Pandula Weerasooriya pandulaDW

🎯

Focusing

Full stack engineer with an affinity towards systems programming. Current stack consists of Golang, Rust, React, Typescript, Node.JS, and Python

pandulaDW / main.rs

Created July 5, 2023 05:20

A command line program to get temporary AWS credentials using an MFA device.

	use aws_sdk_sts as sts;
	use std::env;

	#[tokio::main]
	async fn main() {
	let config = aws_config::load_from_env().await;
	let client = sts::Client::new(&config);

	let token_code = env::args().nth(1);

pandulaDW / main.rs

Created July 16, 2022 09:26

waitgroup full impl

	use std::{thread, time::Duration};

	mod sync_primitives {
	use std::sync::atomic::{AtomicUsize, Ordering};
	use std::sync::{Arc, Condvar, Mutex};

	struct Wg {
	counter: AtomicUsize,
	mu: Mutex<bool>,
	condvar: Condvar,

pandulaDW / main.rs

Last active July 16, 2022 09:12

wait function for wg

	fn wait(&self) {
	let mut started = self.0.mu.lock().unwrap();
	while !*started {
	started = self.0.condvar.wait(started).unwrap();
	if self.0.counter.load(Ordering::Relaxed) == 0 {
	*started = true;
	}
	}

pandulaDW / main.rs

Created July 16, 2022 09:00

impl clone and drop for wg

	impl Clone for WaitGroup {
	fn clone(&self) -> Self {
	self.0.counter.fetch_add(1, Ordering::Relaxed);
	Self(self.0.clone())
	}
	}

	impl Drop for WaitGroup {
	fn drop(&mut self) {
	self.0.counter.fetch_sub(1, Ordering::Relaxed);

pandulaDW / main.rs

Last active July 16, 2022 08:42

wg-impl

	use std::sync::atomic::AtomicUsize;
	use std::sync::{Condvar, Mutex};

	struct Wg {
	counter: AtomicUsize,
	mu: Mutex<bool>,
	condvar: Condvar,
	}

	impl Wg {

pandulaDW / main.go

Created August 7, 2021 13:09

the main function

	package main

	import (
	"fmt"
	"github.com/pandulaDW/go-json-to-proto/transactions"
	"google.golang.org/protobuf/proto"
	"log"
	"os"
	"time"
	)

pandulaDW / ioOps.go

Created August 7, 2021 13:06

full transaction IO code

	package transactions

	import (
	"encoding/binary"
	"google.golang.org/protobuf/proto"
	"io"
	"os"
	)

	func WriteProtoToFile(filepath string, allTransactions []*TransactionJsonType) error {

pandulaDW / ioOps.go

Last active August 7, 2021 13:05

reading transaction by transaction

	buf := make([]byte, 4)
	if _, err := file.ReadAt(buf, offset); err != nil {
	if err == io.EOF {
	break
	}
	return nil, err
	}
	itemSize := binary.LittleEndian.Uint32(buf)
	offset += 4

pandulaDW / ioOps.go

Last active August 7, 2021 13:01

encoding each transaction

	// writing the length of the encoded item before writing the data
	buf := make([]byte, 4)
	binary.LittleEndian.PutUint32(buf, uint32(len(encodedData)))
	if _, err := outFile.Write(buf); err != nil {
	return err
	}

	// writing the actual transaction item to the file
	if _, err := outFile.Write(encodedData); err != nil {
	return err

pandulaDW / conversions.go

Created August 7, 2021 12:47

converting json struct objects to proto struct objects

	package transactions

	func toProtoSingleTransaction(obj SingleJsonTransaction) SingleTransaction {
	return &SingleTransaction{
	Date: obj.Date.Date.UnixNano(),
	Amount: obj.Amount,
	TransactionCode: obj.TransactionCode,
	Price: obj.Price,
	Total: obj.Total,
	}