hdf5_access.h

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/*
 * Copyright 2025 Stanford University, NVIDIA Corporation
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
 
// HDF5-specific instance layouts and accessors
 
#ifndef REALM_HDF5_ACCESS_H
#define REALM_HDF5_ACCESS_H
 
#include "realm/inst_layout.h"
#include <string>
#include <vector>
 
namespace Realm {
 
  // we avoid including hdf5.h here, but we need a definition for something that'll
  //  be compatible with HDF5's hsize_t
  typedef unsigned long long hdf5_size_t;
 
  namespace PieceLayoutTypes {
    static const LayoutType HDF5LayoutType = 2;
  };
 
  // dimension-agnostic form for piece info allows us to get to it without
  //  having to know the template parameters of the HDF5LayoutPiece holding
  //  it
  struct REALM_PUBLIC_API HDF5PieceInfo {
    std::string dsetname;
    // TODO: small vectors
    // this is the offset within the hdf5 dataset, uses its dimensionality
    std::vector<hdf5_size_t> offset;
    // this maps from realm dimensions to hdf5 dimensions - the
    //  dimensionalities may differ - use '-1' for realm dimensions that
    //  do not correspond to an hdf5 dimension
    std::vector<int> dim_order;
    bool read_only;
  };
 
  template <int N, typename T>
  class REALM_PUBLIC_API HDF5LayoutPiece : public InstanceLayoutPiece<N, T>,
                                           public HDF5PieceInfo {
  public:
    HDF5LayoutPiece(void);
 
    template <typename S>
    static InstanceLayoutPiece<N, T> *deserialize_new(S &deserializer);
 
    virtual InstanceLayoutPiece<N, T> *clone(void) const;
 
    virtual size_t calculate_offset(const Point<N, T> &p) const;
 
    virtual void relocate(size_t base_offset);
 
    virtual void print(std::ostream &os) const;
 
    virtual size_t lookup_inst_size() const;
    virtual PieceLookup::Instruction *create_lookup_inst(void *ptr,
                                                         unsigned next_delta) const;
 
    static Serialization::PolymorphicSerdezSubclass<InstanceLayoutPiece<N, T>,
                                                    HDF5LayoutPiece<N, T>>
        serdez_subclass;
 
    template <typename S>
    bool serialize(S &serializer) const;
  };
 
  namespace PieceLookup {
 
    namespace Opcodes {
      static const Opcode OP_HDF5_PIECE = 3; // this is an HDF5Piece<N,T>
    }
 
    static const unsigned ALLOW_HDF5_PIECE = 1U << Opcodes::OP_HDF5_PIECE;
 
    template <int N, typename T>
    struct HDF5Piece : public Instruction {
      // data is: { delta[23:0], opcode[7:0] }
      // top 24 bits of data is jump delta
      HDF5Piece(unsigned next_delta);
 
      unsigned delta() const;
 
      unsigned short dsetname_len;
      const char *dsetname() const;
 
      Rect<N, T> bounds;
      Point<N, hdf5_size_t> offset;
      int dim_order[N];
      bool read_only;
 
      const Instruction *next() const;
    };
 
  }; // namespace PieceLookup
 
  class REALM_PUBLIC_API ExternalHDF5Resource : public ExternalInstanceResource {
  public:
    ExternalHDF5Resource(const std::string &_filename, bool _read_only);
 
    virtual bool satisfies(const InstanceLayoutGeneric &layout) const;
 
    // returns the suggested memory in which this resource should be created
    Memory suggested_memory() const;
 
    virtual ExternalInstanceResource *clone(void) const;
 
    template <typename S>
    bool serialize(S &serializer) const;
 
    template <typename S>
    static ExternalInstanceResource *deserialize_new(S &deserializer);
 
  protected:
    ExternalHDF5Resource();
 
    static Serialization::PolymorphicSerdezSubclass<ExternalInstanceResource,
                                                    ExternalHDF5Resource>
        serdez_subclass;
 
    virtual void print(std::ostream &os) const;
 
  public:
    std::string filename;
    bool read_only;
  };
 
}; // namespace Realm
 
#include "realm/hdf5/hdf5_access.inl"
 
#endif // ifndef REALM_HDF5_ACCESS_H