pick_1d_block_size.hpp

Go to the documentation of this file.

#ifndef RITSUKO_PICK_1D_BLOCK_SIZE_HPP
#define RITSUKO_PICK_1D_BLOCK_SIZE_HPP
 
#include "H5Cpp.h"
 
namespace ritsuko {
 
namespace hdf5 {
 
inline hsize_t pick_1d_block_size(const H5::DSetCreatPropList& cplist, hsize_t full_length, hsize_t buffer_size = 10000) {
    if (full_length < buffer_size) {
        return full_length;
    }
 
    if (cplist.getLayout() != H5D_CHUNKED) {
        return buffer_size;
    }
 
    hsize_t chunk_size;
    cplist.getChunk(1, &chunk_size);
 
    // Finding the number of chunks to load per iteration; this is either
    // the largest multiple below 'buffer_size' or the chunk size.
    int num_chunks = (buffer_size / chunk_size);
    if (num_chunks == 0) {
        num_chunks = 1;
    }
 
    // This is already guaranteed to be less than 'full_length', as 
    // 'chunk_size <= full_length' from HDF5.
    return num_chunks * chunk_size;
}
 
}
 
}
 
#endif