fix(DASH): Improve memory usage with live streams

[avelad]

Related to #6610

[shaka-bot]

Incremental code coverage: 80.00%

[theodab]

If I understand correctly, the purpose of this PR is to remove unnecessary cases of copying the mediaTemplate string to new variables, right? Especially in cases where this copied variable might then get captured by the context of a callback?

Do you think it'd also make sense to get rid of the assignment on line 411, then? And just use the current mediaTemplate variable inside the info?
That one might not be as important since it'd just be one string captured per call to createStreamInfo, as opposed to one string captured per call to a frequently-used method like getUris, admittedly...

[avelad]

If I understand correctly, the purpose of this PR is to remove unnecessary cases of copying the mediaTemplate string to new variables, right? Especially in cases where this copied variable might then get captured by the context of a callback?

Yes that is the purpose, in my tests this reduces memory growth, but it does not eliminate it completely, but it is better than what was before.

Do you think it'd also make sense to get rid of the assignment on line 411, then? And just use the current mediaTemplate variable inside the info? That one might not be as important since it'd just be one string captured per call to createStreamInfo, as opposed to one string captured per call to a frequently-used method like getUris, admittedly...

In theory in that case it is not necessary, because we do not need to update the manifest to obtain new segments.

[cristian-atehortua]

Yes, this was something that we were discussing on #6610. For sure, there was a memory leak on this because the created closure for getUris callback was keeping references to old string values. With this, it is ensured that the closure only keep the reference of the SegmentIndex, so when the mediaTemplate is updated, the old values can be collected.

Thanks @avelad