From a727752c9432096e88da690f9686343e37a720d2 Mon Sep 17 00:00:00 2001 From: Lee Lawlor Date: Mon, 7 Apr 2014 01:17:41 -0400 Subject: [PATCH] fix streaming channel downloads --- app/controllers/stream_controller.rb | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/app/controllers/stream_controller.rb b/app/controllers/stream_controller.rb index 6c19999..d3ad411 100644 --- a/app/controllers/stream_controller.rb +++ b/app/controllers/stream_controller.rb @@ -19,19 +19,24 @@ class StreamController < ApplicationController # get the feed headers csv_headers = Feed.select_options(channel, params) - # set the total records and batch size - total_records = channel.feeds.count - batch = 1000 - # write the headers row response.stream.write "#{CSV.generate_line(csv_headers)}" - # for every 1000 records - (0..(total_records - batch).abs).step(batch) do |i| + # set loop variables + batch_size = 1000 + last_entry_id = channel.last_entry_id + current_entry_id = 0 + + # while there are still entries to process + while current_entry_id < last_entry_id # variable to hold the streaming output for this batch batch_output = "" - # feeds query - feeds = Feed.where(:channel_id => channel.id).order('entry_id asc').offset(i).limit(batch) + + # get the feeds + feeds = Feed.where(:channel_id => channel.id).where("entry_id > ? AND entry_id <= ?", current_entry_id, current_entry_id + batch_size).order('entry_id asc').limit(batch_size) + + # set the current entry id + current_entry_id += batch_size # for each feed, add the data according to the csv_headers feeds.each do |feed| @@ -41,7 +46,8 @@ class StreamController < ApplicationController end # write the output for this batch - response.stream.write batch_output + response.stream.write batch_output if batch_output.present? + # add a slight delay between database queries sleep 0.1 end