Web performance metrics
Web performance metrics
Blog Posts
- 2024 34
- 2023 32
- 2022 34
- 2021 36
- 2020 53
- 2019 36
- 2018 44
- 2017 56
- 2016 34
- 2015 37
- 2014 36
- 2013 67
- 2012 14
- 2011 3
- 2010 5
- 2009 3
- 2008 18
2024
JavaScript - try catch error handling
Nice way to handle try catch error
Cookie SameSite exception for public suffix list
Cookie SameSite attribute will not consider the same origin site for the public suffix list.
Docker - scout
Docker scout can check vulnerabilities in the docker image.
Chrome browser context on rendering
Chrome browser is building the following context on rendering HTML page.
CSS is triggering on rendering
What CSS is triggering what on rendering
Server islands to speed up web site
Another interesting framework called server islands to improve web rendering speed
Spring Modulith
Josh explained about event driven architecture with Spring Modulith
Spring Security for SpringBoot
Another nice video for understanding Spring Security for Spring Boot application
Java - thread dump in JSOn format
Java thread dump with JSON
Spring - testing
Another nice talk about SpringBoot test in Java
Armeria - Netty based reactive microservice framework for HTTP2, gRPC, Thrift etc
Armeria can provide services for HTTP, HTTP2, gRPC, Thrift etc.
React19 - Suspense changes
React19 release is hold because of changes in Suspend
JavaScript - UI dot Dev
JavaScript ecosystem story telling YouTube channel
Rust - Cancellation safety
We need to aware of cancellation safety on using select. Rust doc will describe the method the cancellation safety on IO operations.
Rust - blogs from Without.boat
Rust blogs from Without.boat
Java - JFR create a new configuration from existing one
Creating a new custom(custom.jfc) JFR configuration from the existing profile.jfc
JavaScript - Unit test with fetch
Nice example how Javascript can have a unit test with fetch call by mocking.
JavaScript - signal will be standard?
Signal will be standard in JavaScript?
LangChain(JS) with Llama cpp for embeddings and prompt example
LangChain JS example with Llama cpp for embeddings and prompt.
Understanding llma2
Mastering Llama Math
Signal for React app
Why signal is better choice in React application.
Prompt definition library in JavaScript
The following library will help on defining the prompt for AI.
Java - Spring DB performance
Nice youtube video for Java Spring DB performance
OpenAPI data loader
LlamaHub provides many data loader for OpenAI.
Frontend Master course for OpenAI with NodeJS
Frontend Master course for Open AI with NodeJS
TaskWeaver - automatic data analysis
A code-first agent framework for seamlessly planning and executing data analytics tasks.
Java - enabling CDS steps
Enable CDS steps.
Node for input/output example
Example of getting input and output from system in Node
PySpark dataframe to Opensearch
https://github.com/opensearch-project/opensearch-hadoop/issues/153#issuecomment-1551501905
Tailwind workshop
Tailwind workshop from Front End Master
PySpark - groupby then concatenate values to list
PySpark example to groupby then concatenate values to list in a separated column.
Vite - Create React App with Vite
The following command will create React App with Vite.
TypeScript - Nullish expression
For the following type, we want to get val.value but if it is null or undefined, it should be 10.
2023
Java - Quick tip for checking CPU pressure with JFR
A quick tip for checking CPU pressure with JFR in JDK21. It can support a JFR file recorded in JDK17.
PySpark - Custom aggregation count in groupBy
PySpark custom aggregation count example in groupBy.
Scikit-learn simple training example
Main point of training data is to generate matrix(X) having features(columns) and samples(rows) from provided data which can be text or any form of data.
Electron application development - Front end master course
Electron application development from front end master course.
VS code plugin for V8 JavaScript engine deoptimization
VS code plugin to visualize V8 engine deoptimization for JavaScript and TypeScript
Open standards for event driven applications
Open Async API standard similar to Open API
SpringBoot - Clean Architect
It’s worth to watch a video for explaining clean architect with DDD
SpringBoot - Authorization server example
SpringBoot Authorization Server Example
GraphQL - Pagination with SpringBoot
SpringBoot GraphQL supports a pagination on query by Window mechanism which will use the key to remember current position of cursor.
SpringBoot - @SpringBootTest annotation
@SpringBootTest annotation will search entire beans which @SpringBootApplication defines in ApplicationContext so it requires to have all dependent component...
SpringBoot - Supporting Multi Tenants
The following Youtube shows an example of building SpringBoot application supporting multi tenants.
Pandas - dataframe useful operations
The following Youtube videos show useful operations with pandas dataframe.
PySpark - upsert two dataframe
The following PySpark code will upsert target dataframe with source dataframe even though source column is null when key column matched.
Azure - BlobClient upload/download
The following blog show how to use Azure BlobClient to download/upload blobs
PySpark - Development Environment with Dev Container
It’s hard to setup the Spark cluster to run PySpark job locally or CI system. The following github repository will show how we can use dev container feature ...
Java - Structured Concurrency in JDK 21
As a part of loom project, JDK21 will support the structured concurrency to handle multiple concurrent tasks in a structured way.
JavaScript - Playwright another e2e testing framework
Playwright - another e2e testing tool which can replace Cypress. Playwright can support multiple browsers and running test in parallel
JavaScript - vitest
New JavaScript unit testing framework which can replace jest.
Gradle - BOM project
Gradle supports BOM project to define all dependencies.
Mac - Install Ruby 3.1.2 on M1 processor
Installing Ruby 3.1.2 for M1 Mac
CSS - The first line of code in CSS
The following should be the first line of code to reset box sizing.
Cassandra - Support ACID
Cassandra5 is going to fully support ACID by using Accord protocol(leaderless consensus algorithm).
Qwik - Resumable JavaScript framework
Recently, SSR framework is getting popular such as NextJS, Remix etc. Qwik is quite interesting on optimizing the performance of JavaScript on client side. I...
Web Authentication - Front End Masters course
The following Front End Masters course will explain how password less login using web authentication technology.
TypeScript - Redux tool kit
The following github will show how we can use redux tool kit with typescript.
TypeScript - RequireOnly
Very useful utility type definition when we need to define a type having partial mandatory properties in a type.
Spring Data - How interface class is working
Spring data is using a proxy pattern to implement the interface only class at runtime. The following example will show how it will override findById function...
React with Typescript
The following Github project will show TypeScript types for React project. Such as children, hooks, HTML event handlers and Context etc.
VS code - prettier
After enabling the format on save, please do not forget to set config for Prettier: Require Config so that VS code will format code for each project based on...
Javascript - Testing basics
Javascript testing basics. The following link will show how Javascript testing framework works and provide very useful resources to master Javascript testing.
Java - Gradle detecting JDK version
We can control gradle auto detecting JDK and auto download options as shown in below.
Web development - Frontend master course
The following course will be one of good material for web development beginner. Especially, I strongly recommend to see CSS part.
2022
React - Testing custom hooks
React testing library provides a way to test a custom hook by using renderHook from @testing-library/react.
JavaScript - Rust based bundler SWC
SWC can replace most popular bundlers such as Webpack, Parcel etc. It is super fast than all existing JavaScript based bundler.
JavaScript - Patterns
The following site provides a useful information on JavaScript programming patterns. It covers various topics from the basic design patterns to the latest Re...
Spring Gateway
Spring gateway provides multiple features such as routing, observability, circuit breaker and security(OpenID, OAuth2). The following Youtube will show detai...
Data Science - Data mesh
The following youtube shows a case how to apply data mesh architecture in airline booking industry.
Spring - distributed system solution with Spring framework
The following talk will show a nice overview how Spring can provide a solution for distributed system.
SpringBoot - GraalVM support
SpringBoot for supporting GraalVM. The following youtube video will explain how SpringBoot 3.0 is working. The basic idea is that we need to provide hints fo...
Structure concurrency
Java virtual threads applies structured concurrency concepts. The following blog explains what structure concurrency is.
Java - Pattern matching and virtual threads in Java 19 preview
Java 19 preview improved the pattern matching language feature. The following code shows how we can leverage them with virtual threads.
Java - improving launching time with CDS(class data sharing)
JDK 10+ has introduced a feature called CDS(class data sharing) which will improve the launching time of Java application.
Spring boot - Exception handling
SpringBoot allow to define the exception handler inside of Controller. The following code shows an example.
Spring boot GraphQL authorization with bearer token
The following article show String boot GraphQL authorization with bearer token. This will be a good source to understand how Spring security work too.
NextJS full stack application(Music App)
Frontend master course
React and redux fundamentals
React redux fundamentals
Typescript and GraphQL full stack example
Please switch to a branch named fed for a final solution.
Data visualization - Plot
Data visualization - Plot
TLS verification with openssl command
openssl command to verify TLS connection
TypeScript - type challenges
TypeScript type challenges for practice TS type system
TypeScript - mapping between event name and event type
Type script for mapping between event name and event type
TypeScript - type checking only and prettier format checking
Run type script compiler to check types only. Format checking with prettier
Pyspark - Reading from Confluent Kafka
In order to use confluent schema registry, the following python package should be installed in a spark cluster
Pyspark - Delta Lake Table from Azure Storage Account
Reading data from Azure Storage Account.
Pyspark - explode the nested data
Pyspark can explode the nested structure in object
Pyspark - create a new column with concatenating other columns
Pyspark can create a new column with concatenating other columns
Spring - Supporting multiple tenant for JDBC
Josh Long showed us another very nice Spring tips for supporting multiple tenants with JDBC. Spring provide the AbstractRoutingDataSource to support multiple...
Rust - Async diagnostics and debugging tool
Rust async diagnostics and debugging tool
Youtube with science
Youtube with science
Rust - Cassandra driver
Rust Cassandra driver is not matured enough so far but the blogger recommended the C++ driver for production.
Rust - linker
Alternative rust linker to speed up from https://www.lpalmieri.com/posts/session-based-authentication-in-rust/
RxJS from Frontend master
RxJS from Frontend master
Progressive Web Application
Progressive Web Application course in FrontEndMaster
Rust Benchmark Library
Rust benchmark library based on statistics
Writing a Good Web Contents
We can use the following tools to improve the readability of web contents
SSH configuration for Remote Connection
The following steps will show how to config ssh connection.
2021
React with CSS variables
CSS variables provide a nice way to change styles. The following blog will show how ReactJS framework can work with CSS variables.
Frontend master - CSS
Frontend master brilliant course for CSS
Install FZF/LSP with Ultimate vimrc configuration
Ultimate vimrc supports to install your own vim plugins.
Front end master - Developer productivity
Another great front end master course for developer productivity.
Hight Performance Browser Networking
Anyone who is caring about the web application network performance needs to read the book.
WebSocket - Node JS server implementation
WebSocket server implementation with Node JS.
PySpark and Kafka with Schema registry
PySpark and Kafka with Schema registry
Spring Boot Security Example
Spring boot security example
Spring Boot real world example
The following github shows the real world working application example with SpringBoot. It is demonstrating how to use Spring Data, OAuth, WebClient and REST ...
Rsocket CLI tool
Rsocket CLI
Spring boot with Spock testing framework
Spring boot with a Spock testing framework
Kubernetes using external service
There are often times to use the external services inside of Kubernetes. The following article explain how to set up in Kubernetes.
Spring boot integration test with Testcontainers and Toxiproxy
Spring boot provides a integration testing framework with docker in Junit tests. It is using the test container library as an underline framework.
Spring boot application demo for MariaDB, MongoDB and Neo4J
The following Youtube shows how spring boot provides a common framework on supporting MariaDB, MongoDB and Neo4J.
Modern command line tools replacement
Modern command line tools replacement
SpringData - JDBC
Spring Data JDBC
Python - PyBuilder
PyBuilder will provide an easy way to setup python project.
Apache Beam Model
What: sum, average or machine learning? used to be done with classic batch processing. Where: windowing with event time such as fixed, sliding or session. Wh...
Groovy - missing method
Groovy missing method is used by the gradle syntax
Stream Process - watermark
Apache Beam with Spark streaming runner on Youtube
Spark Structured Stream Process - Watermark
Spark Structured Streaming Watermark Concept.
Kafka - GenericRecord vs SpecificRecord
Kafka has two types of record on producing and consuming Kafka messages which are called GenericRecord and SpecificRecord. Main difference between GenericRec...
Gradle - java-library plugin from 7.x version
Gradle 7+ removed compile configuration so all existing gradle projects using compile configuration should be migrated. Instead java-library plugin was intro...
Apache Beam Key Concepts
Apache Beam has the following key concepts.
React for Vega Lite API
Vega lite api provides an easy way to visualize data based on d3 framework. The following repository shows how react can integrate the vega lite api.
Vim fundamental from front end master course
Vim fundamental from FrontEndMaster course
Java - Jersey and Jackson for JSON serialization in streaming mode
With Jersey and Jackson combination, we can build the streaming API for serializing very large size of data.
Pessimistic Distributed Transaction
Pessimistic distributed transaction will use the following concepts to achieve ACID(Atomic, Consistency, Isolation, Durable).
Distributed caches common issues and solution idea
In order to build distributed caches, we need to solve the following three problems.
Zookeeper - znode types
Zookeeper has a znode to describe the hierarchical accessing data such as kafka/node001
Java - Difference between Set and Set<?>
What is difference between Set and Set<?>
Java - JFR performance regression unit test
JFR unit test framework allow to have a performance regression test by using JFR events.
Rust - Tower library
Rust Tower library provides an abstraction mechanism for network communication with asynchronous request/response. In Rust, in order to define the trait with...
React Server Component and State Management Library - Recoil
Introduction React Server Component
Thundering Herd Issue with Cache
Thundering herd is a performance problem. When using a cache, if the cache item is expired or evicted by any cache eviction logic, many clients can try to ca...
2020
Linearizability
Linearizability
ZooKeeper - Mini Transaction Support
ZooKeeper mini transaction logic
ZooKeeper - Lock Support
The following pseudo logic shows how ZooKeeper is supporting a lock. ```java void acquire_lock() { while (true) { if create(‘f’, ephem=true) { re...
C++ - Lock free programming in C++ and memory ordering
C++ lock free programming in Youtube video https://www.youtube.com/watch?v=qdrp6k4rcP4
Rust - Common Misconception and The Rustonomicon
Most common misconception on Rust programming language. One of favorite explanation is about static lifetime.
Rust - Another Resource for Async/Await Future
Another good resource to learn about Rust async/await with future.
Rust - All About Pin
Excellent explanation about pin API in Rust. 3 hours long video but it’s worth to watch all to understand how async and await are working in Rust with Future...
Rust - Idiomatic Rust API design
Rust is great programming language because of default move semantic and trait system. Idiomatic Rust API is fully utilizing these concept to make it easy to ...
Git - adding a tag with the latest commit date
Adding a git tag with the latest commit date. 1 2 $ GIT_COMMITTER_DATE=$(git log -n1 --pretty=%aD) git tag -a -m "Release 0.0.1" 0.0.1 $ git push --tags
Rust - AsRef usage
AsRef is useful for generic function on accepting specific reference such as str or Path as trait bounds.
Java - JFR start/dump and health reporting agent
From JDK 11, the following command will start recording JFR 1 $ jcmd [pid] JFR.start duration=60s filename=myrecording.jfr
Rust - Procedural Macros
Rust procedural macros.
Rust - Async Await Cancellation
How Rust is handling cancellation for async operation
Rust - Error Conversion
Rust does not have an exception mechanism for error handling they provided the following two types.
Lamport clock
In distributed system, clock can be skewed so if system is relying on wall clock or local clock, it will face unexpected results such as overwriting an exist...
Rust - Understanding Serde
How Rust serde library works. https://www.joshmcguigan.com/blog/understanding-serde/
Rust - Web Crawler example with async-std and surf
Rust web crawler with async-std and surf
Rust - Building Web Application With Actix-Web
A article about building a web application with Actix-web Rust framework. It seems like that final output of this blog will be a book.
Rust - Iterator delegation
Often, container structure having a single vector field needs to expose an iterator. The following code shows how to achieve this in a simple way.
Rust - Json parser implementation in a functional way
The following git hub shows how Rust can implement Json parser by applying functional programming approach.
Rust - Cargo whatfeatures
Cargo whatfeatures can display features, versions and dependencies of crates
Rust - error handling with thiserror crate
One of the most difficult decision to make on developing an application is how we can handle errors. The thiserror crate provide an easy way to handle errors...
Python - using requests with retry
The following example will show how to create a request session with retries.
Zsh - adding a new line in a prompt
The following example will show how to add a newline in zsh prompt.
Linux Container - Base Technologies
As we all know, Docker didn’t invent a new technology for Linux container. But they provided a really convenient way to utilize the existing Linux container ...
Python - Running IO tasks in parallel
Python(3.2 later version) has a feature to run IO tasks in parallel by using futures and ThreadPoolExecutor.
Rust - HTTPS client for self signed certificate
reqwest is a HTTP client in Rust. https://github.com/seanmonstar/reqwest
Vim basic commands
Cheat sheet https://vim.rtorr.com/
Common mistakes on using Cassandra and Kafka
Nice articles on using Cassandra and Kafka
Rust vector iteration
The following example shows difference of iterating vector items between for and with iter() method
Java NIO flip/compact functions in Buffer class
flip function The flip function in Buffer is equivalent to the following operation which means that it will set limit with current position and set current p...
QUIC tranport protocol
QUIC is a multiplexed stream transport over UDP. By using this protocol, it can dramatically reduce the connection establishment time for TCP+TLS.
Git Merge Command
Git commands when merge conflicts happened.
Learing Development Tools and Environment
Learning basic development tools and environment setting such as using it, VIM editor etc
React - Form handler example
The following example shows the basic form submit handling with React
React - useEffect to detect page exit
We can detect the page exit in useEffect Hooks
Intellij - Multi Cursors All Occurence
Intellij idea supports multi cursors for all occurence with the following shortcuts
Crossbeam - Rust Lockfree Data Structure
The following article explain the background of Rust lock free data structure library called Crossbeam
Amethyst - Tiling Windows Manager Mac OS
Amethyst: Tiling Windows Manager for Mac OS
Rust - Live Coding About Life Time Example
The following youtube video will show how rust life time logic works for reference
Java - jhsdb command
jhsdb is a tool which can attach a Java process or launch a postmortem debugger to analyze the content of a core dump from a crashed Java Virtual Machine (JV...
Flame Graph - Cassandra and Java applications
The following article show how to generate the flame graph for Cassandra performance but it is using a generic tools to generate flame graph any Java applica...
Spring - Live Virtual Event
Youtube channel for Spring live virtual events. This channel contains various topics from industrial experts and company including Confluent, Okkta and Pivot...
Python – list all file paths recursively
List all file paths recursively ```python import os
Minimal Mistake – Enabling code block line number with markdown
By adding the following configuration in _config.yml file, we can see the code block line number 1 2 3 4 kramdown: syntax_highlighter_opts: block: ...
Web Assembly – Creating an Web Assembly Application with Rust and React
The following github project shows how to create an WASM application with Rust and React framework
FP – Functional Programming with JavaScript
https://mostly-adequate.gitbooks.io/mostly-adequate-guide/
Rust - how async/await works
https://os.phil-opp.com/async-await/
Sublime - matching multiple lines with regex
Start with (?s) 1 (?s)\[sometag\](.*?)\[\/sometag\]
Java - Dropwizard http request accessing log customizing example
Dropwizard can allow to access the attributes in a request as shown in below example. Full layout logback format details can be found from http://logback.qos...
Linux - Top 10 Performance commands
1. uptime 2. dmesg | tail 3. vmstat 1 4. mpstat -P ALL 1 5. pipstat 1 6. iostat -xz 1 7. free -m 8. sar -n DEV 1 9. sar -n TCP, ETCP 1 10. top
eBPF - Learn eBPF Tracing for Linux application performance
extended Berkeley Packet Filter Linux application performance tracing tool http://www.brendangregg.com/blog/2019-01-01/learn-ebpf-tracing.html
Kubernetes - Container networks
https://www.youtube.com/watch?v=6v_BDHIgOY8 https://github.com/kristenjacobs/container-networking
2019
SpringBoot WebFlux - Reading a request body with Spring WebFlux for Controller
SpringBoot WebFlux 2.2.x requires to load the request body by using an input stream. Below example will show how it can convert the json data into the expect...
React - create-react-app proxy setting
create-react-app allow to configure the proxy setting on calling API. documentation: https://create-react-app.dev/docs/proxying-api-requests-in-development/ ...
Electron - Using reach router for Electron app
Creating a history with a memorySource will allow to work for Electron application with reach/router 1 2 3 4 5 6 7 8 9 10 11 12 import { Router, createMemory...
Electron - Rederer process can use Node feature
Setting nodeIntegration true in webPreferences section in main.js will allow to use Node feature in renderer process such as require. And setting webSecurity...
Electron - creating an electron app with react, typescript and emotion CSS
Please find the following github for details steps and example. https://github.com/nsclass/ns-electron-app
VSCode - Improving productivity with VS code
VS code can do that
JavaScript - find all available functions and properties in an object
The following three functions are very useful on inspecting methods and properties in any Javascrip object. Github code: https://github.com/nsclass/describe-...
JavaScript - Promise.all getting response
Promise.all guarantee the order of response in input promises so that caller can retrieve the result with array index number. 1 2 3 4 5 6 7 8 var allDone = P...
Unix - Sharp bang to specify a command by using a env
Each script file can use a env command to specify the location of command. Below example will show how a shell can find a python3 command location with a env...
Parcel - Proxy setting
In 'package.json', you can defined the proxy table. 1 2 3 4 5 6 7 8 9 10 11 { "proxy": { "/api": { "target": "http://localhost:8000" }, "...
CSS - Design for developers
https://github.com/sdras/design-for-developers
CSS - Grid examples
https://gridbyexample.com/ https://labs.jensimmons.com/ https://cssgridgarden.com/ https://codepen.io/
CSS - CSS Flex and Grid
CSS Flex and Grid examples. https://github.com/jen4web/fluent2018 CSS definition guide. https://estelle.github.io/
Highly scalable/available distributed system whiling maintaining integrity
I think that ACID is a main mechanism to maintain the application consistency but it's hard to make it highly scalable and available system because of synchr...
Java - Spring unit test with custom provided configuration.
The following example will show how to define the custom Spring configuration for unit test with @ContextConfiguration annotation. Full example can be found ...
JVM - Profiling and GC analysis tool
The easiest GC log analysis web site. https://gceasy.io/ Profiling Adding a JVM Option +XX:+PreserveFramePointer https://github.com/jvm-profiling-tools/perf-...
Simple way to generate ssh pub/private key
Very simple way to generate ssh pub/private key in Linux. 1 $ ssh-keygen -t rsa -P "" -m PEM -f filename Copy the content of .ssh/id_rsa.pub to .ssh/autho...
Spark - Cassandra connector example
Github https://github.com/nsclass/spark-cassandra-example 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 object SparkCassandra...
Client side load balancing
https://www.youtube.com/watch?v=6NdxUY1La2I
Kafka - Docker compose example for Kafka
Kafka docker compose example. Please set value of KAFKA_ADVERTISED_HOST_NAME for local host IP address. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 version: '2...
Time - days of clock vs Monotonic clocks
Getting days of clocks - Linux: clock_gettime(CLOCK_REALTIME) - Java: System.currentTimeMillis() Getting monotonic clocks - Linux: clock_gettime(CLOCK_MONOTO...
Database - Partitioning name in various database
Various database called partitioning in various name. It's interesting but they are all same. HBase: region Cassandra: vnode MongoDB: shard Elasticsearch: sh...
Reactive Stream - Example of implementation of Publisher
https://medium.com/@olehdokuka/mastering-own-reactive-streams-implementation-part-1-publisher-e8eaf928a78c
Reactive Programming
It is worth to read through The Reactive Manifesto definition. https://www.reactivemanifesto.org/glossary
Linux - Network settings for high traffic generating application
/etc/sysctl.conf CENT OS example 1 # sysctl -w net.core.wmem_default=262144 # default socket memory buffer per a socker net.core.wmem_default=131072(128KB) ...
Websocket protocol details
Websocket protocol details. http://lucumr.pocoo.org/2012/9/24/websockets-101/
Java - JVM monitoring tool
It is an amazing tool to monitor Java application such as thread cpu usage etc. https://github.com/aragozin/jvm-tools
Python - Spelling correction (Python examples on list comprehension)
It's worth to read Python code as examples of using list comprehension semantics. http://norvig.com/spell-correct.html
Machine Learning For Software Engineer
How Software Engineer can be a ML engineer. https://www.youtube.com/watch?v=u0kyJeLvi0w
Modern Distributed Database Internals and Core Concepts
Alex Petrov talks about modern storage system approaches, discussing storage internals in QCon 2018 https://www.youtube.com/watch?v=wxcCHvQeZ-U https://mediu...
Cassandra - data modeling for historical data(Netflix)
https://medium.com/netflix-techblog/scaling-time-series-data-storage-part-i-ec2b6d44ba39 https://medium.com/netflix-techblog/scaling-time-series-data-storage...
Event Sourcing - Kafka as an event source article.
https://www.confluent.io/blog/event-sourcing-cqrs-stream-processing-apache-kafka-whats-connection/
CRDT - Conflict-Free Replicated Data Types
Eventually consistency mechanism in distributed systems. https://medium.com/@istanbul_techie/a-look-at-conflict-free-replicated-data-types-crdt-221a5f629e7e ...
Rust - Enum serialization example
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 use serde::ser::{ Serialize, Serializer }; use serde::de::...
Rust - using error-chain to report stack traces on errors occurred.
Github https://github.com/rust-lang-nursery/error-chain Example) https://github.com/rust-lang-nursery/error-chain/blob/master/examples/quickstart.rs
Rust - Index, mut Index operator example
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 use std::ops::{Index, IndexMut}; #[derive(Debug)] pub struct ImageArray2 { dat...
2018
Cassandra - Cassandra tuning guide
https://tobert.github.io/pages/als-cassandra-21-tuning-guide.html
Cassandra - Save a table in CSV and loading a CSV to a table in CQLSH
1 2 cqlsh:test_keyspace> COPY test_table TO 'test_table.csv' WITH HEADER=true; cqlsh:test_keyspace> COPY test_table FROM 'test_table.csv' WITH HEADER=t...
Emacs - Learning Emacs
http://www.jesshamrick.com/2012/09/10/absolute-beginners-guide-to-emacs/ C-h C-h : help C-g : quit C-x b : switch buffers C-x right : right-cycle through bu...
RSocket - Resources about RSocket(Next paradigm of communication framework)
https://github.com/linux-china/awesome-rsocket/blob/master/README.md
Rust - Idiomatic rust
https://github.com/mre/idiomatic-rust
Java 11 - Enable Java Flight Recorder JVM option example
1 2 3 4 5 6 -XX:StartFlightRecording=\ disk=true, \ dumponexit=true, \ filename=recording.jfr, \ maxsize=1024m,\ maxa...
Spark - join transformation
join—Equivalent to an inner join in RDBMS, this returns a new pair RDD with the elements (K, (V, W)) containing all possible pairs of values from the first a...
C++ - GDB init profile setting in Linux
1 2 3 4 5 $ cat ~/.gdbinit set history save on set print pretty on set pagination off set confirm off
Cassandra - Docker run example for Cassandra version 2.1 with PropertyFileSnitch
1 sudo docker run -d -v /mnt/ramdisk/:/var/lib/cassandra/ -e CLUSTER_NAME=TEST -e CASSANDRA_ENDPOINT_SNITCH=PropertyFileSnitch -p 9160:9160 -p 9042:9042 -p 7...
Kubernetes - How Flannel network works
Software based packet routing mechanism without NAT. https://blog.laputa.io/kubernetes-flannel-networking-6a1cb1f8ec7c
HTTP - Streaming events delivery with HTTP protocol
HTTP 1.1 has the following header option to deliver the streaming data to clients by opening a TCP connection. 1 Transfer-Encoding: chunked With above heade...
MapReduce - Reduce side join example
https://www.edureka.co/blog/mapreduce-example-reduce-side-join/
Kubenetes - Example of Kubenetes
https://blog.octo.com/en/how-does-it-work-kubernetes-episode-1-kubernetes-general-architecture/ https://blog.octo.com/en/how-does-it-work-kubernetes-episode-...
Docker - difference RUN, CMD and ETRYPOINT
1. CMD vs ENTRYPOINT The ENTRYPOINT specifies a command that will always be executed when the container starts. The CMD specifies arguments that will be fed ...
Java - Loading an entire Cassandra table in parallel
Sometimes, it is required to load all rows in the Cassandra table but it is very slow if loading is performed by a single thread. Let’s say we have the follo...
C++ 17 - Generative Programming in C++ 17
Interesting generative programming in C++ 17. I think that this explains why compile time reflection and declarative programming approach is required for cle...
High scalable application characteristics
1. Stateless - HTTP request/respond structure. 2. Idempotence - database snapshot, recovering data. 3. Monoid - map/reduce, parallelizing operations.
Docker - nsenter tool to access the Docker container
Installing nsenter in /usr/loca/bin directory 1 $ sudo docker run -v /usr/local/bin:/target jpetazzo/nsenter Get the process id of container 1 PID=$(docker ...
C++17 - C++17 feature and boost library documentation
https://www.bfilipek.com/2017/01/cpp17features.html https://theboostcpplibraries.com/
C++17 - Learning STL algorithm
https://www.fluentcpp.com/2018/07/10/105-stl-algorithms-in-less-than-an-hour/ http://www.fluentcpp.com/getTheMap/
C++ - Core dump Linux utility tool from MS
https://github.com/Microsoft/ProcDump-for-Linux
CMake - Adding debug information
-DCMAKE_C_FLAGS_DEBUG="-D_DEBUG" -DCMAKE_BUILD_TYPE=Debug
CMake - How to create C++ projects with modern style of CMake
Resources for CMake https://github.com/onqtam/awesome-cmake Modern CMake example with third-party library https://github.com/nsclass/Optional
Rust - Functional Programming for Rust
https://github.com/algermissen/rustz
FP - Another valuable article about Functor
http://nikgrozev.com/2016/03/14/functional-programming-and-category-theory-part-1-categories-and-functors/ http://nikgrozev.com/2016/04/11/functional-program...
Rust - What makes Rust Programming language special?
I think that the following features in Rust will make it special. 1. Package manager. 2. Functional style programming. 3. No exception. 4. No garbage collect...
Java - Apache HttpClient to access the self signed certification and no host verification
Below code comes from https://memorynotfound.com/ignore-certificate-errors-apache-httpclient/ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 ...
Java - Aspect based measuring the method execution time of function with annotation
Annotation definition. 1 2 3 4 5 @Target({ElementType.METHOD, ElementType.CONSTRUCTOR}) @Retention(RetentionPolicy.RUNTIME) public @interface Measur...
Spring - CGLIB: High performance code generation library
Spring is heavily using the CGLIB for it's framework implementation. CGLib is high performance code generation library. It is using to extend JAVA classes an...
Cache - False sharing
As modern CPU shared memory architecture, false sharing is the major performance bottleneck on multi-thread application. False sharing is caused by sharing t...
Cassandra - Evolvement of Cassandra column oriented row
The following blog explain how Cassandra has been improved the column oriented row. https://www.datastax.com/dev/blog/cql3-for-cassandra-experts
Java - Spring to inject multiple service instances having same interface
Create service for multiple name providers 1 2 3 4 5 6 7 8 9 10 11 interface NameProvider { String name(); } @Service public class SomeName implement Nam...
Java - Importance of final fields for immutable object
Java will guarantee that all thread will see correct values of final fields that were set by the constructor, regardless of how object is published.
C++17 - Simple and clear view of C++17 features
https://github.com/tvaneerd/cpp17_in_TTs/blob/master/ALL_IN_ONE.md
VC++ - Visual C++ package manager for Windows
https://github.com/Microsoft/vcpkg
FP - Designing multi threaded and concurrent enabled software with functional programming
Modern CPU architecture has been enforcing me to create multi-threaded and concurrent enabled software. I have been creating multi-thread software with Gang ...
FP - Relationship between Applicative Functor and Monad
Applicative Functor has the following two properties. Pure: create a functor from value. Apply: a function taking arguments which are a Functor having a func...
Java - Open addressing hash implementation in Java
IdentityHashMap class 1 Map<String,String> iMap = new IdentityHashMap<String,String>();
Java - headMap, tailMap and subMap in NavigableMap
NavigableMap collection on Java provide methods to return the view of Map on sorted order of key. The most common methods are headMap, tailMap and subMap. he...
Java - Java 8 Comparator to replace Guava compound comparing
Guava example 1 2 3 Collection.sort(list, Ordering.from((Comparator<Item>) Comparator.comparingInt(item -> item.getId())) .compound(Comparat...
Java - Guava API to implement compareTo with considering sorting ordering
Example of a chained comparison statement. 1 2 3 4 5 6 7 public int compareTo(Foo that) { return ComparisonChain.start() .compare(this.aStri...
Java - The article of Stream API under the hood
The following article is explaining the under the hood Java 8 Stream API. https://www.ibm.com/developerworks/library/j-java-streams-3-brian-goetz/index.html
Java - Converting Cassandra ResultSet to Java 8 Stream
1 2 3 4 5 6 7 8 Statement stmt = QueryBuilder().select().all().from('table'); ResultSet rs = session.execute(stmt); StreamSupport.stream( Spliterators.sp...
Angular - Proxy settings to avoid CORS
Create a proxy.config.json 1 2 3 4 5 6 { "/api": { "target": "http://localhost:8080", "secure": false } } run ng serve with a configuration file...
2017
Java - Spring Boot 2.0 WebFlux configuration for static resources
1 2 3 4 5 6 7 8 9 10 11 @Value("classpath:/static/index.html") private Resource indexHtml; @Bean RouterFunction<?> routerFunction() { ...
Java - Read CSV file from a stream
1 2 3 4 5 6 7 try (final CSVReader reader = new CSVReader(new BufferedReader(new InputStreamReader(inputStream)))) { String[] line = null; while ((li...
Java - Bean validation 2.0 (JSR-380) with Spring boot
http://www.baeldung.com/javax-validation http://andreinc.net/2017/10/02/writing-an-unified-validation-mechanism-for-rest-apis-using-spring-boot-and-jsr-380/ ...
Java - ForkJoinPool
Good explanation on ForkJoinPool in Java http://www.baeldung.com/java-fork-join
Java - logging components and explanation
LOGGERS: loggers are responsible for capturing events and passing them to the appropriate appender. APPENDERS: also known as handlers, appenders are responsi...
Java - REST API with Spring Security
Securing REST API with Spring Security. http://www.baeldung.com/securing-a-restful-web-service-with-spring-security
Java - Recording Java Flight Recording in Java 9
Command line to enable Java Flight Recording feature in Java9 to measure JVM performance. 1 $ java -XX:+UnlockCommercialFeatures -XX:StartFlightRecording=fil...
Java - JDK9 tool jdeps and jdeprscan to inspect any illegal usage
The following jdeps command will inspect any illegal usage in My.class and provide alternative way to fix problems. This tool exists in JDK9. 1 $ jdeps -jdki...
Java - Guidance of using wildcard in generic
Do not use bounded wildcard as a return value This will force client to use wildcard types
C++11 - Monoid, Functor, Applicative Functor and Monad
How CPP express Monoid, Functor, Applicative Functor and Monad. The below documentation shows a good explanation. https://github.com/boostcon/cppnow_presenta...
Python - HTTP send a JSON object and decoding example
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 5...
Scala - ~> [Tilde arrow] explanation
"~>" is a place holder for type. Main reason to use "~>" is to make readable on type A goes to type B. This is possible because Scala allow to express ...
Java - Covariance, Contravariance and Invariance
https://stackoverflow.com/questions/8481301/covariance-invariance-and-contravariance-explained-in-plain-english
Scala - Higher Kinded Type
https://stackoverflow.com/questions/6246719/what-is-a-higher-kinded-type-in-scala
Scala - By Name Parameters
Syntax: => A 1 2 3 4 5 def ifElse[A](test: Boolean, whenTrue: => A, whenFalse: => A): A = test match { case true => whenTrue case false =&g...
Scala - conversion from for-comprehension to map, flatMap
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 def getProduct(id: String): Try[Product] def getPrice(product: Product): Try[Price] def calculateProductPrice(product: Pr...
FP - expression vs statement
Expression: by combining value and function, it will generate the value with some possible side-effect Statement: standalone unit of execution without return...
Cassandra - import snapshot tables(column family)
The following command will import a table(column family) to the destination Cassandra node. 1 $ sstableloader -d [destination IP address] -p [port number] [t...
tmux switcher with fzf
Tmux switcher with fzf
Functional Programming - Simple Explaining of Keyword
1. Functor -> Mappable 2. Currying -> Currying 3. Applicative -> Applicative 4. Monad -> Chainable 5. Monoid -> Aggregatable 6. Catamorphism -...
Monad - Definition of Monad with Monoid
Monad is a binding function to connect two functions where are different types between returning value and input argument. So Monad will allow to compose two...
Monoid - Simple definition of Monoid
1. Closure: Two same type pair operation results a new result with same type. 2. Associative: Doesn't matter or operation order wit a pair. 3. Identity: Ther...
Mid night commander short cuts
MC commands ----- Esc ----- Quick change directory: Esc + c Quick change directory history: Esc + c and then Esc + h Quick change directory previous entry: E...
Monad - simple example definition
Combines the following concept. 1. Functor - Type constructor. - Value lifting. - class Functor f where fmap :: (a -> b) -> (f a -> f b) 2. Bi...
C++14: Optional.map in Java 8 for functional programming
Pseudo C++ example implementation of map function of optional in Java8 for functional style programming. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 2...
Java - Guava API to sort items in collection with Ordering compound example
1 2 3 Collection.sort(list, Ordering.from((Comparator<Item>) Comparator.comparingInt(item -> item.getId())) .compound(Comparator.comparing(Item::g...
C++17 - new features in C++17
Nice article for C++17 features. http://www.bfilipek.com/2017/07/cpp17-details-simplifications.html
Docker - Best practice to refresh on building image
Adding the date in docker file so that user can update the data for every change. 1 2 FROM ENV REFRESHED_AT 2017-1-1
Docker - Subnet address in Ubuntu
1 $ sudo vi /etc/default/docker modify the following section. DOCKER_OPTS="--bip 192.168.1.1/24"
Java - Spring boot with JAX-RS
Enabling Spring boot to use JAX-RS https://dzone.com/articles/using-jax-rs-with-spring-boot-instead-of-mvc http://blog.codeleak.pl/2015/01/getting-started-wi...
Java 9 - useful commands to inspect Module
List modules 1 2 $ java --list-modules $ java --list-modules java.base Diagnostic module dependencies 1 2 $ java -Xdiag:resolver -p mods [module name]/[clas...
Java 8 - general practice using Optional
0. Never, ever use null for an Optional variable. 1. Optional should be only used as a return value. : never use it for a field in Class and a method para...
Docker - useful command
1 2 3 $ docker log <container id> // show logs $ docker port <container id> // show port mapping $ docker inspect <container id> // inspect...
Java - Task polling example with Java 8
1 2 3 4 5 6 7 8 9 10 11 public void completionService(ExecutorService executor) { CompletionService<CustomTaskResult> completionService = n...
Angular 2 book
Angular 2 Development with TypeScript https://www.manning.com/books/angular-2-development-with-typescript
Rake - useful command line options
1 2 3 4 5 $ rake -P $ rake -T #display description $ rake -T buy #display contains "buy" in name $ rake -W buy #display path of task "buy" $ rake -D
Python - REST API call example with a self certificated SSL connection
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 import time import http.client import ssl import json conn = http.client.HTTPSConnection("loca...
C++ 14 - co-routine with boost library
It is worth to read the following blog if interested in C++ co-routine support. https://blogs.msdn.microsoft.com/vcblog/2017/05/19/using-c-coroutines-with-bo...
Linux - Useful Git book(Linux inside)
https://www.gitbook.com/book/0xax/linux-insides/details
Java - Java application monitoring tools
jcmd: Prints basic class, thread, and VM information for a Java process Example) 1 2 3 4 5 6 7 8 % jcmd <process_id> VM.uptime % jcmd <process_id>...
Linux - useful commands to inspect performance utilization
Memory utilization 1 2 3 4 5 vmstat 1 [/cpde] Disk utilization [code lang="C"] iostat -xm 5 Network utilization tool 1 nicstat Network connection status 1 ...
Java - Recommended GC log options for Java 8 and Java 9
Java 8 -XX:+PrintGCDetails -XX:+PrintReferenceGC -XX:+PrintTenuringDistribution -Xloggc: -XX:+PrintGCTimeStamps Java 9 -Xlog:gc* ,gc+ref=debug ,gc+...
Java - Garbage collectors
1. Serial -XX:+UseSerialGC JVM 2. Parallel default 3. CMS(Current Markup Sweep) -XX:+USeParNewGC 4. G1 –XX:+UseG1GC Note: Java8 and G1 collector can optimize...
Java - ZonedDateTime formatter for ISO-8601
Parse example 1 2 3 4 5 6 7 DateTimeFormatterBuilder builder = new DateTimeFormatterBuilder(); DateTimeFormatter formatter = builder .parseCaseInsens...
Java - heap dump utilities
Heap histogram 1 jmap -histo [pid] Heap usage 1 jmap -heap [pid]
Java - an example code to extract mime type from base64 string of an image
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 private boolean isMatch(byte[] pattern,...
C++ - Measuring execution time library in function level
Interesting tool on measuring the execution time of C++ application in function level. https://github.com/namhyung/uftrace
Cassandra - Resuming pagination
Cassandra provides the page state information and it can be reused to get next iteration. 1 2 3 4 5 6 7 Statement stmt = QueryBuilder .se...
Gradle - Java project setup with Gradle
https://rominirani.com/announcing-gradle-tutorial-series-5fd134223bf8#.kzn6qpx5i
JVM-Cucumber: Setting up example
http://qza.github.io/tutorial/development/2015/10/17/bdd-in-java-with-junit-spring-and-cucumber-jvm/ https://github.com/qza/bdd-cucumber-jvm-spring
Grunt - proxy setup to avoid CORS
http://www.hierax.org/2014/01/grunt-proxy-setup-for-yeoman.html
Functional Programming - Referential transparency
an expression can be replaced with its result
C++ - Transforming C asynchronous function to C++ future
C API definition to read data from a file in asynchronous way. 1 2 void async_read_completed_callback(void* pUserData, char cont* pBuffer, int size); void as...
C++ - Functional programming
Functional programming with C++ https://vittorioromeo.info/index/blog/cpp17_curry.html
Web - Font sizing unit rem
It is worth to read about font size unit of rem other than pixel. https://snook.ca/archives/html_and_css/font-size-with-rem
Gulp - connect proxy example
It will avoid CORS problem during development. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 var Proxy = require('gulp-connect-proxy'); ... // A local web server for dev ...
2016
C++ - Anonymous namespace
The main reason of using anonymous namespace in C++ is to localize declaration in translation unit. The compiler will choose the unique name for unnamed name...
Spring - afterPropertiesSet needed to be called
The static initializer block is only executed when the class is loaded by the class loader. There is no instance of that class at that moment and you will on...
Cassandra - Allow Filtering example
1 2 3 4 5 6 7 create table User( email text, name text, desc text, user_id uuid PRIMARY KEY((email), name, user_id) ) WITH CLUSTERING ORD...
Cassandra - Partition Key, Clustering key
Partition Key: It will be hashed and saved across nodes. Clustering Key: It will group in the same partition key. PRIMARY KEY((partion key), clustering key) ...
Spring - adding a bean in code
1 2 3 AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext(); Set<int> sets = new Set<int>(); ctx.getBeanF...
Cassandra - some articles about Cassandra data modelling
http://intellidzine.blogspot.co.uk/2013/11/cassandra-data-modelling-tables.html http://intellidzine.blogspot.com/2014/01/cassandra-data-modelling-primary-key...
Git - revert to specific commit point
1 2 git revert --no-commit 0766c053..HEAD git commit
Yeoman - AugularJS with Gulp
1 2 npm install -g generator-gulp-angular yo gulp-angular
Yeoman - Angular generation error with “jit-grunt: Plugin for the “karma” task not found”
Please run the following commands, it will help 1 npm install grunt-karma karma karma-phantomjs-launcher karma-jasmine jasmine-core phantomjs-prebuilt --save...
Java - generating a self-signed public key
1 2 3 4 5 6 7 8 9 10 1. Generate self-signed public key $JAVA_HOME/bin/keytool -genkey -alias test_alias --keyalg RSA -keystore test_key.jks -keysize 2048 -d...
Git diff and merge tool with Intellij Idea
Windows 1 2 3 4 5 6 7 8 9 [merge] tool = intellij [mergetool "intellij"] cmd = cmd.exe //c "\"c:/Program Files (x86)/JetBrains/IntelliJ IDEA Communit...
C++ - Exception handling
The following article provides a good way of using Exceptions in C++ http://www.acodersjourney.com/2016/08/top-15-c-exception-handling-mistakes-avoid/
C# - EF lifetime of DBContext
The following article has a useful information on handling the lifetime of DBContext in EF. http://mehdi.me/ambient-dbcontext-in-ef6/
Java - exceptions
Java has 3 different types of exceptions. 1. Checked exception - Use this exception for a case which can be recoverable. 2. Runtime exception - Use this exce...
Java - illegal generic array
The following code will have a compile error 1 new List<E>[]; The reason is that it is not a typesafe. It will violate the generic type system in Java
C++11 - explain SFINAE with example of enable_if
1 2 3 4 template <boolB, typename T> class enable_if {}; template <typename T> class enable_if<true, T> {typedef T type}; Above code will ...
C++11- enum class with underlying type
C++11 allows us to specify the underlying type for enum class as shown below. If specified value is not in the range of the underlying type, compiler can cat...
Git - submodule
Sometimes, a project can depends on another project which is in different git repository. Git can provide a way to maintain this dependencies by a command ca...
C++ - Unit test framework “doctest”
This C++ testing framework is very light and only requires a header file to include. Above all it will allow to have testing code in production code. https:/...
C++ - loop optimization with Sentinel
It is possible to make the loop faster by using an guarded value so it doesn't need to check the variable validation or extran comparing. https://en.wikipedi...
Java - unmarshalling partial XML in XML schema
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 public class XmlPartialMarshaller<T> { ...
Etc - copying a file with putty scp example to linux machine
pscp.exe -i [ppk_path] [file_to_copy] root@[ip]:[dest_path] ex) pscp.exe -i c:\test\id_rsa.ppk c:\temp\test.txt root@[fe80::217:88ff:fe20:4d1]:/tmp
Etc - Screen capturing with GIF animation
Quiet amazing free software on capturing screen shot with GIF animation http://screentogif.codeplex.com/
Java - example of specifying multiple constraints in Generic
1 2 3 4 5 6 7 8 9 10 public interface Operation { } public class enum TestEnum implements Operation { } public class Test { private static <T extends ...
C++11 - Variadic template example
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 #include <iostream> #include <sstream> #include <vector> std::vector&l...
Java - nested class and static class
Java allows us to define a class within another class. Such a class is called a nested class. The class which enclosed nested class is known as Outer class. ...
Improving responsiveness
Normally in order to improve the responsiveness of application, there are two areas that should be considered in modern memory machine architecture. 1. reduc...
C++ - Simple thread example of a string message processor
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 5...
HTTP - Free HTTPS certificate
You can get free 3 month certificate from the following URL. https://letsencrypt.org/
C++11 - Understanding SFINAE
SFINAE(substution failure is not an error) is hard to understand at glance but following article explains the concept of SFINAE eaiser way with a clear examp...
RxJava - execute the custom operation when unsubscribing
The following example will show how to perform the custom operation when unsubscribing 1 2 3 4 5 6 7 8 9 10 Service service = new Service(); Observable<St...
Rx - Difference Hot and Cold observer
Hot: If observerable start emitting items as soon as created, it is called "Hot" Cold: Observerable will start to emit items when it is subscribed.
C++ - Build boost library with MinGW
1. build bjam with boostrap.bat Example) bootstrap gcc 2. run the following command b2 toolset=gcc --build-type=complete architecture=x86 address-model=32 ...
Yeoman - integration with Maven build
https://github.com/trecloux/yeoman-maven-plugin
2015
JOSE - How to encrypt your web api
General article https://jwt.io/introduction/ http://odino.org/securing-your-http-api-with-javascript-object-signing-and-encryption/ Open source https://bitbu...
Authentification and authorisation
http://www.axiomatics.com/blog/entry/authentication-vs-authorization-part-2-saml-and-oauth-2.html
ApacheCXF - oauth 2 example
https://github.com/apache/cxf.git https://github.com/Talend/tesb-rt-se/tree/master/examples/cxf/jaxrs-oauth2
Java - Java concurrency in practice
Recommended book for Java concurrency https://github.com/HackathonHackers/programming-ebooks/blob/master/Java/Java%20Concurrency%20in%20Practice.pdf
Java - RxJava
Recommended reading for RxJava http://akarnokd.blogspot.com.au/2015/06/subjects-part-1.html Another worth reading article about Rx https://gist.github.com/st...
Java - Predefined funtional interface
1. Void return and zero paramter Use Runnable 1 2 3 4 5 6 void runTask(Runnable task) { task.run(); } runTask(()-> { // do something }); 2. Return v...
C++11 - Explanation about RValue reference in C++11
http://thbecker.net/articles/rvalue_references/section_01.html
C++ - SFINA example(Substitution Failure Is Not An error)
How C++11 can help to make C++ meta programming easier http://jguegant.github.io/blogs/tech/sfinae-introduction.html
Git - Getting started git-flow
The following URL has a nice article about git flow http://yakiloo.com/getting-started-git-flow/
Java - Try with resources
From Java7, it introduced the mechanism to release the resource automatically as C# does with using statement. In C#, you can use the using statement to rele...
C++ - A nice example measuring funtion execution time with C++11
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 #include <iostream> #include <chrono> template<typename TimeT = std::chrono::milliseconds> str...
Java - Initializing the Web App with Springframework
In order to initialize the Web application with Springframework, it is required to detect when context has been initialized. You can achieve it by defining a...
ApacheCXF - an example of web.xml
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 <?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/...
Java - ApacheCXF web socket example
Here is the git hub url for an example of ApacheCXF with websocket. https://github.com/apache/cxf/tree/master/distribution/src/main/release/samples/jax_rs/we...
Tomcat - setting for max HTTP header size
you can specify the max HTTP header size for Tomcap by modifying the file in conf/server.xml as shown below. This example set max HTTP header size 24KB(24576...
Java - loading a resource file in unit test code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 String xml = getResourceString("/test_files/TestProperties.xml"); private String getResou...
Maven - Log4j setting for maven with Springframework
In order to enable log4j settings in maven compilation, log4j.properties file should be in the test/resources directory. Sample unit test class 1 2 3 4 5 6 7...
C++ - Actor framework for C++
Nice C++ implementation for Actor framework. https://github.com/actor-framework/actor-framework.git Git branch for vs2015 is remotes/origin/topic/visual_stud...
COM - Generating a manifest file for COM isolation(registry free)
In order to load COM dll without searching from system registry key, application should include the manifest file in resource so that the application can cre...
Windows Performance count - select process with process id
If you have process having same name, it will be really difficult to collect performance counter. Here is a solution for this by modifying the registry key. ...
Java - Maven build plugin configuration to create a jar package
Make a package to be runnable including all dependent libs in a jar file 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 <buil...
C++ - Boost associative containers to maixmize the performance for shared memory architecture machine
Boost associative containers can increase the performance of your C++ applications for modern CPU architecture(shared memory architecutre) by minimizing cach...
Java - iterate all classpath with spring framework
The following code will iterate all available classpath in the application. 1 2 3 4 5 6 7 8 try { Enumeration<URL> resources = ApplicationContextPr...
Maven - Java class naming convention for unit testing
Unit test Java classes should follow the following naming convention otherwise Maven can not find any unit testing class Test* *Test *TestCase If...
Firefox - generate VS project files for Firefox source code
1 mach build-backend --backend=VisualStudio It can be found from the following path. [root source]\mozilla-central\obj-i686-pc-mingw32\msvc\mozilla.sln
x64 - Visual C++ compiler calling convention for x64
VC++ compiler is trying to utilize the 16 registers in x64 CPU which is 8bytes capacity. Due to this reason, first 4 parameters will be placed in registers b...
Tomat - install as a service for Windows
1. run cmd.exe as an administrator 2. go to the bin directory of Tomcat installation 3. execute "service.bat install 'name of service'" by default it will be...
Log4j - setting for logging everying grobally
The following example show how to configure log4j configuration file(log4j.properties) to log all messages. Main point is that rootLogger has to be configure...
Java - Spring framework - adding property file in application
1. Add the following code in applicationContext-config.xml 1 2 3 4 5 6 7 8 <bean id="myProperties" class="org.springframework.beans.factory.config.P...
C# - Simple example implementing concurrent queue
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 5...
Proxy Settings for Bower, Activator and Nodejs on Windows
1. Bower - create a file .bowerrc in C:\Users\userId directory. - content example 1 2 3 4 { "proxy":"http://user:pass@host:portId", "https-proxy":"http://u...
Java - Apache CXF: return response code(HTTP status code)
1 2 3 4 5 6 7 import javax.ws.rs.core.Response; Entity entity = service.getById(uuid); if(entity == null) { return Response.status(Response.S...
Maven Release plugin
Useful commands 1 2 3 4 5 6 7 8 9 10 1. Prepare mvn release:prepare 2. Perform release mvn release:perform 3. Update develop version number mvn release...
Java - Log4j fixed file size setting example
1 2 3 4 5 6 7 8 9 10 log4j.rootLogger=INFO, loggerId log4j.appender.loggerId=org.apache.log4j.rolling.RollingFileAppender log4j.appender.loggerId.rollingPoli...
Apache CXF - getting ServletContext in code
It is common to get a Servlet context on implementing WEB API. Apache CXF has a little different approach to get this instance. The following code show how t...
Java - create a Java application with Maven
With the following command you can create an application directory quickly 1 2 mvn archetype:generate -DgroupId=com.demo.app -DartifactId=appDemo -Darchetyp...
C++11- Move constructor requires “noexcept”
If a class having move constructor needs to be in the container class, it should have "noexcept" qualification. If move constructor may throw exceptions, it ...
2014
Java - a generic Java class instantiation example
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 public class CommandFactory { public static <T extends Command<R>, R extends Comm...
Tomcat - logging all HTTP traffic with Logback
1. Install logback in a tomcat\lib folder logback-access-1.1.2.jar logback-core-1.1.2.jar 2. Create a logback-access.xml in a tomcat\conf foler Example...
Tomcat - Context in server.xml
When Eclipse deploy web application in the existing Tomcat server, it will create Context element in server.xml. The details of Context element in Tomcat is ...
Java - detecting duplicate class define with maven
mvn dependency:analyze -DcheckDuplicateClasses blog for details http://pettermahlen.com/2010/08/05/finding-duplicate-class-definitions-using-maven/
Web - SoapUI is a nice tool to test Web API
http://www.soapui.org/
Java - Message bus library (event subscribe / unsubscribe)
com.google.common.eventbus is a quiet useful library if you would like to create a quick and simple solution for message bus. You can find more details from ...
C# - Log4Net configuration example
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 <?xml version="1.0" encoding="utf-8" ?> ...
C# WCF - Ninject Ioc
In order to use Ioc to instantiate a WCF service class, Ioc should provide implementation of following two interfaces. IInstanceProvider IServiceBehavior Imp...
Design principles that you should not forget on software design
1. The Single Responsibility Principle 2. The Open Closed Principle 3. The Liskov Substitution Principle 4. The Interface Segregation Principle 5. The Depend...
C++11 - Pointer casts
C++11 introduced a new way to cast shared_ptr as shown below. std::dynamic_pointer_cast std::static_pointer_cast std::const_pointer_cast
C++11 - coroutine
The following article is showing a nice example how C++11 can support coroutine feature. C# has already supported this feature from C# 2.0. http://paolosever...
C++11- good to know algorithm
The following algorithm will make your code clean and faster 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 1. std::all_of bool res = std::all_of(std::begin(conta...
C++11 - Shared memory architecture(Modern CPU) performance
Main bottle neck of modern CPU(shared memory architecture) is always related to accessing memory because memory is the slowest part in modern computer archi...
C++11 - Standard way to convert number to string
1 2 3 4 5 6 7 8 9 10 11 12 include<string> using std; std::to_string std::to_wstring stoi: converts a string to a signed integer stol: ...
C# - Changing log4Net logging path at runtime
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 private static void InitLoggingPath() { string progDataPath = Environment.GetF...
XCode - Static library
The following link contains useful information about make a static library for XCode project. http://www.blog.montgomerie.net/easy-xcode-static-library-subpr...
C++ - Simple Dynamic 2D array example
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 5...
Git - useful article about Git workflow
The following link has a useful information about managing git branches. https://www.atlassian.com/git/workflows#!workflow-gitflow
C# - Windows 8 App, using canvas to draw outside of Grid control
Canvas size is always child driven so it will give infinite size for children. Also HorizontalAlignment and VerticalAlignment settings have no effect on a ch...
C# - Windows 8 App, creating custom control with Xaml
The following URL shows how to create custom control with Xaml. http://blogs.msdn.com/b/mim/archive/2013/03/19/create-a-custom-user-control-using-xaml-and-c-...
C# - How RaisePropertyChanged works in MVVM light
MVVM light provides an easy way of the strong typed RaisePropertyChanged with lambda. The following code shows how this can find the correct string for membe...
C++11 - default member initialization
You can initialize the member variable as shown the following in C++11. It will save a lot of typing when you have many constructors. 1 2 3 4 5 6 7 8 9 10 11...
C# - MVVM light
I think that MVVM light is the essential tool for XAML based framework such as WPF, Silverlight, Windows 8, WindowPhone 8 http://www.galasoft.ch/mvvm/doc/
C++ 11 - Exception safe guidline from Jon Kalb
Throw by value. Catch by reference No dynamic exception specifications. Use noexcept. Destructors that throw are evil. Use RAII. (Every responsibility is an...
The most important design guideline
Scott Myer's word for design software. All interface should be easy to use correctly and hard to use incorrectly.
C++11 - std::rethrow_if_nested
std::throw_with_nested will create a class inherited from std::std::nested_exception and user exception then it will get current exception and user exception...
C# - print a file name and line number when an exception was thrown
1 2 3 4 5 6 7 8 9 10 11 12 13 14 public static class ExceptionUtils { public static void PrintException(Exception e) { va...
C# - Rx framework to create Observable from EventHandler
The following code shows how to create IObserable object from EventHandler delegator. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27...
C++ - Hash combine example for hash function in unordered_map
1 2 3 4 5 6 template <class T> inline void hash_combine(std::size_t & seed, const T & v) { std::hash<T> hasher; seed ^= hasher(v) + 0...
C++11 - transporting C++ exceptions between threads
C++11 introduced std::exception_ptr. The main purpose of this class is to allow to tranport C++ exceptions to different threads. in 2012 C++ and Beyond Semin...
C++ - About exception safe code with C++
The following URL is talking about writing exception safe code for C++. http://exceptionsafecode.com/
.NET - CLRMD crash dump and inspection API
Microsoft announced the new API for inspection of dump file which is called CLRMD http://blogs.msdn.com/b/dougste/archive/2013/05/04/clrmd-net-crash-dump-and...
C++11 - Quiz about C++11
It is a good to try to test your C++ knowledge. http://cppquiz.org/
ASP.NET - Web API 2 article
The following link explains about Web API2 with OWIN protocol http://blogs.msdn.com/b/webdev/archive/2013/09/20/understanding-security-features-in-spa-templa...
Boostrap3 - input file example
The following URL shows a good example how to make a nice looking file input button with Boostrap 3 http://www.abeautifulsite.net/blog/2013/08/whipping-file-...
2013
AngularJS service code with ASP .NET WEB API2
The following AngularJS service code shows how to login with bearer token authentication of ASP.NET WEB API2 to access exported restful APIs. 1 2 3 4 5 6 7 8...
ASP.NET - SPA with AngularJS
The following url shows an example of SAP with AngularJS for ASP.NET http://www.codeproject.com/Articles/657139/A-Book-Store-Application-Using-AngularJS-and-...
AngularJS with TypeScript example
The following links shows a good example using AngularJS with TypeScript. http://www.software-architects.com/devblog/2013/10/17/AngularJS-with-TypeScript-and...
ASP .NET - Individual account in WEB API
From MVC5, Microsoft changed a lot on identification mechanism. Web API will also use the updated framework which is based on OWIN. The following article wil...
C# - Continuous task example
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 5...
C++11 - Caution on using lambda inside lambda.
When you create a lambda and if the lambda create another lambda in asynchronous way by using thread, you need to be very careful on capturing values. If you...
Windbg - command types
Windbg has the following command types Native commands: it starts without any prefix vertaget, k, ~, s, lm, lmv m *clr* Meta commands(.): it starts with '...
Modbus - Coils, Discret Inputs etc
discrete inputs: read-only Boolean coils: read-write Boolean input registers: read-only integer(16 bits) holding registers: read-write integer(16 bits)
C# WCF - certification configuration for WCF
Server side configuration 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 static Binding CreateBindi...
Certification - Creating self certification files in Windows
1 2 3 4 5 6 7 8 9 10 // create certification for authority makecert -r -pe -n "CN=Tunnel Project Authority" -ss CA -sr CurrentUser -a sha1 -sky signature -cy...
Windows - disabling BSTR cache
When checking memory usage it might need to disable BSTR cache to avoid misleading information. Add the following environmental variable to disable BSTR cach...
Performance - Windows application heap usage
The following script will show how to profile the heap memory usage of Windows application with Windows Performance Toolkits 1 2 3 4 5 6 7 8 9 10 11 12 @echo...
C# WPF - INotifyPropertyChanged vs DependencyObject
In WPF for binding model data to UI you can choose DependencyObject or INotifyPropertyChanged with POCO. I normally selected INotifyPropertyChanged with POCO...
C# WCF - communication tracing
In order to diagnostic WCF communication, you can log all WCF activities by using tracing mechanism in .NET application. You can add the following section in...
C# WPF - mouse over animation with opacity
Resource XML. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 <Windows.Resources> <Style x:Key="FadeOutButton"...
C# WPF - customizing start up fuction in WPF
When you create a WPF application with visual studio, you will always find app.xaml and app.xaml.cs file. In app.xaml file, you can find the StartupUri attri...
C++11 - Inherited constructors
Now C++11 allow that derived class can inherit the constructors of base class as the following. 1 2 3 4 5 6 7 8 9 10 11 class A { public: A(int a) {} ...
C# - Simple UDP listener in asynchronous way
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 private Socket udpSock; private byte[] buffer; public void Starter(...
C# Performance measurement helper classes
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 ...
C++ Performance measuring utility classes
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 5...
Performance Analysis for Windows - channel9
The following URL contains the useful information about using xperf for analysis of Windows application and OS. http://channel9.msdn.com/Shows/Defrag-Tools/R...
C# example of optimistic concurrency with Entity Framework code first
The following article shows the good example how to use optimistic concurrency control in Entity Framework code first. http://msdn.microsoft.com/en-us/data/j...
C# - Entity Framework : explicitly loading a reference object
1 2 3 4 5 6 7 8 9 10 11 using (var context = new BreakAwayContext()) { var davesDump = (from l in context.Lodgings where l.Name == "Dave...
C# configuration to log .NET library such socket connection
If you create a file named [application].exe.config with the following contents in directory having your application, it can make logs on any socket connecti...
C# SMTP client using CDO
The following code utilize the CDO service of Windows OS to send an email. In my research CDO SMTP client can only support SSL/TLS connection type for using ...
C# WPF extended toolkit
Extended WPF toolkit provide the various UI for building WPF based application. You can find the details from the following link. http://wpftoolkit.codeplex....
C# WCF instance configuration
WCF has the confusing mechanism for management of instance on RPC call. The following separating shows an example of this situation. If you are more interest...
C# generic function to invoke a method of class with static information
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 class Invoker<T> where T : class { static void Invoke(T invokeClass, string methodName, object[] args) ...
C# dynamic keyword
.NET 4.0(vs2010) introduced the dynamic feature to support better integration of dynamic language such as Python, Ruby etc. Example) Without dynamic feature....
C# performance counter example
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 5...
IIS configuration for number of concurrent connection
Open an administrator command prompt at %windir%\System32\inetsrv\ Run the command below to update the appConcurrentRequestLimit attribute to a suitable numb...
C# WCF useful web link containing downloadable example VC projects
Juval Lowy is an expert in WCF. http://www.idesign.net/Downloads
C++ 11, Example of auto for function declaration
1 2 template <class T> auto add(T t, U u) -> decltype(t + u) is equal to 1 2 template <class T> decltype((*(T*)0) + (*(U*)0)) add(T t, U u);
.NET - a nice article about memory allocations profiling with VS2012
http://blogs.msdn.com/b/dotnet/archive/2013/04/04/net-memory-allocation-profiling-with-visual-studio-2012.aspx
C# - a great article about C# monads
http://ericlippert.com http://ericlippert.com/category/monads/
C# - a nice article about C# memory model
http://msdn.microsoft.com/en-us/magazine/jj863136.aspx
UDP Multicast - enable/disable loopback message on sending a message
1 2 3 4 5 6 7 8 9 bool EC_EnableMulticastLoopBack(SOCKET socket, bool IPv6, bool enable) { // enable/disable loop char loop = enable ? 1 : 0; if ...
UDP Multicast - selecting a network adapter interface on sending a multicast message.
1 2 3 4 5 6 7 bool EC_SetMulticastInterfaceIndex(SOCKET socket, bool IPv6, int index) { if (IPv6) { return setsockopt(socket, IPPROTO_IPV6, IPV6_...
C++11 - one line interesting example of C++11 syntax
1 constexpr explicit optional<T>::operator bool() const noexcept;
C# - a good blog about using C# task parallel library
http://blogs.msdn.com/b/csharpfaq/archive/2010/06/01/parallel-programming-in-net-framework-4-getting-started.aspx
C++11 - an example of trailing return type
1 2 3 4 template<typename T, typename S> auto multiply(T lhs, S rhs) -> decltype(lhs * rhs) { return lhs * rhs; }
C++11 - defaulted function
C++11 introduced the defaulted function as the following example. 1 2 3 4 5 6 7 class help { public: help() = default; private: std::string m_text; }...
Git - svn commands
1 2 3 4 git svn clone http://svn.example.com/project/trunk git commit git svn rebase git svn dcommit
URLs - Windows performance tool kits (WPR, WPA, xperf etc)
Channel 9 videos about xperf, xperfview, WPR and WPA http://channel9.msdn.com/Events/Speakers/Michael-Milirud Article about xperf http://blogs.msdn.com/b/ntd...
C++11 - casting from base class shared_ptr to drived class shared_ptr
1 2 3 4 5 6 7 class BaseClass : public std::enable_shared_from_this<BaseClass> { template <typename Derived> std::shared_ptr<Derived> G...
C# - getting a scheduler from the current synchronization context
1 2 3 4 5 6 7 var ui = TaskScheduler.FromCurrentSynchronizationContext(); Task.Factory.ContinueWhenAll(tasks.ToArray(), result => { var ti...
Git - use the last committed message.
1 2 git commit --reedit-message=HEAD --reset-author git commit -c HEAD --res
Git - renormalizing a repository
1 2 3 4 5 6 git rm --cached -r .# Remove everything from the index. git reset --hard# Write both the index and working directory from git's database. git add...
Move constructor may be required if you want to add it into std::vector in C++11
when resizing or relocating memory in std::vector, if item supports move constructor std::vector can optimize on relocation operation.
A good blog about C++11
http://bartoszmilewski.com/
Git - adding the deleted files
1 2 1. git add -u 2. git rm $(git ls-files --deleted)
Git - changing the committed comment
Basic steps. git log --pretty=oneline -10 git rebase -i xxxx -> change 'pick' to 'reword' git commit git rebase --continue details is the following url. h...
ASP .NET MVC4 - example of creating the simple membership
http://weblogs.asp.net/jgalloway/archive/2012/08/29/simplemembership-membership-providers-universal-providers-and-the-new-asp-net-4-5-web-forms-and-asp-net-m...
An example of jmeter stress test
http://nico.vahlas.eu/2010/03/30/some-thoughts-on-stress-testing-web-applications-with-jmeter-part-2/
An example of measuring performance of ASP.NET application using IIIS resource toolkit
ASP.NET iis resource toolkit For performance measurement WCAT 6.3 http://www.iis.net/downloads/community/2007/05/wcat-63-(x86) http://www.iis.net/downloads/...
ASP.NET database connection error - the underlying provider failed on Open
context.Connection.Open() didn't help solving my problem so I tried enabling "Allow Remote Clients" in DTC config, no more error. In windows 7 you can open t...
Git - configuration to use p4merge for diff
On Windows 1 2 3 4 5 6 7 8 9 10 [diff] tool = p4merge [difftool "p4merge"] path = c:\\Program Files\\Perforce\\p4merge.exe [merge] tool = p4merge [mergeto...
C# Observable dictionary
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 5...
C# - an example of comparing C# objects using generic lambda function
1 2 var comparer = Comparer<T>.Default; Func<T,T,T> minOf = (x, y) => comparer.Compare(x, y) < 0 ? x: y;
C# - an example of creating an observable object with C# custom event
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 public class ValueChangeData { public object oldValue; public object newV...
C++11 - a good example of using std::function
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 struct Wanderer { explicit Wanderer(std::vector<std::function>& u...
Simple Makefile example for MPI
1 2 3 4 5 6 7 8 9 10 11 12 13 CC=mpicxx CFLAGS=-c -Wall LDFLAGS= SOURCES=test.cpp OBJECTS=$(SOURCES:.cpp=.o) EXECUTABLE=test all: $(SOURCES) $(EXECUTABLE) $(...
People want to predict every events
People like predictable events but reality is every moment and events are unpredictable. I think that main purpose of software engineering is to make unpredi...
C++ - an example of undefining min, max macro with VC++
1 2 3 4 5 6 7 #pragma push_macro("min") #pragma push_macro("max") #undef min #undef max // call min, max #pragma pop_macro("min") #pragma pop_macro("max")
vim commands
Cursor movement 1 2 3 4 5 6 7 8 9 10 11 12 13 14 h - move left j - move down k - move up l - move right w - jump by start of words (punct...
Markov and Viterbi - implemented by Brian Beckman
https://github.com/rebcabin/DotNetExtensionsImproved From Wikipedia - information on Markov and Viterbi: A hidden Markov model (HMM) is a statistical Markov ...
Compiling open MPI application on Windows
When you compile OpenMPI on Windows, you should define the following preprocessor. OMPI_IMPORTS OPAL_IMPORTS ORTE_IMPORTS Example) c:\>mpicxx test.cpp -DO...
2012
C++11 - a good example of RAII by using unique_ptr
1 2 3 4 5 6 class FileDeleter { void operator()(FILE* fp) { fclose(fp); } }; unique_ptr<FILE, FileDeleter> fp = fopen("blah"); or even unique_ptr<FI...
Simple UML diagram tool and documentation tool
Very useful tools for UML and documentation. Plant UML http://plantuml.sourceforge.net/ sphinx python documentation http://sphinx.pocoo.org/
Spring Roo Postgresql DB Setup Example
database.driverClassName=org.postgresql.Driver database.url=jdbc\:postgresql\://localhost\:5432/
Spring MVC - Redirect to URL after login
Fortunately, Spring Security has built-in functionality for remembering the URL that was originally requested, and redirecting your users there after they su...
How fiddler works
https://groups.google.com/forum/?fromgroups=#!topic/httpfiddler/Az0xW2MJMqU There's tons of information scattered through the various Fiddler sites and this ...
Tab UI example in spring roo
http://stackoverflow.com/questions/6419885/how-to-add-a-tab-container-to-a-spring-roo-page
Spring MVC with google chart API
Good example http://himtech-spring.blogspot.com.au/2012/07/spring-mvc-with-google-chart.html
RDBMS ER diagram source
http://wofford-ecs.org/dataandvisualization/ermodel/material.htm
Windows 7 memory profiling another example
1 2 3 4 5 6 7 8 9 10 11 12 13 @echo off set _NT_SYMBOL_PATH=f:\src\Debug\;srv*c:\WebSymbol*http://msdl.microsoft.com/downloads/symbols xperf -on Base+Cswitch...
Windows 7 memory profiling example
@echo off set _NT_SYMBOL_PATH=F:\src\Release\;srv*c:\WebSymbol*http://msdl.microsoft.com/downloads/symbols</p> xperf -on base xperf -start heapsession...
Windows 7 CPU performance profiling example
@echo off set _NT_SYMBOL_PATH=f:\src\Debug\;srv*c:\WebSymbol*http://msdl.microsoft.com/downloads/symbols</p> xperf -on Latency -stackwalk profile echo...
Load a binary file with C++
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 bool LoadBinaryFile(std::wstring const& path, std::vector<unsigned char>& data) { try { std::basic_ifst...
Load a text file with C++
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 std::wstring fromAscii(const char* str) { std::wstring sOutput; int inputLength ...
Setting up boost unit testing visual studio project
1. Header 1 2 3 #define BOOST_TEST_MODULE TestExample #include using namespace boost::unit_test; 2. Linked library 1 libboost_unit_test_framework-vc100-mt-s...
2011
Understanding COM threading model(Apartment)
I have found very useful articles for understanding COM threading model about Apartment. If you want to understand COM Apartment model, the following article...
C++ exception - difference passing arguments between exception and function
오랜만에 다시 C++책을 읽으면서 아래의 C++ exception에 대한 자세한 사항을 늘어 봅니다. 1. exception object are always copied - 복사할때 항상 static type정보를 이용해서 복사한다는 사실. 2. exception are fewer...
Something about .NET profiler
The following link explains about how .NET profiler works. http://blogs.msdn.com/b/davbr/archive/2007/03/22/enter-leave-tailcall-hooks-part-1-basics.aspx Usi...
2010
WinDbg example for debugging reference count of COM object
One of the hardest things is debugging a reference count leak. COM objects lifetime depends on the reference count (read here for more...). So each client of...
Posting Source Code in WordPress blog
http://en.support.wordpress.com/code/posting-source-code/
Build boost 1.43 for iPhone SDK 4.0
1. modify user.config.jam in tools/build/v2 directory 1 2 3 4 5 6 7 8 9 10 using darwin : 4.2.1~iphone : /Developer/Platforms/iPhoneOS.platform/Developer/usr...
Link Boost library for iPhone
Once you compile the boost libraries you want, right click your target after you made your project, and click Get Info. Then go to the Build Tab and find the...
블로그 시작
오픈 소스 베이스로 만들어진 블로그 중에 괜찮은것 같고 모든 내용을 XML로 Export할 수 있다는 말에 선택하게 되었네요.
2009
Shared Source Common Language Infrastructure 2.0 Release
http://www.microsoft.com/downloads/details.aspx?familyid=8C09FD61-3F26-4555-AE17-3121B4F51D4D&displaylang=en
Mac OSX NVCAP
URL: http://nvinject.free.fr/forums/viewtopic.php?t=214 Thanks to Arti and the lot of experiments we've been doing last weeks on hackintoshes and PowerPC ...
Check out CLR Profiler 2.0
http://blogs.msdn.com/jmstall/archive/2005/12/17/CLR-profiler-2-0-available.aspx</p>
2008
Windows With C++ Asynchronous WinHTTP
http://msdn.microsoft.com/en-us/magazine/cc716528.aspx</p>
Sysinternal source website
http://doc.sch130.nsc.ru/www.sysinternals.com/ntw2k/source.shtml
Playing with ptrace, Part I
http://www.linuxjournal.com/article/6100
An introduction to c# Generics
http://msdn.microsoft.com/en-us/library/ms379564(VS.80).aspx
Writing a script debugger without using the MDM
http://blogs.msdn.com/greggm/archive/2008/06/09/writing-a-script-debugger-without-using-the-mdm.aspx
Visual Studio Debug Engine Sample
http://code.msdn.microsoft.com/debugenginesample/Release/ProjectReleases.aspx?ReleaseId=501
Interesting Visual C++ Resources
http://blogs.msdn.com/vcblog/archive/2008/06/12/interesting-visual-c-resources.aspx
Improve Scalability With New Thread Pool APIs
http://msdn.microsoft.com/en-au/magazine/cc163327.aspx
Strategies for Implementing POSIX Condition Variables on Win32
http://www.cs.wustl.edu/~schmidt/win32-cv-1.html
Modality, part 3: The WM_QUIT message
http://blogs.msdn.com/oldnewthing/archive/2005/02/22/378018.aspx
An Introduction to XML Data Binding in C++
http://www.artima.com/cppsource/xml_data_binding.html
MSDN magazine home
http://msdn.microsoft.com/en-au/magazine/default.aspx
The Humble Dialog Box
http://objectmentor.com/resources/articles/TheHumbleDialogBox.pdf
Registration-Free Activation of COM Components: A Walkthrough
http://msdn.microsoft.com/en-au/ms973913.aspx
Simplified Unit Testing for Native C++ Applications
http://msdn.microsoft.com/en-au/magazine/cc136757.aspx This article discusses: Unit testing philosophy Setting up WinUnit Building test fixture...
Undo and Redo the “Easy” Way
http://www.codeproject.com/KB/cpp/transactions.aspx </p> Languages » C / C++ Language » General Intermediate </p&g...
Duplicate images finder
http://www.codeplex.com/DupliFinder
How do I flash my window caption and taskbar button manually?
Commenter Jonathan Scheepers wonders about those programs that flash their taskbar button indefinitely, overriding the default flash count set by SystePara...