WebAssembly (WASM) is a cutting-edge technology that brings high-performance applications to web pages by executing native code. It's an open standard that's supported by all major web browsers. WASM allows data-intensive applications like 3D graphics, video decoding, or physics simulation to run at near-native speed. For senior engineers like you with ample web development experience, this can be an indispensable tool to streamline and enhance your applications.

Let's take an analogy to understand it better. Imagine you're working on designing an interactive and highly dynamic web application related to basketball matches, which needs real-time statistical analysis of players' performance. Now, you want your application to perform these complex calculations quickly and efficiently. Here is where WASM comes into play. It facilitates the deployment of high-performance C++ (or any other language) modules in your JavaScript environment. Just like Kobe Bryant can add an edge to any basketball team with his quick decisions and spot-on throws, WASM adds an edge to your web application with increased execution speed and performance.

Technically, WASM is a binary instruction format, with a corresponding textual assembly language. It acts as a compilation target for languages like C++, allowing developers to run C++ code snippets directly in a JavaScript environment. The sample C++ code snippet you see in the code field contains a skeleton where WebAssembly would be used to accomplish such tasks.

In the upcoming screens, we will dive deeper into the world of WASM, exploring its many facets and learning about how to leverage it to supercharge web applications.

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#include <iostream>

using namespace std;

int main() {

// Code to use WebAssembly in C++ by importing <emscripten/val.h>

​

}

WebAssembly, abbreviated as wasm, is a powerful technology that has opened up an entirely new universe of possibilities for web developers. It is a binary instruction format designed as a stack-based virtual machine. The principal target of WebAssembly is the execution in a web browser, allowing high-performance applications on web pages, but it does not make any web-specific assumptions or provide web-specific features, hence can be employed in other environments as well.

Imagine you're a seasoned web developer, proficient in JavaScript and you want to create a web app that not only scales well performance-wise, but also has the capabilities to run C++ code. Maybe you're working on a highly optimized gaming engine or an elaborate design tool that would benefit from the raw power and efficiency of C++. Traditionally, running such native code cleanly and efficiently within a browser would be a major challenge. This is where WebAssembly comes in: it equips developers with the power to run native code for web applications straight in the browser.

When it comes to importance of wasm, consider it as an advanced coding advertisement strategy to target potential customers with high-performance applications. The user experience is noticeably more premium with wasm because instead of getting stuck with frustrating load times or choppy performance, the app runs smoothly and efficiently. This is code compilation at its best: compile your C++ once, run it as efficient binary code anywhere.

In summary, in this age of web development, knowing WebAssembly can significantly improve your coding game, and give your applications the competitive performance edge they need before hitting the market.

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#include <iostream>

using namespace std;

int main() {

  // no specific c++ logic for this introduction screen

}

Our previous exploration of WebAssembly (Wasm) helped us understand its immense impact on web development. Now, we delve into a central aspect of working with Wasm: Compiling C++ code into wasm modules. This might initially seem daunting, especially if you're not very familiar with C++, but worry not! We're walking you through every step.

C++ is a general-purpose programming language formed as an extension of the C language with additional features such as classes, which aid in supporting the object-oriented programming concept. The aspect of interest here is that C++ has robust low-level capabilities, making it a good candidate for conversion into Wasm bytecode.

Wasm modules are units of Wasm code that encapsulate your compiled C++ functionalities, ready to be executed in the browser. Transition from C++ to Wasm isn't plain sailing, but isn't an uphill climb either. It entails a systematic process of installing the right tooling, writing some C++ code, and following through with the correct compilation commands.

Fret not if this seems overwhelming. As we move forward, you'll get a hands-on understanding of this process, ensuring you're well equipped to compile your own C++ code into wasm modules. Remember, the aim is to leverage the benefits of efficient, powerful low-level C++ code in the high-level web environment!

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#include <iostream>

using namespace std;

int main() {

  cout << "Executing your first wasm module generated from C++ code.";

  return 0;

}

To create a WebAssembly module, we must first have some C++ code that we wish to utilize within our web application. Let's take as an example a simple C++ function that sums two integers. This function could potentially be part of a much larger and complex system, for instance, the performance evaluation system of a fantasy basketball platform.

Unlike JavaScript, which executes within the browser, C++ code must undergo a compilation process to transform it into a format understandable by the computer. Our simple C++ code is written in high-level language syntax that's easy for humans to understand. However, computers require a low-level language for execution, and we use a C++ compiler to translate our high-level code into machine code. With WebAssembly, we perform a similar process, but instead of creating machine code, we compile our C++ code into WebAssembly, or WASM, modules.

Now, how does this apply to a web application? Consider our fantasy basketball platform, where real-time calculations and large data handling can be a regular operation. Utilizing C++ code to perform some of these heavy operations could bring significant performance improvements due to the efficient low-level operations that C++ offers. These software modules, initially written in C++, can efficiently manage these data-intensive tasks when compiled into WASM modules.

Take a look at the simple C++ function in the code field. It sums two integers and outputs the result. The process to compile this function into a WASM module will be explored in the following screens.

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#include <iostream>

using namespace std;

int main() {

  // A simple C++ function

  int x = 10;

  int y = 20;

  int sum = x + y;

  cout << "Sum: " << sum;

  return 0;

}

In our previous sections, we have familiarized ourselves with WebAssembly (Wasm) and have seen how to compile C++ into wasm modules. Now let's delve deeper into the core concepts of Wasm that include elements like memory management, stack machine, and linear memory.

1. Memory Management: WebAssembly deals with two types of memory: Stack and Heap. The stack is used primarily for storing function call information and local variables, whereas heap is used to store global variables, and for dynamically allocated memory. Remember, Wasm memory is linear and byte-addressable, starting from an index 0.

2. Stack Machine: WebAssembly is based on a stack machine concept. This means computations are based on a stack where operands are pushed onto the stack, and operations like addition and multiplication pop their operands from the stack and push the results back to the stack.

3. Linear Memory: Wasm uses a large contiguous memory array, also known as linear memory. It can be grown dynamically but cannot be shrunk. The memory is shared between all the functions within a Wasm module and can also be accessed and manipulated from JavaScript.

Understanding these core concepts is fundamental to mastering WebAssembly. The stack and linear memory form the backbone of Wasm's execution, while memory management is crucial to efficient and secure operations.

Now, let us dive into some of the low-level details of WebAssembly. Remember, our ultimate goal is to compile our C++ code into a WASM module and call its functions from JavaScript to evaluate its impacts on the performance of your web applications, like our hypothetical fantasy basketball platform.

When we talk about the low-level ebb and flow of WebAssembly, we aim to understand intimately how it functions with respect to its linear memory, control flow, machine types, etc. Understanding these details is akin to knowing your star player's play style, their strengths, and weaknesses in a basketball game. Armed with this knowledge, it provides you, as the coach or the software developer, a clear vantage point to strategize and optimize for performance. It is the cornerstone for maximizing your web application's efficiency and user experience.

For example, DID YOU KNOW? WebAssembly computation is based on a stack machine. Code is organized into individual functions and these functions manipulate values on an implicit operand stack, popping argument values, and pushing result values. A key detail to understand about these operations is that they have 'deterministic semantics.' In other words, operations should yield the same result regardless of the underlying hardware. This deterministic nature ensures consistent performance across different platforms and devices—Think of it as ensuring your star player will be consistent across different basketball courts.

Enhancing our understanding of these low-level dynamics is half the battle in mastering WebAssembly. To aid in your learning, we'll look at a basic C++ snippet provided in the code field, which will be later translated into WebAssembly code. We'll continue unfolding the complexities and intricacies of WebAssembly in upcoming lessons.

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#include <iostream>

using namespace std;

int main() {

  // This is a simple C++ program

  int x = 10;

  int y = 20;

  int result = x + y; 

  cout << "The sum of x and y is: " << result << endl; 

  return 0;

}

In this section, we'll explore the essentials of executing WASM functions directly from our JavaScript code, a crucial aspect when integrating WebAssembly with modern web applications. This will be similar to a basketball coach directly engaging with their star player and implementing game strategies in real-time.

Just as we've compiled our C++ code into WebAssembly modules, we can leverage these modules in our application by loading them into JavaScript. The WebAssembly JavaScript API provides a method called 'WebAssembly.instantiateStreaming()'. This function fetches and compiles a WASM binary and returns a promise that resolves into a 'WebAssembly.instance' object. This object represents an instance of our WASM module and allows us to call the exported WASM functions.

However, we must ensure that we understand the types and number of arguments and the return type of the WASM function that we are about to invoke. The thing to note about WebAssembly and its interface with JavaScript is that currently WASM only understands numerical types which include integers and floating-point values.

Consider a WebAssembly module that exports a function 'add' which takes two integers as arguments and returns an integer. This function can be invoked directly once the WASM module is instantiated, as shown in the code snippet below.

In our upcoming lessons, we'll dive into more complex scenarios like exchanging string and array data between JavaScript and WebAssembly, and handling WebAssembly memory manually. Stay tuned!

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#include <iostream>

using namespace std;

extern "C" int add(int a, int b) {

  return a + b;

}

int main() {

  cout << "WebAssembly module ready" << endl;

}

As a senior engineer, let's deep dive into the practical application of WebAssembly through creating a simple wasm module using C++. Using our C++ skills, we focus on compiling a very simple 'Hello, World!' program into a wasm module.

Step 1: Let's start by writing our 'Hello, World!' program in C++. This program will simply print 'Hello, World!' to the console.

Step 2: Next, you need to compile the C++ code into wasm using Emscripten. Install the Emscripten SDK if you haven't already using the package manager of your choice.

Step 3: Open the terminal, navigate to the directory of the code, and run the Emscripten command to compile the C++ code to wasm.

Step 4: If successful, the compilation will create a wasm file. This is your wasm module.

Tip: It's important to note that this simple example is just scratching the surface. Being able to compile complex C++ programs into wasm modules will unlock the true power of WebAssembly in delivering high-performance web-applications.

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#include <iostream>

using namespace std;

int main() {

  cout << "Hello, World!" << endl;

  return 0;

}

In the previous sections, we've learned to compile and call WASM functions from JavaScript. Inevitably, there will come a time during your WebAssembly journey when you'll encounter bugs and issues within your WASM modules. Think of it as that moment during an intense basketball game when the coach needs to track metrics and analyze the player's performance to adjust the game plan.

To facilitate this, modern browsers have implemented features within their developer tools to allow debugging of WebAssembly code much in the same way you'd debug JavaScript. For instance, you can see functions, variables, and even step though the WASM code in the debugger.

However, to get a readable version of WASM code, it's important to have a source map. This is much like having a match playbook in a basketball game. Without it, WASM code is displayed in its low-level format, which can be harder to navigate than the original C++ code.

Remember, debugging requires two key elements: the debug information and source map; both of which should have been created during the build process of your project. For existing projects, you might need to adjust the build settings to produce these.

Here's an example of how this works:

By switching to the Sources panel in the Chrome developer tools and navigating to our loaded WASM module, we can then set breakpoints and step through our code. The debugger will halt on our breakpoint and we can inspect variables and the call stack. Note that how modules appear can depend on your project structure.

Debugging WebAssembly becomes like any other debugging session in JavaScript, though there are some limitations due to the difference between JavaScript and WASM, such as differences in handling of types and memory.

In conclusion, debugging WASM is a pivotal skill any WASM developer needs. Now, with the tools modern browsers provide, this task is straightforward and integrated into your current development workflow.

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// There's no specific code for this section but keep in "mind" to enable debugging options while compiling your C++ to WASM

To call WebAssembly functions from JavaScript, the WebAssembly JavaScript API makes it pretty straightforward.

The API exposes a few objects in the global namespace, such as WebAssembly.Module, WebAssembly.Instance, and WebAssembly.Memory. Here's how you can use them:

Step 1: Load your WebAssembly module. You can use JavaScript's fetch API to load your module and convert it into an ArrayBuffer.

Step 2: Convert the module into a WebAssembly.Module. Use the WebAssembly.Module constructor for this.

Step 3: Create an instance of your module. The WebAssembly.Instance constructor takes a module and optionally a set of imports.

Step 4: Call your function. The exports property of your instance contains your WebAssembly functions, now callable as JavaScript functions.

This technique of calling wasm functions from JavaScript is useful as it brings the computational speed of WebAssembly into JavaScript apps. However, interoperation between JS and wasm can sometimes lead to overhead, and debugging is more complicated since you're stepping into the WebAssembly world from the JavaScript land. That's all about calling wasm functions from JavaScript!

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#include <iostream>

using namespace std;

int main() {

  // Call from JS:

  // const wasmModule = await WebAssembly.instantiateStreaming(fetch('hello.wasm'), {});

  // wasmModule.instance.exports._Z5hellov();

  cout << 'Hello, JavaScript!';

}

Debugging is an essential part of any development process, and WebAssembly (wasm) is no different. While working with wasm modules, you might face scenarios where the wasm functions are not working as expected or causing unexpected behaviour in the web application. This is where the skill of debugging wasm modules around 'Computer science, coding, product design, marketing' comes into play.

While debugging wasm modules, effective tools to use are the debugging capabilities of modern browsers. Both Firefox and Chrome provide excellent developer tools for debugging wasm modules.

When compiling your C++ code to wasm, make sure to include the -g flag. This flag generates source map information which is crucial for debugging. Here's an example of how to do that:

1emcc -g -o function.wasm function.cpp

With the -g flag, the source maps allow you to debug your wasm code at the language-level (C/C++), rather than the wasm instruction level. So, you'll be able to see exactly which C++ line caused the issue.

Browsers have developer tools that let you load wasm source code, set breakpoints, and observe variable values during runtime. For example, in Chrome, the Developer Tools Javascript debugger can seamlessly step into a C++ function called from Javascript!

However, keep in mind that debugging is only a part of the whole experience of working with wasm. A deep understanding of the wasm architecture, memory management, and function calls will be crucial in not just identifying the problems but also in devising efficient solutions.

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cpp

​

#include <iostream>

using namespace std;

​

// replace with your c++ logic here

​

int main() {

  // This is where your C++ logic will go. Implementing logic relevant to

  // 'Computer science', 'coding', 'product design', or 'marketing' will quite help

  // to make the debugging process more engaging & relatable for you.

  // don't forget to compile with `-g` flag for helpful debugging information.

  return 0;

}

We have traversed through the low-level guts of WebAssembly, compiled C++ code into WASM modules, debugged them, and then called those functions from JavaScript. It's time to bring all these aspects together and look at an end-to-end example of a practical application.

Let's assume we are building a real-time basketball game analytics web application where we need high-speed computations done on every move of a player in an ongoing game. The application needs to analyze moves in real-time and suggest strategies to coaches. The computational intensity of this task can bog down JavaScript performance.

Given our good understanding of C++, we can write the core algorithms as C++ code and compile that to WebAssembly. Let's see a very basic use case. We are writing a simple C++ program, compiling it to WASM, and then using it in a web page.

Here is the basic C++ code that we want to compile to WASM:

1#include <iostream>
2using namespace std;
3int main() {
4  // This will output to the browser console
5  std::cout << "Hello World!"
6}

This C++ code, when written into a .cpp file, can be compiled using Emscripten into a WASM module. This module can be imported into your JavaScript application and its functions can then be called directly from JavaScript.

This example is a simple case, and in a real application, the C++ code would be far more complex. However, the process remains the same. Compile the C++ code into a WASM module, import it into your JavaScript application, and then call the WASM functions from JavaScript. This means you can use WASM to speed up any computations done by your web application while also being able to use the web technologies you are familiar with for designing the UI/UX.

This way, WebAssembly, JavaScript, and C++ come together to form a web application that is both user-friendly and performance-optimized.

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#include <iostream>

using namespace std;

int main() {

  // This will output to the browser console

  std::cout << "Hello World!"

}

In this part, we're going to construct a simple web application using our knowledge of JavaScript and wasm modules. We start from the C++ side, creating a simple module that exports a function triple, which triples an input number. This function will then be compiled to a wasm module and used in our web app. Here is the C++ code:

1#include <iostream>
2using namespace std;
3
4extern "C" {
5  int triple(int x) {
6    return x * 3;
7  }
8}
9
10int main() {
11  return 0;
12}

We export the triple function by enclosing it within extern "C" which prevents C++ name mangling and makes it recognizable in the wasm module as is. With this module, we can now offer functionality to the users of our web app that efficiently multiplies a number by three, which provides a foundational step in integrating more complex functionality in future applications.

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#include <iostream>

using namespace std;

​

extern "C" {

  int triple(int x) {

    return x * 3;

  }

}

​

int main() {

  return 0;

}

Conclusion and Recap

Throughout this course, we deep dived into the world of WebAssembly (wasm) and examined its benefits and real-world applications.

We began by understanding the basics of WebAssembly, its importance, and the problems it solves in the world of web development. We explored how WebAssembly provides a way to run code written in multiple languages on the web at near-native speed, with a focus on compactness, efficiency, and modularity.

In the subsequent sections, we introduced C++ and its compilation to wasm modules. We learned how to compile C++ code into WebAssembly modules using tools like Emscripten and LLVM.

Digging deeper, we got a handle on core WebAssembly concepts such as memory, stack, and linear memory. This knowledge prepared us for the practical aspects of working with wasm.

We learned how to create simple wasm modules using C++, compile them, and call the WebAssembly functions from JavaScript. This made us realize the utility of using WebAssembly in web applications, especially for compute-intensive tasks.

Finally, we delved into debugging wasm modules, understanding how to inspect and step through the wasm code using browser dev tools. In the end, we built a simple web application incorporating all our learnings.

Hope you find this course helpful in enhancing your web development skills and look forward to seeing you use the WebAssembly to supercharge your applications. Keep coding and exploring!