Module: Stalker

Extended by:
Stalker
Included in:
Stalker
Defined in:
lib/stalker.rb

Defined Under Namespace

Classes: BadURL, JobTimeout, NoJobsDefined, NoSuchJob

Instance Method Summary collapse

Instance Method Details

#all_jobs ⇒ Object 



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# File 'lib/stalker.rb', line 175

def all_jobs
  @@handlers.keys
end

#beanstalk ⇒ Object 



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# File 'lib/stalker.rb', line 142

def beanstalk
  @@beanstalk ||= Beanstalk::Pool.new(beanstalk_addresses)
end

#beanstalk_addresses ⇒ Object 



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# File 'lib/stalker.rb', line 153

def beanstalk_addresses
  uris = beanstalk_url.split(/[\s,]+/)
  uris.map {|uri| beanstalk_host_and_port(uri)}
end

#beanstalk_host_and_port(uri_string) ⇒ Object

Raises:



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# File 'lib/stalker.rb', line 158

def beanstalk_host_and_port(uri_string)
  uri = URI.parse(uri_string)
  raise(BadURL, uri_string) if uri.scheme != 'beanstalk'
  "#{uri.host}:#{uri.port || 11300}"
end

#beanstalk_url ⇒ Object 



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# File 'lib/stalker.rb', line 146

def beanstalk_url
  return @@url if defined?(@@url) and @@url
  ENV['BEANSTALK_URL'] || 'beanstalk://localhost/'
end

#before(&block) ⇒ Object 



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# File 'lib/stalker.rb', line 29

def before(&block)
  @@before_handlers ||= []
  @@before_handlers << block
end

#clear! ⇒ Object 



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# File 'lib/stalker.rb', line 183

def clear!
  @@handlers = nil
  @@before_handlers = nil
  @@error_handler = nil
end

#connect(url) ⇒ Object 



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# File 'lib/stalker.rb', line 9

def connect(url)
  @@url = url
  beanstalk
end

#enqueue(job, args = {}, opts = {}) ⇒ Object 



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# File 'lib/stalker.rb', line 14

def enqueue(job, args={}, opts={})
  pri   = opts[:pri]   || 65536
  delay = [0, opts[:delay].to_i].max  
  ttr   = opts[:ttr]   || 120
  beanstalk.use job
  beanstalk.put [ job, args ].to_json, pri, delay, ttr
rescue Beanstalk::NotConnected => e
  failed_connection(e)
end

#error(&blk) ⇒ Object 



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# File 'lib/stalker.rb', line 34

def error(&blk)
  @@error_handler = blk
end

#error_handler ⇒ Object 



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# File 'lib/stalker.rb', line 179

def error_handler
  @@error_handler
end

#exception_message(e) ⇒ Object 



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# File 'lib/stalker.rb', line 164

def exception_message(e)
  msg = [ "Exception #{e.class} -> #{e.message}" ]

  base = File.expand_path(Dir.pwd) + '/'
  e.backtrace.each do |t|
    msg << "   #{File.expand_path(t).gsub(/#{base}/, '')}"
  end

  msg.join("\n")
end

#failed_connection(e) ⇒ Object 



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# File 'lib/stalker.rb', line 108

def failed_connection(e)
  log_error exception_message(e)
  log_error "*** Failed connection to #{beanstalk_url}"
  log_error "*** Check that beanstalkd is running (or set a different BEANSTALK_URL)"
  exit 1
end

#job(j, &block) ⇒ Object 



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# File 'lib/stalker.rb', line 24

def job(j, &block)
  @@handlers ||= {}
  @@handlers[j] = block
end

#log(msg) ⇒ Object 



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# File 'lib/stalker.rb', line 134

def log(msg)
  puts msg
end

#log_error(msg) ⇒ Object 



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# File 'lib/stalker.rb', line 138

def log_error(msg)
  STDERR.puts msg
end

#log_job_begin(name, args) ⇒ Object 



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# File 'lib/stalker.rb', line 115

def log_job_begin(name, args)
  args_flat = unless args.empty?
    '(' + args.inject([]) do |accum, (key,value)|
      accum << "#{key}=#{value}"
    end.join(' ') + ')'
  else
    ''
  end

  log [ "Working", name, args_flat ].join(' ')
  @job_begun = Time.now
end

#log_job_end(name, failed = false) ⇒ Object 



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# File 'lib/stalker.rb', line 128

def log_job_end(name, failed=false)
  ellapsed = Time.now - @job_begun
  ms = (ellapsed.to_f * 1000).to_i
  log "Finished #{name} in #{ms}ms #{failed ? ' (failed)' : ''}"
end

#prep(jobs = nil) ⇒ Object 



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# File 'lib/stalker.rb', line 41

def prep(jobs=nil)
  raise NoJobsDefined unless defined?(@@handlers)
  @@error_handler = nil unless defined?(@@error_handler)

  jobs ||= all_jobs

  jobs.each do |job|
    raise(NoSuchJob, job) unless @@handlers[job]
  end

  log "Working #{jobs.size} jobs: [ #{jobs.join(' ')} ]"

  jobs.each { |job| beanstalk.watch(job) }

  beanstalk.list_tubes_watched.each do |server, tubes|
    tubes.each { |tube| beanstalk.ignore(tube) unless jobs.include?(tube) }
  end
rescue Beanstalk::NotConnected => e
  failed_connection(e)
end

#work(jobs = nil) ⇒ Object 



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# File 'lib/stalker.rb', line 62

def work(jobs=nil)
  prep(jobs)
  loop { work_one_job }
end

#work_one_job ⇒ Object 



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# File 'lib/stalker.rb', line 69

def work_one_job
  job = beanstalk.reserve
  name, args = JSON.parse job.body
  log_job_begin(name, args)
  handler = @@handlers[name]
  raise(NoSuchJob, name) unless handler

  begin
    Timeout::timeout(job.ttr - 1) do
      if defined? @@before_handlers and @@before_handlers.respond_to? :each
        @@before_handlers.each do |block|
          block.call(name)
        end
      end
      handler.call(args)
    end
  rescue Timeout::Error
    raise JobTimeout, "#{name} hit #{job.ttr-1}s timeout"
  end

  job.delete
  log_job_end(name)
rescue Beanstalk::NotConnected => e
  failed_connection(e)
rescue SystemExit
  raise
rescue => e
  log_error exception_message(e)
  job.bury rescue nil
log_job_end(name, 'failed') if @job_begun
  if error_handler
    if error_handler.arity == 1
      error_handler.call(e)
    else
      error_handler.call(e, name, args)
    end
  end
end