Inline a handful of functions from num-integer

The motivation for this is that we use a very small portion of what num-integer provides, but it's a relatively heavy dependency -- it brings in several crates with build scripts. The goal here is to reduce compilation time for projects using chrono.

Cargo.toml

@@ -27,7 +27,6 @@ __internal_bench = ["criterion"]
 __doctest = []
 
 [dependencies]
-num-integer = { version = "0.1.36", default-features = false }
 serde = { version = "1.0.99", default-features = false, optional = true }
 pure-rust-locales = { version = "0.5.2", optional = true }
 criterion = { version = "0.4.0", optional = true }

src/format/mod.rs

@@ -506,7 +506,7 @@ fn format_inner(
 ) -> fmt::Result {
     let locale = Locales::new(locale);
 
-    use num_integer::{div_floor, mod_floor};
+    use crate::utils::{div_floor, mod_floor};
 
     match *item {
         Item::Literal(s) | Item::Space(s) => result.push_str(s),

src/format/parsed.rs

@@ -6,11 +6,10 @@
 
 use core::convert::TryFrom;
 
-use num_integer::div_rem;
-
 use super::{ParseResult, IMPOSSIBLE, NOT_ENOUGH, OUT_OF_RANGE};
 use crate::naive::{NaiveDate, NaiveDateTime, NaiveTime};
 use crate::offset::{FixedOffset, LocalResult, Offset, TimeZone};
+use crate::utils::div_rem;
 use crate::{DateTime, Datelike, TimeDelta, Timelike, Weekday};
 
 /// Parsed parts of date and time. There are two classes of methods:

src/lib.rs

@@ -476,6 +476,8 @@ pub use traits::{Datelike, Timelike};
 #[doc(hidden)]
 pub use naive::__BenchYearFlags;
 
+mod utils;
+
 /// Serialization/Deserialization with serde.
 ///
 /// This module provides default implementations for `DateTime` using the [RFC 3339][1] format and various

src/naive/date.rs

@@ -9,7 +9,6 @@ use core::convert::TryFrom;
 use core::ops::{Add, AddAssign, RangeInclusive, Sub, SubAssign};
 use core::{fmt, str};
 
-use num_integer::div_mod_floor;
 #[cfg(feature = "rkyv")]
 use rkyv::{Archive, Deserialize, Serialize};
 
@@ -23,6 +22,7 @@ use crate::format::{parse, write_hundreds, ParseError, ParseResult, Parsed, Strf
 use crate::format::{Item, Numeric, Pad};
 use crate::month::Months;
 use crate::naive::{IsoWeek, NaiveDateTime, NaiveTime};
+use crate::utils::div_mod_floor;
 use crate::{Datelike, TimeDelta, Weekday};
 
 use super::internals::{self, DateImpl, Mdf, Of, YearFlags};

src/naive/datetime/mod.rs

@@ -11,7 +11,6 @@ use core::fmt::Write;
 use core::ops::{Add, AddAssign, Sub, SubAssign};
 use core::{fmt, str};
 
-use num_integer::div_mod_floor;
 #[cfg(feature = "rkyv")]
 use rkyv::{Archive, Deserialize, Serialize};
 
@@ -20,6 +19,7 @@ use crate::format::DelayedFormat;
 use crate::format::{parse, ParseError, ParseResult, Parsed, StrftimeItems};
 use crate::format::{Fixed, Item, Numeric, Pad};
 use crate::naive::{Days, IsoWeek, NaiveDate, NaiveTime};
+use crate::utils::div_mod_floor;
 use crate::{DateTime, Datelike, LocalResult, Months, TimeDelta, TimeZone, Timelike, Weekday};
 
 /// Tools to help serializing/deserializing `NaiveDateTime`s

src/naive/internals.rs

@@ -18,8 +18,7 @@
 use core::convert::TryFrom;
 use core::{fmt, i32};
 
-use num_integer::{div_rem, mod_floor};
-
+use crate::utils::{div_rem, mod_floor};
 use crate::Weekday;
 
 /// The internal date representation. This also includes the packed `Mdf` value.

src/naive/time/mod.rs

@@ -8,14 +8,14 @@ use core::borrow::Borrow;
 use core::ops::{Add, AddAssign, Sub, SubAssign};
 use core::{fmt, str};
 
-use num_integer::div_mod_floor;
 #[cfg(feature = "rkyv")]
 use rkyv::{Archive, Deserialize, Serialize};
 
 #[cfg(any(feature = "alloc", feature = "std", test))]
 use crate::format::DelayedFormat;
 use crate::format::{parse, write_hundreds, ParseError, ParseResult, Parsed, StrftimeItems};
 use crate::format::{Fixed, Item, Numeric, Pad};
+use crate::utils::div_mod_floor;
 use crate::{TimeDelta, Timelike};
 
 #[cfg(feature = "serde")]

src/offset/fixed.rs

@@ -6,13 +6,13 @@
 use core::fmt;
 use core::ops::{Add, Sub};
 
-use num_integer::div_mod_floor;
 #[cfg(feature = "rkyv")]
 use rkyv::{Archive, Deserialize, Serialize};
 
 use super::{LocalResult, Offset, TimeZone};
 use crate::naive::{NaiveDate, NaiveDateTime, NaiveTime};
 use crate::time_delta::TimeDelta;
+use crate::utils::div_mod_floor;
 use crate::DateTime;
 use crate::Timelike;
 

src/utils.rs

@@ -0,0 +1,84 @@
+// All code cribbed from num-integer. We do this to minimize dependencies and
+// build-time.
+
+pub(crate) trait Integer: Copy {
+    fn div_rem(self, other: Self) -> (Self, Self);
+    fn div_floor(self, other: Self) -> Self;
+    fn mod_floor(self, other: Self) -> Self;
+}
+
+macro_rules! impl_integer_signed {
+    ($t: ty) => {
+        impl Integer for $t {
+            #[inline]
+            fn div_rem(self, other: Self) -> (Self, Self) {
+                (self / other, self % other)
+            }
+
+            #[inline]
+            fn div_floor(self, other: Self) -> Self {
+                // Algorithm from [Daan Leijen. _Division and Modulus for Computer Scientists_,
+                // December 2001](http://research.microsoft.com/pubs/151917/divmodnote-letter.pdf)
+                let (d, r) = self.div_rem(other);
+                if (r > 0 && other < 0) || (r < 0 && other > 0) {
+                    d - 1
+                } else {
+                    d
+                }
+            }
+
+            #[inline]
+            fn mod_floor(self, other: Self) -> Self {
+                // Algorithm from [Daan Leijen. _Division and Modulus for Computer Scientists_,
+                // December 2001](http://research.microsoft.com/pubs/151917/divmodnote-letter.pdf)
+                let r = self % other;
+                if (r > 0 && other < 0) || (r < 0 && other > 0) {
+                    r + other
+                } else {
+                    r
+                }
+            }
+        }
+    };
+}
+
+macro_rules! impl_integer_unsigned {
+    ($t: ty) => {
+        impl Integer for $t {
+            #[inline]
+            fn div_rem(self, other: Self) -> (Self, Self) {
+                (self / other, self % other)
+            }
+
+            #[inline]
+            fn div_floor(self, other: Self) -> Self {
+                self / other
+            }
+
+            #[inline]
+            fn mod_floor(self, other: Self) -> Self {
+                self % other
+            }
+        }
+    };
+}
+
+impl_integer_signed!(i32);
+impl_integer_signed!(i64);
+impl_integer_unsigned!(u32);
+
+pub(crate) fn div_mod_floor<T: Integer>(x: T, y: T) -> (T, T) {
+    (div_floor(x, y), mod_floor(x, y))
+}
+
+pub(crate) fn div_rem<T: Integer>(x: T, y: T) -> (T, T) {
+    x.div_rem(y)
+}
+
+pub(crate) fn div_floor<T: Integer>(x: T, y: T) -> T {
+    x.div_floor(y)
+}
+
+pub(crate) fn mod_floor<T: Integer>(x: T, y: T) -> T {
+    x.mod_floor(y)
+}