Add serialization for sparse matrix and sparse vector.

Eigen/src/SparseCore/SparseVector.h

@@ -495,6 +495,78 @@ struct sparse_vector_assign_selector<Dest,Src,SVA_RuntimeSwitch> {
 
 }
 
+// Specialization for SparseVector.
+// Serializes [size, numNonZeros, innerIndices, values].
+template <typename Scalar, int Options, typename StorageIndex>
+class Serializer<SparseVector<Scalar, Options, StorageIndex>, void> {
+ public:
+  typedef SparseVector<Scalar, Options, StorageIndex> SparseMat;
+
+  struct Header {
+    typename SparseMat::Index size;
+    Index num_non_zeros;
+  };
+
+  EIGEN_DEVICE_FUNC size_t size(const SparseMat& value) const {
+    return sizeof(Header) +
+           (sizeof(Scalar) + sizeof(StorageIndex)) * value.nonZeros();
+  }
+
+  EIGEN_DEVICE_FUNC uint8_t* serialize(uint8_t* dest, uint8_t* end,
+                                       const SparseMat& value) {
+    if (EIGEN_PREDICT_FALSE(dest == nullptr)) return nullptr;
+    if (EIGEN_PREDICT_FALSE(dest + size(value) > end)) return nullptr;
+
+    const size_t header_bytes = sizeof(Header);
+    Header header = {value.innerSize(), value.nonZeros()};
+    EIGEN_USING_STD(memcpy)
+    memcpy(dest, &header, header_bytes);
+    dest += header_bytes;
+
+    // Inner indices.
+    std::size_t data_bytes = sizeof(StorageIndex) * header.num_non_zeros;
+    memcpy(dest, value.innerIndexPtr(), data_bytes);
+    dest += data_bytes;
+
+    // Values.
+    data_bytes = sizeof(Scalar) * header.num_non_zeros;
+    memcpy(dest, value.valuePtr(), data_bytes);
+    dest += data_bytes;
+
+    return dest;
+  }
+
+  EIGEN_DEVICE_FUNC const uint8_t* deserialize(const uint8_t* src,
+                                               const uint8_t* end,
+                                               SparseMat& value) const {
+    if (EIGEN_PREDICT_FALSE(src == nullptr)) return nullptr;
+    if (EIGEN_PREDICT_FALSE(src + sizeof(Header) > end)) return nullptr;
+
+    const size_t header_bytes = sizeof(Header);
+    Header header;
+    EIGEN_USING_STD(memcpy)
+    memcpy(&header, src, header_bytes);
+    src += header_bytes;
+
+    value.setZero();
+    value.resize(header.size);
+    value.resizeNonZeros(header.num_non_zeros);
+
+    // Inner indices.
+    std::size_t data_bytes = sizeof(StorageIndex) * header.num_non_zeros;
+    if (EIGEN_PREDICT_FALSE(src + data_bytes > end)) return nullptr;
+    memcpy(value.innerIndexPtr(), src, data_bytes);
+    src += data_bytes;
+
+    // Values.
+    data_bytes = sizeof(Scalar) * header.num_non_zeros;
+    if (EIGEN_PREDICT_FALSE(src + data_bytes > end)) return nullptr;
+    memcpy(value.valuePtr(), src, data_bytes);
+    src += data_bytes;
+    return src;
+  }
+};
+
 } // end namespace Eigen
 
 #endif // EIGEN_SPARSEVECTOR_H