create cache packages for caching tile servers

src/c3nav/mapdata/render/renderdata.py

@@ -3,6 +3,7 @@ import os
 import pickle
 import threading
 from collections import deque
+from itertools import chain
 
 import numpy as np
 from django.conf import settings
@@ -11,9 +12,10 @@ from shapely import prepared
 from shapely.geometry import GeometryCollection
 from shapely.ops import unary_union
 
-from c3nav.mapdata.models import Level, MapUpdate
+from c3nav.mapdata.models import Level, MapUpdate, Source
 from c3nav.mapdata.render.geometry import AltitudeAreaGeometries, LevelGeometries
 from c3nav.mapdata.utils.cache import AccessRestrictionAffected, MapHistory
+from c3nav.mapdata.utils.cache.package import CachePackage
 from c3nav.mapdata.utils.geometry import get_rings
 
 empty_geometry_collection = GeometryCollection()
@@ -43,6 +45,8 @@ class LevelRenderData:
                                                       'spaces__obstacles', 'spaces__lineobstacles',
                                                       'spaces__groups', 'spaces__ramps'))
 
+        package = CachePackage(bounds=tuple(chain(*Source.max_bounds())))
+
         single_level_geoms = {}
         interpolators = {}
         last_interpolator = None
@@ -212,11 +216,16 @@ class LevelRenderData:
                 for access_restriction, areas in access_restriction_affected.items()
             }
 
-            AccessRestrictionAffected.build(access_restriction_affected).save_level(level.pk, 'composite')
+            access_restriction_affected = AccessRestrictionAffected.build(access_restriction_affected)
+            access_restriction_affected.save_level(level.pk, 'composite')
+
+            map_history.save_level(level.pk, 'composite')
+
+            package.add_level(level.pk, map_history, access_restriction_affected)
 
             render_data.save(level.pk)
 
-            map_history.save(MapHistory.level_filename(level.pk, 'composite'))
+        package.save_all()
 
     cached = {}
     cache_key = None

src/c3nav/mapdata/utils/cache/package.py

@@ -0,0 +1,52 @@
+import os
+import struct
+from collections import namedtuple
+from io import BytesIO
+from tarfile import TarFile, TarInfo
+
+from c3nav.mapdata.utils.cache import AccessRestrictionAffected, GeometryIndexed, MapHistory
+
+CachePackageLevel = namedtuple('CachePackageLevel', ('history', 'restrictions'))
+
+
+class CachePackage:
+    def __init__(self, bounds, levels=None):
+        self.bounds = bounds
+        self.levels = {} if levels is None else levels
+
+    def add_level(self, level_id: int, history: MapHistory, restrictions: AccessRestrictionAffected):
+        self.levels[level_id] = CachePackageLevel(history, restrictions)
+
+    def save(self, filename=None, compression=None):
+        if filename is None:
+            from django.conf import settings
+            filename = os.path.join(settings.CACHE_ROOT, 'package.tar')
+            if compression is not None:
+                filename += '.' + compression
+
+        filemode = 'w'
+        if compression is not None:
+            filemode += ':' + compression
+
+        with TarFile.open(filename, filemode) as f:
+            self._add_bytesio(f, 'bounds', BytesIO(struct.pack('<IIII', *(int(i*100) for i in self.bounds))))
+
+            for level_id, level_data in self.levels.items():
+                self._add_geometryindexed(f, 'history_%d' % level_id, level_data.history)
+                self._add_geometryindexed(f, 'restrictions_%d' % level_id, level_data.restrictions)
+
+    def _add_bytesio(self, f: TarFile, filename: str, data: BytesIO):
+        data.seek(0, os.SEEK_END)
+        tarinfo = TarInfo(name=filename)
+        tarinfo.size = data.tell()
+        data.seek(0)
+        f.addfile(tarinfo, data)
+
+    def _add_geometryindexed(self, f: TarFile, filename: str, obj: GeometryIndexed):
+        data = BytesIO()
+        obj.write(data)
+        self._add_bytesio(f, filename, data)
+
+    def save_all(self, filename=None):
+        for compression in (None, 'gz', 'xz'):
+            self.save(filename, compression)