Implement a new API method to limit the number of returned list object #2491

4 files changed, 79 insertions, 20 deletions

diff --git a/glances/outputs/glances_bottle.py b/glances/outputs/glances_bottle.py
index deb47b19..df6cfc71 100644
--- a/glances/outputs/glances_bottle.py
+++ b/glances/outputs/glances_bottle.py
@@ -2,12 +2,12 @@
 #
 # This file is part of Glances.
 #
-# SPDX-FileCopyrightText: 2022 Nicolas Hennion <nicolas@nicolargo.com>
+# SPDX-FileCopyrightText: 2023 Nicolas Hennion <nicolas@nicolargo.com>
 #
 # SPDX-License-Identifier: LGPL-3.0-only
 #
 
-"""Web interface class."""
+"""RestFull API interface class."""
 
 import os
 import sys
@@ -152,6 +152,7 @@ class GlancesBottle(object):
         self._app.route(
             '/api/%s/<plugin>/history/<nb:int>' % self.API_VERSION, method="GET", callback=self._api_history
         )
+        self._app.route('/api/%s/<plugin>/top/<nb:int>' % self.API_VERSION, method="GET", callback=self._api_top)
         self._app.route('/api/%s/<plugin>/limits' % self.API_VERSION, method="GET", callback=self._api_limits)
         self._app.route('/api/%s/<plugin>/views' % self.API_VERSION, method="GET", callback=self._api_views)
         self._app.route('/api/%s/<plugin>/<item>' % self.API_VERSION, method="GET", callback=self._api_item)
@@ -394,6 +395,36 @@ class GlancesBottle(object):
         return statval
 
     @compress
+    def _api_top(self, plugin, nb=0):
+        """Glances API RESTful implementation.
+
+        Return the JSON representation of a given plugin limited to the top nb items.
+        It is used to reduce the payload of the HTTP response (example: processlist).
+
+        HTTP/200 if OK
+        HTTP/400 if plugin is not found
+        HTTP/404 if others error
+        """
+        response.content_type = 'application/json; charset=utf-8'
+
+        if plugin not in self.plugins_list:
+            abort(400, "Unknown plugin %s (available plugins: %s)" % (plugin, self.plugins_list))
+
+        # Update the stat
+        self.__update__()
+
+        try:
+            # Get the value of the stat ID
+            statval = self.stats.get_plugin(plugin).get_export()
+        except Exception as e:
+            abort(404, "Cannot get plugin %s (%s)" % (plugin, str(e)))
+
+        if isinstance(statval, list):
+            return json_dumps(statval[:nb])
+        else:
+            return json_dumps(statval)
+
+    @compress
     def _api_history(self, plugin, nb=0):
         """Glances API RESTful implementation.
 
diff --git a/glances/outputs/glances_stdout_apidoc.py b/glances/outputs/glances_stdout_apidoc.py
index c57eefa5..ed9c2da1 100644
--- a/glances/outputs/glances_stdout_apidoc.py
+++ b/glances/outputs/glances_stdout_apidoc.py
@@ -163,6 +163,22 @@ def print_all():
     print('')
 
 
+def print_top(stats):
+    time.sleep(1)
+    stats.update()
+    sub_title = 'GET top n items of a specific plugin'
+    print(sub_title)
+    print('-' * len(sub_title))
+    print('')
+    print('Get top 2 processes of the processlist plugin::')
+    print('')
+    print('    # curl {}/processlist/top/2'.format(API_URL))
+    print(indent_stat(stats.get_plugin('processlist').get_export()[:2]))
+    print('')
+    print('Note: Only work for plugin with a list of items')
+    print('')
+
+
 def print_history(stats):
     time.sleep(1)
     stats.update()
@@ -248,6 +264,10 @@ class GlancesStdoutApiDoc(object):
         # Get all stats
         print_all()
 
+        # Get top stats (only for plugins with a list of items)
+        # Example for processlist plugin: get top 2 processes
+        print_top(stats)
+
         # History
         print_history(stats)
 
diff --git a/glances/plugins/wifi/model.py b/glances/plugins/wifi/model.py
index 7d13fcaf..c221d688 100644
--- a/glances/plugins/wifi/model.py
+++ b/glances/plugins/wifi/model.py
@@ -47,8 +47,7 @@ WIRELESS_FILE = '/proc/net/wireless'
 wireless_file_exists = file_exists(WIRELESS_FILE)
 
 if not nmcli_command_exists and not wireless_file_exists:
-    logger.debug("Wifi plugin is disabled (no %s command or %s file found)" % ('nmcli',
-                                                                               WIRELESS_FILE))
+    logger.debug("Wifi plugin is disabled (no %s command or %s file found)" % ('nmcli', WIRELESS_FILE))
 
 
 class PluginModel(GlancesPluginModel):
@@ -121,12 +120,14 @@ class PluginModel(GlancesPluginModel):
                     # Extract the stats
                     wifi_stats = wifi_stats.split()
                     # Add the Wifi link to the list
-                    stats.append({
-                        'key': self.get_key(),
-                        'ssid': wifi_stats[0][:-1],
-                        'signal': float(wifi_stats[3]),
-                        'security': ''
-                    })
+                    stats.append(
+                        {
+                            'key': self.get_key(),
+                            'ssid': wifi_stats[0][:-1],
+                            'signal': float(wifi_stats[3]),
+                            'security': '',
+                        }
+                    )
                     # Next line
                     wifi_stats = f.readline()
 
@@ -202,11 +203,11 @@ class PluginModel(GlancesPluginModel):
             hotspot_name = i['ssid']
             # Cut hotspot_name if it is too long
             if len(hotspot_name) > if_name_max_width:
-                hotspot_name = '_' + hotspot_name[-if_name_max_width - len(i['security']) + 1:]
+                hotspot_name = '_' + hotspot_name[-if_name_max_width - len(i['security']) + 1 :]
             # Add the new hotspot to the message
-            msg = '{:{width}} {security}'.format(nativestr(hotspot_name),
-                                                 width=if_name_max_width - len(i['security']) - 1,
-                                                 security=i['security'])
+            msg = '{:{width}} {security}'.format(
+                nativestr(hotspot_name), width=if_name_max_width - len(i['security']) - 1, security=i['security']
+            )
             ret.append(self.curse_add_line(msg))
             msg = '{:>7}'.format(
                 i['signal'],
@@ -244,12 +245,7 @@ class ThreadHotspot(threading.Thread):
                 if len(h) != 4 or h[0] != 'yes':
                     # Do not process the line if it is not the active hotspot
                     continue
-                nmcli_result.append({
-                    'key': 'ssid',
-                    'ssid': h[1],
-                    'signal': -float(h[2]),
-                    'security': h[3]
-                })
+                nmcli_result.append({'key': 'ssid', 'ssid': h[1], 'signal': -float(h[2]), 'security': h[3]})
             self.thread_stats = nmcli_result
             # Wait refresh time until next scan
             # Note: nmcli cache the result for x seconds
diff --git a/unitest-restful.py b/unitest-restful.py
index a697ff78..17e734e1 100755
--- a/unitest-restful.py
+++ b/unitest-restful.py
@@ -231,6 +231,18 @@ class TestGlances(unittest.TestCase):
         self.assertTrue(req.ok)
         self.assertEqual(req.text, "Active")
 
+    def test_013_top(self):
+        """Values."""
+        method = "processlist"
+        request = "%s/%s/top/2" % (URL, method)
+        print('INFO: [TEST_013] Top nb item of PROCESSLIST')
+        print(request)
+        req = self.http_get(request)
+
+        self.assertTrue(req.ok)
+        self.assertIsInstance(req.json(), list)
+        self.assertEqual(len(req.json()), 2)
+
     def test_999_stop_server(self):
         """Stop the Glances Web Server."""
         print('INFO: [TEST_999] Stop the Glances Web Server')