bench.js

var pull = require('pull-stream')
var cont = require('cont')
const os = require('os')
const path = require('path')

module.exports = function (create, _N, finalCb) {

  console.log({ finalCb })
  if (typeof finalCb !== 'function') {
    console.log('setting')
    finalCb = () => {}
  }

  console.log("name, ops, opts/second, seconds")
  function Timer (name) {
    var start = Date.now()
    return function (ops) {
      var seconds = (Date.now() - start)/1000
      console.log([name, ops, ops/seconds, seconds].join(', '))
    }
  }

  function initialize (db, N, _, cb) {
    var data = []
    for(var i = 0; i < N; i++)
      data.push({key: '#'+i, value: {
        foo: Math.random(), bar: Date.now()
      }})

    db.append(data, function (err, offset) {
      if(err) throw err
      //wait until the view is consistent!
      db.index.since(function (v) {
        if(v < offset) return
        cb(null, N)
      })
    })
  }

  function ordered_para (db, N, _, cb) {
    //ordered reads
    var n = 0
    for(var i = 0; i < N; i++) {
      db.index.get('#'+i, next)
    }

    function next (err, v) {
      if(++n == N) cb(null, N)
    }
  }

  function ordered_series (db, N, _, cb) {
    //ordered reads
    var n = 0, i = 0
    ;(function _next () {
        var key = '#'+(i++)
        db.index.get(i, function (err, v) {
          if(v.key != key) return cb('benchmark failed: incorrect key returned')
          if(i == n) cb(null, N)
          else setImmediate(_next)
        })
    })(0)
  }


  function random_series (db, N, _, cb) {
    ;(function get(i) {
      if(i >= N) return cb(null, N)

      db.index.get('#'+~~(Math.random()*N), function (err, data) {
        setImmediate(function () { get(i+1) })
      })

    })(0)
  }

  function random_para (db, N, _, cb) {
    var n = 0
    for(var i = 0; i < N; i++)
      db.index.get('#'+~~(Math.random()*N), next)

    function next (err, v) {
      if(err && n >= 0) {
        n = -1; cb(err)
      }
      else if(++n == N)
        cb(null, N)
    }
  }


  function random_ranges (db, N, makeOpts, cb) {
    if(!db.index.read) return cb(new Error('not supported'))

    ;(function get(i) {
      if(i >= N) return cb(null, N)

      pull(
        db.index.read(
          makeOpts('#'+~~(Math.random()*N))
        ),
        pull.collect(function (err, ary) {
          if(err) return cb(err)
          setImmediate(function () { get(i + ary.length) })
        })
      )
    })(0)
  }

  function limit10 (key) {
    return {gt: key, limit: 10, keys: false}
  }
  function limit10reverse (key) {
    return {gt: key, limit: 10, keys: false, reverse: true}
  }

  var seed = Date.now()
  var file = path.join(os.tmpdir(), `test-flumeview-index-${seed}`)
  var db = create(file, seed)
  var N = _N || 50000

  function refresh () {
    return function (cb) {
      db.close(function () {
        db = create(file, seed)
        var start = Date.now()
        var rm = db.index.since(function (v) {
          if(v === db.since.value) {
            console.error('reload', Date.now()-start)
            rm()
            cb()
          }
        })
      })
    }
  }

  function run(name, benchmark, opts) {
    return function (cb) {
      var t = Timer(name)
      benchmark(db, N, opts, function (err, n) {
        t(err | n)
        cb()
      })
    }
  }

  cont.series([
    run('append', initialize),
    run('ordered_para', ordered_para),
    run('random_para', random_para),
    run('ordered_series', ordered_para),
    run('random_series', random_para),
    refresh(),
    run('ordered_para (cool)', ordered_para),
    run('ordered_para (warm)', ordered_para),
    refresh(),
    run('random_para (cool)', random_para),
    run('random_para (warm)', random_para),
    refresh(),
    run('ordered_series (cool)', ordered_para),
    run('ordered_series (warm)', ordered_para),
    refresh(),
    run('random_series (cool)', random_para),
    run('random_series (warm)', random_para),
    refresh(),
    run('random-ranges', random_ranges, limit10),
    run('random-ranges (reverse)', random_ranges, limit10reverse),
  ].filter(Boolean)) (function () {
    db.close(finalCb)
  })
}