Upgrade generic-pool to v3

[brianc]

This is a breaking change for v7.0. The next version of the pool has a lot more options. I need to make sure to expose these options in the pg-pool constructor properly.

[gajus]

The next version of the pool has a lot more options

https://github.com/coopernurse/node-pool/tree/v3.1.7

[gajus]

acquireTimeoutMillis is something that'd be definitely useful.

brianc on the note of generic-pool, I think it would appropriate for the pg-pool to declare its own defaults as opposed to replying on the generic-pool configuration.

Similarly, the README.md is a bit misleading – after scanning the docs, I thought that whats presented in the create example (the pool configuration) is what the default configuration is. Thats not the case.

[brianc]

@gajus - what do you mean by declaring it's own defaults? Do you mean instead of just passing undefined for any config value that isn't passed to pg-pool, pass in a preset one - even if it just mirrors what generic-pool uses? That way if generic-pool changes it's defaults in the future we wont break? Do you have a code sample...that might help me understand!

I can also document the defaults if that would help?

[gajus]

pass in a preset one - even if it just mirrors what generic-pool uses? That way if generic-pool changes it's defaults in the future we wont break?

Precisely.

Since the configuration is flat, the simplest way to do that is using Object.assign, e.g.

const createConfiguration = (userConfiguration) => {
  const defaultConfiguration = {
    acquireTimeoutMillis: Infinity,
    autostart: true,
    evictionRunIntervalMillis: 0,
    fifo: true,
    idleTimeoutMillis: 30000,
    max: 1,
    maxWaitingClients: Infinity,
    min: 0,
    numTestsPerRun: 3
    priorityRange: 1,
    Promise: global.Promise,
    softIdleTimeoutMillis: -1,
    testOnBorrow: false
  };

  return Object.assign({}, defaultConfiguration, userConfiguration);
};

As far as I can tell from their docs, these are the defaults for the generic-pool v3.

I can also document the defaults if that would help?

It is a bit odd when they are not in the docs. However, if you are mirroring generic-pool configuration, then simply linking to their documentation would be enough.

The reason this caught my attention in the first place is because I was debugging an instance where I was expecting an idle connection to time out after 1 second (false assumption made after looking into https://github.com/brianc/node-pg-pool). I had to go into the code to scout that you are using generic-pool and then look into their configuration defaults for the respective version.

[brianc]

Handling this here: brianc/node-pg-pool#67