# HG changeset patch # User Tero Marttila # Date 1264388378 -7200 # Node ID 02e5b9b088810e450bc89699a407538f9785291b # Parent 5cc2d044d368887898c9e765ad172529634387d6 rework wsgi.py diff -r 5cc2d044d368 -r 02e5b9b08881 pngtile/wsgi.py --- a/pngtile/wsgi.py Mon Jan 25 04:34:02 2010 +0200 +++ b/pngtile/wsgi.py Mon Jan 25 04:59:38 2010 +0200 @@ -8,22 +8,70 @@ 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 """\ @@ -39,20 +87,28 @@ """ % dict( prefix = prefix, - dir = name, + dir = '/' + name, listing = "\n".join( + #

link """

""" % 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) : - image_name = os.path.basename(image_path) - - img_width, img_height = image.info() +def render_img_viewport (req, name, image) : + """ + HTML for image + """ + + # a little slow, but not so bad - two stats(), heh + info = image.info() + img_width, img_height = info['img_width'], info['img_height'] return """\ @@ -87,7 +143,7 @@ """ % dict( - title = image_name, + title = name, prefix = os.path.dirname(req.script_root).rstrip('/'), tile_url = req.url, @@ -99,6 +155,10 @@ ) def scale_by_zoom (val, zoom) : + """ + Scale coordinates by zoom factor + """ + if zoom > 0 : return val << zoom @@ -108,14 +168,23 @@ 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) @@ -129,80 +198,164 @@ 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") - - elif not os.path.exists(image_path) : - raise exceptions.NotFound(image_name) - - elif not image_name or not image_name.endswith('.png') : - raise exceptions.BadRequest("Not a PNG file") - +def get_image (name, path) : + """ + Gets an Image object from the cache, ensuring that it is cached + """ # 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 - if not os.path.exists(image_path) : - raise exceptions.NotFound(image_name) + # open + image = pt.Image(path) + + # 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 : - raise exceptions.InternalServerError("Image not cached: " + image_name) + return image + + + +### 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 Response(image_view(req, image_path, image), content_type="text/html") + return handle_img_viewport(req, image, name) elif 'w' in req.args and 'h' in req.args and 'cx' in req.args and 'cy' in req.args : - # 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_image(image, cx, cy, zoom, width, height), content_type="image/png") + return handle_img_region(req, image) elif 'x' in req.args and 'y' in req.args : - # tile - 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") - + return handle_img_tile(req, image) + 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