refactor: port div_ceil from rust stdlib

Author: sunng87

src/common/time/src/timestamp.rs

@@ -26,6 +26,7 @@ use snafu::{OptionExt, ResultExt};
 
 use crate::error;
 use crate::error::{ArithmeticOverflowSnafu, Error, ParseTimestampSnafu, TimestampOverflowSnafu};
+use crate::util::div_ceil;
 
 #[derive(Debug, Clone, Default, Copy, Serialize, Deserialize)]
 pub struct Timestamp {
@@ -143,8 +144,7 @@ impl Timestamp {
             Some(Timestamp::new(value, unit))
         } else {
             let mul = unit.factor() / self.unit().factor();
-            let new_ts = self.value as f64 / mul as f64;
-            Some(Timestamp::new(new_ts.ceil() as i64, unit))
+            Some(Timestamp::new(div_ceil(self.value, mul as i64), unit))
         }
     }
 

src/common/time/src/util.rs

@@ -17,6 +17,17 @@ pub fn current_time_millis() -> i64 {
     chrono::Utc::now().timestamp_millis()
 }
 
+/// Port of rust unstable features `int_roundings`.
+pub(crate) fn div_ceil(this: i64, rhs: i64) -> i64 {
+    let d = this / rhs;
+    let r = this % rhs;
+    if r > 0 && rhs > 0 {
+        d + 1
+    } else {
+        d
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use std::time::{self, SystemTime};