Right now when an image node enters preload state, we kick off an image request with the default priority. Then when it enters display state, we change the priority to "imminent" which is mapped to the default priority as well. This means that requests from preload and display nodes have the same priority and are put to the same pool. The right behavior would be that preload requests should have a lower priority from the beginning.
Another problem is that, due to the execution order of -didEnter(Preload|Display|Visible)State calls, a node may kick off a low priority request when it enters preload state even though it knows that it's also visible. By the time -didEnterVisibleState is called, the low priority request may have already been consumed and the download/data task won't pick up the new higher priority, or some work needs to be done to move it to another queue. A better behavior would be to always use the current interface state to determine the priority. This means that visible nodes will kick off high priority requests as soon as -didEnterPreloadState is called.
The last (and smaller) issue is that a node marks its request as preload/low priority as soon as it exits visible state. I'd argue that this is too agressive. It may be reasonble for nodes in the trailing direction. Even so, we already handle this case by (almost always) have smaller trailing buffers. So this diff makes sure that nodes that exited visible state will have imminent/default priority if they remain in the display range.
All of these new behaviors are wrapped in an experiment and will be tested carefully before being rolled out.
* Add imports
* Fix build failure
* Encapsulate common logics into methods
* Address comments
* [License] Simplify the Texture license to be pure Apache 2 (removing ASDK-Licenses)
With permission of the Facebook Open Source team, we are simplifying the Texture
license so that clients can rely on the Apache 2 terms that most of Texture is
already covered by. This means that code originally forked from AsyncDisplayKit
will be re-licensed from "BSD 3-clause + PATENTS v2" to Apache 2 without a
PATENTS file.
After getting confirmation that the updates to these core files look good, we'll
propagate this new license header to all files (in this same PR) and get sign-off
from all parties before landing.
* [License] Update all Texture source files to be pure Apache 2.
* Changelog entry for Apache 2 license update.
* Revert "[License] Update all Texture source files to be pure Apache 2."
This reverts commit ffa0fbbba9.
* [License] Update all Texture source files to be pure Apache 2, maintaining copyrights.
* [License] Update CONTRIBUTING, README, Podspec & Dangerfile.
* Add support for piping arbitrary user info from ASImageDownloader to the ASNetworkImageNodeDelegate
* s/source/sourceType
* Fix stuff and take Michael's advice
* Add support for downloading a set of URLs on ASNetworkImageNode
* Should be building now;
* Remove old unused code
* Add a changelog message
* Bump PINRemoteImage
* Huy's comments
* Adds support for resuming downloads that were canceled due to exiting preload range.
* Update to latest PINRemoteImage
* Fix warnings
* Address comments. Thanks @nguyenhuy!
* [ASMultiplex/NetworkImageNode] Ensure ASImageProtocols are not called with nil arguments.
* [ASBasic/PINRemoteImageDownloader] Do not check for nil downloadIdentifier needlessly.
* [ASImageCacheProtocol] Make synchronouslyFetchedCachedImageWithURL URL nonnull.
Huy Nguyen
appleguy
Adlai Holler
Garrett Moon
Michael Schneider
Flo
Adlai Holler