ubuntu-sdk-bugs team mailing list archive

[Albert Astals Cid <albert.astals@xxxxxxxxxxxxx>]

Public bug reported:

 * Take the following simple example of a listview with an image.
 * run it with strace qmlscene
 * scroll the list to the bottom


When not including "import Ubuntu.Components 1.3" there is exactly one disk access to load the image
open("/home/tsdgeos_work/test/face.png", O_RDONLY|O_CLOEXEC) = 19

When including "import Ubuntu.Components 1.3" there are around 500 disk
access including stats for the file and listing the directory containing
the file (see disk_access file).

Also for each of those directory listings we're also creating and
destroying the same QRegExp again and again.

I understand that some of this overhead is needed since we have that
thing that loads the best possible file for the given grid units, but
doing it again and again for the same file seems a bit of overkill,
maybe we could cache that?

** Affects: ubuntu-ui-toolkit (Ubuntu)
     Importance: Undecided
         Status: New

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https://bugs.launchpad.net/bugs/1558663

Title:
  Ubuntu Components is hard on the disk and CPU when loading images

Status in ubuntu-ui-toolkit package in Ubuntu:
  New

Bug description:
   * Take the following simple example of a listview with an image.
   * run it with strace qmlscene
   * scroll the list to the bottom

  
  When not including "import Ubuntu.Components 1.3" there is exactly one disk access to load the image
  open("/home/tsdgeos_work/test/face.png", O_RDONLY|O_CLOEXEC) = 19

  When including "import Ubuntu.Components 1.3" there are around 500
  disk access including stats for the file and listing the directory
  containing the file (see disk_access file).

  Also for each of those directory listings we're also creating and
  destroying the same QRegExp again and again.

  I understand that some of this overhead is needed since we have that
  thing that loads the best possible file for the given grid units, but
  doing it again and again for the same file seems a bit of overkill,
  maybe we could cache that?

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