hyperlog-index/example/kv.js

forking indexes for hyperlog

var level = require('level')
var indexer = require('../')
var hyperlog = require('hyperlog')
var sub = require('subleveldown')
var mkdirp = require('mkdirp')

var minimist = require('minimist')
var argv = minimist(process.argv.slice(2), {
  default: { d: '/tmp/kv.db' }
})
mkdirp.sync(argv.d)

var hdb = level(argv.d + '/h')
var idb = level(argv.d + '/i')
var log = hyperlog(hdb, { valueEncoding: 'json' })
var db = sub(idb, 'x', { valueEncoding: 'json' })

var dex = indexer({
  log: log,
  db: sub(idb, 'i'),
  map: function (row, next) {
    // This method reduces our new state. In this example, db is used for the state.
    db.get(row.value.k, function (err, doc) {
      if (!doc) doc = {}
      row.links.forEach(function (link) {
        delete doc[link]
      })
      doc[row.key] = row.value.v
      db.put(row.value.k, doc, next)
    })
  }
})

if (argv._[0] === 'get') {
  dex.ready(function () {
    db.get(argv._[1], function (err, values) {
      if (err) console.error(err)
      else console.log(values)
    })
  })
} else if (argv._[0] === 'put') {
  // Structure `doc` as expected by `map` above
  var doc = { k: argv._[1], v: JSON.parse(argv._[2]) }
  dex.ready(function () {
    db.get(doc.k, function (err, values) {
      // Link the new entry to the "parents", from the current index, if any
      log.add(Object.keys(values || {}), doc, function (err, node) {
        if (err) console.error(err)
      })
    })
  })
} else if (argv._[0] === 'sync') {
  var r = log.replicate()
  process.stdin.pipe(r).pipe(process.stdout)
  r.on('end', function () { process.stdin.pause() })
}