SEARCH KEYWORD -- Error detection


  Capture video stream with WebRTC

WebRTC(Web Real-Time Communication) is an API supporting real time audio and video communication through a browser. It is now a recommended W3C standard. This post is to show you how to capture video stream and screenshot with WebRTC. Capture video stream To play video stream from the video camera, we first need to put a video tag in our code: <video id="video"></video> The main function to get the video stream is the navigator.getUserMedia, as of now only few of the browsers support...

   WebRTC,Video,Screenshot     2013-10-24 21:04:41

  Implementing DESede/ECB/NoPadding cipher algorithm in GoLang

By default, GoLang doesn't provide the ECB mode cipher for DESede though there is CBC mode provided. In cases we need to encrypt/decrypt data with ECB mode, we need to implement those by ourselves. This mode is frequently used when encrypting/decrypting PIN block which is small block data less than 16 bytes. In this post, we will introduce how to implement the DESede/ECB/NoPadding algorithm in GoLang by using the existing cipher support. Here we will not cover how DESede works in detail, instead...

   SECURITY,SAMPLE,GOLANG,DES,DESEDE,3DES     2019-07-29 06:43:50

  The evolving history of asynchronous operation in JavaScript

JavaScript is single threaded, it means there would be only one task running at any point of time. But this would slow down the overall program execution if there is long running task, hence asynchronous task execution is desired in complex cases. To achieve asynchronous task execution, there are a few options introduced in JavaScript. setTimeout/setInterval Event Promise Async/Await setTimeout/setInterval is one of the first mechanisms introduced in JavaScript to simulate asynchronous operati...

   JAVASCRIPT,ASYNC,PROMISE,AWAIT     2019-11-09 08:21:56

  A plugin to update last_error in Delayed Job

delayed_job is a process based asynchronous task processing gem which can be ran at background. It will fork the specified number of processes to execute the tasks asynchronously. The task status is usually stored in the database so that it can be easily integrated into a Rails application where asynchronous job execution is desired. Normally when a job fails to execute or error occurs, it would save the error into the database with the column last_error. Ideally all these will be handled b...

   RUBY,RUBY ON RAILS,DELAYED JOB,LAST_ERROR     2017-11-18 13:05:49

  Error handling style in C

Following are three error handling styles in C.Which one you like the most? Or you don't like any one?1. /* Problem : Not enough. Easy to be wrong */int foo(int bar){        int return_value = 0;        int doing_okay = 1;        doing_okay = do_something( bar );        if (doing_okay)        { ...

   C,Error handling style,Goto,Nested if     2012-04-24 06:51:00

  Why init() is not recommended in Go

golangci lint Currently, the unified CI's .golangci.yml includes the gochecknoinits checker: # golangci-lint v1.46.2 # https://golangci-lint.run/usage/linters linters: disable-all: true enable: ... - gochecknoinits # Checks that no init functions are present in Go code. ref: https://github.com/leighmcculloch/gochecknoinits ... If Go code uses the init() function, the following error will occur: # golangci-lint run foo/foo.go:3:1: don't use `init` function (gochecknoinits) func i...

   GOLANG,INIT(),SYNC.ONCE,PANIC     2024-05-10 07:46:18

  A strange behavior of printing struct with nested struct in GoLang

Normally when trying to print a struct , we would use %v to show all data of the struct. It will print the default format for each field in the struct. %v the value in a default format when printing structs, the plus flag (%+v) adds field names But recently we observed a strange behavior when printing a struct with nested struct which has a String() string implemented, the %v format prints an 'unexpected' output per our understanding.   Let's see the example snippet first. pa...

   PROGRAMMING,GOLANG     2018-10-29 09:59:49

  Fix issue "cannot load such file -- bcrypt_ext (LoadError)"

bcrypt() is a sophisticated and secure hash algorithm designed by The OpenBSD project for hashing passwords. The bcrypt Ruby gem provides a simple wrapper for safely handling passwords. However, sometimes the rails application would fail to start after installing the bcrypt gem on Windows. The error would look similar to below. The issue is that it fails to load the bcrypt_ext which is the native built extension, the reason may be the library is wrongly built. To fix this issue, below steps can...

   RUBY,SOLUTION,RUBY ON RAILS,BCRYPT,LOAD ERROR     2017-03-05 00:21:10

  Maintain multiple versions of Go in one single environment

In a development environment, there might be multiple projects going on at the same time and they may require different development environments with different versions of build tool. In many programming languages, it is possible to have multiple versions of different build tool or development tool on a single environment. For example, there can be multiple JDKs, multiple versions of Ruby using RVM. For GoLang, there is a similar tool called GVM which can also be used to maintain multiple versio...

   GOLANG,GVM,GVM PKGSET,RVM     2019-11-10 00:43:47

  No support of $.browser in jQuery 1.9

Starting from jQuery 1.9, $.browser is no longer supported to detect the nrpwser type and version. The substitute is $.support. In the newer jQuery 2.x versions, IE 6/7/8 are also not supported. If users want to support IE 6/7/8, they must use jQuery 1.9. If you want to fully support IE and want to use jQuery 1.9 and jQuery 2.0, the official solution is: <!--[if lt IE 9]> <script src='jquery-1.9.0.js'></script> <![endif]--> <!--[if gte IE 9]> <script src=...

   jQuery,$.browser,$.browser.version     2013-08-27 03:10:12

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