Support for container and TTL nodes

[dreusel]

Description

Enables creating container nodes and TTL nodes

Motivation and Context

Fixes #210

How Has This Been Tested?

For both cases, it can take anywhere between 20 seconds and way more before Zookeeper actually cleans up the nodes

For container nodes

const Zookeeper = require('zookeeper');

const zkClient = new Zookeeper({
	connect: 'localhost:2181',
	timeout: 5000,
	debug_level: Zookeeper.ZOO_LOG_LEVEL_WARN,
	host_order_deterministic: false,
});

zkClient.on('connect', async () => {
	const nodeName = `/containerTest-${('' + Math.random()).split('.')[1]}`;
	await zkClient.create(`${nodeName}`, null, Zookeeper.ZOO_CONTAINER).catch((e) => console.log('create failed', e));
	await zkClient.create(`${nodeName}/child`).catch(console.log);
	await zkClient.delete_(`${nodeName}/child`).catch(console.log);
	const start = Date.now();
	while (true) {
		await new Promise(r => setTimeout(r, 1000));
		try {
			await zkClient.exists(nodeName);
			console.log(`it still exists after ${Date.now() - start}`);
		} catch(e) {
			console.log(`it was deleted after ${Date.now() - start}`, e);
			break;
		};
	}
	zkClient.close();
});

zkClient.init();

For TTL nodes:

const Zookeeper = require('zookeeper');

const zkClient = new Zookeeper({
	connect: 'localhost:2181',
	timeout: 5000,
	debug_level: Zookeeper.ZOO_LOG_LEVEL_WARN,
	host_order_deterministic: false,
});

zkClient.on('connect', async () => {
	const nodeName = `/ttlTest-${('' + Math.random()).split('.')[1]}`;
	console.log('nodeName: ' + nodeName);
	await zkClient.create(`${nodeName}`, '', Zookeeper.ZOO_PERSISTENT_WITH_TTL, 1000).catch((e) => console.log('create failed', e));
	const start = Date.now();
	while (true) {
		await new Promise(r => setTimeout(r, 1000));
		try {
			await zkClient.exists(nodeName);
			console.log(`it still exists after ${Date.now() - start}`);
		} catch(e) {
			console.log(`it was deleted after ${Date.now() - start}`, e);
			break;
		};
	}
	zkClient.close();
});

zkClient.init();

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• I have read the code of conduct.
• I have read the contributing guide.
• I have updated the documentation accordingly (if applicable).

[DavidVujic]

Very cool!

I'll have a look within a couple of days, not more than a week.

[DavidVujic]

One thing that I just thought of is Windows support. Currently there is a (undocumented) workaround for Windows clients: because of not yet solved issues in the official C client, the version built on windows is 3.4.14 (some background can be found in the changelog).

What I'm thinking about is that it maybe is necessary to handle that, by some "if windows" clause, or if it is possible to determine the current client version running, and branch out with if/else?

[dreusel]

AH, yeah. Can you tell me what #ifdef to use? Then I'll put that in. Unfortunately I don't have Windows available to test on though.
I suppose we'd #else define the constants as -1 (or something) then, so we can throw if people try to use them in a Windows environment.

[dreusel]

Does the exception also apply to cygwin?

[DavidVujic]

Hello again @dreusel!

I'm sorry for the delay. I think I need more time to test, review and give feedback. Hope that it is ok!

[dreusel]

That's okay 👍

[DavidVujic]

Hi @dreusel!

Your pull request inspired me to try and fix the Windows issue with using an outdated ZooKeeper Client version. And I think I've succeeded 😄

Now, all platforms will use v.3.5.8 of the C client code and there is no longer any need to handle Windows separately for the Container and TTL features.

This means that your Pull Request need some updates.

But don't worry about the prebuilds, I think it is totally fine to just delete them. I will build new ones in a separate release build.

I will also have a look at the changes in your PR and share some feedback.

If you are on vacay - no worries! Come back to this PR when you have an opportunity, there is no hurry from my point of view.

[DavidVujic]

Hi again @dreusel!

Do you want to continue with this PR?

[dreusel]

Hey there @DavidVujic , sorry, I was planning to continue on it but I didn't find the time.

[dreusel]

I've also removed the win32 workarounds, but I dont have time to actually test it.

[DavidVujic]

Great @dreusel, thank you!

I'm planning to review and test this within a couple of days and want to release a new version next week. I will also will have a closer look and take your good suggestions about the API in consideration. Thank you for doing this!

[DavidVujic]

@dreusel I'm going to create a new feature branch and add your changes to it, together with updates to the prebuilds, readme and the feedback in this PR.

I'll squash and rebase the commits before merging, and will make sure your name will be in the commits (both our names will be there as "co-authored by").

I will reference the new PR to this one too, so we can keep track of the history and conversations.

[DavidVujic]

(will fix in separate branch): missing ttl parameter.

[dreusel]

Sounds good @DavidVujic! Let me know if there's anything specific you want my help with

[DavidVujic]

Closing this one. Thank you for adding this feature! I think this package is the only one out there with TTL and Container support for Node.js. Great work @dreusel!

Merged with co-authored: b625f40