{"action":"created","issue":{"url":"https://api.github.com/repos/mozilla/pdf.js/issues/6977","repository_url":"https://api.github.com/repos/mozilla/pdf.js","labels_url":"https://api.github.com/repos/mozilla/pdf.js/issues/6977/labels{/name}","comments_url":"https://api.github.com/repos/mozilla/pdf.js/issues/6977/comments","events_url":"https://api.github.com/repos/mozilla/pdf.js/issues/6977/events","html_url":"https://github.com/mozilla/pdf.js/issues/6977","id":133260614,"number":6977,"title":"Rendering slowing down from 300ms to >3000 in Firefox","user":{"login":"mbmleone","id":1589653,"avatar_url":"https://avatars.githubusercontent.com/u/1589653?v=3","gravatar_id":"","url":"https://api.github.com/users/mbmleone","html_url":"https://github.com/mbmleone","followers_url":"https://api.github.com/users/mbmleone/followers","following_url":"https://api.github.com/users/mbmleone/following{/other_user}","gists_url":"https://api.github.com/users/mbmleone/gists{/gist_id}","starred_url":"https://api.github.com/users/mbmleone/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/mbmleone/subscriptions","organizations_url":"https://api.github.com/users/mbmleone/orgs","repos_url":"https://api.github.com/users/mbmleone/repos","events_url":"https://api.github.com/users/mbmleone/events{/privacy}","received_events_url":"https://api.github.com/users/mbmleone/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/mozilla/pdf.js/labels/4-information-requested","name":"4-information-requested","color":"0b02e1"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":2,"created_at":"2016-02-12T14:54:40Z","updated_at":"2016-02-12T15:20:57Z","closed_at":null,"body":"There seems to be a problem with rendering speed in Firefox of specific large PDFs.\r\nFor example this file:\r\n[testfile.pdf](https://github.com/mozilla/pdf.js/files/128068/testfile.pdf) \r\nThe first pages of this file render in roughly 300ms.\r\nAfter rendering a couple pages it increases, eventually resulting in delays of 3000-4000ms .\r\nThe pages are the exactly the same, so delay may not increase.\r\n\r\nThis happens independently of the order in which you render the pages.\r\nThis increasing delay happens in Firefox. \r\nChrome doesn't show it. \r\nIn MS Edge it also increases, there the delay increase is smaller, but happens sooner.\r\nSo the investigation should focus on Firefox.\r\n\r\nI have made a test to show this:\r\nhttps://jsfiddle.net/7xm2Ltfh/7/\r\n\r\nTry it in this way:\r\n(1) Select the provided PDF\r\n(2) Press Test 1.\r\n(3) Delays of rendering full page will be printed.\r\n\r\nTest 1 simply renders the pages one after each other.\r\nHere you see the delay increasing and the latest delays will be >3000ms.\r\n\r\nTest 2 reloads the PDF after each rendering.\r\nThat doesn't show the increase in rendering speed, but does have reload delay.\r\n\r\nHopefully one of you has on idea what causes this issue.\r\n"},"comment":{"url":"https://api.github.com/repos/mozilla/pdf.js/issues/comments/183371088","html_url":"https://github.com/mozilla/pdf.js/issues/6977#issuecomment-183371088","issue_url":"https://api.github.com/repos/mozilla/pdf.js/issues/6977","id":183371088,"user":{"login":"mbmleone","id":1589653,"avatar_url":"https://avatars.githubusercontent.com/u/1589653?v=3","gravatar_id":"","url":"https://api.github.com/users/mbmleone","html_url":"https://github.com/mbmleone","followers_url":"https://api.github.com/users/mbmleone/followers","following_url":"https://api.github.com/users/mbmleone/following{/other_user}","gists_url":"https://api.github.com/users/mbmleone/gists{/gist_id}","starred_url":"https://api.github.com/users/mbmleone/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/mbmleone/subscriptions","organizations_url":"https://api.github.com/users/mbmleone/orgs","repos_url":"https://api.github.com/users/mbmleone/repos","events_url":"https://api.github.com/users/mbmleone/events{/privacy}","received_events_url":"https://api.github.com/users/mbmleone/received_events","type":"User","site_admin":false},"created_at":"2016-02-12T15:20:57Z","updated_at":"2016-02-12T15:20:57Z","body":"Firefox 44.0.1 - Windows 10\r\n\r\n<img width=\"185\" alt=\"delay\" src=\"https://cloud.githubusercontent.com/assets/1589653/13010907/8f47738a-d1a4-11e5-92f1-e0ea7b60504e.png\">\r\n"}}