPStatus.OK
+    body = await resp.read()
+    assert body == fakeimgbytes_png
+
+    # Still only 300ms have passed, should have returned the cached image
+    assert respx.calls.call_count == 2
+
+
 @respx.mock
 async def test_fetching_without_verify_ssl(
     hass: HomeAssistant, hass_client: ClientSessionGenerator, fakeimgbytes_png
@@ -468,6 +548,7 @@ async def test_timeout_cancelled(
                 "still_image_url": "http://example.com",
                 "username": "user",
                 "password": "pass",
+                "framerate": 20,
             }
         },
     )
@@ -497,6 +578,8 @@ async def test_timeout_cancelled(
     ]
 
     for total_calls in range(2, 4):
+        # sleep .1 seconds to make cached image expire
+        await asyncio.sleep(0.1)
         resp = await client.get("/api/camera_proxy/camera.config_test")
         assert respx.calls.call_count == total_calls
         assert resp.status == HTTPStatus.OK