add ping monitor1.5

Signed-off-by: Mattias Andrée <maandree@operamail.com>

1 files changed, 190 insertions, 0 deletions

diff --git a/src/plugins/ping.py b/src/plugins/ping.py
new file mode 100644
index 0000000..add8254
--- /dev/null
+++ b/src/plugins/ping.py
@@ -0,0 +1,190 @@
+# -*- python -*-
+'''
+xpybar – xmobar replacement written in python
+Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+'''
+
+import os
+
+from util import *
+
+from plugins.linereader import LineReader
+
+
+
+class Ping:
+    '''
+    Network connectivity monitor using ICMP echos
+    
+    @variable  monitors:dict<str, list<Ping.create_monitor.PingMonitor>>
+                   Map from network interface to list of network monitors
+                   connected against the server specified by the corresponding
+                   element in `targets` of `__init__`
+    '''
+    
+    DEFAULT_GATEWAY = ...
+    '''
+    Selects the default gateway's IP address
+    '''
+    
+    UNITS = { 'ns' : 0.000001, 'us' : 0.001, 'µs' : 0.001, 'ms' : 1.0, 's' : 1000.0 }
+    
+    
+    def __init__(self, targets = None, interval = 5, arguments = None, buffer_size = 8):
+        '''
+        Constructor
+        
+        @param  targets:dict<str, itr<str|...>>  Map from network interfaces to servers to ping
+        @param  interval:float                   The pinging interval, in seconds
+        @param  arguments:itr<str>?              Extra arguments for the `ping` command
+        '''
+        if targets is None:
+            targets = Ping.get_nics()
+        gateways = Ping.get_default_gateways()
+        args = ['ping', '-i', str(interval)] + (arguments if arguments is not None else [])
+        def get(nic, target):
+            if target == Ping.DEFAULT_GATEWAY:
+                target = None if nic not in gateways else gateways[nic]
+            if target is None:
+                return None
+            command = args + ['-I', nic, target]
+            return Ping.create_monitor(command, buffer_size, interval)
+        self.monitors = dict((nic, [get(nic, t) for t in targets[nic]]) for nic in targets.keys())
+    
+    
+    @staticmethod
+    def get_nics(server = ...):
+        '''
+        List all network interfaces with a default gateway
+        and map them to `server`
+        
+        @return  :dict<str, [`server`]>  Dictionary of network interfaces mapped to `server`
+        '''
+        data = spawn_read('ip', 'route').split('\n')
+        def get(fields):
+            device = fields[fields.index('dev') + 1]
+            return (device, [server])
+        return dict(get(line.split(' ')) for line in data if line.startswith('default via '))
+    
+    
+    @staticmethod
+    def get_default_gateways():
+        '''
+        All network interfaces with a default gateway mapped to their default gateways
+        
+        @return  :dict<str, str>  Map from network interfaces to their default gateways
+        '''
+        data = spawn_read('ip', 'route').split('\n')
+        def get(fields):
+            gateway = fields[2]
+            device = fields[fields.index('dev') + 1]
+            return (device, gateway)
+        return dict(get(line.split(' ')) for line in data if line.startswith('default via '))
+    
+    
+    @staticmethod
+    def create_monitor(command, buffer_size, interval):
+        import time
+        class PingMonitor:
+            def __init__(self):
+                self.latency_buffer = [None] * buffer_size
+                self.semaphore = threading.Semaphore()
+                self.last_read = time.monotonic()
+                self.last_icmp_seq = 0
+            
+            def start(self):
+                with LineReader(spawn(*command)) as reader:
+                    reader.next()
+                    while True:
+                        line = reader.next()
+                        self.semaphore.acquire()
+                        try:
+                            line = line.replace('=', ' ').split(' ')
+                            icmp_seq = int(line[line.index('icmp_seq') + 1])
+                            ping_time = float(line[line.index('time') + 1])
+                            ping_time *= Ping.UNITS[line[line.index('time') + 2]]
+                            dropped_pkgs = icmp_seq - self.last_icmp_seq - 1
+                            dropped_pkgs = [None] * dropped_pkgs
+                            self.last_icmp_seq = icmp_seq
+                            self.latency_buffer[:] = ([ping_time] + dropped_pkgs + self.latency_buffer)[:buffer_size]
+                            self.last_read = time.monotonic()
+                        except:
+                            pass
+                        finally:
+                            self.semaphore.release()
+            
+            
+            def get_latency(self, acquired = False):
+                '''
+                Get the average responses-time
+                
+                @return  :list<float?>  For index `n` (limited to `buffer_size` inclusively):
+                                        the average response time for the latest `n - d` received
+                                        pongs, where `d` is not number of dropped packages of the
+                                        latest `n` sent pings. If the average response time cannot
+                                        be calculated (if all packages have been dropped), the
+                                        value will be `None`. Note that the value at index 0 will
+                                        always be `None`, because index 0 means no packages.
+                '''
+                if not acquired:
+                    self.semaphore.acquire()
+                try:
+                    rc = [None]
+                    cursum = 0
+                    samples = 0
+                    for i in range(buffer_size):
+                        if self.latency_buffer[i] is not None:
+                            cursum += self.latency_buffer[i]
+                            samples += 1
+                        rc.append(None if samples == 0 else cursum / samples)
+                    return rc
+                finally:
+                    if not acquired:
+                        self.semaphore.release()
+            
+            def dropped(self, acquired = False):
+                '''
+                Estimate how many echos have been dropped since the last pong
+                
+                @return  :int  The estimated number of dropped packages
+                '''
+                if not acquired:
+                    self.semaphore.acquire()
+                try:
+                    return (time.monotonic() - self.last_read) // interval
+                finally:
+                    if not acquired:
+                        self.semaphore.release()
+            
+            def dropped_time(self, acquired = False):
+                '''
+                Estimate for how long packages have been dropping
+                
+                @return  :float  The estimated time packages have been dropping, in seconds
+                '''
+                if not acquired:
+                    self.semaphore.acquire()
+                try:
+                    time_diff = time.monotonic() - self.last_read
+                    return 0 if time_diff < interval else time_diff
+                finally:
+                    if not acquired:
+                        self.semaphore.release()
+        
+        monitor = PingMonitor()
+        async(monitor.start)
+        return monitor
+