log streams of data over time on a hyperlog
npm install cycularlog 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.
``javascript
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
// key: '919a6686d23f73961e194e3e96a44561173ccd6e4623001bc92ad7d65a8c977e',
// identity: null,
// signature: null,
// value: { metadata: [Object], payload: 42 },
// links: [],
// seq: 1,
// change: 1 } ]
//
// [...]
`
`
npm i --save cycular
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
BSD