Add decimal support to substrait serde

datafusion/substrait/src/consumer.rs

@@ -606,7 +606,8 @@ pub async fn from_substrait_rex(
  ))),
  }
  }
- Some(RexType::Literal(lit)) => match &lit.literal_type {
+ Some(RexType::Literal(lit)) => {
+ match &lit.literal_type {
  Some(LiteralType::I8(n)) => {
  Ok(Arc::new(Expr::Literal(ScalarValue::Int8(Some(*n as i8)))))
  }
@@ -631,6 +632,30 @@ pub async fn from_substrait_rex(
  Some(LiteralType::Fp64(f)) => {
  Ok(Arc::new(Expr::Literal(ScalarValue::Float64(Some(*f)))))
  }
+ Some(LiteralType::Decimal(d)) => {
+ let value: [u8; 16] = d.value.clone().try_into().or(Err(
+ DataFusionError::Substrait(
+ "Failed to parse decimal value".to_string(),
+ ),
+ ))?;
+ let p = d.precision.try_into().map_err(|e| {
+ DataFusionError::Substrait(format!(
+ "Failed to parse decimal precision: {}",
+ e
+ ))
+ })?;
+ let s = d.scale.try_into().map_err(|e| {
+ DataFusionError::Substrait(format!(
+ "Failed to parse decimal scale: {}",
+ e
+ ))
+ })?;
+ Ok(Arc::new(Expr::Literal(ScalarValue::Decimal128(
+ Some(std::primitive::i128::from_le_bytes(value)),
+ p,
+ s,
+ ))))
+ }
  Some(LiteralType::String(s)) => {
  Ok(Arc::new(Expr::Literal(ScalarValue::Utf8(Some(s.clone())))))
  }
@@ -643,7 +668,8 @@ pub async fn from_substrait_rex(
  lit.literal_type
  )))
  }
- },
+ }
+ }
  _ => Err(DataFusionError::NotImplemented(
  "unsupported rex_type".to_string(),
  )),

datafusion/substrait/src/producer.rs

@@ -35,7 +35,7 @@ use substrait::proto::{
  expression::{
  field_reference::ReferenceType,
  if_then::IfClause,
- literal::LiteralType,
+ literal::{Decimal, LiteralType},
  mask_expression::{StructItem, StructSelect},
  reference_segment, FieldReference, IfThen, Literal, MaskExpression,
  ReferenceSegment, RexType, ScalarFunction,
@@ -579,6 +579,13 @@ pub fn to_substrait_rex(
  ScalarValue::Boolean(Some(b)) => Some(LiteralType::Boolean(*b)),
  ScalarValue::Float32(Some(f)) => Some(LiteralType::Fp32(*f)),
  ScalarValue::Float64(Some(f)) => Some(LiteralType::Fp64(*f)),
+ ScalarValue::Decimal128(v, p, s) if v.is_some() => {
+ Some(LiteralType::Decimal(Decimal {
+ value: v.unwrap().to_le_bytes().to_vec(),
+ precision: *p as i32,
+ scale: *s as i32,
+ }))
+ }
  ScalarValue::Utf8(Some(s)) => Some(LiteralType::String(s.clone())),
  ScalarValue::LargeUtf8(Some(s)) => Some(LiteralType::String(s.clone())),
  ScalarValue::Binary(Some(b)) => Some(LiteralType::Binary(b.clone())),

datafusion/substrait/tests/roundtrip.rs

@@ -22,6 +22,7 @@ use datafusion_substrait::producer;
 mod tests {
 
  use crate::{consumer::from_substrait_plan, producer::to_substrait_plan};
+ use datafusion::arrow::datatypes::{DataType, Field, Schema};
  use datafusion::error::Result;
  use datafusion::prelude::*;
  use substrait::proto::extensions::simple_extension_declaration::MappingType;
@@ -95,6 +96,11 @@ mod tests {
  roundtrip("SELECT a, c, avg(b) FROM data GROUP BY a, c").await
  }
 
+ #[tokio::test]
+ async fn decimal_literal() -> Result<()> {
+ roundtrip("SELECT * FROM data WHERE b > 2.5").await
+ }
+
  #[tokio::test]
  async fn simple_distinct() -> Result<()> {
  test_alias(
@@ -290,9 +296,17 @@ mod tests {
 
  async fn create_context() -> Result<SessionContext> {
  let ctx = SessionContext::new();
- ctx.register_csv("data", "tests/testdata/data.csv", CsvReadOptions::new())
+ let mut explicit_options = CsvReadOptions::new();
+ let schema = Schema::new(vec![
+ Field::new("a", DataType::Int64, true),
+ Field::new("b", DataType::Decimal128(5, 2), true),
+ Field::new("c", DataType::Date32, true),
+ Field::new("d", DataType::Boolean, true),
+ ]);
+ explicit_options.schema = Some(&schema);
+ ctx.register_csv("data", "tests/testdata/data.csv", explicit_options.clone())
  .await?;
- ctx.register_csv("data2", "tests/testdata/data.csv", CsvReadOptions::new())
+ ctx.register_csv("data2", "tests/testdata/data.csv", explicit_options)
  .await?;
  Ok(ctx)
  }

datafusion/substrait/tests/testdata/data.csv

@@ -1,3 +1,3 @@
 a,b,c,d
-1,2,2020-01-01,false
-3,4,2020-01-01,true
+1,2.0,2020-01-01,false
+3,4.5,2020-01-01,true