pngtile: comparison pngtile/wsgi.py

equal deleted inserted replaced

-:5cc2d044d368
+:02e5b9b08881
 from werkzeug import exceptions
 import os.path, os
 import pypngtile as pt
+## Settings
+# path to images
 DATA_ROOT = os.environ.get("PNGTILE_DATA_PATH") or os.path.abspath('data/')
+# only open each image once
 IMAGE_CACHE = {}
+# width of a tile
 TILE_WIDTH = 256
 TILE_HEIGHT = 256
 # max. output resolution to allow
 MAX_PIXELS = 1920 * 1200
-def dir_view (req, name, path) :
+def dir_url (prefix, name, item) :
+"""
+Join together an absolute URL prefix, an optional directory name, and a directory item
+"""
+url = prefix
+if name :
+url = os.path.join(url, name)
+url = os.path.join(url, item)
+return url
+def dir_list (dir_path) :
+"""
+Yield a series of directory items to show for the given dir
+"""
+# link to parent
+yield '..'
+for item in os.listdir(dir_path) :
+path = os.path.join(dir_path, item)
+# skip dotfiles
+if item.startswith('.') :
+continue
+# show dirs
+if os.path.isdir(path) :
+yield item
+# examine ext
+base, ext = os.path.splitext(path)
+# show .png files with a .cache file
+if ext == '.png' and os.path.exists(base + '.cache') :
+yield item
+### Render HTML data
+def render_dir (req, name, path) :
+"""
+Directory index
+"""
 prefix = os.path.dirname(req.script_root).rstrip('/')
 script_prefix = req.script_root
 name = name.rstrip('/')
 return """\
 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
 <head>
 <title>Index of %(dir)s</title>
 %(listing)s
 </ul>
 </body>
 </html>""" % dict(
 prefix          = prefix,
-dir             = name,
+dir             = '/' + name,
 listing         = "\n".join(
+# <li> link
 """<li><a href="%(url)s">%(name)s</a></li>""" % dict(
-url         = '/'.join((script_prefix, name, item)),
+# URL to dir
+url         = dir_url(script_prefix, name, item),
+# item name
 name        = item,
-) for item in ['..'] + [i for i in os.listdir(path) if i.endswith('.png') or os.path.isdir(os.path.join(path, i))]
+) for item in dir_list(path)
 ),
 )
-def image_view (req, image_path, image) :
+def render_img_viewport (req, name, image) :
-image_name = os.path.basename(image_path)
+"""
+HTML for image
-img_width, img_height = image.info()
+"""
+# a little slow, but not so bad - two stats(), heh
+info = image.info()
+img_width, img_height = info['img_width'], info['img_height']
 return """\
 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
 <head>
 <title>%(title)s</title>
 var tile_source = new Source("%(tile_url)s", %(tile_width)d, %(tile_height)d, -4, 0, %(img_width)d, %(img_height)d);
 var main = new Viewport(tile_source, "viewport");
 </script>
 </body>
 </html>""" % dict(
-title           = image_name,
+title           = name,
 prefix          = os.path.dirname(req.script_root).rstrip('/'),
 tile_url        = req.url,
 tile_width      = TILE_WIDTH,
 tile_height     = TILE_HEIGHT,
 img_width       = img_width,
 img_height      = img_height,
 )
 def scale_by_zoom (val, zoom) :
+"""
+Scale coordinates by zoom factor
+"""
 if zoom > 0 :
 return val << zoom
 elif zoom > 0 :
 return val >> -zoom
 else :
 return val
-def render_tile (image, x, y, zoom, width=TILE_WIDTH, height=TILE_HEIGHT) :
+### Render PNG Data
+def render_img_tile (image, x, y, zoom, width=TILE_WIDTH, height=TILE_HEIGHT) :
+"""
+Render given tile, returning PNG data
+"""
 return image.tile_mem(
 width, height,
 scale_by_zoom(x, -zoom), scale_by_zoom(y, -zoom),
 zoom
 )
-def render_image (image, cx, cy, zoom, width, height) :
+def render_img_region (image, cx, cy, zoom, width, height) :
+"""
+Render arbitrary tile, returning PNG data
+"""
 x = scale_by_zoom(cx - width / 2, -zoom)
 y = scale_by_zoom(cy - height / 2, -zoom)
 # safely limit
 if width * height > MAX_PIXELS :
 width, height,
 x, y,
 zoom
 )
-def handle_main (req) :
+### Manipulate request data
+def get_req_path (req) :
+"""
+Returns the name and path requested
+"""
 # path to image
 image_name = req.path.lstrip('/')
 # build absolute path
 image_path = os.path.abspath(os.path.join(DATA_ROOT, image_name))
 # ensure the path points inside the data root
 if not image_path.startswith(DATA_ROOT) :
 raise exceptions.NotFound(image_name)
+return image_name, image_path
-if os.path.isdir(image_path) :
-return Response(dir_view(req, image_name, image_path), content_type="text/html")
+def get_image (name, path) :
+"""
-elif not os.path.exists(image_path) :
+Gets an Image object from the cache, ensuring that it is cached
-raise exceptions.NotFound(image_name)
+"""
-elif not image_name or not image_name.endswith('.png') :
-raise exceptions.BadRequest("Not a PNG file")
 # get Image object
-if image_path in IMAGE_CACHE :
+if path in IMAGE_CACHE :
 # get from cache
-image = IMAGE_CACHE[image_path]
+image = IMAGE_CACHE[path]
 else :
-# ensure exists
+# open
-if not os.path.exists(image_path) :
+image = pt.Image(path)
-raise exceptions.NotFound(image_name)
+# check
+if image.status() not in (pt.CACHE_FRESH, pt.CACHE_STALE) :
+raise exceptions.InternalServerError("Image cache not available: %s" % name)
+# load
+image.open()
 # cache
-image = IMAGE_CACHE[image_path] = pt.Image(image_path)
+IMAGE_CACHE[path] = image
-if image.status() == pt.CACHE_NONE :
+return image
-raise exceptions.InternalServerError("Image not cached: " + image_name)
+### Handle request
+def handle_dir (req, name, path) :
+"""
+Handle request for a directory
+"""
+return Response(render_dir(req, name, path), content_type="text/html")
+def handle_img_viewport (req, image, name) :
+"""
+Handle request for image viewport
+"""
+# viewport
+return Response(render_img_viewport(req, name, image), content_type="text/html")
+def handle_img_region (req, image) :
+"""
+Handle request for an image region
+"""
+# specific image
+width = int(req.args['w'])
+height = int(req.args['h'])
+cx = int(req.args['cx'])
+cy = int(req.args['cy'])
+zoom = int(req.args.get('zl', "0"))
+# yay full render
+return Response(render_img_region(image, cx, cy, zoom, width, height), content_type="image/png")
+def handle_img_tile (req, image) :
+"""
+Handle request for image tile
+"""
+# tile
+x = int(req.args['x'])
+y = int(req.args['y'])
+zoom = int(req.args.get('zl', "0"))
+# yay render
+return Response(render_img_tile(image, x, y, zoom), content_type="image/png")
+## Dispatch req to handle_img_*
+def handle_img (req, name, path) :
+"""
+Handle request for an image
+"""
+# get image object
+image = get_image(name, path)
 # what view?
 if not req.args :
-# viewport
+return handle_img_viewport(req, image, name)
-return Response(image_view(req, image_path, image), content_type="text/html")
 elif 'w' in req.args and 'h' in req.args and 'cx' in req.args and 'cy' in req.args :
-# specific image
+return handle_img_region(req, image)
-width = int(req.args['w'])
-height = int(req.args['h'])
-cx = int(req.args['cx'])
-cy = int(req.args['cy'])
-zoom = int(req.args.get('zl', "0"))
-# yay full render
-return Response(render_image(image, cx, cy, zoom, width, height), content_type="image/png")
 elif 'x' in req.args and 'y' in req.args :
-# tile
+return handle_img_tile(req, image)
-x = int(req.args['x'])
-y = int(req.args['y'])
-zoom = int(req.args.get('zl', "0"))
-# yay render
-return Response(render_tile(image, x, y, zoom), content_type="image/png")
 else :
 raise exceptions.BadRequest("Unknown args")
+## Dispatch request to handle_*
+def handle_req (req) :
+"""
+Main request handler
+"""
+# decode req
+name, path = get_req_path(req)
+# determine dir/image
+if os.path.isdir(path) :
+# directory
+return handle_dir(req, name, path)
+elif not os.path.exists(path) :
+# no such file
+raise exceptions.NotFound(name)
+elif not name or not name.endswith('.png') :
+# invalid file
+raise exceptions.BadRequest("Not a PNG file")
+else :
+# image
+return handle_img(req, name, path)
 @responder
 def application (env, start_response) :
+"""
+Main WSGI entry point
+"""
 req = Request(env, start_response)
 try :
-return handle_main(req)
+return handle_req(req)
 except exceptions.HTTPException, e :
 return e

changeset 89	02e5b9b08881
parent 47	201257cbd887
child 90	1c317e0628a7