SWAN: Stuff We All Need (Unosquare's collection of C# extension methods and classes)

⭐️ Please star this project if you find it useful!

SWAN stands for Stuff We All Need

Repeating code and reinventing the wheel is generally considered bad practice. At Unosquare we are committed to beautiful code and great software. Swan is a collection of classes and extension methods that we (and other good developers) have written and evolved over the years. We found ourselves copying and pasting the same code for every project every time we started them. We decided to kill that cycle once and for all. This is the result of that idea. Our philosophy is that Swan should have no external dependencies, it should be cross-platform, and it should be useful.

Table of contents

• 📚 Libraries
• 💾Installation
• What's in the library
  • The SwanRuntime component
  • The Terminal class
  • The Json formatter
  • The CsvWriter class
  • The CsvReader class
  • The JsonClient class
  • The SmtpClient class
  • The ObjectMapper component
  • The Network component
  • The ObjectComparer component
  • The ObjectValidator component
  • The DependencyContainer component
  • The MessageHub component
  • The LdapConnection class
  • The ProcessRunner class
  • The ArgumentParser component
  • The SettingsProvider abstraction
  • The Connection class
  • The DelayProvider component
  • The WaitEventFactory component
  • Atomic Types
• Running Unit Tests

📚 Libraries

We offer the Swan library in two flavors since version 0.24. Swan Lite provides basic classes and extension methods and Swan Standard (we call it Fat Swan) provides everything in Swan Lite plus Network, DI and more. See the following table to understand the components available to these flavors of Swan.

If you are developing an ASP.NET Core application, we recommend to use SWAN ASP.NET Core.

💾 Installation:

Swan Standard Installation:

PM> Install-Package Unosquare.Swan

Swan Lite Installation:

PM> Install-Package Unosquare.Swan.Lite

What's in the library

In this section, we present the different components that are available in the Swan library. Please keep in mind that everything in the library is opt-in. Swan is completely opt-in. It won't force you to use any of its components, classes or methods.

The SwanRuntime component

SwanRuntime provides properties and methods that provide information about the application environment (including Assemblies and OS).

Runtime API Doc

The Terminal class

Many times, we find ourselves implementing Console output code as some NLog or Log4Net logger or adapter, especially when writing console applications, daemons, and Windows services or Linux daemons. We also tend to write Console code for reading user input because it can't be some logger or adapter. And then you have the System.Diagnostics.Debug class to write to the debugger output. And finally, all your Console user interaction looks primitive and unprofessional. In other words, you end up with 3 things you are unsure of how to put together in the different configurations and runtime environments: Console, Debug and some logging mechanism. In return you have placed unintended logging code, Console code, and Debug code everywhere in your application and it makes it look silly, bloated and written by an amateur.

The Swan Terminal is all of the following:

• Console Standard Output Writer
• Console Standard Error Writer
• Debug Writer
• Console Standard Input Reader

It is also very easy to use, it's thread-safe, and it does not require you to learn anything new. In fact, it simplifies logging messages and displaying Console messages by providing string extension methods.

Terminal API Doc

Example 1: Writing to the Terminal

This only writes messages out to the TerminalWriters if there are any available. In practice, we typically DO NOT use the Write and WriteLine methods but they are provided for convenience, extensibility and customization. Please note that these methods do not forward messages as logging events and therefore whatever is written via these methods will not show up in your logging subsystem.

// The simplest way of writing a line of text -- equivalent to `Console.WriteLine`:
Terminal.WriteLine($"Hello, today is {DateTime.Today}");

// Now, let's add some color:
Terminal.WriteLine($"Hello, today is {DateTime.Today}", ConsoleColor.Green);

// Write it out to the debugger as well!
Terminal.WriteLine($"Hello, today is {DateTime.Today}", ConsoleColor.Green, TerminalWriters.StandardOutput | TerminalWriters.Diagnostics);

// You could have also set the color argument to null and just use the configured default
Terminal.WriteLine($"Hello, today is {DateTime.Today}", null, TerminalWriters.StandardOutput | TerminalWriters.Diagnostics);

Example 2: Configuring Output

Swan's Terminal provides both, flexibility and consistency for all of its output. While it will pick the most common defaults for a given build or runtime scenario, you are able to modify such defaults and adjust them to your liking. You can change the output colors,

Example 3: User Interaction

The Swan Terminal would not be complete without a way to read user input. The good news is that Terminal can create decent-looking user prompts if a very convenient way.

// Reads a line of text from the console.
var lineResult = Terminal.ReadLine();

// Reads a number from the input. If unable to parse, it returns the default number, in this case (default 0).
var numberResult = Terminal.ReadNumber("Read Number", 0);

// Creates a table prompt where the user can enter an option based on the options dictionary provided.
var promptResult = Terminal.ReadPrompt("Read Promp", options, "A");

// Reads a key from the terminal preventing the key from being echoed.
var keyResult = Terminal.ReadKey("Read Key");

Example 4: Other Useful Functions

Swan's Terminal also provides additional methods to accomplish very specific tasks. Given the fact that Terminal is an asynchronous, thread-safe output queue, we might under certain situations require all of the output queues to be written out to the Console before the program exits. For example, when we write a console application that requires its usage to be fully printed out before the process is terminated. In these scenarios, we use Terminal.Flush which blocks the current thread until the entire output queue becomes empty.

The Json Formatter

You can serialize and deserialize strings and objects using Swan's Json Formatter. It's a great way to transform objects to JSON format and vice versa. For example, you need to send information as JSON format to another point of your application and when arrives it's necessary to get back to the object that is going to be used, and thanks to JSON format the data can interchange in a lightweight way.

Json API Doc

Example 1: Serialize

Serializes the specified object into a JSON string.

// The object to be serialize
var basicObject = new { One = "One", Two = "Two", Three = "Three" };
// Serializes the specified object into a JSON string.
var data = Json.Serialize(basicObject);

Example 2: Serialize included properties

Serializes the specified object only including the specified property names.

// The object to be serialize
var basicObject = new { One = "One", Two = "Two", Three = "Three" };
// The included names
var includedNames  = new[] { "Two", "Three" };
// Serialization Only.
var data = Json.SerializeOnly(basicObject, true, includedNames);

Example 3: Serialize excluding properties

Serializes the specified object excluding the specified property names.

// The object to be serialize
var basicObject = new { One = "One", Two = "Two", Three = "Three" };
// The excluded names
var excludeNames  = new[] { "Two", "Three" };
// Serialization Excluding
var data = Json.SerializeExcluding(basicObject, true, excludeNames);

Example 4: Serialize an object using attributes

Serializes the specified object whose properties have a JsonPropertyAttribute

 class JsonPropertyExample
{
   [JsonProperty("data")]
   public string Data { get; set; }
   
   [JsonProperty("ignoredData", true)]
   public string IgnoredData { get; set; }
}

 var obj = new JsonPropertyExample() { Data = "OK", IgnoredData = "OK" };
 
 // {"data": "OK"}
 var serializedObj = Json.Serialize(obj);

Example 5: Deserialize

Deserializes the specified JSON string as either a Dictionary<string, object> or as a List<object> depending on the syntax of the JSON string.

// The json to be deserialize
var basicJson = "{\"One\":\"One\",\"Two\":\"Two\",\"Three\":\"Three\"}";
// Deserializes the specified json into Dictionary<string, object>.
var data = Json.Deserialize(basicJson);

Example 6: Deserialize a generic type <T>

Deserializes the specified JSON string and converts it to the specified object type. Non-public constructors and property setters are ignored.

// The json Type BasicJson to be deserialize
var basicJson = "{\"One\":\"One\",\"Two\":\"Two\",\"Three\":\"Three\"}";
// Deserializes the specified string in a new instance of the type BasicJson.
var data = Json.Deserialize<BasicJson>(basicJson);

The CsvWriter class

Many projects require the use of CSV files to export and import data. With CsvWriter you can easily write objects and data to CSV format. It also provides a useful way to save data into a file.

CsvWriter API Doc

Example 1: Writing a List of objects

This is the way to write a list of objects into a CSV format.

 // The list of objects to be written as CSV
var basicObj = new List<BasicJson>();

using (var stream = new MemoryStream(Encoding.ASCII.GetBytes(basicObj.ToString())))
{               
    // The CSV writer
    var reader = new CsvWriter(stream);
};

Example 2: Writing a List of objects into a file

You also can write the object into a file or a temporal file.

// The list of objects to be written as CSV
var basicObj = new List<BasicJson>();
// This is where the object is save into a file
CsvWriter.SaveRecords(basicObj, "C:/Users/user/Documents/CsvFile");

The CsvReader class

When you need to parse data in CSV files you'll always need an easy way to read and load their contents into lists and classes that are usable by your application. Swan provides the CsvReader class to read and load CSV files into objects.

CsvReader API Doc

Example 1: Reading a CSV data string

This is a way to read CSV formatted string.

 // The data to be read
var data = @"Company,OpenPositions,MainTechnology,Revenue
            Co,2,""C#, MySQL, JavaScript, HTML5 and CSS3"",500 
            Ca,2,""C#, MySQL, JavaScript, HTML5 and CSS3"",600";

using (var stream = new MemoryStream(Encoding.UTF8.GetBytes(data)))
{               
    // The CSV reader
    var reader = new CsvReader(stream, true, Encoding.UTF8);
};

Example 2: Reading a CSV file

From a CSV file, you can read and load the information into a generic list.

// The list of object to be written as CSV
var basicObj = new List<BasicJson>();
// This is where the object is save into a file
CsvWriter.SaveRecords(basicObj, "C:/Users/user/Documents/CsvFile");
// This is how you can load the records of the CSV file
var loadedRecords = CsvReader.LoadRecords<BasicJson>("C:/Users/user/Documents/CsvFile");

The JsonClient class

Represents a wrapper HttpClient with extended methods to use with JSON payloads and bearer tokens authentication.

JsonClient API Doc

Example 1: Authentication

You can add Authentication to your requests easily.

// The Authenticate
var data = JsonClient.Authenticate("https://mywebsite.com/api/token", "admin", "password");

Example 2: An HTTP GET request

An easy way to HTTP GET using JsonClient.

// The GET
var data = JsonClient.Get<BasicJson>("https://mywebsite.com/api/data");

Example 3: An HTTP POST request

An easy way to HTTP POST using JsonClient.

// The POST
var data = JsonClient.Post<BasicJson>("https://mywebsite.com/api/data", new { filter = true });

Example 4: Making a PUT

An easy way to HTTP PUT using JsonClient.

// The PUT
var data = JsonClient.Put<BasicJson>("https://mywebsite.com/api/data", new { filter = true });

The SmtpClient class

It's a basic SMTP client that can submit messages to an SMTP server. It's very easy to configure and it provides a very handy way to make send email messages in your application.

SmtpClient API Doc

Example 1: Using System.Net.Mail.MailMessage

SmtpClient uses the classic System.Net.Mail.MailMessage provided by .NET to send emails asynchronously.

// Create a new smtp client using google's smtp server
var client = new SmtpClient("smtp.gmail.com", 587);

// Send an email 
client.SendMailAsync(new MailMessage("[email protected]", "[email protected]", "Subject", "Body"));

Example 2: Using a SMTP session state

// Create a new session state with a sender address
var session = new SmtpSessionState {SenderAddress = "[email protected]"};

// Add a recipient
session.Recipients.Add("[email protected]");

// Send
client.SendMailAsync(session);

Example 3: Adding an attachment with SMTP session state

When using SmtpSessionState you have to deal with raw data manipulation, in order to parse MIME attachments MimeKit is recommended.

// Create a new session state with a sender address
var session = new SmtpSessionState { SenderAddress = "[email protected]" };

// Add a recipient
session.Recipients.Add("[email protected]");

// load a file as an attachment
var attachment = new MimePart("image", "gif")
{
    Content = new MimeContent(File.OpenRead("meme.gif"), ContentEncoding.Default),
    ContentDisposition = new ContentDisposition(ContentDisposition.Attachment),
    ContentTransferEncoding = ContentEncoding.Base64,
    FileName = Path.GetFileName("meme.gif")
};


using (var memory = new MemoryStream())
{
    //Decode the attachment content
    attachment.Content.DecodeTo(memory);
    
    //Convert it into a byte array and add it to the session DataBuffer
    session.DataBuffer.AddRange(memory.ToArray());
}

// Send
client.SendMailAsync(session);

The ObjectMapper component

The ObjectMapper is a component to translate and copy property data from one type to another. You can access a default instance of ObjectMapper through the Runtime class.

ObjectMapper API Doc

Example 1: Mapping with default map

The conversion generates a map automatically between the properties in the base of the properties names.

// Here is mapping the specific user to a destination
var destination = Runtime.ObjectMapper.Map<UserDto>(user);

Example 2: Mapping with a custom map

With CreateMap you generate a new map and you can map one custom property with MapProperty.

// Creating an Object Mapper
var mapper = new ObjectMapper();
// Creating the map and mapping the property
mapper.CreateMap<User, UserDto>().MapProperty(d => d.Role, s => s.Role.Name);
// Then you map the custom map to a destination
var destination = mapper.Map<UserDto>(user);            

Example 3: Removing a property from the map

To remove a custom property, you also use CreateMap and then remove the custom property of the mapping.

// Create an Object Mapper
var mapper = new ObjectMapper();
// Creating a map and removing a property
mapper.CreateMap<User, UserDto>().RemoveMapProperty(t => t.Name);
// Then you map the custom map to a destination
var destination = mapper.Map<UserDto>(user);

The Network component

When you are working with projects related to network or you want to extend your application to use some network functionality the Swan's Network provides miscellaneous network utilities such as a Public IP finder, a DNS client to query DNS records of any kind, and an NTP client.

Network API Doc

Example 1: IPv4 and adapters information

It's always useful to have a tool that gives you access to your adapters information and your IP address local and public and use it in your application.

// Gets the active IPv4 interfaces.
var interfaces = Network.GetIPv4Interfaces();

// Retrieves the local IP addresses.
var address = Network.GetIPv4Addresses();

// Gets the public IP address using ipify.org.
var publicAddress = Network.GetPublicIPAddress();

Example 2: DNS and NTP

Also, you can use the Network utility to access the IPs of the DNS servers and the UTC from the NTP servers.

// Gets the configured IPv4 DNS servers for the active network interfaces.
var dnsServers = Network.GetIPv4DnsServers();

// Gets the DNS host entry (a list of IP addresses) for the domain name.
var dnsAddresses = Network.GetDnsHostEntry("google-public-dns-a.google.com");

// Gets the reverse lookup FQDN of the given IP Address.
var dnsPointer = Network.GetDnsPointerEntry(IPAddress.Parse("8.8.8.8"));

// Queries the DNS server for the specified record type.
var mxRecord = Network.QueryDns("google-public-dns-a.google.com", DnsRecordType.MX);

// Gets the UTC time by querying from an NTP server
var dateTime = Network.GetNetworkTimeUtc();

The ObjectComparer component

Many times, you need to compare the values inside of an object, array, struct or enum, to do so you need to implement your own code or iterate to find if the values are equals. With ObjectComparer you easily compare the properties. It represents a quick object comparer using the public properties of an object or the public members in a structure.

ObjectComparer API Doc

// Compare if two variables of the same type are equal.
ObjectComparer.AreEqual(first, second)

// Compare if two objects of the same type are equal. 
ObjectComparer.AreObjectsEqual(first, second);

// Compare if two structures of the same type are equal.
ObjectComparer.AreStructsEqual(first, second)

// Compare if two enumerables are equal.
ObjectComparer.AreEnumsEqual(first, second)

The ObjectValidator component

A simple object validator that allows you to set custom validations and identify if an object satisfies them.

ObjectValidator API Doc

ObjectValidationResult API Doc

Example 1: Simple object validation

Our Simple class to validate

  public class Simple
    {
        public string Name { get; set; }
    }

// create an instance of ObjectValidator
var obj = new ObjectValidator();

// Add a validation to the 'Simple' class with a custom error message
obj.AddValidator<Simple>(x => !string.IsNullOrEmpty(x.Name), "Name must not be empty");

// validate and return a boolean
var res = obj.IsValid(new Simple { Name = "Name" });

Example 2: Using Attributes

Both IsValid and Validate methods verify that the object satisfies all custom validators and/or attributes, but instead of just returning a boolean, Validate returns a ObjectValidatorResult which includes all the errors with their properties.

Our Simple class to validate

  public class Simple
    {
        [NotNull]
        public string Name { get; set; }
        
        [Range(1, 10)]
        public int Number { get; set; }
        
        [Email]
        public string Email { get; set; }
    }

This time we'll be using both custom validators and attributes

// using the Runtime's ObjectValidator singleton
Runtime.ObjectValidator.AddValidator<Simple>(x => !x.Name.Equals("Name"), "Name must not be 'Name'");
 
var res =  Runtime.ObjectValidator.Validate(new Simple{ Name = "name", Number = 5, Email ="[email protected]"})

Example 3: Using the extension method

In this example, we'll use the previous Sample class to validate an object using the built-in extension method which in turn uses the Runtime's ObjectValidator singleton to validate our object.

// using the Runtime's ObjectValidator singleton
Runtime.ObjectValidator.AddValidator<Simple>(x => !x.Name.Equals("Name"), "Name must not be 'Name'");

// using the extension method
var res = new Simple{ Name = "name", Number = 5, Email ="[email protected]"}.IsValid();

The DependencyContainer component

It's an easy to use IoC Inversion of Control Container of your classes and interfaces, you can register and associate your class with the interface that is going to use and then when you finish working with that you can unregister them. You can access a singleton instance of DependencyContainer called Current by DependencyContainer class.

DependencyContainer API Doc

Example 1: Basic Example

// Initialize a new instance of DependencyContainer
var container = new DependencyContainer();

// Creates/replaces a named container class registration with a given implementation and default options. 
container.Register<IAnimal, Cat>();

// Attempts to resolve a type using specified options.
var resolve = container.Resolve<IAnimal>();

// Remove a named container class registration.
container.Unregister<IAnimal>();            

Example 2: Using the DependencyContainer Current singleton

// Creates/replaces a named container class registration with a given implementation and default options. 
DependencyContainer.Current.Register<IAnimal, Dog>();

// Attempts to resolve a type using specified options.
var resolve = DependencyContainer.Current.Resolve<IAnimal>();

// Remove a named container class registration.
DependencyContainer.Current.Unregister<IAnimal>();    

Example 3: CanResolve

A very handy method to determine if a type can be resolved.

// Using CanResolve to check if type can be resolve
if (Runtime.Container.CanResolve<IAnimal>())
{
    // Attempts to resolve a type using specified options.
    Runtime.Container.Resolve<IAnimal>();
}

The MessageHub component

A simple Publisher-Subscriber pattern implementation. It's a good alternative when your application requires independent, long-running processes to communicate with each other without the need for events which can make code difficult to write and maintain.

MessageHub API Doc

In many scenarios you need a way to know when something happens to an object, there are usually two ways of achieving this: constantly checking the object's properties or using the pub-sub pattern. To avoid any problems caused by the former method like a possible modification of the object's properties it is a good practice to use the latter. With the pub-sub pattern, any object can "subscribe" to the publisher's publish event. When a message is "published" the event is triggered and the custom content of the message is sent. Neither the publisher nor the subscriber knows the existence of one another, therefore the publisher does not directly notify its subscribers, instead there is another component called MessageHub which is known by both(subscriber and publisher) and that filters all incoming messages and distributes them accordingly.

Example 1: Subscribing to a MessageHub

A simple example using the DependencyContainer discussed above. Keep in mind that in this example both the subscription and the message sending are done in the same place but this is only for explanatory purposes.

// use DependencyContainer to create an instance of MessageHub
 var messageHub = DependencyContainer.Current.Resolve<IMessageHub>() as MessageHub;
 
 // create an instance of the publisher class which has a string as its content
 var message = new MessageHubGenericMessage<string>(this, "SWAN");
 
 // subscribe to the publisher's event and just print its content which is a string 
 // a token is returned which can be used to unsubscribe later on
 var token = messageHub.Subscribe<MessageHubGenericMessage<string>>(m => m.Content.Info());
 
 //publish a message and SWAN should be printed on the console
 messageHub.Publish(message);
 
 // unsuscribe, we will no longer receive any messages 
 messageHub.Unsubscribe<MessageHubGenericMessage<string>>(token);

The LDAPConnection class

The LDAP Client was moved to a standalone assembly at SWAN LDAP.

The ProcessRunner class

A class that provides methods that helps us create external processes and capture their output.

ProcessRunner API Doc

Example 1: Running a process async

RunProcessAsync runs an external process asynchronously and returns the exit code. It provides error and success callbacks to capture binary data from the output and error stream.

// executes a process and returns the exit code
var result = await ProcessRunner.RunProcessAsync(
               // The path of the program to be executed
               "dotnet",
               //Parameters
               "--help",
               // A success callback with a reference to the output and the process itself
               (data, proc) =>
               {
               // If it executes correctly, print the output
                 Encoding.GetEncoding(0).GetString(data).WriteLine();
               },
               // An error callback with a reference to the error and the process itself
               (data, proc) =>
               {
               // If an error ocurred, print out the error
                   Encoding.GetEncoding(0).GetString(data).WriteLine();
               }
              );

Example 2: Getting a process output

If you are more concern about the output than the process itself, you can use GetProcessOutputAsync to get just a string containing either the output or the error text.

// Execute a process asynchronously and return either the ouput or the error
var data = await ProcessRunner.GetProcessOutputAsync("dotnet", "--help");

// Print the result
data.WriteLine();

Example 3: Getting a process result

If you don't want to deal with callbacks but you need more information after running an external process, you can use GetProcessResultAsync to get not just the output and error texts but also the exit code.

// Execute a process asynchronously and returns a ProcessResult object
var data = await ProcessRunner.GetProcessResultAsync("dotnet", "--help");

// Print out the exit code
$"{data.ExitCode}".WriteLine();

// The output
data.StandardOutput.WriteLine();

// And the error
data.StandardError.WriteLine();

Keep in mind that both GetProcessOutputAsync and GetProcessResultAsync are meant to be used for programs that output a relatively small amount of text

The ArgumentParser component

This component allows us to parse command line arguments and reconstruct those values into an object, making them much easier to manipulate.

ArgumentParser API Doc

Example 1: Using basic options

In order to parse arguments first, we need to create a class which the arguments will be parsed into using the ArgumentOption attribute.

In order to set an ArgumentOption, we need to supply at least a short name, a long name or both

  internal class Options
    {
        // This attribute maps a command line option to a property 
        // with 'v' as its short name and 'verbose' as its long name
        [ArgumentOption('v', "verbose", HelpText = "Set verbose mode.")]
        public bool Verbose { get; set; }
       
        [ArgumentOption('u', Required = true, HelpText = "Set user name.")]
        public string Username { get; set; }
    }

When a program is executed using a command line shell, the OS usually allows passing additional information provided along the program name. For instance example.exe -u user will execute example.exe and the additional text will be passed to it, making the additional arguments accessible to the program using the args parameter in the Main method.

// the variable args contains all the additional information(arguments)
// that were passed during the execution
static void Main(string[] args)
  {
    // create a new instance of the class that we want to parse the arguments into
    var options = new Options();

    // if everything went out fine the ParseArguments method will return true
    Runtime.ArgumentParser.ParseArguments(args, options);

  }

Example 2: Using an Array

In here the complete argument string will be split into an array using the separator provided.

internal class Options
  {   
      [ArgumentOption('n', "names", Separator=',', 
      Required = true, HelpText = "A list of names separated by a comma")]
      public string Names[] { get; set; }
  }

Example 3: Using an Enum

This maps the argument --color to an Enum which accepts any of the colors defined in ConsoleColor and sets Red as the default value.

internal class Options
  {        
      [ArgumentOption("color", DefaultValue = ConsoleColor.Red, HelpText = "Set a color.")]
      public ConsoleColor Color { get; set; }
  }

The SettingsProvider abstraction

It represents a provider that helps you save and load settings using plain JSON file.

SettingsProvider API Doc

Example 1: Loading and saving settings

Here we define a Settings class that contains all the properties we want.

internal class Settings 
    {
       public int Port { get; set; } = 9696;

       public string User { get; set; } = "User";    
    }

Once we define our settings we can access them using the Global property inside Instance.

//Get user from settings
var user = SettingsProvider<Settings>.Instance.Global.User;

 //Modify the port 
 SettingsProvider<Settings>.Instance.Global.Port = 20;
 
 //if we want those settings to persist
 SettingsProvider<Settings>.Instance.PersistGlobalSettings();

The Connection class

It represents a wrapper for TcpClient (a TCP network connection) either on the server or on the client. It provides access to the input and output network streams. It is capable of working in 2 modes.

Connection API Doc

ConnectionListener API Doc

Example 1: Creating an TCP server

When dealing with a connection on the server side, continuous reading must be enabled, thus deactivating Read methods. If these methods are used an invalid operation exception will be thrown. This example uses a ConnectionListener which is a TCP listener manager with built-in events and asynchronous functionality.

// create a new connection listener on a specific port
var connectionListener = new ConnectionListener(1337);

// handle the OnConnectionAccepting event
connectionListener.OnConnectionAccepted += (s, e) =>
{
// create a new connection with a blocksize of 6
    using (var con = new Connection(e.Client,6))
    {
      // an event which will be raised when data is received
        con.DataReceived += (o, y) =>
        {
            var response = Encoding.UTF8.GetChars(y.Buffer);
        };

      con.WriteLineAsync("world!").Wait();
    }                
};
connectionListener.Start();

Example 2: Creating an TCP client

Continuous reading is usually used on the server side so, you may want to disable them on the client side.

// create a new TcpCLient object
var client = new TcpClient();

// connect to a specific address and port
client.Connect("localhost",1337);

//create a new connection with specific encoding, new line sequence and continous reading disabled
using (var cn = new Connection(client, Encoding.UTF8, "\r\n", true, 0))
{
     await cn.WriteDataAsync(Encoding.UTF8.GetBytes("Hello "), true);
     var response = await cn.ReadTextAsync();
}

The DelayProvider component

A useful component that implements several delay mechanisms.

DelayProvider API Doc

Example 1: Creating a delay

// using the ThreadSleep strategy
using (var delay = new DelayProvider(DelayProvider.DelayStrategy.ThreadSleep))
 {
     // retrieve how much time we delayed
     var time = delay.WaitOne();
 }  

The WaitEventFactory component

WaitEventFactory provides a standard ManualResetEvent factory with a unified API. ManualResetEvent is a variation of AutoResetEvent that doesn't automatically reset after a thread is let through on a WaitOne call. Calling Set on a ManualResetEvent serves like an open gate allowing any number of threads that WaitOne pass throughCalling and Reset closes this gate. This type of event is usually used to signal that a certain operation has completed.

WaitEventFactory API Doc

Example 1: Using the WaitEventFactory

// creates a WaitEvent using the slim version of ManualResetEvent
private static readonly IWaitEvent waitEvent = WaitEventFactory.CreateSlim(false);

static void Main()
{
 // start two tasks
    Task.Factory.StartNew(() =>
    {
        Work(1);
    });

    Task.Factory.StartNew(() =>
    {
        Work(2);
    });

    //Send first signal to retrieve data
    waitEvent.Complete();
    waitEvent.Begin();

    Thread.Sleep(TimeSpan.FromSeconds(2));

    // Send second signal
    waitEvent.Complete();

    Console.ReadLine();
}

static void Work(int taskNumber)
 {
     $"Data retrieved:{taskNumber}".WriteLine();
     waitEvent.Wait();

     Thread.Sleep(TimeSpan.FromSeconds(2));
     $"All finished up {taskNumber}".WriteLine();
 }

Atomic types

Atomic operations are indivisible which means that they cannot interrupted partway through. SWAN provides Atomic types which include mechanisms to perform these kinds of operations on Built-In types like: bool, long, and double. This is quite useful in situations where we have to deal with lots of threads performing writes on variables because we can assure that threads will not interrupt each other in the middle of an operation and perform a torn write.

AtomicBoolean API Doc

AtomicLong API Doc

AtomicDouble API Doc

Running Unit Tests

If you want to run the .NET Unit test project, you may need to start some services. These services are Javascript files and you need NodeJS to execute them. I know why Javascript files for a .NET project, but it's the easy way to start up some network services, anyway PR with .NET Core services are welcome.

Before running them, please execute npm install. This command will install all the required dependencies to start the network services.

The following files, located in the root folder, should be run in any order before start running unit tests:

• ./mail.js - This script will mount a SMTP server, this service is required to run SmtpClient tests.
• ./web.js - This script will provide a web server responding JSON files for JsonClient tests.
• ./tcp.js - This script will open a basic TCP Socket for TcpConnection tests.
• ./ntp.js - This script will mount a NTP server for general Network methods.

You can also check the CI files (Travis and AppVeyor for details how to run them.