Updated version that fixes a couple bugs

tumblr-likes-downloader.rb

require 'tumblr_client'
require 'mechanize'
require 'date'
require 'yaml'
require 'uri'

=begin 
To configure:

1) Go to this URL:  https://www.tumblr.com/oauth/apps

2) Add an application.  Use the following settings:
Application Name: Personal Tumblr likes downloader
Application Website: This gist.
App Store URL: (blank)
Google Play Store URL: (blank)
Application Description: ruby script to download personal likes
Administrative Contact Email: your email address
Default callback URL: This gist.

3) A new application shows up, and shows the OAuth Consumer key.
Click "Explore API" below it and allow the app access.

4) Click the "Ruby" link in the box underneath the Authentication
section.  You'll be using the four lines after the line that
reads like this:  client = Tumblr::Client.new({

5) The following is the mapping of the ExploreAPI -> the config
block below.  Copy and paste the values accordingly:
:APIValue           -> Config block variable in this script
:consumer_key       -> config.consumer_key
:consumer_secret    -> config.consumer_secret
:oauth_token        -> config.oauth_token
:oauth_token_secret -> config.oauth_token_secret
=end 

Tumblr.configure do |config|
  config.consumer_key = "consumer_key"
  config.consumer_secret = "consumer_secret"
  config.oauth_token = "oauth_token"
  config.oauth_token_secret = "oauth_token_secret"
end

THREADPOOL_SIZE = 4
SEGMENT_SIZE = 25

HISTORY_FILE = File.join(File.dirname(__FILE__), "previous.yml")


previous_dled_ids = YAML.load(File.open(HISTORY_FILE)) rescue []

directory = "tumblr-likes"

client = Tumblr::Client.new
likes = client.likes
liked_count = likes["liked_count"]

puts liked_count

likes = []

(0...liked_count).each do |i|
  if i==0 or i%SEGMENT_SIZE==0
    p "getting #{SEGMENT_SIZE} more likes starting at #{i}: #{likes.count} thus far"
    client.likes({:limit => SEGMENT_SIZE, :offset => i})["liked_posts"].each do |like|
     likes << like if like['type'] == 'photo' and !previous_dled_ids.include?(like['id'])
   end
 end

end

if likes.empty? 
  p "no new likes!"
  exit 0
end 

puts "#{likes.count} new likes!"



# some of this code comes from https://github.com/jamiew/tumblr-photo-downloader

already_had = 0

threads = []

if likes.count < THREADPOOL_SIZE
  SLICE_SIZE = likes.count
else
  SLICE_SIZE = likes.count / THREADPOOL_SIZE
end

likes.each_slice(SLICE_SIZE).each do |group|

  threads << Thread.new {
    begin
      p "launching thread #{threads.size}"

      group.each do |like|

        i = 0
        like["photos"].each do |photo|
          url = photo["original_size"]["url"]

          filename = "#{like["blog_name"]}-#{like["slug"]}-"
          filename += "#{i}-" if i > 0
          filename += File.basename(URI.parse(url).path.split('?')[0])
          if File.exists?("#{directory}/#{filename}")
            puts "Already have #{url}"
            already_had += 1
          else
            begin
              puts "Saving photo #{url}"
              file = Mechanize.new.get(url)
              file.save_as("#{directory}/#{filename}")
            rescue Mechanize::ResponseCodeError => e
              puts "Error #{e.response_code} getting file for #{url}"
            end
          end
          i += 1  
          previous_dled_ids << like['id']            
        end
      end
    rescue Exception => e
      puts "unhandled exception:, #{$!}"
    end
    p "closing thread"
  }
  
end

threads.each{|t| t.join }

YAML.dump(previous_dled_ids, File.open(HISTORY_FILE, "w"))