progressive_io

• http://github.com/julik/progressive_io

A wrapper for IO objects that allows a callback to be set which is called when an object is read from.

• Wraps any IO

require "progressive_io"

io = ProgressiveIO.new(File.open("/bigfile.dat")) do | pos |
  puts "Read %d bytes" % [ pos ]
end

# Then, elsewhere deep in the calling code...
io.each do | line | # Each yielded line will call the callback block
   # Do stuff
end

For example, you can make any IO a provider for a progressbar:

require "progressive_io"
require "progressbar"

# If you know the total size, you can create a progress bar
total_size = File.size("/bigfile.dat")
pbar = Progressbar.new("Pumping data", total_size)
io_with_progress = ProgressiveIO.new(File.open("/bigfile.dat")) { |pos| pbar.set(pos) }

# Then, elsewhere deep in the calling code...
io_with_progress.each do | line | # Each yielded line will call the callback block
   # Each read operation will properly advance the progressbar
end

• Ruby 1.8.6+

gem install progressive_io

(The MIT License)

Copyright (c) 2011 Julik Tarkhanov me@julik.nl

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.