plumber-rs

This is the Rust library that provides the connection between Plumber Dataflow Framework and the Rust Programming language.

With this library, the servlet can be written in Rust programming language. Unlike C and C++, the Rust servlet needs a runtime environment, which can be setup with the Rust Servlet Loader language/rust.

How to build a Rust servlet

With Cargo you should be able to create a servlet with Rust quite easily.

Step 1 you should create a library crate with cargo

cargo init hello-rust --lib

Step 2 we should change the Cargo.toml.

We need to make sure the cargo can produce a dynamic library that can be loaded by Plumber Rust Servlet Loader. Also, we need to add some depdendencies to the crate.

[lib]
name = "hello-rust"
crate-type= ["cdylib"]

[dependencies]
libc="0.2.0"
plumber-rs = {git = "https://github.com/38/plumber-rs.git"}

Step 3 Create the servlet object.

In Rust, a servlet is actually a trait. For the sync servlet, we can implemnet the trait plumber_rs::servlet::sync_servlet.

use plumber_rs::servlet::{SyncServlet, Unimplemented, ServletMode, ServletFuncResult, Bootstrap};

struct HelloServlet {}

impl SyncServlet for HelloServlet {
    fn init(&mut self, _args:&[&str]) -> ServletFuncResult 
    {
        plumber_log!(N "Hello World");
        return Ok(());
    }
    fn exec(&mut self) -> ServletFuncResult  { Ok(()) }
    fn cleanup(&mut self) -> ServletFuncResult { Ok(()) }
}

Step 4 Create the bootstrap type and export the entry point

struct BootstrapType{}

impl Bootstrap for BootstrapType {
    type SyncServletType = HelloServlet;
    type AsyncServletType = Unimplemented;
    fn get(_args:&[&str]) -> Result<ServletMode<Unimplemented, HelloServlet>, ()>
    {
        return Ok(ServletMode::SyncMode(HelloServlet{}));
    }
}

export_bootstrap!(BootstrapType);

Step 5 Build the servlet

To build the servlet you should export two environment variable PSTD_LIB_PATH which is the path for libpstd.

And to build the servlet, you can simple run cargo build

export PSTD_LIB_PATH="/usr/lib"
cargo build

Full Servlet Code

#[macro_use]
extern crate plumber_rs;
extern crate libc;

use plumber_rs::servlet::{SyncServlet, Unimplemented, ServletMode, ServletFuncResult, Bootstrap};

struct HelloServlet {}

impl SyncServlet for HelloServlet {
    fn init(&mut self, _args:&[&str]) -> ServletFuncResult 
    {
        plumber_log!(N "Hello World");
        return Ok(());
    }
    fn exec(&mut self) -> ServletFuncResult  { Ok(()) }
    fn cleanup(&mut self) -> ServletFuncResult { Ok(()) }
}

struct BootstrapType{}

impl Bootstrap for BootstrapType {
    type SyncServletType = HelloServlet;
    type AsyncServletType = Unimplemented;
    fn get(_args:&[&str]) -> Result<ServletMode<Unimplemented, HelloServlet>, ()>
    {
        return Ok(ServletMode::SyncMode(HelloServlet{}));
    }
}

export_bootstrap!(BootstrapType);