Source Code for Module ClusterShell.Event

  1  # 
  2  # Copyright (C) 2007-2015 CEA/DAM 
  3  # Copyright (C) 2015 Stephane Thiell <sthiell@stanford.edu> 
  4  # 
  5  # This file is part of ClusterShell. 
  6  # 
  7  # ClusterShell is free software; you can redistribute it and/or 
  8  # modify it under the terms of the GNU Lesser General Public 
  9  # License as published by the Free Software Foundation; either 
 10  # version 2.1 of the License, or (at your option) any later version. 
 11  # 
 12  # ClusterShell is distributed in the hope that it will be useful, 
 13  # but WITHOUT ANY WARRANTY; without even the implied warranty of 
 14  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU 
 15  # Lesser General Public License for more details. 
 16  # 
 17  # You should have received a copy of the GNU Lesser General Public 
 18  # License along with ClusterShell; if not, write to the Free Software 
 19  # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 
 20   
 21  """ 
 22  ClusterShell Event handling. 
 23   
 24  This module contains the base class **EventHandler** which defines a simple 
 25  interface through methods to handle events coming from ClusterShell I/O Engine 
 26  clients. Events are generated by Worker, EngineTimer or EnginePort objects. 
 27  """ 
 28   
 29 -class EventHandler(object): 
 30      """ClusterShell EventHandler interface. 
 31   
 32      Derived class should implement the following methods to listen for Worker, 
 33      EngineTimer or EnginePort chosen events. 
 34      """ 
 35   
 36 -    def ev_start(self, worker): 
 37          """ 
 38          Called to indicate that a worker has just started. 
 39   
 40          :param worker: :class:`.Worker` object 
 41          """ 
 42   
 43 -    def ev_pickup(self, worker): 
 44          """ 
 45          Called to indicate that a worker command for a specific node (or key) 
 46          has just started. Called for each node. 
 47   
 48          :param worker: :class:`.Worker` object 
 49   
 50          Available worker attributes: 
 51   
 52          * :attr:`.Worker.current_node` - node (or key) 
 53          """ 
 54   
 55 -    def ev_read(self, worker): 
 56          """ 
 57          Called to indicate that a worker has data to read from a specific 
 58          node (or key). 
 59   
 60          :param worker: :class:`.Worker` object 
 61   
 62          Available worker attributes: 
 63   
 64          * :attr:`.Worker.current_node` - node (or key) 
 65          * :attr:`.Worker.current_msg` - read message 
 66          """ 
 67   
 68 -    def ev_error(self, worker): 
 69          """ 
 70          Called to indicate that a worker has error to read on stderr from 
 71          a specific node (or key). 
 72   
 73          :param worker: :class:`.Worker` object 
 74   
 75          Available worker attributes: 
 76   
 77          * :attr:`.Worker.current_node` - node (or key) 
 78          * :attr:`.Worker.current_errmsg` - read error message 
 79          """ 
 80   
 81 -    def ev_written(self, worker, node, sname, size): 
 82          """ 
 83          Called to indicate that some writing has been done by the worker to a 
 84          node on a given stream. This event is only generated when ``write()`` 
 85          is previously called on the worker. 
 86   
 87          This handler may be called very often depending on the number of target 
 88          nodes, the amount of data to write and the block size used by the 
 89          worker. 
 90   
 91          Note: up to ClusterShell 1.6, this event handler wasn't implemented. To 
 92          properly handle ev_written after 1.6, the method signature must consist 
 93          of the following parameters: 
 94   
 95          :param worker: :class:`.Worker` object 
 96          :param node: node (or) key 
 97          :param sname: stream name 
 98          :param size: amount of bytes that has just been written to node/stream 
 99              associated with this event 
100          """ 
101   
102 -    def ev_hup(self, worker): 
103          """ 
104          Called to indicate that a worker command for a specific node (or key) 
105          has just finished. Called for each node. 
106   
107          :param worker: :class:`.Worker` object 
108   
109          Available worker attributes: 
110   
111          * :attr:`.Worker.current_node` - node (or key) 
112          * :attr:`.Worker.current_rc` - command return code 
113          """ 
114   
115 -    def ev_timeout(self, worker): 
116          """ 
117          Called to indicate that a worker has timed out (worker timeout only). 
118   
119          :param worker: :class:`.Worker` object 
120          """ 
121   
122 -    def ev_close(self, worker): 
123          """ 
124          Called to indicate that a worker has just finished (it may already 
125          have failed on timeout). 
126   
127          :param worker: :class:`.Worker` object 
128          """ 
129   
130 -    def ev_msg(self, port, msg): 
131          """ 
132          Called to indicate that a message has been received on an EnginePort. 
133   
134          Used to deliver messages reliably between tasks. 
135   
136          :param port: EnginePort object on which a message has been received 
137          :param msg: the message object received 
138          """ 
139   
140 -    def ev_timer(self, timer): 
141          """ 
142          Called to indicate that a timer is firing. 
143   
144          :param timer: :class:`.EngineTimer` object that is firing 
145          """ 
146   
147 -    def _ev_routing(self, worker, arg): 
148          """ 
149          Routing event (private). Called to indicate that a (meta)worker has just 
150          updated one of its route path. You can safely ignore this event. 
151          """ 
152