Implement Serialize, Deserialize for SparsityPattern

nalgebra-sparse/src/pattern.rs

@@ -4,6 +4,9 @@ use crate::SparseFormatError;
 use std::error::Error;
 use std::fmt;
 
+#[cfg(feature = "serde-serialize")]
+use serde::{de, Deserialize, Deserializer, Serialize, Serializer};
+
 /// A representation of the sparsity pattern of a CSR or CSC matrix.
 ///
 /// CSR and CSC matrices store matrices in a very similar fashion. In fact, in a certain sense,
@@ -285,6 +288,54 @@ pub enum SparsityPatternFormatError {
     NonmonotonicMinorIndices,
 }
 
+#[cfg(feature = "serde-serialize")]
+#[derive(Serialize)]
+struct SparsityPatternSerializationData<'a> {
+    major_dim: usize,
+    minor_dim: usize,
+    major_offsets: &'a [usize],
+    minor_indices: &'a [usize],
+}
+
+#[cfg(feature = "serde-serialize")]
+impl Serialize for SparsityPattern {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        SparsityPatternSerializationData {
+            major_dim: self.major_dim(),
+            minor_dim: self.minor_dim(),
+            major_offsets: self.major_offsets(),
+            minor_indices: self.minor_indices(),
+        }
+        .serialize(serializer)
+    }
+}
+
+#[cfg(feature = "serde-serialize")]
+#[derive(Deserialize)]
+struct SparsityPatternDeserializationData {
+    major_dim: usize,
+    minor_dim: usize,
+    major_offsets: Vec<usize>,
+    minor_indices: Vec<usize>,
+}
+
+#[cfg(feature = "serde-serialize")]
+impl<'de> Deserialize<'de> for SparsityPattern {
+    fn deserialize<D>(deserializer: D) -> Result<SparsityPattern, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let de = SparsityPatternDeserializationData::deserialize(deserializer)?;
+        SparsityPattern::try_from_offsets_and_indices(de.major_dim, de.minor_dim, de.major_offsets, de.minor_indices)
+            .map(|m| m.into())
+            // TODO: More specific error
+            .map_err(|_e| de::Error::invalid_value(de::Unexpected::Other("invalid sparsity pattern"), &"a valid sparsity pattern"))
+    }
+}
+
 impl From<SparsityPatternFormatError> for SparseFormatError {
     fn from(err: SparsityPatternFormatError) -> Self {
         use crate::SparseFormatErrorKind;

nalgebra-sparse/tests/serde.rs

@@ -9,6 +9,7 @@ pub mod common;
 use nalgebra_sparse::coo::CooMatrix;
 use nalgebra_sparse::csc::CscMatrix;
 use nalgebra_sparse::csr::CsrMatrix;
+use nalgebra_sparse::pattern::SparsityPattern;
 
 use proptest::prelude::*;
 use serde::{Deserialize, Serialize};
@@ -21,6 +22,44 @@ fn json_roundtrip<T: Serialize + for<'a> Deserialize<'a>>(csr: &T) -> T {
     deserialized
 }
 
+#[test]
+fn pattern_roundtrip() {
+    {
+        // A pattern with zero explicitly stored entries
+        let pattern =
+            SparsityPattern::try_from_offsets_and_indices(3, 2, vec![0, 0, 0, 0], Vec::new())
+                .unwrap();
+
+        assert_eq!(json_roundtrip(&pattern), pattern);
+    }
+
+    {
+        // Arbitrary pattern
+        let offsets = vec![0, 2, 2, 5];
+        let indices = vec![0, 5, 1, 2, 3];
+        let pattern =
+            SparsityPattern::try_from_offsets_and_indices(3, 6, offsets.clone(), indices.clone())
+                .unwrap();
+
+        assert_eq!(json_roundtrip(&pattern), pattern);
+    }
+}
+
+#[test]
+#[rustfmt::skip]
+fn pattern_deserialize_invalid() {
+    assert!(serde_json::from_str::<SparsityPattern>(r#"{"major_dim":3,"minor_dim":6,"major_offsets":[0,2,2,5],"minor_indices":[0,5,1,2,3]}"#).is_ok());
+    assert!(serde_json::from_str::<SparsityPattern>(r#"{"major_dim":0,"minor_dim":0,"major_offsets":[],"minor_indices":[]}"#).is_err());
+    assert!(serde_json::from_str::<SparsityPattern>(r#"{"major_dim":3,"minor_dim":6,"major_offsets":[0, 3, 5],"minor_indices":[0, 1, 2, 3, 5]}"#).is_err());
+    assert!(serde_json::from_str::<SparsityPattern>(r#"{"major_dim":3,"minor_dim":6,"major_offsets":[1, 2, 2, 5],"minor_indices":[0, 5, 1, 2, 3]}"#).is_err());
+    assert!(serde_json::from_str::<SparsityPattern>(r#"{"major_dim":3,"minor_dim":6,"major_offsets":[0, 2, 2, 4],"minor_indices":[0, 5, 1, 2, 3]}"#).is_err());
+    assert!(serde_json::from_str::<SparsityPattern>(r#"{"major_dim":3,"minor_dim":6,"major_offsets":[0, 2, 2],"minor_indices":[0, 5, 1, 2, 3]}"#).is_err());
+    assert!(serde_json::from_str::<SparsityPattern>(r#"{"major_dim":3,"minor_dim":6,"major_offsets":[0, 3, 2, 5],"minor_indices":[0, 1, 2, 3, 4]}"#).is_err());
+    assert!(serde_json::from_str::<SparsityPattern>(r#"{"major_dim":3,"minor_dim":6,"major_offsets":[0, 2, 2, 5],"minor_indices":[0, 2, 3, 1, 4]}"#).is_err());
+    assert!(serde_json::from_str::<SparsityPattern>(r#"{"major_dim":3,"minor_dim":6,"major_offsets":[0, 2, 2, 5],"minor_indices":[0, 6, 1, 2, 3]}"#).is_err());
+    assert!(serde_json::from_str::<SparsityPattern>(r#"{"major_dim":3,"minor_dim":6,"major_offsets":[0, 2, 2, 5],"minor_indices":[0, 5, 2, 2, 3]}"#).is_err());
+}
+
 #[test]
 fn coo_roundtrip() {
     {
@@ -46,6 +85,7 @@ fn coo_roundtrip() {
 #[test]
 fn coo_deserialize_invalid() {
     // Valid matrix: {"nrows":3,"ncols":5,"row_indices":[0,1,0,0,2],"col_indices":[0,2,1,3,3],"values":[2,3,7,3,1]}
+    assert!(serde_json::from_str::<CooMatrix<i32>>(r#"{"nrows":3,"ncols":5,"row_indices":[0,1,0,0,2],"col_indices":[0,2,1,3,3],"values":[2,3,7,3,1]}"#).is_ok());
     assert!(serde_json::from_str::<CooMatrix<i32>>(r#"{"nrows":0,"ncols":0,"row_indices":[0,1,0,0,2],"col_indices":[0,2,1,3,3],"values":[2,3,7,3,4]}"#).is_err());
     assert!(serde_json::from_str::<CooMatrix<i32>>(r#"{"nrows":-3,"ncols":5,"row_indices":[0,1,0,0,2],"col_indices":[0,2,1,3,3],"values":[2,3,7,3,4]}"#).is_err());
     assert!(serde_json::from_str::<CooMatrix<i32>>(r#"{"nrows":3,"ncols":5,"row_indices":[0,1,0,0,2],"col_indices":[0,2,1,3,3],"values":[2,3,7,3]}"#).is_err());
@@ -101,6 +141,7 @@ fn csc_roundtrip() {
 #[test]
 fn csc_deserialize_invalid() {
     // Valid matrix: {"nrows":6,"ncols":3,"col_offsets":[0,2,2,5],"row_indices":[0,5,1,2,3],"values":[0,1,2,3,4]}
+    assert!(serde_json::from_str::<CscMatrix<i32>>(r#"{"nrows":6,"ncols":3,"col_offsets":[0,2,2,5],"row_indices":[0,5,1,2,3],"values":[0,1,2,3,4]}"#).is_ok());
     assert!(serde_json::from_str::<CscMatrix<i32>>(r#"{"nrows":0,"ncols":0,"col_offsets":[0,2,2,5],"row_indices":[0,5,1,2,3],"values":[0,1,2,3,4]}"#).is_err());
     assert!(serde_json::from_str::<CscMatrix<i32>>(r#"{"nrows":-6,"ncols":3,"col_offsets":[0,2,2,5],"row_indices":[0,5,1,2,3],"values":[0,1,2,3,4]}"#).is_err());
     assert!(serde_json::from_str::<CscMatrix<i32>>(r#"{"nrows":6,"ncols":3,"col_offsets":[0,2,2,5],"row_indices":[0,5,1,2,3],"values":[0,1,2,3]}"#).is_err());
@@ -140,6 +181,7 @@ fn csr_roundtrip() {
 #[test]
 fn csr_deserialize_invalid() {
     // Valid matrix: {"nrows":3,"ncols":6,"row_offsets":[0,2,2,5],"col_indices":[0,5,1,2,3],"values":[0,1,2,3,4]}
+    assert!(serde_json::from_str::<CsrMatrix<i32>>(r#"{"nrows":3,"ncols":6,"row_offsets":[0,2,2,5],"col_indices":[0,5,1,2,3],"values":[0,1,2,3,4]}"#).is_ok());
     assert!(serde_json::from_str::<CsrMatrix<i32>>(r#"{"nrows":0,"ncols":0,"row_offsets":[0,2,2,5],"col_indices":[0,5,1,2,3],"values":[0,1,2,3,4]}"#).is_err());
     assert!(serde_json::from_str::<CsrMatrix<i32>>(r#"{"nrows":-3,"ncols":6,"row_offsets":[0,2,2,5],"col_indices":[0,5,1,2,3],"values":[0,1,2,3,4]}"#).is_err());
     assert!(serde_json::from_str::<CsrMatrix<i32>>(r#"{"nrows":3,"ncols":6,"row_offsets":[0,2,2,5],"col_indices":[0,5,1,2,3],"values":[0,1,2,3]}"#).is_err());