Source code for TileCache.Service

#!/usr/bin/python

# BSD Licensed, Copyright (c) 2006-2010 TileCache Contributors

[docs]class TileCacheException(Exception): pass
import sys, cgi, time, os, traceback, email, ConfigParser import Cache, Caches import Layer, Layers # Windows doesn't always do the 'working directory' check correctly. if sys.platform == 'win32': workingdir = os.path.abspath(os.path.join(os.getcwd(), os.path.dirname(sys.argv[0]))) cfgfiles = (os.path.join(workingdir, "tilecache.cfg"), os.path.join(workingdir,"..","tilecache.cfg")) else: cfgfiles = ("/etc/tilecache.cfg", os.path.join("..", "tilecache.cfg"), "tilecache.cfg")
[docs]class Capabilities (object): def __init__ (self, format, data): self.format = format self.data = data
[docs]class Request (object): def __init__ (self, service): self.service = service
[docs] def getLayer(self, layername): try: return self.service.layers[layername] except: raise TileCacheException("The requested layer (%s) does not exist. Available layers are: \n * %s" % (layername, "\n * ".join(self.service.layers.keys())))
[docs]def import_module(name): """Helper module to import any module based on a name, and return the module.""" mod = __import__(name) components = name.split('.') for comp in components[1:]: mod = getattr(mod, comp) return mod
[docs]class Service (object): __slots__ = ("layers", "cache", "metadata", "tilecache_options", "config", "files") def __init__ (self, cache, layers, metadata = {}): self.cache = cache self.layers = layers self.metadata = metadata def _loadFromSection (cls, config, section, module, **objargs): type = config.get(section, "type") for opt in config.options(section): if opt not in ["type", "module"]: objargs[opt] = config.get(section, opt) object_module = None if config.has_option(section, "module"): object_module = import_module(config.get(section, "module")) else: if module is Layer: type = type.replace("Layer", "") object_module = import_module("TileCache.Layers.%s" % type) else: type = type.replace("Cache", "") object_module = import_module("TileCache.Caches.%s" % type) if object_module == None: raise TileCacheException("Attempt to load %s failed." % type) section_object = getattr(object_module, type) if module is Layer: return section_object(section, **objargs) else: return section_object(**objargs) loadFromSection = classmethod(_loadFromSection) def _load (cls, *files): cache = None metadata = {} layers = {} config = None try: config = ConfigParser.ConfigParser() config.read(files) if config.has_section("metadata"): for key in config.options("metadata"): metadata[key] = config.get("metadata", key) if config.has_section("tilecache_options"): if 'path' in config.options("tilecache_options"): for path in config.get("tilecache_options", "path").split(","): sys.path.insert(0, path) cache = cls.loadFromSection(config, "cache", Cache) layers = {} for section in config.sections(): if section in cls.__slots__: continue layers[section] = cls.loadFromSection( config, section, Layer, cache = cache) except Exception, E: metadata['exception'] = E metadata['traceback'] = "".join(traceback.format_tb(sys.exc_traceback)) service = cls(cache, layers, metadata) service.files = files service.config = config return service load = classmethod(_load)
[docs] def generate_crossdomain_xml(self): """Helper method for generating the XML content for a crossdomain.xml file, to be used to allow remote sites to access this content.""" xml = ["""<?xml version="1.0"?> <!DOCTYPE cross-domain-policy SYSTEM "http://www.macromedia.com/xml/dtds/cross-domain-policy.dtd"> <cross-domain-policy> """] if self.metadata.has_key('crossdomain_sites'): sites = self.metadata['crossdomain_sites'].split(',') for site in sites: xml.append(' <allow-access-from domain="%s" />' % site) xml.append("</cross-domain-policy>") return ('text/xml', "\n".join(xml))
[docs] def renderTile (self, tile, force = False): from warnings import warn start = time.time() # do more cache checking here: SRS, width, height, layers layer = tile.layer image = None if not force: image = self.cache.get(tile) if not image: data = layer.render(tile, force=force) if (data): image = self.cache.set(tile, data) else: raise Exception("Zero length data returned from layer.") if layer.debug: sys.stderr.write( "Cache miss: %s, Tile: x: %s, y: %s, z: %s, time: %s\n" % ( tile.bbox(), tile.x, tile.y, tile.z, (time.time() - start)) ) else: if layer.debug: sys.stderr.write( "Cache hit: %s, Tile: x: %s, y: %s, z: %s, time: %s, debug: %s\n" % ( tile.bbox(), tile.x, tile.y, tile.z, (time.time() - start), layer.debug) ) return (layer.mime_type, image)
[docs] def expireTile (self, tile): bbox = tile.bounds() layer = tile.layer for z in range(len(layer.resolutions)): bottomleft = layer.getClosestCell(z, bbox[0:2]) topright = layer.getClosestCell(z, bbox[2:4]) for y in range(bottomleft[1], topright[1] + 1): for x in range(bottomleft[0], topright[0] + 1): coverage = Layer.Tile(layer,x,y,z) self.cache.delete(coverage)
[docs] def dispatchRequest (self, params, path_info="/", req_method="GET", host="http://example.com/"): if self.metadata.has_key('exception'): raise TileCacheException("%s\n%s" % (self.metadata['exception'], self.metadata['traceback'])) if path_info.find("crossdomain.xml") != -1: return self.generate_crossdomain_xml() if path_info.split(".")[-1] == "kml": from TileCache.Services.KML import KML return KML(self).parse(params, path_info, host) if params.has_key("scale") or params.has_key("SCALE"): from TileCache.Services.WMTS import WMTS tile = WMTS(self).parse(params, path_info, host) elif params.has_key("service") or params.has_key("SERVICE") or \ params.has_key("REQUEST") and params['REQUEST'] == "GetMap" or \ params.has_key("request") and params['request'] == "GetMap": from TileCache.Services.WMS import WMS tile = WMS(self).parse(params, path_info, host) elif params.has_key("L") or params.has_key("l") or \ params.has_key("request") and params['request'] == "metadata": from TileCache.Services.WorldWind import WorldWind tile = WorldWind(self).parse(params, path_info, host) elif params.has_key("interface"): from TileCache.Services.TileService import TileService tile = TileService(self).parse(params, path_info, host) elif params.has_key("v") and \ (params['v'] == "mgm" or params['v'] == "mgmaps"): from TileCache.Services.MGMaps import MGMaps tile = MGMaps(self).parse(params, path_info, host) elif params.has_key("tile"): from TileCache.Services.VETMS import VETMS tile = VETMS(self).parse(params, path_info, host) elif params.has_key("format") and params['format'].lower() == "json": from TileCache.Services.JSON import JSON return JSON(self).parse(params, path_info, host) else: from TileCache.Services.TMS import TMS tile = TMS(self).parse(params, path_info, host) if isinstance(tile, Layer.Tile): if req_method == 'DELETE': self.expireTile(tile) return ('text/plain', 'OK') else: return self.renderTile(tile, params.has_key('FORCE')) elif isinstance(tile, list): if req_method == 'DELETE': [self.expireTile(t) for t in tile] return ('text/plain', 'OK') else: try: import PIL.Image as Image except ImportError: raise Exception("Combining multiple layers requires Python Imaging Library.") try: import cStringIO as StringIO except ImportError: import StringIO result = None for t in tile: (format, data) = self.renderTile(t, params.has_key('FORCE')) image = Image.open(StringIO.StringIO(data)) if not result: result = image else: try: result.paste(image, None, image) except Exception, E: raise Exception("Could not combine images: Is it possible that some layers are not \n8-bit transparent images? \n(Error was: %s)" % E) buffer = StringIO.StringIO() result.save(buffer, result.format) buffer.seek(0) return (format, buffer.read()) else: return (tile.format, tile.data)
[docs]def modPythonHandler (apacheReq, service): from mod_python import apache, util try: if apacheReq.headers_in.has_key("X-Forwarded-Host"): host = "http://" + apacheReq.headers_in["X-Forwarded-Host"] else: host = "http://" + apacheReq.headers_in["Host"] host += apacheReq.uri[:-len(apacheReq.path_info)] format, image = service.dispatchRequest( util.FieldStorage(apacheReq), apacheReq.path_info, apacheReq.method, host ) apacheReq.content_type = format apacheReq.status = apache.HTTP_OK if format.startswith("image/"): if service.cache.sendfile: apacheReq.headers_out['X-SendFile'] = image if service.cache.expire: apacheReq.headers_out['Expires'] = email.Utils.formatdate(time.time() + service.cache.expire, False, True) apacheReq.set_content_length(len(image)) apacheReq.send_http_header() if format.startswith("image/") and service.cache.sendfile: apacheReq.write("") else: apacheReq.write(image) except TileCacheException, E: apacheReq.content_type = "text/plain" apacheReq.status = apache.HTTP_NOT_FOUND apacheReq.send_http_header() apacheReq.write("An error occurred: %s\n" % (str(E))) except Exception, E: apacheReq.content_type = "text/plain" apacheReq.status = apache.HTTP_INTERNAL_SERVER_ERROR apacheReq.send_http_header() apacheReq.write("An error occurred: %s\n%s\n" % ( str(E), "".join(traceback.format_tb(sys.exc_traceback)))) return apache.OK
[docs]def wsgiHandler (environ, start_response, service): from paste.request import parse_formvars try: path_info = host = "" if "PATH_INFO" in environ: path_info = environ["PATH_INFO"] if "HTTP_X_FORWARDED_HOST" in environ: host = "http://" + environ["HTTP_X_FORWARDED_HOST"] elif "HTTP_HOST" in environ: host = "http://" + environ["HTTP_HOST"] host += environ["SCRIPT_NAME"] req_method = environ["REQUEST_METHOD"] fields = parse_formvars(environ) format, image = service.dispatchRequest( fields, path_info, req_method, host ) headers = [('Content-Type',format)] if format.startswith("image/"): if service.cache.sendfile: headers.append(('X-SendFile', image)) if service.cache.expire: headers.append(('Expires', email.Utils.formatdate(time.time() + service.cache.expire, False, True))) start_response("200 OK", headers) if service.cache.sendfile and format.startswith("image/"): return [] else: return [image] except TileCacheException, E: start_response("404 Tile Not Found", [('Content-Type','text/plain')]) return ["An error occurred: %s" % (str(E))] except Exception, E: start_response("500 Internal Server Error", [('Content-Type','text/plain')]) return ["An error occurred: %s\n%s\n" % ( str(E), "".join(traceback.format_tb(sys.exc_traceback)))]
[docs]def cgiHandler (service): try: params = {} input = cgi.FieldStorage() for key in input.keys(): params[key] = input[key].value path_info = host = "" if "PATH_INFO" in os.environ: path_info = os.environ["PATH_INFO"] if "HTTP_X_FORWARDED_HOST" in os.environ: host = "http://" + os.environ["HTTP_X_FORWARDED_HOST"] elif "HTTP_HOST" in os.environ: host = "http://" + os.environ["HTTP_HOST"] host += os.environ["SCRIPT_NAME"] req_method = os.environ["REQUEST_METHOD"] format, image = service.dispatchRequest( params, path_info, req_method, host ) print "Content-type: %s" % format if format.startswith("image/"): if service.cache.sendfile: print "X-SendFile: %s" % image if service.cache.expire: print "Expires: %s" % email.Utils.formatdate(time.time() + service.cache.expire, False, True) print "" if (not service.cache.sendfile) or (not format.startswith("image/")): if sys.platform == "win32": binaryPrint(image) else: print image except TileCacheException, E: print "Cache-Control: max-age=10, must-revalidate" # make the client reload print "Content-type: text/plain\n" print "An error occurred: %s\n" % (str(E)) except Exception, E: print "Cache-Control: max-age=10, must-revalidate" # make the client reload print "Content-type: text/plain\n" print "An error occurred: %s\n%s\n" % ( str(E), "".join(traceback.format_tb(sys.exc_traceback)))
theService = {} lastRead = {}
[docs]def handler (apacheReq): global theService, lastRead options = apacheReq.get_options() cfgs = cfgfiles fileChanged = False if options.has_key("TileCacheConfig"): configFile = options["TileCacheConfig"] lastRead[configFile] = time.time() cfgs = cfgs + (configFile,) try: cfgTime = os.stat(configFile)[8] fileChanged = lastRead[configFile] < cfgTime except: pass else: configFile = 'default' if not theService.has_key(configFile) or fileChanged: theService[configFile] = Service.load(*cfgs) return modPythonHandler(apacheReq, theService[configFile])
[docs]def wsgiApp (environ, start_response): global theService cfgs = cfgfiles if not theService: theService = Service.load(*cfgs) return wsgiHandler(environ, start_response, theService)
[docs]def binaryPrint(binary_data): """This function is designed to work around the fact that Python in Windows does not handle binary output correctly. This function will set the output to binary, and then write to stdout directly rather than using print.""" try: import msvcrt msvcrt.setmode(sys.__stdout__.fileno(), os.O_BINARY) except: pass sys.stdout.write(binary_data)
[docs]def paste_deploy_app(global_conf, full_stack=True, **app_conf): if 'tilecache_config' in app_conf: cfgfiles = (app_conf['tilecache_config'],) else: raise TileCacheException("No tilecache_config key found in configuration. Please specify location of tilecache config file in your ini file.") theService = Service.load(*cfgfiles) if 'exception' in theService.metadata: raise theService.metadata['exception'] def pdWsgiApp (environ,start_response): return wsgiHandler(environ,start_response,theService) return pdWsgiApp
if __name__ == '__main__': svc = Service.load(*cfgfiles) cgiHandler(svc)