darxtrix

'''
    Disk Sensor Plugin
'''
from ptop.core import Plugin
import psutil

class DiskSensor(Plugin):
    def __init__(self,**kwargs):
        super(DiskSensor,self).__init__(**kwargs)
        # there can be many text (key,value) pairs to display corresponding to each key

darxtrix

/*
  Assume 1M total subscribers on ticker_INR channel 
*/

// Without sharding 
go func() {
  // 1M subscribers since ticker_INR is a public channel 
  subscribersBST := channelSubscriberStateMap.Get("ticker_INR") 
  subscribers := subscribersBST.inorder()

darxtrix

• JAVA : 1-4 MB
• C++ : 1 MB
• Python : 64 KB
• Golang : 2-4 KB
• Node.js : Single threaded and event driven

darxtrix

• https://github.com/chubin/cheat.sh
• ngrok
• tcp-spy

darxtrix

• An array has a fixed size where as the slices can be of dynamic types
• Array slices are references that are easier to pass to the functions as compared to pointers. (https://stackoverflow.com/questions/2439453/using-a-pointer-to-array)
• Go arrays are full objects, when we pass them to functions they are fully copied. Its not like in case of C, i.e pass by reference.
• The type specification of a go slice is []T where the T is the type of the slice.

letters := []string{"a", "b", "c", "d"}

func make([]T, len, cap) []T

darxtrix

Memory mapped IO caching policies

• https://stackoverflow.com/questions/15853526/cache-behaviour-of-memory-mapped-i-o?utm_medium=organic&utm_source=google_rich_qa&utm_campaign=google_rich_qa

Buffered io with disk is the another optimization that can be done

• https://medium.com/golangspec/introduction-to-bufio-package-in-golang-ad7d1877f762

TCP packet sending guarantees

• During send() if it is blocking, if we try to send some data from buffer, some less data might be send because of CPU interruption
• https://stackoverflow.com/a/19698872/2679770

darxtrix

var p = (i) => {
	return new Promise((resolve,reject) => {
		setTimeout(() => {
			resolve(i);
		},1000);
	});
}

async function test() {
    for (let i = 0; i < 2; i++) {

darxtrix

# firefox

catalog column chase globe awesome paddle hand sibling solve crisp state page

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#!/bin/bash
#globals
export LOCKFILE="/var/tmp/trade_engine.lockfile"
export CMD="python print.py"
#release lock in case of trap signal
trap 'rm -f "$LOCKFILE"; exit $?' INT TERM
#acquire lock
flock -n $LOCKFILE $CMD
if [ $? -eq 0 ]; then 
    echo "Another process running of "$CMD

darxtrix

import time
import lehar

# Try to hide the cursor 

data = [5,4,3,2,1,3,5,1,2]


for i in range(len(data)):
    print("     ",end="")