Replace 2d map with flat map

components/plurals/src/provider.rs

@@ -18,7 +18,7 @@
 use crate::rules::runtime::ast::Rule;
 use icu_provider::prelude::*;
 use icu_provider::DataMarker;
-use zerovec::ZeroMap2d;
+use zerovec::ZeroMap;
 
 #[cfg(feature = "compiled_data")]
 #[derive(Debug)]
@@ -121,14 +121,6 @@ pub enum RawPluralCategory {
  Many = 5,
 }
 
-impl RawPluralCategory {
- #[inline]
- /// Converts to an [`UnvalidatedPluralCategory`].
- pub fn to_unvalidated(self) -> UnvalidatedPluralCategory {
- UnvalidatedPluralCategory(self as u8)
- }
-}
-
 impl From<PluralCategory> for RawPluralCategory {
  fn from(value: PluralCategory) -> Self {
  match value {
@@ -142,7 +134,7 @@ impl From<PluralCategory> for RawPluralCategory {
  }
 }
 
-/// An `u8` that is expected to be a `PluralCategory` tag but does not enforce this variant.
+/// An `u8` that is expected to be a plural range, but does not enforce this invariant.
 ///
 /// <div class="stab unstable">
 /// 🚧 This code is considered unstable; it may change at any time, in breaking or non-breaking ways,
@@ -155,30 +147,52 @@ impl From<PluralCategory> for RawPluralCategory {
  derive(databake::Bake),
  databake(path = icu_plurals::provider),
 )]
-#[zerovec::make_ule(UnvalidatedPluralCategoryULE)]
-pub struct UnvalidatedPluralCategory(pub u8);
+#[zerovec::make_ule(UnvalidatedPluralRangeULE)]
+pub struct UnvalidatedPluralRange(pub u8);
+
+impl UnvalidatedPluralRange {
+ /// Creates a new `UnvalidatedPluralRange` from a category range.
+ pub fn from_range(start: RawPluralCategory, end: RawPluralCategory) -> Self {
+ let start = start as u8;
+ let end = end as u8;
+
+ debug_assert!(start < 16);
+ debug_assert!(end < 16);
+
+ let range = (start << 4) | end;
+
+ Self(range)
+ }
+}
 
 #[cfg(feature = "datagen")]
-impl serde::Serialize for UnvalidatedPluralCategory {
+impl serde::Serialize for UnvalidatedPluralRange {
  fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
  where
  S: serde::Serializer,
  {
  use serde::ser::Error;
- RawPluralCategory::new_from_u8(self.0)
- .ok_or_else(|| S::Error::custom("invalid tag in UnvalidatedPluralCategory"))?
- .serialize(serializer)
+ if serializer.is_human_readable() {
+ let start = RawPluralCategory::new_from_u8(self.0 >> 4)
+ .ok_or_else(|| S::Error::custom("invalid tag in UnvalidatedPluralRange"))?;
+ let end = RawPluralCategory::new_from_u8(self.0 & 0x0F)
+ .ok_or_else(|| S::Error::custom("invalid tag in UnvalidatedPluralRange"))?;
+ (start, end).serialize(serializer)
+ } else {
+ self.0.serialize(serializer)
+ }
  }
 }
 
 #[cfg(feature = "serde")]
-impl<'de> serde::Deserialize<'de> for UnvalidatedPluralCategory {
+impl<'de> serde::Deserialize<'de> for UnvalidatedPluralRange {
  fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
  where
  D: serde::Deserializer<'de>,
  {
  if deserializer.is_human_readable() {
- Ok(RawPluralCategory::deserialize(deserializer)?.to_unvalidated())
+ let (start, end) = <(RawPluralCategory, RawPluralCategory)>::deserialize(deserializer)?;
+ Ok(UnvalidatedPluralRange::from_range(start, end))
  } else {
  Ok(Self(<u8>::deserialize(deserializer)?))
  }
@@ -210,9 +224,8 @@ pub struct PluralRangesV1<'data> {
  /// Map between the categories of the endpoints of a range and its corresponding
  /// category.
  ///
- /// - `key0` corresponds to the start category of the range.
- /// - `key1` corresponds to the end category of the range.
+ /// This is roughly equivalent to a `BTreeMap<(PluralCategory, PluralCategory), PluralCategory>`,
+ /// where the key is `(start category, end category)`.
  #[cfg_attr(feature = "serde", serde(borrow))]
- pub ranges:
- ZeroMap2d<'data, UnvalidatedPluralCategory, UnvalidatedPluralCategory, RawPluralCategory>,
+ pub ranges: ZeroMap<'data, UnvalidatedPluralRange, RawPluralCategory>,
 }

provider/datagen/src/transform/cldr/plurals/mod.rs

@@ -131,7 +131,7 @@ impl From<&cldr_serde::plural_ranges::LocalePluralRanges> for PluralRangesV1<'st
  .expect("category parsing failed.")
  .into()
  }
- let mut map: BTreeMap<RawPluralCategory, BTreeMap<RawPluralCategory, RawPluralCategory>> =
+ let mut map: BTreeMap<(RawPluralCategory, RawPluralCategory), RawPluralCategory> =
  BTreeMap::new();
  for (range, result) in &other.0 {
  let start = convert(&range.start);
@@ -144,17 +144,15 @@ impl From<&cldr_serde::plural_ranges::LocalePluralRanges> for PluralRangesV1<'st
  // We can use that to save a lot of memory by not inserting the ranges that
  // have end == result.
  if end != result {
- map.entry(start).or_default().insert(end, result);
+ map.insert((start, end), result);
  }
  }
 
  PluralRangesV1 {
  ranges: map
  .into_iter()
- .flat_map(|(start, rest)| {
- rest.into_iter().map(move |(end, result)| {
- (start.to_unvalidated(), end.to_unvalidated(), result)
- })
+ .map(|((start, end), result)| {
+ (UnvalidatedPluralRange::from_range(start, end), result)
  })
  .collect(),
  }
@@ -210,51 +208,57 @@ fn test_ranges() {
  .unwrap();
 
  assert_eq!(
- plural_ranges.get().ranges.get_copied_2d(
- &RawPluralCategory::Few.to_unvalidated(),
- &RawPluralCategory::One.to_unvalidated()
- ),
+ plural_ranges
+ .get()
+ .ranges
+ .get_copied(&UnvalidatedPluralRange::from_range(
+ RawPluralCategory::Few,
+ RawPluralCategory::One
+ )),
  Some(RawPluralCategory::Few)
  );
  assert_eq!(
- plural_ranges.get().ranges.get_copied_2d(
- &RawPluralCategory::Other.to_unvalidated(),
- &RawPluralCategory::One.to_unvalidated()
- ),
+ plural_ranges
+ .get()
+ .ranges
+ .get_copied(&UnvalidatedPluralRange::from_range(
+ RawPluralCategory::Other,
+ RawPluralCategory::One
+ )),
  Some(RawPluralCategory::Few)
  );
  assert!(plural_ranges
  .get()
  .ranges
- .get_copied_2d(
- &RawPluralCategory::Zero.to_unvalidated(),
- &RawPluralCategory::One.to_unvalidated()
- )
+ .get_copied(&UnvalidatedPluralRange::from_range(
+ RawPluralCategory::Zero,
+ RawPluralCategory::One
+ ))
  .is_none());
  assert!(plural_ranges
  .get()
  .ranges
- .get_copied_2d(
- &RawPluralCategory::One.to_unvalidated(),
- &RawPluralCategory::Zero.to_unvalidated()
- )
+ .get_copied(&UnvalidatedPluralRange::from_range(
+ RawPluralCategory::One,
+ RawPluralCategory::Zero
+ ))
  .is_none());
 
  // tests that the space optimization succeeds
  assert!(plural_ranges
  .get()
  .ranges
- .get_copied_2d(
- &RawPluralCategory::One.to_unvalidated(),
- &RawPluralCategory::Other.to_unvalidated()
- )
+ .get_copied(&UnvalidatedPluralRange::from_range(
+ RawPluralCategory::One,
+ RawPluralCategory::Other
+ ))
  .is_none());
  assert!(plural_ranges
  .get()
  .ranges
- .get_copied_2d(
- &RawPluralCategory::Few.to_unvalidated(),
- &RawPluralCategory::Two.to_unvalidated()
- )
+ .get_copied(&UnvalidatedPluralRange::from_range(
+ RawPluralCategory::Few,
+ RawPluralCategory::Two
+ ))
  .is_none());
 }