require 'proj4'
require 'xml/libxml'
require 'set'
-require 'pg'
require 'time'
+require 'mmap'
module Expire
# projection object to go from latlon -> spherical mercator
- PROJ = Proj4::Projection.new(["+proj=merc", "+a=6378137", "+b=6378137",
+ PROJ = Proj4::Projection.new(["+proj=merc", "+a=6378137", "+b=6378137",
"+lat_ts=0.0", "+lon_0=0.0", "+x_0=0.0",
- "+y_0=0", "+k=1.0", "+units=m",
+ "+y_0=0", "+k=1.0", "+units=m",
"+nadgrids=@null", "+no_defs +over"])
-
+
# width/height of the spherical mercator projection
- SIZE=40075016.6855784
+ SIZE = 40075016.6855784
# the size of the meta tile blocks
METATILE = 8
# the directory root for meta tiles
HASH_ROOT = "/tiles/default/"
- # lowest zoom that we want to expire
- # MIN_ZOOM=12
- MIN_ZOOM=13
- # highest zoom that we want to expire
- MAX_ZOOM=18
- # database parameters
- DBNAME="gis"
- DBHOST=""
- #DBPORT=5432
- DBPORT=5432
- DBTABLE="planet_osm_nodes"
-
+ # node cache file
+ NODE_CACHE_FILE = "/store/database/nodes"
+
# turns a spherical mercator coord into a tile coord
- def Expire.tile_from_merc(point, zoom)
+ def self.tile_from_merc(point, zoom)
# renormalise into unit space [0,1]
point.x = 0.5 + point.x / SIZE
point.y = 0.5 - point.y / SIZE
# transform into tile space
- point.x = point.x * 2 ** zoom
- point.y = point.y * 2 ** zoom
+ point.x = point.x * 2**zoom
+ point.y = point.y * 2**zoom
# chop of the fractional parts
[point.x.to_int, point.y.to_int, zoom]
end
-
+
# turns a latlon -> tile x,y given a zoom level
- def Expire.tile_from_latlon(latlon, zoom)
+ def self.tile_from_latlon(latlon, zoom)
# first convert to spherical mercator
point = PROJ.forward(latlon)
tile_from_merc(point, zoom)
end
-
+
# this must match the definition of xyz_to_meta in mod_tile
- def Expire.xyz_to_meta(x, y, z)
+ def self.xyz_to_meta(x, y, z)
# mask off the final few bits
x &= ~(METATILE - 1)
y &= ~(METATILE - 1)
# generate the path
- hash_path = (0..4).collect { |i|
- (((x >> 4*i) & 0xf) << 4) | ((y >> 4*i) & 0xf)
- }.reverse.join('/')
+ hash_path = (0..4).collect do |i|
+ (((x >> 4 * i) & 0xf) << 4) | ((y >> 4 * i) & 0xf)
+ end.reverse.join('/')
z.to_s + '/' + hash_path + ".meta"
end
-
+
# time to reset to, some very stupidly early time, before OSM started
EXPIRY_TIME = Time.parse("2000-01-01 00:00:00")
- # expire the meta tile by setting the modified time back
- def Expire.expire_meta(meta)
+ # expire the meta tile by setting the modified time back
+ def self.expire_meta(meta)
puts "Expiring #{meta}"
File.utime(EXPIRY_TIME, EXPIRY_TIME, meta)
end
-
- def Expire.expire(change_file, tile_dirs)
- do_expire(change_file) do |set|
+
+ def self.expire(change_file, min_zoom, max_zoom, tile_dirs)
+ do_expire(change_file, min_zoom, max_zoom) do |set|
new_set = Set.new
meta_set = Set.new
# so that we don't expire things multiple times
set.each do |xy|
# this has to match the routine in mod_tile
- meta = xyz_to_meta(HASH_ROOT, xy[0], xy[1], xy[2])
+ meta = xyz_to_meta(xy[0], xy[1], xy[2])
# check each style working out what needs expiring
tile_dirs.each do |tile_dir|
meta_set.add(tile_dir + "/" + meta) if File.exist?(tile_dir + "/" + meta)
end
-
+
# add the parent into the set for the next round
new_set.add([xy[0] / 2, xy[1] / 2, xy[2] - 1])
end
-
+
# expire all meta tiles
meta_set.each do |meta|
expire_meta(meta)
end
end
- def Expire.do_expire(change_file, &block)
+ def self.do_expire(change_file, min_zoom, max_zoom, &_)
# read in the osm change file
doc = XML::Document.file(change_file)
-
+
# hash map to contain all the nodes
- nodes = Hash.new
-
+ nodes = {}
+
# we put all the nodes into the hash, as it doesn't matter whether the node was
# added, deleted or modified - the tile will need updating anyway.
doc.find('//node').each do |node|
if lat > 85
lat = 85
end
- point = Proj4::Point.new(Math::PI * node['lon'].to_f / 180,
+ 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'].to_i] = tile_from_latlon(point, max_zoom)
end
-
+
# now we look for all the ways that have changed and put all of their nodes into
# the hash too. this will add too many nodes, as it is possible a long way will be
# changed at only a portion of its length. however, due to the non-local way that
# mapnik does text placement, it may stil not be enough.
#
- # also, we miss cases where nodes are deleted from ways where that node is not
+ # also, we miss cases where nodes are deleted from ways where that node is not
# itself deleted and the coverage of the point set isn't enough to encompass the
# change.
- conn = PG::Connection.new(:host => DBHOST, :port => DBPORT, :dbname => DBNAME)
+ node_cache = NodeCache.new(NODE_CACHE_FILE)
doc.find('//way/nd').each do |node|
node_id = node['ref'].to_i
unless nodes.include? node_id
# this is a node referenced but not added, modified or deleted, so it should
- # still be in the postgis DB.
- res = conn.query("select lon, lat from #{DBTABLE} where id=#{node_id};")
-
- # loop over results, adding tiles to the change set
- res.each do |row|
- point = Proj4::Point.new(row[0].to_f / 100.0, row[1].to_f / 100.0)
- nodes[node_id] = tile_from_merc(point, MAX_ZOOM)
+ # still be in the node cache.
+ if entry = node_cache[node_id]
+ point = Proj4::Point.new(entry.lon, entry.lat)
+ nodes[node_id] = tile_from_merc(point, max_zoom)
end
-
- # Discard results
- res.clear
end
end
-
- # create a set of all the tiles at the maximum zoom level which are touched by
+
+ # 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
# by a simple recursion.
set = Set.new nodes.values
-
+
# expire tiles and shrink to the set of parents
- (MAX_ZOOM).downto(MIN_ZOOM) do |z|
+ (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
end
end
+
+ # wrapper to access the osm2pgsql node cache
+ class NodeCache
+ # node cache entry
+ class Node
+ attr_reader :lon, :lat
+
+ def initialize(lon, lat)
+ @lat = lat.to_f / 100.0
+ @lon = lon.to_f / 100.0
+ end
+ end
+
+ # open the cache
+ def initialize(filename)
+ @cache = Mmap.new(filename)
+
+ 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[8..15].unpack("q").first
+ end
+
+ # lookup a node
+ def [](id)
+ if id <= @max_id
+ offset = 16 + id * 8
+
+ lon, lat = @cache[offset..offset + 7].unpack("ll")
+
+ if lon != -2147483648 && lat != -2147483648
+ node = Node.new(lon, lat)
+ end
+ end
+
+ node
+ end
+ end
end
projects / chef.git / blobdiff