PHP is a popular server-side scripting language that is widely used for web development. However, there are situations where PHP might not be the best tool for the job, especially when it comes to performance-intensive tasks. In such cases, it might be a good idea to use a different programming language, like Golang. But how do you use Golang code in PHP? The answer is through FFI.

FFI stands for Foreign Function Interface, and it is a feature in PHP that allows you to call functions in shared libraries or other programming languages. This means that you can write performance-critical code in a language like Golang and call it from PHP using FFI.

Here is a step-by-step guide on how to use FFI in PHP with Golang:

Write your Golang code Let's say you want to write a function in Golang that adds two numbers. Here's what the code would look like:

package main

import "C"

//export add
func add(a, b int) int {
    return a + b
}

func main() {}

This code defines a function called "add" that takes two integers as arguments and returns their sum.

Compile your Golang code To use the Golang code in PHP, you need to compile it into a shared library. You can do this by running the following command:

go build -o libadd.so -buildmode=c-shared add.go

This will create a shared library called "libadd.so" that contains your Golang code.

Write your PHP code Now that you have your Golang code compiled into a shared library, you can use FFI to call the "add" function from PHP. Here's what the PHP code would look like:

$ffi = FFI::cdef("
    int add(int a, int b);
", "libadd.so");

echo $ffi->add(2, 3);

This code uses the FFI extension in PHP to define a function called "add" that takes two integers as arguments and returns an integer. The second argument to the cdef function is the name of the shared library that contains the Golang code.

Run your PHP code To run your PHP code, you need to make sure that the shared library containing the Golang code is in the correct location. You can do this by adding the following line to your PHP code:

ini_set("ffi.load_library", "/path/to/libadd.so");

Replace "/path/to/libadd.so" with the actual path to your shared library.

Now you can run your PHP code and it should output "5", which is the result of adding 2 and 3 using the Golang code.

In conclusion, FFI is a powerful feature in PHP that allows you to call functions in shared libraries or other programming languages. By using FFI with Golang, you can write performance-critical code in Golang and call it from PHP. This can help you improve the performance of your PHP applications without having to rewrite everything in a different language.