[Proposal] formalize logs

[peaBerberian]

This is a proposal to add a little "formalization" for our logs, as those became our central focus for debugging complex issues.

BEFORE:

AFTER:

(namespace is now mse to make it clear this is about the MSE API, values appended are clearly identified)

(namespace is now SF for "segment fetching" as this is what it is about, here also values are clear)

(values are clearly identified here)

(values are more formalized than before, with the key=value format of the others, though here keys are very briefs to reduce verbosity, me may document those key names somewhere)

There's already an implicit log API we have to maintain as we rely on a given format in our RxPaired live debugger but this was just enforced by not changing too much the lready-present logs.

We also noticed that multiple partners outside of canal+ were using RxPaired and looking at our logs for debugging on their side first.

---

Consequently I tried a strategy which attempts to:

• Facilitate the readability of our logs by people relying on the RxPlayer. This is here done in two ways:

  1. The "namespace" (first part of the log, before :) has to be taken from a smallish list of authorized namespaces, enforced by TypeScript. E.g. ABR for adaptive, DRM for decryption, mse for MSE-linked code, SF for segment fetching code etc.

     The end idea would even to add clear documentation for those namespaces so that people using the RxPlayer have a vague idea of what the various messages we log are about.

     It also helps by enforcing more stability (NOTE: I do not consider the namespace as part of our API, but we should always have a very good reason to break it) for external tools exploiting those.

  2. When there's data associated with the log, it was previously just appended to the message without description (e.g. some numbers after a vague message about ABR).

     Now the preferred syntax is under a JS Object which is then written as key1=value1 key2=value2 In our log messages. This helps people (including us here :p) quicly understand what those values are about.

• Try to put some more stability in our log for our external tools like RxPaired, through the same aforementioned strategies

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The main downside I see is that adding logs needs a little more looking around to get the namespace and format right.

Thoughts?

[github-actions]

✅ Automated performance checks have passed on commit d1562b4dd736524e0f13740e8847c7ba8c86d030 with the base branch dev.

Details

Performance tests 1st run output

No significative change in performance for tests:

Name	Mean	Median
loading	20.48ms -> 20.75ms (-0.262ms, z: 1.89646)	28.35ms -> 28.50ms
seeking	23.33ms -> 16.60ms (6.736ms, z: 1.06796)	11.10ms -> 11.10ms
audio-track-reload	26.65ms -> 26.81ms (-0.157ms, z: 0.66839)	39.15ms -> 39.15ms
cold loading multithread	47.60ms -> 47.35ms (0.246ms, z: 6.52117)	70.50ms -> 69.75ms
seeking multithread	55.76ms -> 65.15ms (-9.396ms, z: 0.78348)	10.05ms -> 10.05ms
audio-track-reload multithread	26.31ms -> 26.58ms (-0.265ms, z: 1.82958)	38.85ms -> 38.85ms
hot loading multithread	16.13ms -> 16.08ms (0.048ms, z: 1.06973)	23.40ms -> 23.25ms