Improved filesystem efficiency

Previously, `sheets.print()` would query the filesystem every time it
was invoked. This was inelegant, because it is called multiple times
every time `cheat` is executed. Thus, unnecessary calls were being made
out to the filesystem.

Now the result of that function is being buffered into a module variable
when it is executed the first time, and served from there thereafter. I
broke the "functional" paradigm to a degree by doing this, but it wasn't
worth the complexity of implementing proper memoization (decorators,
etc) for such a trivial case.

Bumped the version number accordingly.

bin/cheat

@@ -38,7 +38,7 @@ from docopt import docopt
 
 if __name__ == '__main__':
     # parse the command-line options
-    options = docopt(__doc__, version='cheat 2.0.2')
+    options = docopt(__doc__, version='cheat 2.0.4')
 
     # list directories
     if options['--directories']:

cheat/sheets.py

@@ -2,6 +2,12 @@ from cheat import cheatsheets
 from cheat.utils import *
 import os
 
+# @kludge: it breaks the functional paradigm to a degree, but declaring this
+# var here (versus within get()) gives us a "poor man's" memoization on the
+# call to get(). This, in turn, spares us from having to call out to the
+# filesystem more than once.
+cheats = {}
+
 
 def default_path():
     """ Returns the default cheatsheet path """
@@ -35,10 +41,15 @@ def default_path():
     return default_sheets_dir
 
 
-# @todo: memoize result
 def get():
     """ Assembles a dictionary of cheatsheets as name => file-path """
-    cheats = {}
+
+    # if we've already reached out to the filesystem, just return the result
+    # from memory
+    if cheats:
+      return cheats
+
+    # otherwise, scan the filesystem
     for cheat_dir in reversed(paths()):
         cheats.update(
             dict([

setup.py

@@ -1,9 +1,18 @@
 from distutils.core import setup
 import os
 
+data = [
+       ('/usr/share/zsh/site-functions', ['cheat/autocompletion/_cheat.zsh']),
+       ('/etc/bash_completion.d'       , ['cheat/autocompletion/cheat.bash']),
+       ('/usr/share/fish/completions'  , ['cheat/autocompletion/cheat.fish'])
+       ]
+
+if os.name == 'nt':
+    data = []
+
 setup(
     name         = 'cheat',
-    version      = '2.0.2',
+    version      = '2.0.4',
     author       = 'Chris Lane',
     author_email = 'chris@chris-allen-lane.com',
     license      = 'GPL3',
@@ -21,11 +30,7 @@ setup(
         'cheat.cheatsheets': [f for f in os.listdir('cheat/cheatsheets') if '.' not in f]
     },
     scripts      = ['bin/cheat'],
-    data_files   = [
-        ('/usr/share/zsh/site-functions', ['cheat/autocompletion/_cheat.zsh']),
-        ('/etc/bash_completion.d'       , ['cheat/autocompletion/cheat.bash']),
-        ('/usr/share/fish/completions'  , ['cheat/autocompletion/cheat.fish'])
-    ],
+    data_files   = data,
     install_requires = [
         'docopt >= 0.6.1',
         'pygments >= 1.6.0',