xml["comments_count"] = res.num_tuples.to_s
# early return if there aren't any comments
- return unless res.num_tuples > 0
+ return unless res.num_tuples.positive?
discussion = XML::Node.new("discussion")
res.each do |row|
end
end
+##
+# sync a file to guarantee it's on disk
+def fsync(f)
+ File.open(f, &:fsync)
+end
+
+##
+# sync a directory to guarantee it's on disk. have to recurse to the root
+# to guarantee sync for newly created directories.
+def fdirsync(d)
+ while d != "/"
+ Dir.open(d) do |dh|
+ io = IO.for_fd(dh.fileno)
+ io.fsync
+ end
+ d = File.dirname(d)
+ 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
+ @config = YAML.safe_load(File.read(config))
+ @state = YAML.safe_load(File.read(@config["state_file"]), [Time])
+ @conn = PG::Connection.connect(@config["db"])
+ # get current time from the database rather than the current system
+ @now = @conn.exec("select now() as now").map { |row| Time.parse(row["now"]) }[0]
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
new_ids = @conn
.exec("select distinct changeset_id from changeset_comments where created_at >= '#{last_run}' and created_at < '#{@now}' and visible")
.map { |row| row["changeset_id"].to_i }
- .select { |c_id| !cs_ids.include?(c_id) }
+ .reject { |c_id| cs_ids.include?(c_id) }
new_ids.each do |id|
@conn
{ "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/" }
+ "attribution" => "https://www.openstreetmap.org/copyright",
+ "license" => "https://opendatacommons.org/licenses/odbl/1-0/" }
.each { |k, v| doc.root[k] = v }
builder = ChangesetBuilder.new(@now, @conn)
doc.to_s
end
+ def sequence
+ @state.key?("sequence") ? @state["sequence"] + 1 : 0
+ end
+
+ def data_stem
+ @config["data_dir"] + format("/%03d/%03d/%03d", sequence / 1000000, (sequence / 1000) % 1000, (sequence % 1000))
+ end
+
+ def write_tmp_files!(changesets)
+ data_file = data_stem + ".osm.gz"
+ tmp_state = @config["state_file"] + ".tmp"
+ tmp_data = data_file + ".tmp"
+
+ FileUtils.mkdir_p(File.dirname(data_file))
+ Zlib::GzipWriter.open(tmp_data) do |fh|
+ fh.write(changeset_dump(changesets))
+ end
+ File.open(tmp_state, "w") do |fh|
+ fh.write(YAML.dump(@state))
+ end
+
+ # fsync the files in their old locations.
+ fsync(tmp_data)
+ fsync(tmp_state)
+
+ # sync the directory as well, to ensure that the file is reachable
+ # from the dirent and has been updated to account for any allocations.
+ fdirsync(File.dirname(tmp_data))
+ fdirsync(File.dirname(tmp_state))
+
+ # sanity check: the files we're moving into place
+ # should be non-empty.
+ raise "Temporary gzip file should exist, but doesn't." unless File.exist?(tmp_data)
+ raise "Temporary state file should exist, but doesn't." unless File.exist?(tmp_state)
+ raise "Temporary gzip file should be non-empty, but isn't." if File.zero?(tmp_data)
+ raise "Temporary state file should be non-empty, but isn't." if File.zero?(tmp_state)
+ end
+
+ def move_tmp_files_into_place!
+ data_file = data_stem + ".osm.gz"
+ data_state_file = data_stem + ".state.txt"
+ tmp_state = @config["state_file"] + ".tmp"
+ tmp_data = data_file + ".tmp"
+
+ FileUtils.mv(tmp_data, data_file)
+ FileUtils.cp(tmp_state, @config["state_file"])
+ FileUtils.mv(tmp_state, data_state_file)
+
+ # fsync the files in their new locations, in case the inodes have
+ # changed in the move / copy.
+ fsync(data_file)
+ fsync(@config["state_file"])
+ fsync(data_state_file)
+
+ # sync the directory as well, to ensure that the file is reachable
+ # from the dirent and has been updated to account for any allocations.
+ fdirsync(File.dirname(data_file))
+ fdirsync(File.dirname(@config["state_file"]))
+ end
+
# saves new state (including the changeset dump xml)
def save!
- File.open(@config["state_file"], "r") do |fl|
- fl.flock(File::LOCK_EX)
+ File.open(@config["lock_file"], File::RDWR | File::CREAT, 0o600) do |fl|
+ # take the lock in non-blocking mode. if this process doesn't get the lock
+ # then another will be run from cron shortly. this prevents a whole bunch
+ # of processes queueing on the lock and causing weirdness if/when they
+ # get woken up in a random order.
+ got_lock = fl.flock(File::LOCK_EX | File::LOCK_NB)
+ return unless got_lock
- sequence = (@state.key?("sequence") ? @state["sequence"] + 1 : 0)
- data_file = @config["data_dir"] + format("/%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))
- fh.fdatasync
- end
+ changesets = open_changesets
@state["sequence"] = sequence
- File.open(tmp_state, "w") do |fh|
- fh.write(YAML.dump(@state))
- fh.fdatasync
- end
-
- # sanity check: the files we're moving into place
- # should be non-empty.
- raise "Temporary gzip file should exist, but doesn't." unless File.exist?(tmp_data)
- raise "Temporary state file should exist, but doesn't." unless File.exist?(tmp_state)
- raise "Temporary gzip file should be non-empty, but isn't." if File.zero?(tmp_data)
- raise "Temporary state file should be non-empty, but isn't." if File.zero?(tmp_state)
-
- FileUtils.mv(tmp_data, data_file)
- FileUtils.mv(tmp_state, @config["state_file"])
- fl.flock(File::LOCK_UN)
+ @state["last_run"] = @now
- rescue
- STDERR.puts("Error! Couldn't update state.")
+ write_tmp_files!(changesets)
+
+ move_tmp_files_into_place!
+
+ fl.flock(File::LOCK_UN)
+ rescue StandardError
+ warn "Error! Couldn't update state."
fl.flock(File::LOCK_UN)
raise
end
rep = Replicator.new(ARGV[0])
rep.save!
rescue StandardError => e
- STDERR.puts "ERROR: #{e.message}"
+ warn "ERROR: #{e.message}"
exit 1
end
projects / chef.git / blobdiff