couchrest_model/lib/couchrest/helper/streamer.rb
2008-10-14 15:08:17 -07:00

44 lines
No EOL
1 KiB
Ruby

module CouchRest
class Streamer
attr_accessor :db
def initialize db
@db = db
end
# Stream a view, yielding one row at a time. Shells out to <tt>curl</tt> to keep RAM usage low when you have millions of rows.
def view name, params = nil, &block
urlst = /^_/.match(name) ? "#{@db.root}/#{name}" : "#{@db.root}/_view/#{name}"
url = CouchRest.paramify_url urlst, params
# puts "stream #{url}"
first = nil
IO.popen("curl --silent #{url}") do |view|
first = view.gets # discard header
while line = view.gets
row = parse_line(line)
block.call row
end
end
parse_first(first)
end
private
def parse_line line
return nil unless line
if /(\{.*\}),?/.match(line.chomp)
JSON.parse($1)
end
end
def parse_first first
return nil unless first
parts = first.split(',')
parts.pop
line = parts.join(',')
JSON.parse("#{line}}")
rescue
nil
end
end
end