Changeset 9549 for src/django_gheat/wlheatmap/tile.py

Timestamp:

Aug 23, 2011, 8:38:09 PM (13 years ago)

Author:

rick

Message:

• Caches are now fully-file based as memcached was not working well with large entries (like images).
• OSM django proxy is way to slow, rewrite to use apache balanced proxy members.
• Use HTTPD mod_cache to cache heavy image generation work.

File:

• src/django_gheat/wlheatmap/tile.py (modified) (8 diffs)

src/django_gheat/wlheatmap/tile.py

@@ -9 +9 @@
 from django.views.decorators.cache import cache_page
 from gheat.models import *
+import os
 import pygame
 import sys
@@ -36 +37 @@
     self.surf = new_surf
 
-  def write(self, fh,format='png'):
-    # XXX: How to get a PNG stream directly to the output
-    f = tempfile.NamedTemporaryFile(suffix=format)
-    pygame.image.save(self.surf,f.name)
-    f.seek(0)
-    fh.write(f.read())
+  def save_and_get_image(self,filename):
+    """ Save the file to the location and return the file """
+    basedir = os.path.dirname(filename)
+    if not os.path.isdir(basedir):
+      os.makedirs(basedir)
+    pygame.image.save(self.surf,filename)
+    return open(filename,'r').read()
 
   def get_image(self,format='png'):
@@ -48 +50 @@
     f.seek(0)
     return f.read()
+
 
 
@@ -199 +202 @@
     'longitude__gte' : nw_deg.lon
   })
-  # TODO: This is currently hard-coded to display _all_ metingen
-  metingen = Meting.objects.select_related().filter(**filter)
+  # Limit such that high level zooms does not get the whole database
+  metingen = Meting.objects.filter(**filter)[:1000].values_list('latitude', 'longitude', 'signaal')
 
   # XXX: Signal is not normalized in the database making it unknown when a
@@ -219 +222 @@
     return max(x,y) - min(x,y)
   
-  for meting in metingen:
-    lat_min = min(lat_min, meting.latitude)
-    lat_max = max(lat_max, meting.latitude)
-    lon_min = min(lon_min, meting.longitude)
-    lon_max = max(lon_max, meting.longitude)
-    xcoord = int(dif(nw_deg.lon,meting.longitude) / (resolution_deg.lon))
-    ycoord = int(dif(nw_deg.lat,meting.latitude) / (resolution_deg.lat))
+  for (latitude, longitude, signaal) in metingen:
+    lat_min = min(lat_min, latitude)
+    lat_max = max(lat_max, latitude)
+    lon_min = min(lon_min, longitude)
+    lon_max = max(lon_max, longitude)
+    xcoord = int(dif(nw_deg.lon,longitude) / (resolution_deg.lon))
+    ycoord = int(dif(nw_deg.lat,latitude) / (resolution_deg.lat))
 
     # TODO: Please note that this 'logic' technically does apply to WiFi signals,
@@ -239 +242 @@
     # with examples like this: 
     # http://stackoverflow.com/questions/3104781/inverse-distance-weighted-idw-interpolation-with-python
-    signal_normalized = MAX_RANGE - (MAX_SIGNAL - meting.signaal)
-    im.add_circle((xcoord,ycoord),float(signal_normalized) / meters_per_pixel,colour, MAX_SIGNAL - meting.signaal)
+    signal_normalized = MAX_RANGE - (MAX_SIGNAL - signaal)
+    im.add_circle((xcoord,ycoord),float(signal_normalized) / meters_per_pixel,colour, MAX_SIGNAL - signaal)
     #im.add_point((xcoord,ycoord),float(signal_normalized) / meters_per_pixel,colour, MAX_SIGNAL - meting.signaal)
   
@@ -246 +249 @@
   return im
 
-
-# Create your views here.
-@cache_page(60 * 60 * 24, key_prefix="wlheatmap_tile")
-def serve_tile(request,zoom,x,y):
+def pre_process_tile(request,zoom,x,y):
   filter = {}
   colour = (255,0,0)
@@ -259 +259 @@
   now = time.time()
   im = make_tile(int(x),int(y),int(zoom),filter=filter,colour=colour)
+  return im
+
+# Create your views here.
+@cache_page(60 * 60 * 24, cache="tile_cache")
+def serve_tile(request,zoom,x,y):
+  im = pre_process_tile(request,zoom,x,y)
   data = im.get_image('png')
-
-  response = HttpResponse(mimetype="image/png")
-  response.write(data)
-  return response
-
+  return HttpResponse(data,mimetype="image/png")
+
+def fixed_wl_only(request,zoom,x,y): 
+  """ Pre-render and save attempt """
+  im = pre_process_tile(request,zoom,x,y)
+  data = im.save_and_get_image('/usr/local/var/django/tile/fixed/wl-only/%s/%s,%s.png' % (zoom, x, y))
+  return HttpResponse(data,mimetype="image/png")