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use std::time::{SystemTime, UNIX_EPOCH};
#[derive(Copy, Clone)]
pub struct SnowflakeIdGenerator {
machine_id: u32,
idx: u64,
}
impl SnowflakeIdGenerator {
pub fn new(machine_id: u32) -> SnowflakeIdGenerator {
SnowflakeIdGenerator {
machine_id: machine_id,
idx: 0,
}
}
pub fn generate(&mut self) -> i64 {
self.idx = self.idx + 1;
let millis = SystemTime::now()
.duration_since(UNIX_EPOCH)
.expect("Time went mackward")
.as_millis();
(millis << 22) as i64 | ((self.machine_id << 12) as i64) | (self.idx as i64)
}
}
#[cfg(test)]
mod test {
use super::SnowflakeIdGenerator;
#[test]
fn test_generate() {
let mut idgen = SnowflakeIdGenerator::new(1);
let mut ids = vec![];
for _ in 0..10 {
ids.push(idgen.generate());
}
for id in ids {
println!("id: {}", id);
assert!(format!("{}", id).len() >= 18);
}
}
}