Oral  Brekke

Oral Brekke

1652520660

Merge2: Merge Multiple Streams into one Stream In Sequence Or Parallel

merge2

Merge multiple streams into one stream in sequence or parallel. 

Install

Install with npm

npm install merge2

Usage

const gulp = require('gulp')
const merge2 = require('merge2')
const concat = require('gulp-concat')
const minifyHtml = require('gulp-minify-html')
const ngtemplate = require('gulp-ngtemplate')

gulp.task('app-js', function () {
  return merge2(
      gulp.src('static/src/tpl/*.html')
        .pipe(minifyHtml({empty: true}))
        .pipe(ngtemplate({
          module: 'genTemplates',
          standalone: true
        })),
      gulp.src([
        'static/src/js/app.js',
        'static/src/js/locale_zh-cn.js',
        'static/src/js/router.js',
        'static/src/js/tools.js',
        'static/src/js/services.js',
        'static/src/js/filters.js',
        'static/src/js/directives.js',
        'static/src/js/controllers.js'
      ])
    )
    .pipe(concat('app.js'))
    .pipe(gulp.dest('static/dist/js/'))
})
const stream = merge2([stream1, stream2], stream3, {end: false})
//...
stream.add(stream4, stream5)
//..
stream.end()
// equal to merge2([stream1, stream2], stream3)
const stream = merge2()
stream.add([stream1, stream2])
stream.add(stream3)
// merge order:
//   1. merge `stream1`;
//   2. merge `stream2` and `stream3` in parallel after `stream1` merged;
//   3. merge 'stream4' after `stream2` and `stream3` merged;
const stream = merge2(stream1, [stream2, stream3], stream4)

// merge order:
//   1. merge `stream5` and `stream6` in parallel after `stream4` merged;
//   2. merge 'stream7' after `stream5` and `stream6` merged;
stream.add([stream5, stream6], stream7)
// nest merge
// equal to merge2(stream1, stream2, stream6, stream3, [stream4, stream5]);
const streamA = merge2(stream1, stream2)
const streamB = merge2(stream3, [stream4, stream5])
const stream = merge2(streamA, streamB)
streamA.add(stream6)

API

const merge2 = require('merge2')

merge2()

merge2(options)

merge2(stream1, stream2, ..., streamN)

merge2(stream1, stream2, ..., streamN, options)

merge2(stream1, [stream2, stream3, ...], streamN, options)

return a duplex stream (mergedStream). streams in array will be merged in parallel.

mergedStream.add(stream)

mergedStream.add(stream1, [stream2, stream3, ...], ...)

return the mergedStream.

mergedStream.on('queueDrain', function() {})

It will emit 'queueDrain' when all streams merged. If you set end === false in options, this event give you a notice that should add more streams to merge or end the mergedStream.

stream

option Type: Readable or Duplex or Transform stream.

options

option Type: Object.

end - Boolean - if end === false then mergedStream will not be auto ended, you should end by yourself. Default: undefined

pipeError - Boolean - if pipeError === true then mergedStream will emit error event from source streams. Default: undefined

objectMode - Boolean . Default: true

objectMode and other options(highWaterMark, defaultEncoding ...) is same as Node.js Stream.

Author: Teambition
Source Code: https://github.com/teambition/merge2 
License: MIT license

#node #javascript 

What is GEEK

Buddha Community

Merge2: Merge Multiple Streams into one Stream In Sequence Or Parallel
Gerhard  Brink

Gerhard Brink

1622108520

Stateful stream processing with Apache Flink(part 1): An introduction

Apache Flink, a 4th generation Big Data processing framework provides robust **stateful stream processing capabilitie**s. So, in a few parts of the blogs, we will learn what is Stateful stream processing. And how we can use Flink to write a stateful streaming application.

What is stateful stream processing?

In general, stateful stream processing is an application design pattern for processing an unbounded stream of events. Stateful stream processing means a** “State”** is shared between events(stream entities). And therefore past events can influence the way the current events are processed.

Let’s try to understand it with a real-world scenario. Suppose we have a system that is responsible for generating a report. It comprising the total number of vehicles passed from a toll Plaza per hour/day. To achieve it, we will save the count of the vehicles passed from the toll plaza within one hour. That count will be used to accumulate it with the further next hour’s count to find the total number of vehicles passed from toll Plaza within 24 hours. Here we are saving or storing a count and it is nothing but the “State” of the application.

Might be it seems very simple, but in a distributed system it is very hard to achieve stateful stream processing. Stateful stream processing is much more difficult to scale up because we need different workers to share the state. Flink does provide ease of use, high efficiency, and high reliability for the**_ state management_** in a distributed environment.

#apache flink #big data and fast data #flink #streaming #streaming solutions ##apache flink #big data analytics #fast data analytics #flink streaming #stateful streaming #streaming analytics

Merge-stream: Merge Multiple Streams into one Interleaved Stream

merge-stream

Merge (interleave) a bunch of streams.

Synopsis

var stream1 = new Stream();
var stream2 = new Stream();

var merged = mergeStream(stream1, stream2);

var stream3 = new Stream();
merged.add(stream3);
merged.isEmpty();
//=> false

Description

This is adapted from event-stream separated into a new module, using Streams3.

API

mergeStream

Type: function

Merges an arbitrary number of streams. Returns a merged stream.

merged.add

A method to dynamically add more sources to the stream. The argument supplied to add can be either a source or an array of sources.

merged.isEmpty

A method that tells you if the merged stream is empty.

When a stream is "empty" (aka. no sources were added), it could not be returned to a gulp task.

So, we could do something like this:

stream = require('merge-stream')();
// Something like a loop to add some streams to the merge stream
// stream.add(streamA);
// stream.add(streamB);
return stream.isEmpty() ? null : stream;

Gulp example

An example use case for merge-stream is to combine parts of a task in a project's gulpfile.js like this:

const gulp =          require('gulp');
const htmlValidator = require('gulp-w3c-html-validator');
const jsHint =        require('gulp-jshint');
const mergeStream =   require('merge-stream');

function lint() {
  return mergeStream(
    gulp.src('src/*.html')
      .pipe(htmlValidator())
      .pipe(htmlValidator.reporter()),
    gulp.src('src/*.js')
      .pipe(jsHint())
      .pipe(jsHint.reporter())
  );
}
gulp.task('lint', lint);

Author: Grncdr
Source Code: https://github.com/grncdr/merge-stream 
License: MIT license

#node #stream 

Oral  Brekke

Oral Brekke

1652520660

Merge2: Merge Multiple Streams into one Stream In Sequence Or Parallel

merge2

Merge multiple streams into one stream in sequence or parallel. 

Install

Install with npm

npm install merge2

Usage

const gulp = require('gulp')
const merge2 = require('merge2')
const concat = require('gulp-concat')
const minifyHtml = require('gulp-minify-html')
const ngtemplate = require('gulp-ngtemplate')

gulp.task('app-js', function () {
  return merge2(
      gulp.src('static/src/tpl/*.html')
        .pipe(minifyHtml({empty: true}))
        .pipe(ngtemplate({
          module: 'genTemplates',
          standalone: true
        })),
      gulp.src([
        'static/src/js/app.js',
        'static/src/js/locale_zh-cn.js',
        'static/src/js/router.js',
        'static/src/js/tools.js',
        'static/src/js/services.js',
        'static/src/js/filters.js',
        'static/src/js/directives.js',
        'static/src/js/controllers.js'
      ])
    )
    .pipe(concat('app.js'))
    .pipe(gulp.dest('static/dist/js/'))
})
const stream = merge2([stream1, stream2], stream3, {end: false})
//...
stream.add(stream4, stream5)
//..
stream.end()
// equal to merge2([stream1, stream2], stream3)
const stream = merge2()
stream.add([stream1, stream2])
stream.add(stream3)
// merge order:
//   1. merge `stream1`;
//   2. merge `stream2` and `stream3` in parallel after `stream1` merged;
//   3. merge 'stream4' after `stream2` and `stream3` merged;
const stream = merge2(stream1, [stream2, stream3], stream4)

// merge order:
//   1. merge `stream5` and `stream6` in parallel after `stream4` merged;
//   2. merge 'stream7' after `stream5` and `stream6` merged;
stream.add([stream5, stream6], stream7)
// nest merge
// equal to merge2(stream1, stream2, stream6, stream3, [stream4, stream5]);
const streamA = merge2(stream1, stream2)
const streamB = merge2(stream3, [stream4, stream5])
const stream = merge2(streamA, streamB)
streamA.add(stream6)

API

const merge2 = require('merge2')

merge2()

merge2(options)

merge2(stream1, stream2, ..., streamN)

merge2(stream1, stream2, ..., streamN, options)

merge2(stream1, [stream2, stream3, ...], streamN, options)

return a duplex stream (mergedStream). streams in array will be merged in parallel.

mergedStream.add(stream)

mergedStream.add(stream1, [stream2, stream3, ...], ...)

return the mergedStream.

mergedStream.on('queueDrain', function() {})

It will emit 'queueDrain' when all streams merged. If you set end === false in options, this event give you a notice that should add more streams to merge or end the mergedStream.

stream

option Type: Readable or Duplex or Transform stream.

options

option Type: Object.

end - Boolean - if end === false then mergedStream will not be auto ended, you should end by yourself. Default: undefined

pipeError - Boolean - if pipeError === true then mergedStream will emit error event from source streams. Default: undefined

objectMode - Boolean . Default: true

objectMode and other options(highWaterMark, defaultEncoding ...) is same as Node.js Stream.

Author: Teambition
Source Code: https://github.com/teambition/merge2 
License: MIT license

#node #javascript 

Teresa  Jerde

Teresa Jerde

1597452410

Spark Structured Streaming – Stateful Streaming

Welcome back folks to this blog series of Spark Structured Streaming. This blog is the continuation of the earlier blog “Internals of Structured Streaming“. And this blog pertains to Stateful Streaming in Spark Structured Streaming. So let’s get started.

Let’s start from the very basic understanding of what is Stateful Stream Processing. But to understand that, let’s first understand what Stateless Stream Processing is.

In my previous blogs of this series, I’ve discussed Stateless Stream Processing.

You can check them before moving ahead – Introduction to Structured Streaming and Internals of Structured Streaming

#analytics #apache spark #big data and fast data #ml #ai and data engineering #scala #spark #streaming #streaming solutions #tech blogs #stateful streaming #structured streaming

I am Developer

1597559012

Multiple File Upload in Laravel 7, 6

in this post, i will show you easy steps for multiple file upload in laravel 7, 6.

As well as how to validate file type, size before uploading to database in laravel.

Laravel 7/6 Multiple File Upload

You can easily upload multiple file with validation in laravel application using the following steps:

  1. Download Laravel Fresh New Setup
  2. Setup Database Credentials
  3. Generate Migration & Model For File
  4. Make Route For File uploading
  5. Create File Controller & Methods
  6. Create Multiple File Blade View
  7. Run Development Server

https://www.tutsmake.com/laravel-6-multiple-file-upload-with-validation-example/

#laravel multiple file upload validation #multiple file upload in laravel 7 #multiple file upload in laravel 6 #upload multiple files laravel 7 #upload multiple files in laravel 6 #upload multiple files php laravel