javascript - window.URL.revokeObjectURL() doesn't release memory immediately (or not at all)? -

-

i'm making html interface upload images on server drag & drop , multiple selection files. want display pictures before sending them server. first try use filereader have had problems in this post. change way , decided use blob:url ebidel recommands in post, window.url.createobjecturl() , window.url.revokeobjecturl() release memory.

but now, i've got problem, wich similar this one. want client upload 200 images @ time if wants. browser crashed , ram used high! thought maybe images displayed @ same time, , set system waiting queue of files using array, in order treat 10 files @ time. problem still occurs.

on google chrome, if check chrome://blob-internals/ files (which released window.url.revokeobjecturl()) released approximatively after 8 seconds delay. on firefox i'm not sure seems if files not released (i check on about:memory -> images that)

is code bad, or problem independent of me? there solution force navigators release immediatelly memory? if can help, part of javascripton wich problems occurs: (sorry give here link because of image spam mechanism new members) http://www26.zippyshare.com/v/14195278/file.html.

edit

this kind of own answer + answer bennlich (too long text comment)

i understood answer of user1835582 indeed remove blob/file while browser needs images keeps them somewhere in memory (which logical). it's fact display images (many & heavy) gave me crashes & slow downs, not revokeobjecturl method. moreover, each browser manages memory own way, leading different behaviors. here how came conclusion.

first, let's try revokeobjecturl works well, simple example using source code of https://developer.mozilla.org/en-us/docs/using_files_from_web_applications#example.3a_using_object_urls_to_display_images. using chrome can verify blob revoked, checking chrome://blob-internals/ or trying open displayed images new tab blank. note : release blob references, add document.getelementbyid("fileelem").value = "". when posted question years ago, 8 seconds release blob, it's immediate (probably due improvements in chrome & / or better computer)

then, time charge test. did hundred of jpg of ~2.5 mo each. after images have been displayed, scrolled page. chrome crashed , firefox slow (not tested on others browsers). however, when commented li.appendchild(img) went well, huge bunch of images. shows problems not coming revokeobjecturl method in fact works properly, displaying lot of heavy images. can test create simple html page hundreds of heavy images , scroll => same result (crash / slow down).

finally deeper images memory management, it's interesting on firefox about:memory. example saw when window active, firefox uncompresses images (images -> uncompressed-heap goes up), while raw (images -> raw) stable (relative the quantity of images loaded). there discussion memory management here : http://jeff.ecchi.ca/blog/2010/09/19/free-my-memory.

with window.url.revokeobjecturl() can [blob] or [file] object. can not force remove memory.

note. browsers not finalized , can leak these facilities. if implement animation, have understand @ own risk.


Comments

Post a Comment

Popular posts from this blog

objective c - Change font of selected text in UITextView -

-
can suggest me how change font of selected text in uitextview.i cannot use uiwebview since have edit text. have seen pages app.how possible in app. see formatting text within uilabel differently . since need editing, should @ javascript-based editors such ckeditor or tinymce . highly recommend wwdc 2011 video session 511: "rich text editing in safari on ios."
Read more

php - Accessing POST data in Facebook cavas app -

-
so i've got simple form in canvas / iframe facebook app, , i'm trying pass along values post. reading on s.o. , fb's latest docs, understand it, data send via post form can accessed on receiving end $_request object. i read on thread on s.o. in order post forms work need pass along input named "signed_request" value current signed_request (i have signed request working ok otherwise...all login , authentication stuff working fine). isnt mentioned anywhere in official fb docs. so problem comes in $_request object signed request, , bunch of other session stuff. form inputs found. the way can read them set method of form "request" isn't real form method. takes of inputs , sends them args in url. horrible. here's sample page canvas app form i'm using try debug (leaving out authentication stuff): <form enctype="application/x-www-form-urlencoded" method="post" target="_top" id="my_form" action=...
Read more

c# - Getting control value when switching a view as part of a multiview -

-
i have following code in aspx page: <asp:button id="display_button" runat="server" text="display" onclick="button1_click" /> &nbsp; <asp:button id="edit_button" runat="server" text="edit" onclick="button2_click" /> &nbsp; <asp:button id="save_button" runat="server" text="save" onclick="button3_click" visible="false" /> &nbsp; <asp:multiview id="multiview1" runat="server" activeviewindex="0"> <asp:view id="view1" runat="server"> <asp:formview id="view_program" runat="server"> <itemtemplate> <%# eval("status").tostring().trim() %> </itemtemplate> </asp:formview> </asp:view> <asp:view id="view2" runat="server"> ...
Read more