Downloads: Support per-download requirements

[TheSikh]

I am trying to download dash content from a network storage device to client device using ExoPlayer's DownloadManager, However When I submit the downloadrequest and their is no internet connection. Downloadmanager simply put the download in Stop state and wait for internet connection requirement to be met.

I am downloading from local network so internet is not needed but current DownloadManager add Network as a mandatory requirement for process downloads.

Is there any way or api I can use to tell DownloadManager to skip Internet requirement because I am downloading content from local network.

here is the stack over flow question
https://stackoverflow.com/questions/70496661/downloading-content-from-local-network-storage-using-exoplayer

[ojw28]

You can tell DownloadManager not to require network simply by passing it a Requirements object that doesn't specify any requirements:

downloadManager.setRequirements(new Requirements(0));

See also the documentation here.

[TheSikh]

Requirements Assume to be either Network_Unmetered or it adds Network to requirement flags by itself.

ExoPlayer/library/core/src/main/java/com/google/android/exoplayer2/scheduler/Requirements.java

Lines 67 to 75 in 029a2b2

	/** @param requirements A combination of requirement flags. */
	public Requirements(@RequirementFlags int requirements) {
	if ((requirements & NETWORK_UNMETERED) != 0) {
	// Make sure network requirement flags are consistent.
	requirements |= NETWORK;
	}
	this.requirements = requirements;
	}

[ojw28]

Requirements Assume to be either Network_Unmetered or it adds Network to requirement flags by itself.

That's not what that code does. It adds NETWORK if NETWORK_UNMETERED is set, not if it's unset. This is because a requirement for an unmetered network implies that there must also be a requirement for a network. If you pass 0 to the Requirements constructor, you should get a Requirements object that does not require anything.

[TheSikh]

@ojw28 I understand that but Requirement imposes restriction on all downloads not on a single download. Suppose I am migrating X downloads from local and Y downloads from internet. the Y downloads will fail because there is no internet.

[ojw28]

In that case, I think we'd need to add support with a generalized version of #9822, as per the comment I left there: #9822 (comment).

This feels like a pretty niche feature, so marking as a low priority enhancement. It may be easier for you to fork the relevant pieces of ExoPlayer into your own codebase to get the functionality you need, but we will also consider a high quality and complete pull request adding support.