import tornado . ioloop
import tornado . web
import io
import os
from sqlalchemy import Column , ForeignKey , Integer , String
from sqlalchemy . ext . declarative import declarative_base
from sqlalchemy . orm import relationship
from sqlalchemy import create_engine
from sqlalchemy import inspect
from sqlalchemy import text
from sqlalchemy . orm import sessionmaker
import mercantile
import pyproj
import yaml
import sys
import itertools
def GetTM2Source ( file ) :
with open ( file , ' r ' ) as stream :
tm2source = yaml . load ( stream )
return tm2source
def GeneratePrepared ( layers ) :
queries = [ ]
prepared = " PREPARE gettile(geometry, numeric, numeric, numeric) AS "
for layer in layers [ ' Layer ' ] :
layer_query = layer [ ' Datasource ' ] [ ' table ' ] . lstrip ( ) . rstrip ( ) # Remove lead and trailing whitespace
layer_query = layer_query [ 1 : len ( layer_query ) - 6 ] # Remove enough characters to remove first and last () and "AS t"
layer_query = layer_query . replace ( " geometry " , " ST_AsMVTGeom(geometry,!bbox!,4096,0,true) AS mvtgeometry " )
base_query = " SELECT ST_ASMVT( ' " + layer [ ' id ' ] + " ' , 4096, ' mvtgeometry ' , tile) FROM ( " + layer_query + " WHERE ST_AsMVTGeom(geometry, !bbox!,4096,0,true) IS NOT NULL) AS tile "
queries . append ( base_query . replace ( " !bbox! " , " $1 " ) . replace ( " !scale_denominator! " , " $2 " ) . replace ( " !pixel_width! " , " $3 " ) . replace ( " !pixel_height! " , " $4 " ) )
prepared = prepared + " UNION ALL " . join ( queries ) + " ; "
print ( prepared )
return ( prepared )
layers = GetTM2Source ( " /mapping/data.yml " )
prepared = GeneratePrepared ( layers )
engine = create_engine ( ' postgresql:// ' + os . getenv ( ' POSTGRES_USER ' , ' openmaptiles ' ) + ' : ' + os . getenv ( ' POSTGRES_PASSWORD ' , ' openmaptiles ' ) + ' @ ' + os . getenv ( ' POSTGRES_HOST ' , ' postgres ' ) + ' : ' + os . getenv ( ' POSTGRES_PORT ' , ' 5432 ' ) + ' / ' + os . getenv ( ' POSTGRES_DB ' , ' openmaptiles ' ) )
inspector = inspect ( engine )
DBSession = sessionmaker ( bind = engine )
session = DBSession ( )
session . execute ( prepared )
def bounds ( zoom , x , y ) :
inProj = pyproj . Proj ( init = ' epsg:4326 ' )
outProj = pyproj . Proj ( init = ' epsg:3857 ' )
lnglatbbox = mercantile . bounds ( x , y , zoom )
ws = ( pyproj . transform ( inProj , outProj , lnglatbbox [ 0 ] , lnglatbbox [ 1 ] ) )
en = ( pyproj . transform ( inProj , outProj , lnglatbbox [ 2 ] , lnglatbbox [ 3 ] ) )
return { ' w ' : ws [ 0 ] , ' s ' : ws [ 1 ] , ' e ' : en [ 0 ] , ' n ' : en [ 1 ] }
def zoom_to_scale_denom ( zoom ) : # For !scale_denominator!
# From https://github.com/openstreetmap/mapnik-stylesheets/blob/master/zoom-to-scale.txt
map_width_in_metres = 40075016.68557849
tile_width_in_pixels = 256.0
standardized_pixel_size = 0.00028
map_width_in_pixels = tile_width_in_pixels * ( 2.0 * * zoom )
return str ( map_width_in_metres / ( map_width_in_pixels * standardized_pixel_size ) )
def replace_tokens ( query , s , w , n , e , scale_denom ) :
return query . replace ( " !bbox! " , " ST_MakeBox2D(ST_Point( " + w + " , " + s + " ), ST_Point( " + e + " , " + n + " )) " ) . replace ( " !scale_denominator! " , scale_denom ) . replace ( " !pixel_width! " , " 256 " ) . replace ( " !pixel_height! " , " 256 " )
def get_mvt ( zoom , x , y ) :
try : # Sanitize the inputs
sani_zoom , sani_x , sani_y = float ( zoom ) , float ( x ) , float ( y )
del zoom , x , y
except :
print ( ' suspicious ' )
return 1
scale_denom = zoom_to_scale_denom ( sani_zoom )
tilebounds = bounds ( sani_zoom , sani_x , sani_y )
s , w , n , e = str ( tilebounds [ ' s ' ] ) , str ( tilebounds [ ' w ' ] ) , str ( tilebounds [ ' n ' ] ) , str ( tilebounds [ ' e ' ] )
final_query = " EXECUTE gettile(!bbox!, !scale_denominator!, !pixel_width!, !pixel_height!); "
sent_query = replace_tokens ( final_query , s , w , n , e , scale_denom )
response = list ( session . execute ( sent_query ) )
print ( sent_query )
layers = filter ( None , list ( itertools . chain . from_iterable ( response ) ) )
final_tile = b ' '
for layer in layers :
final_tile = final_tile + io . BytesIO ( layer ) . getvalue ( )
return final_tile
class GetTile ( tornado . web . RequestHandler ) :
def get ( self , zoom , x , y ) :
self . set_header ( " Content-Type " , " application/x-protobuf " )
self . set_header ( " Content-Disposition " , " attachment " )
self . set_header ( " Access-Control-Allow-Origin " , " * " )
response = get_mvt ( zoom , x , y )
self . write ( response )
def m ( ) :
if __name__ == " __main__ " :
# Make this prepared statement from the tm2source
application = tornado . web . Application ( [ ( r " /tiles/([0-9]+)/([0-9]+)/([0-9]+).pbf " , GetTile ) ] )
print ( " Postserve started.. " )
application . listen ( 8080 )
tornado . ioloop . IOLoop . instance ( ) . start ( )
m ( )