Improve extension activation performance

[bwateratmsft]

(Self explanatory)

Here's the data from a webpacked activation:

{
	"messages": [],
	"activationTimes": {
		"codeLoadingTime": 1537,
		"activateCallTime": 14,
		"activateResolvedTime": 3152,
		"activationReason": {
			"startup": false,
			"extensionId": {
				"value": "ms-azuretools.vscode-docker",
				"_lower": "ms-azuretools.vscode-docker"
			},
			"activationEvent": "onView:dockerContainers"
		}
	},
	"runtimeErrors": []
}

From not-webpacked activation:

{
	"messages": [],
	"activationTimes": {
		"codeLoadingTime": 9422,
		"activateCallTime": 5,
		"activateResolvedTime": 3082,
		"activationReason": {
			"startup": false,
			"extensionId": {
				"value": "ms-azuretools.vscode-docker",
				"_lower": "ms-azuretools.vscode-docker"
			},
			"activationEvent": "onView:dockerContainers"
		}
	},
	"runtimeErrors": []
}

So our actual activation takes ~3 seconds, and code loading from ~1.5 seconds (webpacked) to 9.5 seconds (not webpacked).

[bwateratmsft]

I investigated the activation time itself (called activateResolvedTime above), essentially all of the time is spent on the docker context inspect call. This takes around 3 seconds on Windows, for me at least. Global average seems to be around 1300 ms. We know that it is faster on Mac and Linux, about 600 ms.

[bwateratmsft]

I did some perf testing of the code loading, based on the approach from here: https://medium.com/the-node-js-collection/timing-is-everything-6d43fc9fd416

I've attached the data. Please note that the actual loading is in a tree, but the file is flat--so when it says, for example, loading extension.bundle.js took 950 ms, that means loading it and everything under it in the load tree cumulatively took 950 ms.

• Packed Load Perf.txt
• Unpacked Load Perf.txt

The data confirms what I already knew...everything to do with Azure takes quite a while to load.

[bwateratmsft]

Some telemetry data:

From extension version 1.0.0, last 30 days:

Platform	AvgLoadTime	AvgActivationTime	Samples
Mac	955	618	2,221,756
Windows	1317	1317	1,677,449
Linux	828	633	979,105

From all versions (with big-enough sample sizes), last 30 days:

Version	AvgLoadTime	AvgActivationTime	Samples
0.7.0	964	48	44,362
0.8.2	882	39	116,594
0.9.0	1332	976	11,005
0.10.0	929	870	1,121,856
1.0.0	1054	861	4,879,119

Calls to docker context inspect began in 0.9.0, hence the big jump in activation time.

UPDATE 3 Apr 2020: I found that some of the averages were dragged too high by some obviously-invalid, way-too-high numbers. I removed them and corrected the data above.

[bwateratmsft]

#1818 partially covers docker context inspect.