sublink

Like level-sublevel but with links to nested keyspaces.

Why

So you can make traversable hierarchies.

How

Keys are sorted as utf8. U+10FFFF (0xF4, 0x8F, 0xBF, 0xBF) is used as a separator (so you can use any unicode string as a key), and keys pointing to nested keyspaces are suffixed with U+0000 (0x00) so they can be detected without reading any value data.

Example

var memup = require('memdb')
var Sublink = require('../')
 
var db = Sublink(memup())
 
db.put('x', '42', function () {
  var y = db.sublink('y')
  y.put('x', '42', function () {
    var rs = db.createReadStream()
    rs.on('data', function (chunk) {
      console.log(chunk.key + ': ' + chunk.value)
      // should print
      // x: 42
      // y: <Sublink y>
    })
  })
})

Install

$ npm install sublink

Test

$ npm run test

Notes

• Currently options are passed through to underlying levelup calls, however altering keyEncoding would break this module so maybe don't do that.

Changelog

4.0.0

• Add read / write locking. The implementation is primitive for now, it requires all write operations to hold a global lock.

3.0.0

• Don't require explictly deletes before overwrites - higher level modules can handle this
• Expose public name property
• Add public superlink method

2.0.0

• Require explicitly deleting sublinks before overwriting with a value and vice-versa

1.0.0

• First working version

License

WTFPL