require "xml/libxml"
require "set"
require "time"
-require "simple-mmap"
module Expire
# projection object to go from latlon -> spherical mercator
# the size of the meta tile blocks
METATILE = 8
# the directory root for meta tiles
- HASH_ROOT = "/tiles/default/"
+ HASH_ROOT = "/tiles/default/".freeze
# node cache file
- NODE_CACHE_FILE = "/store/database/nodes"
+ NODE_CACHE_FILE = "/store/database/nodes".freeze
# turns a spherical mercator coord into a tile coord
def self.tile_from_merc(point, zoom)
# added, deleted or modified - the tile will need updating anyway.
doc.find("//node").each do |node|
lat = node["lat"].to_f
- if lat < -85
- lat = -85
- end
- if lat > 85
- lat = 85
- end
+ lat = -85 if lat < -85
+ lat = 85 if lat > 85
point = Proj4::Point.new(Math::PI * node["lon"].to_f / 180,
Math::PI * lat / 180)
nodes[node["id"].to_i] = tile_from_latlon(point, max_zoom)
nodes[node_id] = tile_from_merc(point, max_zoom)
end
end
+ node_cache.close
# create a set of all the tiles at the maximum zoom level which are touched by
# any of the nodes we've collected. we'll create the tiles at other zoom levels
set = Set.new nodes.values
# expire tiles and shrink to the set of parents
- (max_zoom).downto(min_zoom) do |_|
+ max_zoom.downto(min_zoom) do |_|
# allow the block to work on the set, returning the set at the next
# zoom level
set = yield set
# open the cache
def initialize(filename)
- @cache = SimpleMmap::FileWindow.open(filename)
+ @cache = File.new(filename, "r")
+
+ throw "Unexpected format" unless @cache.sysread(4).unpack("l").first == 1
+ throw "Unexpected ID size" unless @cache.sysread(4).unpack("l").first == 8
- throw "Unexpected format" unless @cache[0..3].unpack("l").first == 1
- throw "Unexpected ID size" unless @cache[4..7].unpack("l").first == 8
+ @max_id = @cache.sysread(8).unpack("q").first
+ end
- @max_id = @cache[8..15].unpack("q").first
+ # close the cache
+ def close
+ @cache.close
end
# lookup a node
if id <= @max_id
offset = 16 + id * 8
- lon, lat = @cache[offset..offset + 7].unpack("ll")
+ @cache.sysseek(offset)
- if lon != -2147483648 && lat != -2147483648
- node = Node.new(lon, lat)
- end
+ lon, lat = @cache.sysread(8).unpack("ll")
+
+ node = Node.new(lon, lat) if lon != -2147483648 && lat != -2147483648
end
node