chooser.py

   1 import os
   2 import random
   3 import re
   4 import sys
   5 import time
   6 import glob
   7 import constants
   8 import trigger
   9
  10 class chooser(object):
  11     """Base class of a thing that chooses pages"""
  12     def get_page_list(self):
  13         now = time.time()
  14         valid_filename = re.compile("([^_]+)_(\d+)_([^\.]+)\.html")
  15         filenames = []
  16         pages = [ f for f in os.listdir(constants.pages_dir)
  17                   if os.path.isfile(os.path.join(constants.pages_dir, f))]
  18         for page in pages:
  19             result = re.match(valid_filename, page)
  20             if result != None:
  21                 print(('chooser: candidate page: "%s"' % page))
  22                 if (result.group(3) != "none"):
  23                     freshness_requirement = int(result.group(3))
  24                     last_modified = int(os.path.getmtime(
  25                         os.path.join(constants.pages_dir, page)))
  26                     age = (now - last_modified)
  27                     if (age > freshness_requirement):
  28                         print(('"%s" is too old.' % page))
  29                         continue
  30                 filenames.append(page)
  31         return filenames
  32
  33     def choose_next_page(self):
  34         pass
  35
  36 class weighted_random_chooser(chooser):
  37     """Chooser that does it via weighted RNG"""
  38     def __init__(self):
  39         self.last_choice = ""
  40         self.valid_filename = re.compile("([^_]+)_(\d+)_([^\.]+)\.html")
  41         self.pages = None
  42         self.count = 0
  43
  44     def choose_next_page(self):
  45         if (self.pages == None or
  46             self.count % 100 == 0):
  47             self.pages = self.get_page_list()
  48
  49         total_weight = 0
  50         weights = []
  51         for page in self.pages:
  52             result = re.match(self.valid_filename, page)
  53             if result != None:
  54                 weight = int(result.group(2))
  55                 weights.append(weight)
  56                 total_weight += weight
  57
  58         if (total_weight <= 0):
  59             raise error
  60
  61         while True:
  62             pick = random.randrange(0, total_weight - 1)
  63             so_far = 0
  64             for x in range(0, len(weights)):
  65                 so_far += weights[x]
  66                 if (so_far > pick and
  67                     self.pages[x] != self.last_choice):
  68                     self.last_choice = self.pages[x]
  69                     self.count += 1
  70                     return self.pages[x]
  71
  72 class weighted_random_chooser_with_triggers(weighted_random_chooser):
  73     """Same as WRC but has trigger events"""
  74     def __init__(self, trigger_list):
  75         weighted_random_chooser.__init__(self)
  76         self.trigger_list = trigger_list
  77         self.page_queue = set(())
  78
  79     def check_for_triggers(self):
  80         triggered = False
  81         for t in self.trigger_list:
  82             x = t.get_triggered_page_list()
  83             if x != None and len(x) > 0:
  84                 for y in x:
  85                     self.page_queue.add(y)
  86                     triggered = True
  87         return triggered
  88
  89     def choose_next_page(self):
  90         if (self.pages == None or
  91             self.count % 100 == 0):
  92             self.pages = self.get_page_list()
  93
  94         triggered = self.check_for_triggers()
  95
  96         # First try to satisfy from the page queue
  97         if (len(self.page_queue) > 0):
  98             print("Pulling page from queue")
  99             page = None
 100             priority = None
 101             for t in self.page_queue:
 102                 if priority == None or t[1] > priority:
 103                     page = t[0]
 104                     priority = t[1]
 105             self.page_queue.remove((page, priority))
 106             return page, triggered
 107
 108         # Fall back on weighted random choice.
 109         else:
 110             return weighted_random_chooser.choose_next_page(self), False
 111
 112 class rotating_chooser(chooser):
 113     """Chooser that does it in a rotation"""
 114     def __init__(self):
 115         self.valid_filename = re.compile("([^_]+)_(\d+)_([^\.]+)\.html")
 116         self.pages = None
 117         self.current = 0
 118         self.count = 0
 119
 120     def choose_next_page(self):
 121         if (self.pages == None or
 122             self.count % 100 == 0):
 123             self.pages = self.get_page_list()
 124
 125         if len(self.pages) == 0:
 126             raise error
 127
 128         if (self.current >= len(self.pages)):
 129             self.current = 0
 130
 131         page = self.pages[self.current]
 132         self.current += 1
 133         self.count += 1
 134         return page
 135
 136 #x = weighted_random_chooser_with_triggers(None)