index.js

'use strict'

var EventEmitter = require('events').EventEmitter
var index = require('hypercore-index')
var encoding = require('hyperdrive-encoding')
var inherits = require('util').inherits
var objectAssign = require('object-assign')
var assert = require('assert')

module.exports = Stats
inherits(Stats, EventEmitter)

function Stats (opts) {
  if (!(this instanceof Stats)) return new Stats(opts)
  EventEmitter.call(this)

  assert(opts.archive, '.archive required')
  assert(opts.db, '.db required')

  var archive = opts.archive
  var db = opts.db
  var self = this
  this._stats = {
    bytesTotal: 0,
    blocksProgress: 0,
    blocksTotal: 0,
    filesTotal: 0
  }

  db.get('stats', function (err, stats) {
    if (err && !err.notFound) return self.emit('error', err)
    if (stats) {
      objectAssign(self._stats, JSON.parse(stats))
      self.update()
    }

    archive.open(function (err) {
      if (err && /is closed/.test(err.message)) return
      if (err) return self.emit('error', err)

      if (!archive.owner) {
        var blocksProgress = 0
        for (var i = 0; i < archive.content.blocks; i++) {
          if (archive.content.has(i)) blocksProgress++
        }
        self.update({ blocksProgress: blocksProgress })
        archive.content.on('download', function () {
          self.update({ blocksProgress: self._stats.blocksProgress + 1 })
        })
      }

      index(
        {
          feed: opts.archive.metadata,
          db: db
        },
        function (buf, cb) {
          var entry = encoding.decode(buf)
          if (entry.type === 'file') {
            db.get('!entry!' + entry.name, function (err, last) {
              if (err && !err.notFound) return cb(err)
              var lastFound = !!last
              last = JSON.parse(last || '{}')

              var update = {
                bytesTotal: self._stats.bytesTotal +
                  entry.length -
                  (last.length || 0),
                blocksTotal: self._stats.blocksTotal +
                  entry.blocks -
                  (last.blocks || 0)
              }
              if (archive.owner) update.blocksProgress = update.blocksTotal
              if (!lastFound) update.filesTotal = self._stats.filesTotal + 1

              self.update(update)
              db
                .batch()
                .put('!entry!' + entry.name, JSON.stringify(entry))
                .put('stats', JSON.stringify(self._stats))
                .write(cb)
            })
          } else {
            cb()
          }
        },
        function (err) {
          if (err) self.emit('error', err)
        }
      )
    })
  })
}

Stats.prototype.update = function (data) {
  var keys = Object.keys(data || {})
  for (var i = 0; i < keys.length; i++) {
    var key = keys[i]
    this._stats[key] = data[key]
    this.emit('update:' + key)
  }
  this.emit('update')
}

Stats.prototype.get = function () {
  return objectAssign({}, this._stats)
}