Separate out transforms and fetching logic to separate module; added Rotate transform

PILServ/__init__.py

@@ -1,80 +1,15 @@
 #!/usr/bin/env python
 
-import Image
-import os
 import re
-import pdb
-import sys
-import time
 
 from StringIO import StringIO
 
 from eventlet import api
-from eventlet.green import urllib2
 from eventlet.green import BaseHTTPServer
 
-class TransformException(Exception):
-    pass
+from PILServ import fetch
+from PILServ import transforms
 
-class BaseTransform(object):
-    command = None
-    @classmethod
-    def execute(cls, path, out):
-        raise TransformException('Subclasses of BaseTransform must override execute()')
-
-    @classmethod
-    def parsePositionals(cls, rawbuf):
-        if not rawbuf:
-            return []
-        return [p.strip() for p in rawbuf[1:-1].split(',')]
-
-class Resize(BaseTransform):
-    command = 'resize'
-    @classmethod
-    def execute(cls, infile, args, **kwargs):
-        args = cls.parsePositionals(args)
-        return cls._execute(infile, *args, **kwargs)
-
-    @classmethod
-    def _execute(cls, infile, size, **kwargs):
-        if not size:
-            size = (64, 64)
-        else:
-            size = tuple(size.split('x'))
-        outfile = StringIO()
-        im = Image.open(infile)
-        im.thumbnail(size)
-        im.save(outfile, 'png')
-        return outfile.getvalue()
-
-class Flip(BaseTransform):
-    command = 'flip'
-    @classmethod
-    def execute(cls, infile, args, **kwargs):
-        args = cls.parsePositionals(args)
-        return cls._execute(infile, *args, **kwargs)
-
-    @classmethod
-    def _execute(cls, infile, *args, **kwargs):
-        outfile = StringIO()
-        im = Image.open(infile)
-        im = im.rotate(180, expand=True)
-        im.save(outfile, 'png')
-        return outfile.getvalue()
-
-def __aggregate():
-    module = sys.modules[__name__]
-    for name in dir(module):
-        attr = getattr(module, name)
-        if not isinstance(attr, type):
-            continue
-        if not issubclass(attr, BaseTransform):
-            continue
-        if attr == BaseTransform:
-            continue
-        yield attr
-
-transform_commands = dict(((t.command, t) for t in __aggregate()))
 
 class PILHandler(BaseHTTPServer.BaseHTTPRequestHandler):
     nongreedy = '.*?' 
@@ -87,16 +22,17 @@ class PILHandler(BaseHTTPServer.BaseHTTPRequestHandler):
         print ('do_GET', self.__dict__)
         m = self.url_regex.search(self.path)
         if not m:
+            # No URL parsed out!
             return # XXX: Error condition
+
         image = m.group(1)
 
+        # Grab the precending commands from the URL
         rest = self.path[:-(len(image))]
         commands = rest.split('/')
 
-        # Fetch image 
-        fd = urllib2.urlopen(image)
-        image = fd.read()
-        fd.close()
+        # Fetch a string buffer representing the image
+        image = fetch.fetchBuffer(image)
 
         # Chain commands together
         for command in reversed(commands):
@@ -105,9 +41,11 @@ class PILHandler(BaseHTTPServer.BaseHTTPRequestHandler):
             args = self.arguments_regex.search(command)
             if args:
                 args = args.group(1)
+                # `command` is formatted like "resize(32x32)" here, 
+                # strip off the latter bits
                 command = command[:-(len(args))]
-            command = transform_commands.get(command)
 
+            command = transforms.commands.get(command)
             if not command:
                 continue
 
@@ -130,6 +68,3 @@ def main():
         return -1
     return 0
 
-if __name__ == '__main__':
-    sys.exit(main())
-

PILServ/fetch.py

@@ -0,0 +1,18 @@
+#!/usr/bin/env python
+
+from eventlet.green import urllib2
+
+
+def __url(url):
+    buf = None
+    try:
+        buf = urllib2.urlopen(url)
+        return buf.read()
+    finally:
+        if buf:
+            buf.close()
+
+def fetchBuffer(url, cache=True):
+    # Fetch image 
+    return __url(url)
+

PILServ/transforms.py

@@ -0,0 +1,69 @@
+#!/usr/bin/env python
+
+import Image
+import sys
+
+from StringIO import StringIO
+
+class TransformException(Exception):
+    pass
+
+class BaseTransform(object):
+    command = None
+    @classmethod
+    def execute(cls, infile, args, **kwargs):
+        args = cls.parsePositionals(args)
+        return cls._execute(infile, *args, **kwargs)
+
+    @classmethod
+    def parsePositionals(cls, rawbuf):
+        if not rawbuf:
+            return []
+        return [p.strip() for p in rawbuf[1:-1].split(',')]
+
+class Resize(BaseTransform):
+    command = 'resize'
+    @classmethod
+    def _execute(cls, infile, size, **kwargs):
+        if not size:
+            size = (64, 64)
+        else:
+            size = tuple(size.split('x'))
+        outfile = StringIO()
+        im = Image.open(infile)
+        im.thumbnail(size)
+        im.save(outfile, 'png')
+        return outfile.getvalue()
+
+
+class Rotate(BaseTransform):
+    command = 'rotate'
+    @classmethod
+    def _execute(cls, infile, angle, **kwargs):
+        outfile = StringIO()
+        im = Image.open(infile)
+        im = im.rotate(float(angle), expand=True)
+        im.save(outfile, 'png')
+        return outfile.getvalue()
+
+class Flip(Rotate):
+    command = 'flip'
+    @classmethod
+    def _execute(cls, infile, *args, **kwargs):
+        return Rotate._execute(infile, 180, **kwargs)
+
+
+def __aggregate():
+    module = sys.modules[__name__]
+    for name in dir(module):
+        attr = getattr(module, name)
+        if not isinstance(attr, type):
+            continue
+        if not issubclass(attr, BaseTransform):
+            continue
+        if attr == BaseTransform:
+            continue
+        yield attr
+
+commands = dict(((t.command, t) for t in __aggregate()))
+

pilserv.py

@@ -0,0 +1,7 @@
+#!/usr/bin/env python
+
+import PILServ
+
+if __name__ == '__main__':
+    PILServ.main()
+