From 45f94d4b14923e834cc027830b27e0d9a0725225 Mon Sep 17 00:00:00 2001
From: Crista Lopes <crista@tagide.com>
Date: Wed, 23 Oct 2013 11:19:12 -0700
Subject: [PATCH] Added free agents style

---
 25-free-agents/README.md |  26 ++++++++
 25-free-agents/tf-25.py  | 138 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 164 insertions(+)
 create mode 100644 25-free-agents/README.md
 create mode 100644 25-free-agents/tf-25.py

diff --git a/25-free-agents/README.md b/25-free-agents/README.md
new file mode 100644
index 0000000..b32672e
--- /dev/null
+++ b/25-free-agents/README.md
@@ -0,0 +1,26 @@
+Style #25
+==============================
+
+Similar to the letterbox style, but where the 'things' have
+independent threads of execution.
+
+Constraints:
+
+- The larger problem is decomposed into 'things' that make sense for
+  the problem domain 
+
+- Each 'thing' is a capsule of data that exposes one single procedure,
+  namely the ability to receive and dispatch messages that are sent to
+  it
+
+- Each 'thing' has its own thread of execution independent of the others
+
+- Each 'thing' has a queue where messages to it are placed
+
+- Message dispatch can result in sending the message to another 'thing'
+
+Possible names:
+
+- Free agents
+- Active letterbox
+- Actors
diff --git a/25-free-agents/tf-25.py b/25-free-agents/tf-25.py
new file mode 100644
index 0000000..6458929
--- /dev/null
+++ b/25-free-agents/tf-25.py
@@ -0,0 +1,138 @@
+#!/usr/bin/env python
+
+import sys, re, operator, string
+from threading import Thread
+from Queue import Queue
+
+class ActiveWFObject(Thread):
+    def __init__(self):
+        Thread.__init__(self)
+        self.name = str(type(self))
+        self.queue = Queue()
+        self._stop = False
+        self.start()
+
+    def run(self):
+        while not self._stop:
+            message = self.queue.get()
+            self.dispatch(message)
+            if message[0] == 'die':
+                self._stop = True
+
+class DataStorageManager(ActiveWFObject):
+    _queue = Queue()
+    """ Models the contents of the file """
+    _data = ''
+
+    def dispatch(self, message):
+        if message[0] == 'init':
+            self._init(message[1:])
+        elif message[0] == 'send_word_freqs':
+            self._process_words(message[1:])
+        else:
+            # forward
+            self._stop_word_manager.queue.put(message)
+ 
+    def _init(self, message):
+        path_to_file = message[0]
+        self._stop_word_manager = message[1]
+        f = open(path_to_file)
+        self._data = f.read()
+        f.close()
+        pattern = re.compile('[\W_]+')
+        self._data = pattern.sub(' ', self._data).lower()
+
+    def _process_words(self, message):
+        recipient = message[0]
+        data_str = ''.join(self._data)
+        words = data_str.split()
+        for w in words:
+            self._stop_word_manager.queue.put(['filter', w])
+        self._stop_word_manager.queue.put(['top25', recipient])
+
+
+class StopWordManager(ActiveWFObject):
+    """ Models the stop word filter """
+    _stop_words = []
+
+    def dispatch(self, message):
+        if message[0] == 'init':
+            self._init(message[1:])
+        elif message[0] == 'filter':
+            return self._filter(message[1:])
+        else:
+            # forward
+            self._word_freqs_manager.queue.put(message)
+ 
+    def _init(self, message):
+        f = open('../stop_words.txt')
+        self._stop_words = f.read().split(',')
+        f.close()
+        self._stop_words.extend(list(string.ascii_lowercase))
+        self._word_freqs_manager = message[0]
+
+    def _filter(self, message):
+        word = message[0]
+        if word not in self._stop_words:
+            self._word_freqs_manager.queue.put(['word', word])
+
+class WordFrequencyManager(ActiveWFObject):
+    """ Keeps the word frequency data """
+    _word_freqs = {}
+
+    def dispatch(self, message):
+        if message[0] == 'word':
+            self._increment_count(message[1:])
+        elif message[0] == 'top25':
+            self._top25(message[1:])
+ 
+    def _increment_count(self, message):
+        word = message[0]
+        if word in self._word_freqs:
+            self._word_freqs[word] += 1 
+        else: 
+            self._word_freqs[word] = 1
+
+    def _top25(self, message):
+        recipient = message[0]
+        freqs_sorted = sorted(self._word_freqs.iteritems(), key=operator.itemgetter(1), reverse=True)
+        recipient.queue.put(['top25', freqs_sorted])
+
+class WordFrequencyController(ActiveWFObject):
+
+    def dispatch(self, message):
+        if message[0] == 'run':
+            self._run(message[1:])
+        elif message[0] == 'top25':
+            self._display(message[1:])
+        else:
+            raise Exception("Message not understood " + message[0])
+ 
+    def _run(self, message):
+        self._storage_manager = message[0]
+        self._storage_manager.queue.put(['send_word_freqs', self])
+
+    def _display(self, message):
+        word_freqs = message[0]
+        for (w, f) in word_freqs[0:25]:
+            print w, ' - ', f
+        self._storage_manager.queue.put(['die'])
+        self._stop = True
+
+
+#
+# The main function
+#
+word_freq_manager = WordFrequencyManager()
+
+stop_word_manager = StopWordManager()
+stop_word_manager.queue.put(['init', word_freq_manager])
+
+storage_manager = DataStorageManager()
+storage_manager.queue.put(['init', sys.argv[1], stop_word_manager])
+
+wfcontroller = WordFrequencyController()
+wfcontroller.dispatch(['run', storage_manager])
+
+# Wait for the active objects to finish
+[t.join() for t in [word_freq_manager, stop_word_manager, storage_manager, wfcontroller]]