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dft_tools/triqs/h5/base.cpp
Olivier Parcollet 4af1afbdaf hdf5 : clean up
- For users : only change is :
   H5::H5File in apps. to be replaced by triqs::h5::file, same API.

- using only the C API because :
   - it is cleaner, better documented, more examples.
   - it is the native hdf5 interface.
   - simplify the installation e.g. on mac. Indeed, hdf5 is
     usually installed without C++ interface, which is optional.
     E.g. EPD et al., brew by default.
     Also the infamous mpi+ hdf5_cpp bug, for which we have no clean solution.

- clean the notion of parent of a group. Not needed, better iterate function in C LT API.
- modified doc : no need for C++ bindings any more.
- modified cmake to avoid requiring CPP bindings.
2014-06-22 13:57:47 +02:00

103 lines
3.7 KiB
C++

/*******************************************************************************
*
* TRIQS: a Toolbox for Research in Interacting Quantum Systems
*
* Copyright (C) 2011-2014 by O. Parcollet
*
* TRIQS is free software: you can redistribute it and/or modify it under the
* terms of the GNU General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later
* version.
*
* TRIQS is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* TRIQS. If not, see <http://www.gnu.org/licenses/>.
*
******************************************************************************/
#include "./base.hpp"
namespace triqs {
namespace h5 {
//------------------------------------------------
// dataspace from lengths and strides. Correct for the complex. strides must be >0
dataspace dataspace_from_LS(int R, bool is_complex, hsize_t const *Ltot, hsize_t const *L, hsize_t const *S,
hsize_t const *offset) {
int rank = R + (is_complex ? 1 : 0);
hsize_t totdimsf[rank], dimsf[rank], stridesf[rank], offsetf[rank]; // dataset dimensions
for (size_t u = 0; u < R; ++u) {
offsetf[u] = (offset ? offset[u] : 0);
dimsf[u] = L[u];
totdimsf[u] = Ltot[u];
stridesf[u] = S[u];
}
if (is_complex) {
offsetf[rank - 1] = 0;
dimsf[rank - 1] = 2;
totdimsf[rank - 1] = 2;
stridesf[rank - 1] = 1;
}
dataspace ds = H5Screate_simple(rank, totdimsf, NULL);
if (!ds.is_valid()) TRIQS_RUNTIME_ERROR << "Can not create the dataset";
herr_t err = H5Sselect_hyperslab(ds, H5S_SELECT_SET, offsetf, stridesf, dimsf, NULL);
if (err < 0) TRIQS_RUNTIME_ERROR << "Can not set hyperslab";
return ds;
}
/****************** Write string attribute *********************************************/
void write_string_attribute(hid_t id, std::string name, std::string value) {
datatype strdatatype = H5Tcopy(H5T_C_S1);
auto status = H5Tset_size(strdatatype, value.size() + 1);
// auto status = H5Tset_size(strdatatype, H5T_VARIABLE);
if (status < 0) TRIQS_RUNTIME_ERROR << "Internal error in H5Tset_size";
dataspace space = H5Screate(H5S_SCALAR);
attribute attr = H5Acreate2(id, name.c_str(), strdatatype, space, H5P_DEFAULT, H5P_DEFAULT);
if (!attr.is_valid()) TRIQS_RUNTIME_ERROR << "Can not create the attribute " << name;
status = H5Awrite(attr, strdatatype, (void *)(value.c_str()));
if (status < 0) TRIQS_RUNTIME_ERROR << "Can not write the attribute " << name;
}
/****************** Read string attribute *********************************************/
/// Return the attribute name of obj, and "" if the attribute does not exist.
std::string read_string_attribute(hid_t id, std::string name) {
// if the attribute is not present, return 0
if (H5LTfind_attribute(id, name.c_str()) == 0) return ""; // not present
attribute attr = H5Aopen(id, name.c_str(), H5P_DEFAULT);
if (!attr.is_valid()) TRIQS_RUNTIME_ERROR << "Can not open the attribute " << name;
dataspace space = H5Aget_space(attr);
int rank = H5Sget_simple_extent_ndims(space);
if (rank != 0) TRIQS_RUNTIME_ERROR << "Reading a string attribute and got rank !=0";
datatype strdatatype = H5Aget_type(attr);
std::vector<char> buf(H5Aget_storage_size(attr) + 1, 0x00);
auto err = H5Aread(attr, strdatatype, (void *)(&buf[0]));
if (err < 0) TRIQS_RUNTIME_ERROR << "Can not read the attribute" << name;
std::string ret = "";
ret.append(&(buf.front()));
return ret;
}
}
}