Hashing strings in a View


I’m just beginning to learn Couchbase, so if my question seems like I’m fundamentally misunderstanding something, please correct me!

I have a set of documents containing lines of text. Each line is four or five words long.

I want to create a view where the ID of each result is a hash of a line and who’s data contains the text of the line, as well as the hash of the line before and after. Something like this:

Key: 742929dcb631403d7c1c1efad2ca2700,
Value: {
Text: ‘chicken’,
PrevKey: d9f4b96fcf222c8fd607c101756b2303,
NextKey: c2e055acd7ea39b9762acfa672a74136

I have a few questions about this:

  • First, I’m no stranger to Javascript, but I’m not sure the right way to make a hash of a string. Should I write a function in the body of the Map, or is there a way to import a hashing library?
  • Second, Lets say the same line of text occurs multiple times. Can I have multiple results in a view with the same ID? Is that antipattern?

Thanks very much!


Hi There,

  • There is no way to import libraries.
  • you can certainly email multiple values and keys in the body, that is a common pattern.

You can add the function in the body of the map. That’s the best way to do things at the moment and it works quite well. I once saw someone bring a javascript PHP serializer in. Of course, you’re better off if you can a hash function that’s in the platform in many cases. I don’t know what v8’s javascript has out of the box of the top of my head.

You can have multiple results in a view with the same document key/ID. The view results will be ordered by key (unicode collated), value (unicode collated), document key/id (value comparison, effectively memcmp()).

Thank you for the responses!

ingenthr: Does Couchbase use V8 as it’s JS interpreter? I’ve been trying to find some documentation describing the javascript programming environment inside the Couchbase View system.

Yes, it’s v8. The best documentation on the programming model is in the Views Section of the admin guide.

If you find anything missing or confusing, please post an issue. There is a “docs” component. Thanks!