use parking_lot::Mutex;
use std::collections::HashMap;
use std::net::{SocketAddr, TcpListener};
use std::sync::Arc;
use anyhow::{anyhow, Result};
use lazy_static::lazy_static;
lazy_static! {
pub static ref GLOBAL_PORT_ALLOCATOR: PortAllocator = PortAllocator::new();
}
#[derive(Debug)]
pub struct PortAllocator {
allocated_ports: Arc<Mutex<HashMap<String, u16>>>,
port_range: (u16, u16),
}
impl PortAllocator {
pub fn new() -> Self {
Self {
allocated_ports: Arc::new(Mutex::new(HashMap::new())),
port_range: (11435, 65535), }
}
pub fn find_available_port(&self, service_name: &str) -> Result<u16> {
let mut allocated = self.allocated_ports.lock();
if let Some(&existing_port) = allocated.get(service_name) {
if self.is_port_available(existing_port) {
return Ok(existing_port);
} else {
allocated.remove(service_name);
}
}
for port in self.port_range.0..=self.port_range.1 {
if self.is_port_available(port) {
allocated.insert(service_name.to_string(), port);
return Ok(port);
}
}
Err(anyhow!("No available ports in range {}..{}", self.port_range.0, self.port_range.1))
}
#[allow(dead_code)]
pub fn allocate_ephemeral_port(&self, service_name: &str) -> Result<u16> {
let mut allocated = self.allocated_ports.lock();
let port = self.find_ephemeral_port()?;
allocated.insert(service_name.to_string(), port);
Ok(port)
}
#[allow(dead_code)]
pub fn release_port(&self, port: u16) {
let mut allocated = self.allocated_ports.lock();
allocated.retain(|_, &mut v| v != port);
}
fn is_port_available(&self, port: u16) -> bool {
match TcpListener::bind(SocketAddr::from(([127, 0, 0, 1], port))) {
Ok(_) => true,
Err(_) => false,
}
}
#[allow(dead_code)]
fn find_ephemeral_port(&self) -> Result<u16> {
let listener = TcpListener::bind("127.0.0.1:0")?;
let port = listener.local_addr()?.port();
drop(listener); Ok(port)
}
#[allow(dead_code)]
pub fn get_allocated_ports(&self) -> HashMap<String, u16> {
self.allocated_ports.lock().clone()
}
}
impl Default for PortAllocator {
fn default() -> Self {
Self::new()
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_port_allocation() {
let allocator = PortAllocator::new();
let port1 = allocator.allocate_ephemeral_port("test1").unwrap();
let port2 = allocator.allocate_ephemeral_port("test2").unwrap();
assert_ne!(port1, port2);
allocator.release_port(port1);
allocator.release_port(port2);
}
#[test]
fn test_find_available_port() {
let allocator = PortAllocator::new();
let port = allocator.find_available_port("test-service").unwrap();
assert!(port >= 11435);
let port2 = allocator.find_available_port("test-service").unwrap();
assert_eq!(port, port2);
allocator.release_port(port);
}
}