cycular

log streams of data over time on a hyperlog

values across multiple kefir streams are assigned monotonic timestamps, and batch-written to a hyperlog, in which batches are causally linked through time.

example

var memdb = require('memdb')
var hyperlog = require('hyperlog')
var log = hyperlog(memdb(), {
  valueEncoding: 'json'
})
var cycular = require('cycular')

function exampleSource (name, interval) {
  var kefir = require('kefir')
  var randomStream = kefir.stream(emitter => {
    setInterval(function () {
      var random = Math.floor(Math.random()*100)
      emitter.emit(random)
    }, interval)
  })
  return cycular.source(randomStream)
}

var loggedDataS   = cycular.store(log, [
  exampleSource('example-source-1', 500),
  exampleSource('example-source-2', 1000),
], 50, 100)

loggedDataS
  .log('logged data')

// logged data <value> [ { log: 'cis209l9m000003x3wtwhq686',
//     key: '919a6686d23f73961e194e3e96a44561173ccd6e4623001bc92ad7d65a8c977e',
//     identity: null,
//     signature: null,
//     value: { metadata: [Object], payload: 42 },
//     links: [],
//     seq: 1,
//     change: 1 } ]
//
// [...]

install

npm i --save cycular

api

cycular.source(inputS, [metadataF])

inputS is a kefir stream.

optional metdataF(timestamp) method takes a monotonic timestamp, and returns a value to be stored in value.metadata. (by default, metadata: { timestamp: [monotonic timestamp] }.

see example/example.js for a more robust example

license

BSD