From 7e79753478255a67313d0d39560e742ddef7b218 Mon Sep 17 00:00:00 2001
From: QuenKar <47681251+QuenKar@users.noreply.github.com>
Date: Thu, 14 Sep 2023 22:18:24 +0800
Subject: [PATCH] refactor code.

---
 src/common/time/src/date.rs               |  4 +++
 src/common/time/src/time.rs               | 13 ++++++++
 src/datatypes/src/types/date_type.rs      |  5 +--
 src/datatypes/src/types/datetime_type.rs  |  5 +--
 src/datatypes/src/types/primitive_type.rs | 18 +++--------
 src/datatypes/src/types/time_type.rs      | 17 +++++++++-
 src/datatypes/src/types/timestamp_type.rs | 39 +++++++++++++----------
 7 files changed, 61 insertions(+), 40 deletions(-)

diff --git a/src/common/time/src/date.rs b/src/common/time/src/date.rs
index e9b1d76246c7..021085f06013 100644
--- a/src/common/time/src/date.rs
+++ b/src/common/time/src/date.rs
@@ -82,6 +82,10 @@ impl Date {
     pub fn to_chrono_date(&self) -> Option<NaiveDate> {
         NaiveDate::from_num_days_from_ce_opt(UNIX_EPOCH_FROM_CE + self.0)
     }
+
+    pub fn to_secs(&self) -> i64 {
+        self.0 as i64 * 24 * 3600
+    }
 }
 
 #[cfg(test)]
diff --git a/src/common/time/src/time.rs b/src/common/time/src/time.rs
index 7400e22c0fe5..197353501fbc 100644
--- a/src/common/time/src/time.rs
+++ b/src/common/time/src/time.rs
@@ -77,6 +77,19 @@ impl Time {
         self.value
     }
 
+    /// Convert a timestamp to given time unit.
+    /// Return `None` if conversion causes overflow.
+    pub fn convert_to(&self, unit: TimeUnit) -> Option<Time> {
+        if self.unit().factor() >= unit.factor() {
+            let mul = self.unit().factor() / unit.factor();
+            let value = self.value.checked_mul(mul as i64)?;
+            Some(Time::new(value, unit))
+        } else {
+            let mul = unit.factor() / self.unit().factor();
+            Some(Time::new(self.value.div_euclid(mul as i64), unit))
+        }
+    }
+
     /// Split a [Time] into seconds part and nanoseconds part.
     /// Notice the seconds part of split result is always rounded down to floor.
     fn split(&self) -> (i64, u32) {
diff --git a/src/datatypes/src/types/date_type.rs b/src/datatypes/src/types/date_type.rs
index 2451850170ba..f109fdf11c9b 100644
--- a/src/datatypes/src/types/date_type.rs
+++ b/src/datatypes/src/types/date_type.rs
@@ -59,10 +59,7 @@ impl DataType for DateType {
     fn cast(&self, from: Value) -> Option<Value> {
         match from {
             Value::Int32(v) => Some(Value::Date(Date::from(v))),
-            Value::String(v) => match Date::from_str(v.as_utf8()) {
-                Ok(d) => Some(Value::Date(d)),
-                Err(_) => None,
-            },
+            Value::String(v) => Date::from_str(v.as_utf8()).map(Value::Date).ok(),
             Value::Timestamp(v) => v.to_chrono_date().map(|date| Value::Date(date.into())),
             _ => None,
         }
diff --git a/src/datatypes/src/types/datetime_type.rs b/src/datatypes/src/types/datetime_type.rs
index 124c81a331c6..9710566807a2 100644
--- a/src/datatypes/src/types/datetime_type.rs
+++ b/src/datatypes/src/types/datetime_type.rs
@@ -58,10 +58,7 @@ impl DataType for DateTimeType {
         match from {
             Value::Int64(v) => Some(Value::DateTime(DateTime::from(v))),
             Value::Timestamp(v) => v.to_chrono_datetime().map(|d| Value::DateTime(d.into())),
-            Value::String(v) => match DateTime::from_str(v.as_utf8()) {
-                Ok(d) => Some(Value::DateTime(d)),
-                Err(_) => None,
-            },
+            Value::String(v) => DateTime::from_str(v.as_utf8()).map(Value::DateTime).ok(),
             _ => None,
         }
     }
diff --git a/src/datatypes/src/types/primitive_type.rs b/src/datatypes/src/types/primitive_type.rs
index 1cadf4bcd6a8..7ad3a4a8d38e 100644
--- a/src/datatypes/src/types/primitive_type.rs
+++ b/src/datatypes/src/types/primitive_type.rs
@@ -277,15 +277,11 @@ macro_rules! define_non_timestamp_primitive {
 
             fn cast(&self, from: Value) -> Option<Value> {
                 match from {
-                    Value::Boolean(v) => bool_to_numeric(v).map(|val|Value::$TypeId(val)),
-                    Value::String(v) => match v.as_utf8().parse::<$Native>(){
-                        Ok(val) => Some(Value::from(val)),
-                        Err(_)=> None,
-                    }
+                    Value::Boolean(v) => bool_to_numeric(v).map(Value::$TypeId),
+                    Value::String(v) => v.as_utf8().parse::<$Native>().map(|val| Value::from(val)).ok(),
                     $(
                         Value::$TargetType(v) => num::cast::cast(v).map(Value::$TypeId),
                     )*
-
                     _ => None,
                 }
             }
@@ -377,10 +373,7 @@ impl DataType for Int64Type {
             Value::Int64(v) => Some(Value::Int64(v)),
             Value::Float32(v) => num::cast::cast(v).map(Value::Int64),
             Value::Float64(v) => num::cast::cast(v).map(Value::Int64),
-            Value::String(v) => match v.as_utf8().parse::<i64>() {
-                Ok(val) => Some(Value::Int64(val)),
-                Err(_) => None,
-            },
+            Value::String(v) => v.as_utf8().parse::<i64>().map(Value::Int64).ok(),
             Value::DateTime(v) => Some(Value::Int64(v.val())),
             Value::Timestamp(v) => Some(Value::Int64(v.value())),
             Value::Time(v) => Some(Value::Int64(v.value())),
@@ -434,10 +427,7 @@ impl DataType for Int32Type {
             Value::Int32(v) => Some(Value::Int32(v)),
             Value::Float32(v) => num::cast::cast(v).map(Value::Int32),
             Value::Float64(v) => num::cast::cast(v).map(Value::Int32),
-            Value::String(v) => match v.as_utf8().parse::<i32>() {
-                Ok(val) => Some(Value::Int32(val)),
-                Err(_) => None,
-            },
+            Value::String(v) => v.as_utf8().parse::<i32>().map(Value::Int32).ok(),
             Value::Date(v) => Some(Value::Int32(v.val())),
             Value::Interval(v) => match v.unit() {
                 IntervalUnit::YearMonth => Some(Value::Int32(v.to_i32())),
diff --git a/src/datatypes/src/types/time_type.rs b/src/datatypes/src/types/time_type.rs
index 491b343c9564..6608d797b235 100644
--- a/src/datatypes/src/types/time_type.rs
+++ b/src/datatypes/src/types/time_type.rs
@@ -119,7 +119,7 @@ macro_rules! impl_data_type_for_time {
                 fn cast(&self, from: Value) -> Option<Value> {
                     match from {
                         Value::$TargetType(v) => Some(Value::Time(Time::new(v as i64, TimeUnit::$unit))),
-                        Value::Time(v) => Some(Value::Time(v)),
+                        Value::Time(v) => v.convert_to(TimeUnit::$unit).map(Value::Time),
                         _ => None,
                     }
                 }
@@ -263,5 +263,20 @@ mod tests {
         let val = Value::Int32(123);
         let time = ConcreteDataType::time_microsecond_datatype().cast(val);
         assert_eq!(time, None);
+
+        // TimeSecond -> TimeMicroSecond
+        let second = Value::Time(Time::new_second(2023));
+        let microsecond = ConcreteDataType::time_microsecond_datatype()
+            .cast(second)
+            .unwrap();
+        assert_eq!(
+            microsecond,
+            Value::Time(Time::new_microsecond(2023 * 1000000))
+        );
+
+        // test overflow
+        let second = Value::Time(Time::new_second(i64::MAX));
+        let microsecond = ConcreteDataType::time_microsecond_datatype().cast(second);
+        assert_eq!(microsecond, None);
     }
 }
diff --git a/src/datatypes/src/types/timestamp_type.rs b/src/datatypes/src/types/timestamp_type.rs
index a496fc85880d..923072d8e8fb 100644
--- a/src/datatypes/src/types/timestamp_type.rs
+++ b/src/datatypes/src/types/timestamp_type.rs
@@ -135,20 +135,11 @@ macro_rules! impl_data_type_for_timestamp {
 
                 fn cast(&self, from: Value)-> Option<Value>{
                     match from {
-                        Value::Timestamp(v) => Some(Value::Timestamp(v)),
-                        Value::String(v) => match Timestamp::from_str(v.as_utf8()){
-                            Ok(ts) => Some(Value::Timestamp(ts)),
-                            Err(_) => None
-                        }
+                        Value::Timestamp(v) => v.convert_to(TimeUnit::$unit).map(Value::Timestamp),
+                        Value::String(v) => Timestamp::from_str(v.as_utf8()).map(Value::Timestamp).ok(),
                         Value::Int64(v) => Some(Value::Timestamp(Timestamp::new(v, TimeUnit::$unit))),
-                        Value::DateTime(v) => match v.to_chrono_datetime(){
-                            Some(dt) => Some(Value::Timestamp(Timestamp::from_chrono_datetime(dt)?)),
-                            None => None
-                        },
-                        Value::Date(v) => match v.to_chrono_date(){
-                            Some(d) => Some(Value::Timestamp(Timestamp::from_chrono_date(d)?)),
-                            None => None
-                        },
+                        Value::DateTime(v) => Timestamp::new_second(v.val()).convert_to(TimeUnit::$unit).map(Value::Timestamp),
+                        Value::Date(v) => Timestamp::new_second(v.to_secs()).convert_to(TimeUnit::$unit).map(Value::Timestamp),
                         _ => None
                     }
                 }
@@ -243,32 +234,46 @@ mod tests {
     #[test]
     fn test_timestamp_cast() {
         std::env::set_var("TZ", "Asia/Shanghai");
-        // string -> timestamp
+        // String -> TimestampSecond
         let s = Value::String("2021-01-01 01:02:03".to_string().into());
         let ts = ConcreteDataType::timestamp_second_datatype()
             .cast(s)
             .unwrap();
         assert_eq!(ts, Value::Timestamp(Timestamp::new_second(1609434123)));
+        // String cast failed
+        let s = Value::String("12345".to_string().into());
+        let ts = ConcreteDataType::timestamp_second_datatype().cast(s);
+        assert_eq!(ts, None);
 
         let n = Value::Int64(1694589525);
-        // Int64 -> timestamp
+        // Int64 -> TimestampSecond
         let ts = ConcreteDataType::timestamp_second_datatype()
             .cast(n)
             .unwrap();
         assert_eq!(ts, Value::Timestamp(Timestamp::new_second(1694589525)));
 
-        // datetime -> timestamp
+        // Datetime -> TimestampSecond
         let dt = Value::DateTime(DateTime::from(1234567));
         let ts = ConcreteDataType::timestamp_second_datatype()
             .cast(dt)
             .unwrap();
         assert_eq!(ts, Value::Timestamp(Timestamp::new_second(1234567)));
 
-        // date -> timestamp
+        // Date -> TimestampMillisecond
         let d = Value::Date(Date::from_str("1970-01-01").unwrap());
         let ts = ConcreteDataType::timestamp_millisecond_datatype()
             .cast(d)
             .unwrap();
         assert_eq!(ts, Value::Timestamp(Timestamp::new_millisecond(0)));
+
+        // TimestampSecond -> TimestampMicrosecond
+        let second = Value::Timestamp(Timestamp::new_second(123));
+        let microsecond = ConcreteDataType::timestamp_microsecond_datatype()
+            .cast(second)
+            .unwrap();
+        assert_eq!(
+            microsecond,
+            Value::Timestamp(Timestamp::new_microsecond(123 * 1000000))
+        )
     }
 }