Implement a basic memory cache with TTL for API call (set to ~1 second) #3202

glances/globals.py

@@ -476,18 +476,32 @@ def folder_size(path, errno=0):
         return ret_size, ret_err
 
 
-def weak_lru_cache(maxsize=128, typed=False):
+def _get_ttl_hash(ttl):
+    """A simple (dummy) function to return a hash based on the current second.
+    TODO: Implement a real TTL mechanism.
+    """
+    if ttl is None:
+        return 0
+    now = datetime.now()
+    return now.second
+
+
+def weak_lru_cache(maxsize=1, typed=False, ttl=None):
     """LRU Cache decorator that keeps a weak reference to self
+
+    Warning: When used in a class, the class should implement __eq__(self, other) and __hash__(self) methods
+
     Source: https://stackoverflow.com/a/55990799"""
 
     def wrapper(func):
         @functools.lru_cache(maxsize, typed)
-        def _func(_self, *args, **kwargs):
+        def _func(_self, *args, ttl_hash=None, **kwargs):
+            del ttl_hash  # Unused parameter, but kept for compatibility
             return func(_self(), *args, **kwargs)
 
         @functools.wraps(func)
         def inner(self, *args, **kwargs):
-            return _func(weakref.ref(self), *args, **kwargs)
+            return _func(weakref.ref(self), *args, ttl_hash=_get_ttl_hash(ttl), **kwargs)
 
         return inner
 

glances/outputs/glances_restful_api.py

@@ -18,7 +18,7 @@ from urllib.parse import urljoin
 
 from glances import __apiversion__, __version__
 from glances.events_list import glances_events
-from glances.globals import json_dumps
+from glances.globals import json_dumps, weak_lru_cache
 from glances.logger import logger
 from glances.password import GlancesPassword
 from glances.processes import glances_processes
@@ -141,6 +141,12 @@ class GlancesRestfulApi:
         self.TEMPLATE_PATH = os.path.join(webui_root_path, 'static/templates')
         self._templates = Jinja2Templates(directory=self.TEMPLATE_PATH)
 
+        # FastAPI Enable GZIP compression
+        # https://fastapi.tiangolo.com/advanced/middleware/
+        # Should be done before other middlewares to avoid
+        # LocalProtocolError("Too much data for declared Content-Length")
+        self._app.add_middleware(GZipMiddleware, minimum_size=1000)
+
         # FastAPI Enable CORS
         # https://fastapi.tiangolo.com/tutorial/cors/
         self._app.add_middleware(
@@ -152,10 +158,6 @@ class GlancesRestfulApi:
             allow_headers=config.get_list_value('outputs', 'cors_headers', default=["*"]),
         )
 
-        # FastAPI Enable GZIP compression
-        # https://fastapi.tiangolo.com/advanced/middleware/
-        self._app.add_middleware(GZipMiddleware, minimum_size=1000)
-
         # FastAPI Define routes
         self._app.include_router(self._router())
 
@@ -196,7 +198,7 @@ class GlancesRestfulApi:
     def authentication(self, creds: Annotated[HTTPBasicCredentials, Depends(security)]):
         """Check if a username/password combination is valid."""
         if creds.username == self.args.username:
-            # check_password and get_hash are (lru) cached to optimize the requests
+            # check_password
             if self._password.check_password(self.args.password, self._password.get_hash(creds.password)):
                 return creds.username
 
@@ -453,6 +455,7 @@ class GlancesRestfulApi:
 
         return GlancesJSONResponse(self.servers_list.get_servers_list() if self.servers_list else [])
 
+    @weak_lru_cache(maxsize=1, ttl=1)
     def _api_all(self):
         """Glances API RESTful implementation.
 
@@ -480,6 +483,7 @@ class GlancesRestfulApi:
 
         return GlancesJSONResponse(statval)
 
+    @weak_lru_cache(maxsize=1, ttl=1)
     def _api_all_limits(self):
         """Glances API RESTful implementation.
 
@@ -496,6 +500,7 @@ class GlancesRestfulApi:
 
         return GlancesJSONResponse(limits)
 
+    @weak_lru_cache(maxsize=1, ttl=1)
     def _api_all_views(self):
         """Glances API RESTful implementation.
 
@@ -512,6 +517,7 @@ class GlancesRestfulApi:
 
         return GlancesJSONResponse(limits)
 
+    @weak_lru_cache(maxsize=1, ttl=1)
     def _api(self, plugin: str):
         """Glances API RESTful implementation.
 
@@ -541,6 +547,7 @@ class GlancesRestfulApi:
             status.HTTP_400_BAD_REQUEST, f"Unknown plugin {plugin} (available plugins: {self.plugins_list})"
         )
 
+    @weak_lru_cache(maxsize=1, ttl=1)
     def _api_top(self, plugin: str, nb: int = 0):
         """Glances API RESTful implementation.
 
@@ -569,6 +576,7 @@ class GlancesRestfulApi:
 
         return GlancesJSONResponse(statval)
 
+    @weak_lru_cache(maxsize=1, ttl=1)
     def _api_history(self, plugin: str, nb: int = 0):
         """Glances API RESTful implementation.
 
@@ -591,6 +599,7 @@ class GlancesRestfulApi:
 
         return statval
 
+    @weak_lru_cache(maxsize=1, ttl=1)
     def _api_limits(self, plugin: str):
         """Glances API RESTful implementation.
 
@@ -609,6 +618,7 @@ class GlancesRestfulApi:
 
         return GlancesJSONResponse(ret)
 
+    @weak_lru_cache(maxsize=1, ttl=1)
     def _api_views(self, plugin: str):
         """Glances API RESTful implementation.
 

glances/outputs/static/css/style.scss

@@ -197,6 +197,15 @@ body {
     width: 8em;
 }
 
+#system {
+    span {
+        padding-left: 10px;
+    }
+    span:nth-child(1) {
+        padding-left: 0px;
+    }
+}
+
 #ip {
     span {
         padding-left: 10px;

glances/outputs/static/js/components/plugin-system.vue

@@ -2,7 +2,7 @@
     <section id="system" class="plugin">
         <span v-if="isDisconnected" class="critical">Disconnected from</span>
         <span class="title">{{ hostname }}</span>
-        <span class="text-truncate">{{ humanReadableName }}</span>
+        <span v-if="!isDisconnected" class="text-truncate">{{ humanReadableName }}</span>
     </section>
 </template>
 

glances/outputs/static/package-lock.json

@@ -1176,9 +1176,9 @@
             }
         },
         "node_modules/@typescript-eslint/typescript-estree/node_modules/brace-expansion": {
-            "version": "2.0.1",
-            "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-2.0.1.tgz",
-            "integrity": "sha512-XnAIvQ8eM+kC6aULx6wuQiwVsnzsi9d3WxzV3FpWTGA19F621kwdbsAcFKXgKUHZWsy+mY6iL1sHTxWEFCytDA==",
+            "version": "2.0.2",
+            "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-2.0.2.tgz",
+            "integrity": "sha512-Jt0vHyM+jmUBqojB7E1NIYadt0vI0Qxjxd2TErW94wDz+E2LAm5vKMXXwg6ZZBTHPuUlDgQHKXvjGBdfcF1ZDQ==",
             "dev": true,
             "license": "MIT",
             "dependencies": {
@@ -1878,9 +1878,9 @@
             }
         },
         "node_modules/brace-expansion": {
-            "version": "1.1.11",
-            "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.11.tgz",
-            "integrity": "sha512-iCuPHDFgrHX7H2vEI/5xpz07zSHB00TpugqhmYtVmMO6518mCuRMoOYFldEBl0g187ufozdaHgWKcYFb61qGiA==",
+            "version": "1.1.12",
+            "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.12.tgz",
+            "integrity": "sha512-9T9UjW3r0UW5c1Q7GTwllptXwhvYmEzFhzMfZ9H7FQWt+uZePjZPjBP/W1ZEyZ1twGWom5/56TF4lPcqjnDHcg==",
             "dev": true,
             "license": "MIT",
             "dependencies": {

tests/test_restful.py

@@ -22,6 +22,7 @@ import requests
 from glances import __version__
 from glances.globals import text_type
 from glances.outputs.glances_restful_api import GlancesRestfulApi
+from glances.timer import Counter
 
 SERVER_PORT = 61234
 API_VERSION = GlancesRestfulApi.API_VERSION
@@ -71,10 +72,29 @@ class TestGlances(unittest.TestCase):
         method = "all"
         print('INFO: [TEST_001] Get all stats')
         print(f"HTTP RESTful request: {URL}/{method}")
-        req = self.http_get(f"{URL}/{method}")
-
-        self.assertTrue(req.ok)
-        self.assertTrue(req.json(), dict)
+        # First call is not cached
+        counter_first_call = Counter()
+        first_req = self.http_get(f"{URL}/{method}")
+        self.assertTrue(first_req.ok)
+        self.assertTrue(first_req.json(), dict)
+        counter_first_call_result = counter_first_call.get()
+        # Second call (if it is in the same second) is cached
+        counter_second_call = Counter()
+        second_req = self.http_get(f"{URL}/{method}")
+        self.assertTrue(second_req.ok)
+        self.assertTrue(second_req.json(), dict)
+        counter_second_call_result = counter_second_call.get()
+        # Check if result of first call is equal to second call
+        self.assertEqual(first_req.json(), second_req.json(), "The result of the first and second call should be equal")
+        # Check cache result
+        print(
+            f"First API call took {counter_first_call_result:.2f} seconds"
+            f" and second API call (cached) took {counter_second_call_result:.2f} seconds"
+        )
+        self.assertTrue(
+            counter_second_call_result < counter_first_call_result,
+            "The second call should be cached (faster than the first one)",
+        )
 
     def test_002_pluginslist(self):
         """Plugins list."""