guarded try_from_months_days_usecs

pgcentralfoundation · Aug 26, 2022 · 408e610 · 408e610
1 parent e6315c0
commit 408e610
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Showing 3 changed files with 47 additions and 10 deletions.
diff --git a/pgx-tests/src/tests/datetime_tests.rs b/pgx-tests/src/tests/datetime_tests.rs
@@ -402,12 +402,28 @@ mod tests {
 
     #[pg_test]
     fn test_interval_serialization() {
-        let interval = Interval::from_months_days_usecs(3, 4, 5_000_000);
+        let interval = Interval::try_from_months_days_usecs(3, 4, 5_000_000).unwrap();
         let json = json!({ "interval test": interval });
 
         assert_eq!(json!({"interval test":"3 mons 4 days 00:00:05"}), json);
     }
 
+    #[pg_test]
+    fn test_try_from_months_days_usecs_err() {
+        let result = Interval::try_from_months_days_usecs(3, 30, 5_000_000);
+        match result {
+            Err(IntervalConversionError::FromDaysOutOfBounds) => (),
+            _ => panic!("invalid try_from_months_days_usecs conversion succeeded"),
+        };
+
+        let result =
+            Interval::try_from_months_days_usecs(3, 4, pg_sys::SECS_PER_DAY as i64 * 1_000_000i64);
+        match result {
+            Err(IntervalConversionError::FromUSecOutOfBounds) => (),
+            _ => panic!("invalid try_from_months_days_usecs conversion succeeded"),
+        };
+    }
+
     #[pg_test]
     fn test_duration_to_interval_err() {
         // normal limit of i32::MAX months
@@ -416,7 +432,7 @@ mod tests {
         let result = TryInto::<Interval>::try_into(duration);
         match result {
             Ok(_) => (),
-            Err(_) => panic!("failed duration -> interval conversion"),
+            _ => panic!("failed duration -> interval conversion"),
         };
 
         // one month too many, expect error
@@ -425,8 +441,8 @@ mod tests {
 
         let result = TryInto::<Interval>::try_into(duration);
         match result {
-            Ok(_) => panic!("invalid duration -> interval conversion succeeded"),
-            Err(_) => (),
+            Err(IntervalConversionError::DurationMonthsOutOfBounds) => (),
+            _ => panic!("invalid duration -> interval conversion succeeded"),
         };
     }
 }
diff --git a/pgx/src/datum/interval.rs b/pgx/src/datum/interval.rs
@@ -9,7 +9,7 @@ Use of this source code is governed by the MIT license that can be found in the
 
 use std::ops::{Mul, Sub};
 
-use crate::{direct_function_call, pg_sys, FromDatum, IntoDatum, USECS_PER_SEC};
+use crate::{direct_function_call, pg_sys, FromDatum, IntoDatum, USECS_PER_DAY, USECS_PER_SEC};
 use pg_sys::{DAYS_PER_MONTH, SECS_PER_DAY};
 use time::Duration;
 
@@ -20,12 +20,22 @@ const MONTH_DURATION: Duration = Duration::days(DAYS_PER_MONTH as i64);
 pub struct Interval(pg_sys::Interval);
 
 impl Interval {
-    pub fn from_months_days_usecs(months: i32, days: i32, usecs: i64) -> Self {
-        Interval(pg_sys::Interval {
+    pub fn try_from_months_days_usecs(
+        months: i32,
+        days: i32,
+        usecs: i64,
+    ) -> Result<Self, IntervalConversionError> {
+        if days.abs() >= pg_sys::DAYS_PER_MONTH as i32 {
+            return Err(IntervalConversionError::FromDaysOutOfBounds);
+        }
+        if usecs.abs() >= USECS_PER_DAY {
+            return Err(IntervalConversionError::FromUSecOutOfBounds);
+        }
+        Ok(Interval(pg_sys::Interval {
             day: days,
             month: months,
             time: usecs,
-        })
+        }))
     }
 
     pub fn months(&self) -> i32 {
@@ -72,7 +82,7 @@ impl FromDatum for Interval {
 }
 
 impl TryFrom<Duration> for Interval {
-    type Error = &'static str;
+    type Error = IntervalConversionError;
     fn try_from(duration: Duration) -> Result<Interval, Self::Error> {
         let total_months = duration.whole_days() / (pg_sys::DAYS_PER_MONTH as i64);
 
@@ -95,7 +105,7 @@ impl TryFrom<Duration> for Interval {
 
             Ok(Interval(pg_sys::Interval { day, month, time }))
         } else {
-            Err("duration's total month count outside of valid i32::MIN..=i32::MAX range")
+            Err(IntervalConversionError::DurationMonthsOutOfBounds)
         }
     }
 }
@@ -140,3 +150,13 @@ impl serde::Serialize for Interval {
         }
     }
 }
+
+#[derive(thiserror::Error, Debug, Clone, Copy)]
+pub enum IntervalConversionError {
+    #[error("duration's total month count outside of valid i32::MIN..=i32::MAX range")]
+    DurationMonthsOutOfBounds,
+    #[error("try_from_months_days_usecs's days abs count must be < DAYS_PER_MONTH (30)")]
+    FromDaysOutOfBounds,
+    #[error("try_from_months_days_usecs's usec abs count must be < USECS_PER_DAY")]
+    FromUSecOutOfBounds,
+}
diff --git a/pgx/src/datum/time.rs b/pgx/src/datum/time.rs
@@ -14,6 +14,7 @@ use time::format_description::FormatItem;
 pub(crate) const USECS_PER_HOUR: i64 = 3_600_000_000;
 pub(crate) const USECS_PER_MINUTE: i64 = 60_000_000;
 pub(crate) const USECS_PER_SEC: i64 = 1_000_000;
+pub(crate) const USECS_PER_DAY: i64 = pg_sys::SECS_PER_DAY as i64 * USECS_PER_SEC;
 pub(crate) const MINS_PER_HOUR: i64 = 60;
 pub(crate) const SEC_PER_MIN: i64 = 60;