use chrono::Utc;
use parking_lot::Mutex;
use std::sync::Arc;
#[derive(Debug)]
pub struct Snowflake {
epoch: i64,
worker_id: i64,
datacenter_id: i64,
sequence: i64,
time: Arc<Mutex<i64>>,
}
impl Default for Snowflake {
fn default() -> Snowflake {
Snowflake {
epoch: 1_573_948_800,
worker_id: 1,
datacenter_id: 1,
sequence: 0,
time: Arc::new(Mutex::new(0)),
}
}
}
impl Snowflake {
pub fn new(epoch: i64, worker_id: i64, datacenter_id: i64) -> Snowflake {
Self {
epoch,
worker_id,
datacenter_id,
..Default::default()
}
}
pub fn generate(&mut self) -> i64 {
let mut last_timestamp = self.time.lock();
let mut timestamp = self.get_time();
if timestamp == *last_timestamp {
self.sequence = (self.sequence + 1) & (-1 ^ (-1 << 12));
if self.sequence == 0 && timestamp <= *last_timestamp {
timestamp = self.get_time();
}
} else {
self.sequence = 0;
}
*last_timestamp = timestamp;
(timestamp << 22) | (self.worker_id << 17) | (self.datacenter_id << 12) | self.sequence
}
pub fn generate_u8_u64(&mut self) -> [u8; 8] {
self.generate().to_le_bytes()
}
fn get_time(&self) -> i64 {
Utc::now().timestamp_millis() - self.epoch
}
}