Add .close() method

[danielfdsilva]

We have a very specific use case for the osm-p2p-db. The main process that runs the server creates a database. Subsequently, when we try to connect to the database from a different node process, we get a Resource temporarily unavailable because of the LOCK.

Looking through the documentation I wasn't able to find any way to close the db connection. What would be the best way to go about this?

Cc @olafveerman @gmaclennan

[gmaclennan]

Hi @danielfdsilva,

If you're using osm-p2p-db (as opposed to osm-p2p - a simple wrapper) then you have control of the db instances you pass to the constructor, namely the hyperlog, the leveldb for join indexes, and the abstract-chunk-store (used for the kdb spatial index).

Each of these stores has a close() method usually, that takes a callback. You basically need to close each one yourself. It would result in problems trying to do this in osm-p2p-db because you control the data stores that are passed to osm-p2p-db and they could vary with their methods for closing.

This should be documented better somewhere, and I don't know if their is a better solution.

[hackergrrl]

This makes me realize that osm-p2p really ought to have a close() method.

[danielfdsilva]

@gmaclennan I'm actually using osm-p2p, since it prepares all the databases needed to work with osm-p2p-server.

I tried to access the different databases from the instance returned by osm-p2p, but I still get the LOCK error. I'm pretty sure I'm missing some.

I've tried:

db.db.close()
db.log.db.close()
db.kdb.db.close()

Any pointers at which I should be targeting?

[hackergrrl]

Run .close() on:

• db.db
• db.log.db
• db.kdb.kdb.store

(Fun caveat: db.kdb.kdb doesn't exist at creation time; you need to wait a few ticks for it to silently set itself up async in the background.)

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Looking at how much source code digging was necessary in order for me to figure that out, it seems a bit unreasonable that osm-p2p and osm-p2p-db don't expose close() methods.

[danielfdsilva]

@noffle That seems to have done it! thanks :)

[hackergrrl]

Fixed in 4.2.0 :tada: