Dry tilestache

TileStache/Goodies/VecTiles/geojson.py

@@ -6,8 +6,6 @@
 from shapely.wkb import loads
 from shapely.geometry import asShape
 
-from ... import getTile
-from ...Core import KnownUnknown
 from .ops import transform
 
 float_pat = compile(r'^-?\d+\.\d+(e-?\d+)?$')
@@ -16,32 +14,6 @@
 # floating point lat/lon precision for each zoom level, good to ~1/4 pixel.
 precisions = [int(ceil(log(1<<zoom + 8+2) / log(10)) - 2) for zoom in range(23)]
 
-def get_tiles(names, config, coord):
-    ''' Retrieve a list of named GeoJSON layer tiles from a TileStache config.
-
-        Check integrity and compatibility of each, looking at known layers,
-        correct JSON mime-types and "FeatureCollection" in the type attributes.
-    '''
-    unknown_layers = set(names) - set(config.layers.keys())
-
-    if unknown_layers:
-        raise KnownUnknown("%s.get_tiles didn't recognize %s when trying to load %s." % (__name__, ', '.join(unknown_layers), ', '.join(names)))
-
-    layers = [config.layers[name] for name in names]
-    mimes, bodies = zip(*[getTile(layer, coord, 'json') for layer in layers])
-    bad_mimes = [(name, mime) for (mime, name) in zip(mimes, names) if not mime.endswith('/json')]
-
-    if bad_mimes:
-        raise KnownUnknown('%s.get_tiles encountered a non-JSON mime-type in %s sub-layer: "%s"' % ((__name__, ) + bad_mimes[0]))
-
-    geojsons = map(json.loads, bodies)
-    bad_types = [(name, topo['type']) for (topo, name) in zip(geojsons, names) if topo['type'] != 'FeatureCollection']
-
-    if bad_types:
-        raise KnownUnknown('%s.get_tiles encountered a non-FeatureCollection type in %s sub-layer: "%s"' % ((__name__, ) + bad_types[0]))
-
-    return geojsons
-
 def mercator((x, y)):
     ''' Project an (x, y) tuple to spherical mercator.
     '''
@@ -91,33 +63,24 @@ def encode(file, features, zoom, is_clipped):
             feature.update(dict(clipped=True))
 
     geojson = dict(type='FeatureCollection', features=features)
-    encoder = json.JSONEncoder(separators=(',', ':'))
-    encoded = encoder.iterencode(geojson)
-    flt_fmt = '%%.%df' % precisions[zoom]
-
-    for token in encoded:
-        if charfloat_pat.match(token):
-            # in python 2.7, we see a character followed by a float literal
-            file.write(token[0] + flt_fmt % float(token[1:]))
-
-        elif float_pat.match(token):
-            # in python 2.6, we see a simple float literal
-            file.write(flt_fmt % float(token))
-
-        else:
-            file.write(token)
 
-def merge(file, names, config, coord):
+    write_to_file(file, geojson, zoom)
+
+def merge(file, names, tiles, config, coord):
     ''' Retrieve a list of GeoJSON tile responses and merge them into one.
 
         get_tiles() retrieves data and performs basic integrity checks.
     '''
-    inputs = get_tiles(names, config, coord)
-    output = dict(zip(names, inputs))
+    output = dict(zip(names, tiles))
+    write_to_file(file, output, coord.zoom)
+
+def write_to_file(file, geojson, zoom):
+    ''' Write GeoJSON stream to a file
 
+    '''
     encoder = json.JSONEncoder(separators=(',', ':'))
-    encoded = encoder.iterencode(output)
-    flt_fmt = '%%.%df' % precisions[coord.zoom]
+    encoded = encoder.iterencode(geojson)
+    flt_fmt = '%%.%df' % precisions[zoom]
 
     for token in encoded:
         if charfloat_pat.match(token):
@@ -129,4 +92,4 @@ def merge(file, names, config, coord):
             file.write(flt_fmt % float(token))
 
         else:
-            file.write(token)
+            file.write(token)

TileStache/Goodies/VecTiles/server.py

@@ -12,6 +12,10 @@
 from urllib import urlopen
 from os.path import exists
 
+import json
+from ... import getTile
+from ...Core import KnownUnknown
+
 try:
     from psycopg2.extras import RealDictCursor
     from psycopg2 import connect
@@ -320,14 +324,36 @@ def save(self, out, format):
         '''
         '''
         if format == 'TopoJSON':
-            topojson.merge(out, self.names, self.config, self.coord)
+            topojson.merge(out, self.names, self.get_tiles(format), self.config, self.coord)
 
         elif format == 'JSON':
-            geojson.merge(out, self.names, self.config, self.coord)
+            geojson.merge(out, self.names, self.get_tiles(format), self.config, self.coord)
 
         else:
             raise ValueError(format)
 
+    def get_tiles(self, format):
+        unknown_layers = set(self.names) - set(self.config.layers.keys())
+
+        if unknown_layers:
+            raise KnownUnknown("%s.get_tiles didn't recognize %s when trying to load %s." % (__name__, ', '.join(unknown_layers), ', '.join(self.names)))
+
+        layers = [self.config.layers[name] for name in self.names]
+        mimes, bodies = zip(*[getTile(layer, self.coord, format.lower()) for layer in layers])
+        bad_mimes = [(name, mime) for (mime, name) in zip(mimes, self.names) if not mime.endswith('/json')]
+
+        if bad_mimes:
+            raise KnownUnknown('%s.get_tiles encountered a non-JSON mime-type in %s sub-layer: "%s"' % ((__name__, ) + bad_mimes[0]))
+
+        tiles = map(json.loads, bodies)
+        bad_types = [(name, topo['type']) for (topo, name) in zip(tiles, self.names) if topo['type'] != ('FeatureCollection' if (format.lower()=='json') else 'Topology')]
+
+        if bad_types:
+            raise KnownUnknown('%s.get_tiles encountered a non-%sCollection type in %s sub-layer: "%s"' % ((__name__, ('Feature' if (format.lower()=='json') else 'Topology'), ) + bad_types[0]))
+
+        return tiles
+
+
 def query_columns(dbinfo, srid, subquery, bounds):
     ''' Get information about the columns returned for a subquery.
     '''

TileStache/Goodies/VecTiles/topojson.py

@@ -1,42 +1,8 @@
 from shapely.wkb import loads
 import json
 
-from ... import getTile
 from ...Core import KnownUnknown
 
-def get_tiles(names, config, coord):
-    ''' Retrieve a list of named TopoJSON layer tiles from a TileStache config.
-
-        Check integrity and compatibility of each, looking at known layers,
-        correct JSON mime-types, "Topology" in the type attributes, and
-        matching affine transformations.
-    '''
-    unknown_layers = set(names) - set(config.layers.keys())
-
-    if unknown_layers:
-        raise KnownUnknown("%s.get_tiles didn't recognize %s when trying to load %s." % (__name__, ', '.join(unknown_layers), ', '.join(names)))
-
-    layers = [config.layers[name] for name in names]
-    mimes, bodies = zip(*[getTile(layer, coord, 'topojson') for layer in layers])
-    bad_mimes = [(name, mime) for (mime, name) in zip(mimes, names) if not mime.endswith('/json')]
-
-    if bad_mimes:
-        raise KnownUnknown('%s.get_tiles encountered a non-JSON mime-type in %s sub-layer: "%s"' % ((__name__, ) + bad_mimes[0]))
-
-    topojsons = map(json.loads, bodies)
-    bad_types = [(name, topo['type']) for (topo, name) in zip(topojsons, names) if topo['type'] != 'Topology']
-
-    if bad_types:
-        raise KnownUnknown('%s.get_tiles encountered a non-Topology type in %s sub-layer: "%s"' % ((__name__, ) + bad_types[0]))
-
-    transforms = [topo['transform'] for topo in topojsons]
-    unique_xforms = set([tuple(xform['scale'] + xform['translate']) for xform in transforms])
-
-    if len(unique_xforms) > 1:
-        raise KnownUnknown('%s.get_tiles encountered incompatible transforms: %s' % (__name__, list(unique_xforms)))
-
-    return topojsons
-
 def update_arc_indexes(geometry, merged_arcs, old_arcs):
     ''' Updated geometry arc indexes, and add arcs to merged_arcs along the way.
 
@@ -190,12 +156,16 @@ def encode(file, features, bounds, is_clipped):
 
     json.dump(result, file, separators=(',', ':'))
 
-def merge(file, names, config, coord):
+def merge(file, names, inputs, config, coord):
     ''' Retrieve a list of TopoJSON tile responses and merge them into one.
 
         get_tiles() retrieves data and performs basic integrity checks.
     '''
-    inputs = get_tiles(names, config, coord)
+    transforms = [topo['transform'] for topo in inputs]
+    unique_xforms = set([tuple(xform['scale'] + xform['translate']) for xform in transforms])
+
+    if len(unique_xforms) > 1:
+        raise KnownUnknown('%s.merge encountered incompatible transforms: %s' % (__name__, list(unique_xforms)))
 
     output = {
         'type': 'Topology',