terom@93: import os, os.path
terom@93: import pypngtile as pt
terom@93: 
terom@93: from werkzeug import Response, exceptions
terom@93: 
terom@93: from pngtile import render
terom@93: 
terom@93: # path to images
terom@93: DATA_ROOT = os.environ.get("PNGTILE_DATA_PATH") or os.path.abspath('data/')
terom@93: 
terom@93: # only open each image once
terom@93: IMAGE_CACHE = {}
terom@93: 
terom@93: ### Parse request data
terom@93: def get_path (req_path) :
terom@93:     """
terom@93:         Returns the name and path requested
terom@93:     """
terom@93:     
terom@93:     # check DATA_ROOT exists..
terom@93:     if not os.path.isdir(DATA_ROOT) :
terom@93:         raise exceptions.InternalServerError("Missing DATA_ROOT")
terom@93: 
terom@93:     # path to image
terom@93:     image_name = req_path.lstrip('/')
terom@93:     
terom@93:     # build absolute path
terom@93:     image_path = os.path.abspath(os.path.join(DATA_ROOT, image_name))
terom@93: 
terom@93:     # ensure the path points inside the data root
terom@93:     if not image_path.startswith(DATA_ROOT) :
terom@93:         raise exceptions.NotFound(image_name)
terom@93: 
terom@93:     return image_name, image_path
terom@93: 
terom@93: def get_image (name, path) :
terom@93:     """
terom@93:         Gets an Image object from the cache, ensuring that the cached is available
terom@93:     """
terom@93: 
terom@93:     # get Image object
terom@93:     if path in IMAGE_CACHE :
terom@93:         # get from cache
terom@93:         image = IMAGE_CACHE[path]
terom@93: 
terom@93:     else :
terom@93:         # open
terom@93:         image = pt.Image(path)
terom@93: 
terom@93:         # check
terom@93:         if image.status() not in (pt.CACHE_FRESH, pt.CACHE_STALE) :
terom@93:             raise exceptions.InternalServerError("Image cache not available: %s" % name)
terom@93: 
terom@93:         # load
terom@93:         image.open()
terom@93: 
terom@93:         # cache
terom@93:         IMAGE_CACHE[path] = image
terom@93:     
terom@93:     return image
terom@93: 
terom@93: 
terom@93: ### Handle werkzeug.Request objects -> werkzeug.Response
terom@93: def handle_dir (req, name, path) :
terom@93:     """
terom@93:         Handle request for a directory
terom@93:     """
terom@93:     
terom@107:     prefix = req.script_root
terom@107:     
terom@93:     return Response(render.dir_html(prefix, name, path), content_type="text/html")
terom@93: 
terom@93: 
terom@93: 
terom@93: def handle_img_viewport (req, image, name) :
terom@93:     """
terom@93:         Handle request for image viewport
terom@93:     """
terom@93:     
terom@107:     prefix = req.script_root
terom@93: 
terom@93:     # viewport
terom@93:     return Response(render.img_html(prefix, name, image), content_type="text/html")
terom@93: 
terom@93: 
terom@103: def handle_img_region (req, image, cache) :
terom@93:     """
terom@93:         Handle request for an image region
terom@93:     """
terom@93: 
terom@93:     # specific image
terom@93:     width = int(req.args['w'])
terom@93:     height = int(req.args['h'])
terom@93:     cx = int(req.args['cx'])
terom@93:     cy = int(req.args['cy'])
terom@93:     zoom = int(req.args.get('zl', "0"))
terom@93:     
terom@93:     try :
terom@93:         # yay full render
terom@103:         return Response(render.img_png_region(image, cx, cy, zoom, width, height, cache), content_type="image/png")
terom@93: 
terom@93:     except ValueError, ex :
terom@93:         # too large
terom@93:         raise exceptions.Forbidden(str(ex))
terom@93: 
terom@93: 
terom@103: def handle_img_tile (req, image, cache) :
terom@93:     """
terom@93:         Handle request for image tile
terom@93:     """
terom@93: 
terom@93:     # tile
terom@93:     x = int(req.args['x'])
terom@93:     y = int(req.args['y'])
terom@93:     zoom = int(req.args.get('zl', "0"))
terom@103: 
terom@103:     # cache?
terom@93:         
terom@93:     # yay render
terom@103:     return Response(render.img_png_tile(image, x, y, zoom, cache), content_type="image/png")
terom@93: 
terom@93: ## Dispatch req to handle_img_*
terom@103: def handle_img (req, name, path, cache) :
terom@93:     """
terom@93:         Handle request for an image
terom@93:     """
terom@93: 
terom@93:     # get image object
terom@93:     image = get_image(name, path)
terom@93: 
terom@93:     # what view?
terom@93:     if not req.args :
terom@93:         return handle_img_viewport(req, image, name)
terom@93: 
terom@93:     elif 'w' in req.args and 'h' in req.args and 'cx' in req.args and 'cy' in req.args :
terom@103:         return handle_img_region(req, image, cache)
terom@93: 
terom@93:     elif 'x' in req.args and 'y' in req.args :
terom@103:         return handle_img_tile(req, image, cache)
terom@93: 
terom@93:     else :
terom@93:         raise exceptions.BadRequest("Unknown args")
terom@93: 
terom@93: 
terom@93: 
terom@93: ## Dispatch request to handle_*
terom@103: def handle_req (req, cache) :
terom@93:     """
terom@93:         Main request handler
terom@93:     """
terom@93:     
terom@93:     # decode req
terom@93:     name, path = get_path(req.path)
terom@93: 
terom@93:     # determine dir/image
terom@93:     if os.path.isdir(path) :
terom@93:         # directory
terom@93:         return handle_dir(req, name, path)
terom@93:     
terom@93:     elif not os.path.exists(path) :
terom@93:         # no such file
terom@93:         raise exceptions.NotFound(name)
terom@93: 
terom@93:     elif not name or not name.endswith('.png') :
terom@93:         # invalid file
terom@93:         raise exceptions.BadRequest("Not a PNG file")
terom@93:     
terom@93:     else :
terom@93:         # image
terom@103:         return handle_img(req, name, path, cache)
terom@93: 
terom@93: