--- /dev/null
+#!/usr/bin/ruby
+
+require 'rubygems'
+require 'pg'
+require 'yaml'
+require 'time'
+require 'fileutils'
+require 'xml/libxml'
+require 'zlib'
+
+# after this many changes, a changeset will be closed
+CHANGES_LIMIT=50000
+
+# this is the scale factor for lat/lon values stored as integers in the database
+GEO_SCALE=10000000
+
+##
+# changeset class keeps some information about changesets downloaded from the
+# database - enough to let us know which changesets are closed/open & recently
+# closed.
+class Changeset
+ attr_reader :id, :created_at, :closed_at, :num_changes
+
+ def initialize(row)
+ @id = row['id'].to_i
+ @created_at = Time.parse(row['created_at'])
+ @closed_at = Time.parse(row['closed_at'])
+ @num_changes = row['num_changes'].to_i
+ end
+
+ def closed?(t)
+ (@closed_at < t) || (@num_changes >= CHANGES_LIMIT)
+ end
+
+ def open?(t)
+ not closed?(t)
+ end
+
+ def activity_between?(t1, t2)
+ ((@closed_at >= t1) && (@closed_at < t2)) || ((@created_at >= t1) && (@created_at < t2))
+ end
+end
+
+##
+# state and connections associated with getting changeset data
+# replicated to a file.
+class Replicator
+ def initialize(config)
+ @config = YAML.load(File.read(config))
+ @state = YAML.load(File.read(@config['state_file']))
+ @conn = PGconn.connect(@config['db'])
+ @now = Time.now.getutc
+ end
+
+ def open_changesets
+ last_run = @state['last_run']
+ last_run = (@now - 60) if last_run.nil?
+ @state['last_run'] = @now
+ # pretty much all operations on a changeset will modify its closed_at
+ # time (see rails_port's changeset model). so it is probably enough
+ # for us to look at anything that was closed recently, and filter from
+ # there.
+ @conn.
+ exec("select id, created_at, closed_at, num_changes from changesets where closed_at > ((now() at time zone 'utc') - '1 hour'::interval)").
+ map {|row| Changeset.new(row) }.
+ select {|cs| cs.activity_between?(last_run, @now) }
+ end
+
+ # creates an XML file containing the changeset information from the
+ # list of changesets output by open_changesets.
+ def changeset_dump(changesets)
+ doc = XML::Document.new
+ doc.root = XML::Node.new("osm")
+ { 'version' => '0.6',
+ 'generator' => 'replicate_changesets.rb',
+ 'copyright' => "OpenStreetMap and contributors",
+ 'attribution' => "http://www.openstreetmap.org/copyright",
+ 'license' => "http://opendatacommons.org/licenses/odbl/1-0/" }.
+ each { |k,v| doc.root[k] = v }
+
+ changesets.each do |cs|
+ xml = XML::Node.new("changeset")
+ xml['id'] = cs.id.to_s
+ xml['created_at'] = cs.created_at.getutc.xmlschema
+ xml['closed_at'] = cs.closed_at.getutc.xmlschema if cs.closed?(@now)
+ xml['open'] = cs.open?(@now).to_s
+
+ res = @conn.exec("select u.id, u.display_name, c.min_lat, c.max_lat, c.min_lon, c.max_lon from users u join changesets c on u.id=c.user_id where c.id=#{cs.id}")
+ xml['user'] = res[0]['display_name']
+ xml['uid'] = res[0]['id']
+
+ unless (res[0]['min_lat'].nil? ||
+ res[0]['max_lat'].nil? ||
+ res[0]['min_lon'].nil? ||
+ res[0]['max_lon'].nil?)
+ xml['min_lat'] = (res[0]['min_lat'].to_f / GEO_SCALE).to_s
+ xml['max_lat'] = (res[0]['max_lat'].to_f / GEO_SCALE).to_s
+ xml['min_lon'] = (res[0]['min_lon'].to_f / GEO_SCALE).to_s
+ xml['max_lon'] = (res[0]['max_lon'].to_f / GEO_SCALE).to_s
+ end
+
+ res = @conn.exec("select k, v from changeset_tags where changeset_id=#{cs.id}")
+ res.each do |row|
+ tag = XML::Node.new("tag")
+ tag['k'] = row['k']
+ tag['v'] = row['v']
+ xml << tag
+ end
+
+ doc.root << xml
+ end
+
+ doc.to_s
+ end
+
+ # saves new state (including the changeset dump xml)
+ def save!
+ File.open(@config['state_file'], "r") do |fl|
+ fl.flock(File::LOCK_EX)
+
+ sequence = (@state.has_key?('sequence') ? @state['sequence'] + 1 : 0)
+ data_file = @config['data_dir'] + sprintf("/%03d/%03d/%03d.osm.gz", sequence / 1000000, (sequence / 1000) % 1000, (sequence % 1000));
+ tmp_state = @config['state_file'] + ".tmp"
+ tmp_data = "/tmp/changeset_data.osm.tmp"
+ # try and write the files to tmp locations and then
+ # move them into place later, to avoid in-progress
+ # clashes, or people seeing incomplete files.
+ begin
+ FileUtils.mkdir_p(File.dirname(data_file))
+ Zlib::GzipWriter.open(tmp_data) do |fh|
+ fh.write(changeset_dump(open_changesets))
+ end
+ @state['sequence'] = sequence
+ File.open(tmp_state, "w") do |fh|
+ fh.write(YAML.dump(@state))
+ end
+ FileUtils.mv(tmp_data, data_file)
+ FileUtils.mv(tmp_state, @config['state_file'])
+ fl.flock(File::LOCK_UN)
+
+ rescue
+ STDERR.puts("Error! Couldn't update state.")
+ fl.flock(File::LOCK_UN)
+ raise
+ end
+ end
+ end
+end
+
+rep = Replicator.new(ARGV[0])
+rep.save!
+
projects / chef.git / commitdiff