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// Copyright (C) 2010, Guy Barrand. All rights reserved.
// See the file tools.license for terms.
 
#ifndef tools_hdf5_tools
#define tools_hdf5_tools
 
#include "hdf5_h"
 
#include <cstdlib>
 
namespace tools {
namespace hdf5 {
 
inline bool check_sizes(){
  if(sizeof(bool)!=1) return false;
  if(sizeof(char)!=1) return false;
  if(sizeof(short)!=2) return false;
  if(sizeof(int)!=4) return false;
  if(sizeof(float)!=4) return false;
  if(sizeof(double)!=8) return false;
  return true;
}
 
inline int failure() {return -1;}
 
inline hid_t string_datatype(size_t aSize){
  // aSize should include the trailing null char.
  hid_t datatype = ::H5Tcopy(H5T_C_S1);
  if(datatype<0) return failure();
 
  if(::H5Tset_size(datatype,aSize)<0) {
    ::H5Tclose(datatype);
    return failure();
  }
 
  if(::H5Tset_strpad(datatype,H5T_STR_NULLTERM)<0) {
    ::H5Tclose(datatype);
    return failure();
  }
 
  return datatype;
}
 
inline hid_t str_datatype() {
  hid_t datatype = ::H5Tcopy(H5T_C_S1);
  if(datatype<0) return failure();
  if(::H5Tset_size(datatype,H5T_VARIABLE)<0) {
    ::H5Tclose(datatype);
    return failure();
  }
  if(::H5Tset_strpad(datatype,H5T_STR_NULLTERM)<0) {
    ::H5Tclose(datatype);
    return failure();
  }
  return datatype;
}
 
inline hid_t basic_mem_type(hid_t a_file_type){
  H5T_class_t mclass = H5Tget_class(a_file_type);
  size_t msize = H5Tget_size(a_file_type);
  if(mclass==H5T_INTEGER) {
    H5T_sign_t msign = H5Tget_sign(a_file_type);
    if(msize==1) {
      if(msign==H5T_SGN_NONE) {
        return H5Tcopy(H5T_NATIVE_UCHAR);
      } else {
        return H5Tcopy(H5T_NATIVE_CHAR);
      }
    } else if(msize==4) {
      if(msign==H5T_SGN_NONE) {
        return H5Tcopy(H5T_NATIVE_UINT);
      } else {
        return H5Tcopy(H5T_NATIVE_INT);
      }
    } else if(msize==8) { //for osc_file::header::fDate.
      if(msign==H5T_SGN_NONE) {
        return H5Tcopy(H5T_NATIVE_UINT64);
      } else {
        return H5Tcopy(H5T_NATIVE_INT64);
      }
    } else {
      return failure();
    }
  } else if(mclass==H5T_FLOAT) {
    if(msize==4) {
      return H5Tcopy(H5T_NATIVE_FLOAT);
    } else if(msize==8) {
      return H5Tcopy(H5T_NATIVE_DOUBLE);
    } else {
      return failure();
    }
  } else if(mclass==H5T_STRING) {
    return H5Tcopy(a_file_type);
  }
 
  return failure();
}
 
}}
 
#include <vector>
 
namespace tools {
namespace hdf5 {
 
inline hid_t compound_mem_type(hid_t a_file_type){
  // FIXME : In principle H5T_get_native_type should do the job but it crashes.
 
  H5T_class_t t_class = H5Tget_class(a_file_type);
  if(t_class!=H5T_COMPOUND) return failure();
 
  size_t sz = H5Tget_size(a_file_type);
  //printf("debug : compound_mem_type : sz %lu\n",sz);
 
  hid_t mem_type = ::H5Tcreate(H5T_COMPOUND,sz);
  if(mem_type<0) return failure();
 
  //FIXME : WARNING : is order the booked order ?
 
  int mn = H5Tget_nmembers(a_file_type);
  std::vector<unsigned int> szs(mn);
  //printf("debug : members : %d\n",mn);
  for(int index=0;index<mn;index++) {
    char* mname = H5Tget_member_name(a_file_type,index);
    size_t moffset = H5Tget_member_offset(a_file_type,index);
    hid_t mtype = H5Tget_member_type(a_file_type,index);
    //printf("debug : members :   %d (%d) : %s : begin\n",index,mn,mname);
 
   {H5T_class_t mclass = H5Tget_class(mtype);
    if( (mclass==H5T_INTEGER) ||
        (mclass==H5T_STRING)  ||
        (mclass==H5T_FLOAT)   ) {
      hid_t mmem_type = basic_mem_type(mtype);
      if(mmem_type<0) {
        ::H5Tclose(mtype);
        if(mname) tools_H5free_memory(mname);
        ::H5Tclose(mem_type);
        return failure();
      }
      if(H5Tinsert(mem_type,mname,moffset,mmem_type)<0) {
        ::H5Tclose(mmem_type);
        ::H5Tclose(mtype);
        if(mname) tools_H5free_memory(mname);
        ::H5Tclose(mem_type);
        return failure();
      }
      ::H5Tclose(mmem_type);
 
    } else if(mclass==H5T_ARRAY) {
      int dimn = ::H5Tget_array_ndims(mtype); //Should be 1;
      hsize_t* dims = new hsize_t[dimn];
      int* perms = new int[dimn];
      if(tools_H5Tget_array_dims(mtype,dims,perms)<0) {
        delete [] dims;
        delete [] perms;
        ::H5Tclose(mtype);
        if(mname) tools_H5free_memory(mname);
        ::H5Tclose(mem_type);
        return failure();
      }
      hid_t base_type = H5Tget_super(mtype);
      if(base_type<0) {
        delete [] dims;
        delete [] perms;
        ::H5Tclose(mtype);
        if(mname) tools_H5free_memory(mname);
        ::H5Tclose(mem_type);
        return failure();
      }
      hid_t mmem_type = basic_mem_type(base_type);
      if(mmem_type<0) {
        delete [] dims;
        delete [] perms;
        ::H5Tclose(base_type);
        ::H5Tclose(mtype);
        if(mname) tools_H5free_memory(mname);
        ::H5Tclose(mem_type);
        return failure();
      }
      ::H5Tclose(base_type);
      hid_t array_type = tools_H5Tarray_create(mmem_type,dimn,dims,perms);
      delete [] dims;
      delete [] perms;
      if(array_type<0) {
        ::H5Tclose(mmem_type);
        ::H5Tclose(mtype);
        if(mname) tools_H5free_memory(mname);
        ::H5Tclose(mem_type);
        return failure();
      }
      ::H5Tclose(mmem_type);
 
      if(H5Tinsert(mem_type,mname,moffset,array_type)<0) {
        ::H5Tclose(array_type);
        ::H5Tclose(mtype);
        if(mname) tools_H5free_memory(mname);
        ::H5Tclose(mem_type);
        return failure();
      }
      ::H5Tclose(array_type);
 
    } else if(mclass==H5T_COMPOUND) {
      hid_t mmem_type = compound_mem_type(mtype);
      if(mem_type<0) {
        ::H5Tclose(mtype);
        if(mname) tools_H5free_memory(mname);
        ::H5Tclose(mem_type);
        return failure();
      }
      if(H5Tinsert(mem_type,mname,moffset,mmem_type)<0) {
        ::H5Tclose(mmem_type);
        ::H5Tclose(mtype);
        if(mname) tools_H5free_memory(mname);
        ::H5Tclose(mem_type);
        return failure();
      }
      ::H5Tclose(mmem_type);
    } else {
      ::H5Tclose(mtype);
      if(mname) tools_H5free_memory(mname);
      ::H5Tclose(mem_type);
      return failure();
    }}
    ::H5Tclose(mtype);
    //printf("debug : compound_mem_type :   %d (%d) : %s : end\n",index,mn,mname);
    if(mname) tools_H5free_memory(mname);
  }
 
  return mem_type;
}
 
}}
 
#include "atb"
#include <string>
 
namespace tools {
namespace hdf5 {
 
inline bool read_atb(hid_t a_id,const std::string& a_name,std::string& a_data,unsigned int aSize = 100){
  // From H5LT.c/H5LTget_attribute_string.
  if(!H5LT_find_attribute(a_id,a_name.c_str())) {a_data.clear();return false;}
  char* b = new char[aSize];
  if(H5LT_get_attribute_disk(a_id,a_name.c_str(),b)<0) {
    delete [] b;
    a_data.clear();
    return false;
  }
  a_data = std::string(b);
  delete [] b;
  return true;
}
 
inline bool read_atb(hid_t a_id,const std::string& a_name,unsigned int& a_data){
  if(!H5LT_find_attribute(a_id,a_name.c_str())) {a_data=0;return false;}
  if(H5LT_get_attribute_mem(a_id,a_name.c_str(),H5T_NATIVE_UINT,&a_data)<0) {a_data=0;return false;}
  return true;
}
 
inline bool read_atb(hid_t a_id,const std::string& a_name,int& a_data){
  if(!H5LT_find_attribute(a_id,a_name.c_str())) {a_data=0;return false;}
  if(H5LT_get_attribute_mem(a_id,a_name.c_str(),H5T_NATIVE_INT,&a_data)<0) {a_data=0;return false;}
  return true;
}
 
inline hid_t H5T_STD_U8XX() {return H5T_STD_U8LE;}
inline hid_t H5T_STD_U32XX() {return H5T_STD_U32LE;}
inline hid_t H5T_STD_U64XX() {return H5T_STD_U64LE;}
inline hid_t H5T_STD_I8XX() {return H5T_STD_I8LE;}
inline hid_t H5T_STD_I16XX() {return H5T_STD_I16LE;}
inline hid_t H5T_STD_I32XX() {return H5T_STD_I32LE;}
inline hid_t H5T_STD_I64XX() {return H5T_STD_I64LE;}
inline hid_t H5T_IEEE_F32XX() {return H5T_IEEE_F32LE;}
inline hid_t H5T_IEEE_F64XX() {return H5T_IEEE_F64LE;}
 
inline bool dataset_vec_size(hid_t a_loc,const std::string& a_name,hsize_t& a_size) {
  hid_t dataset = tools_H5Dopen(a_loc,a_name.c_str());
  if(dataset<0) {
    a_size = 0;
    return false; // data set not found.
  }
 
  hid_t file_space = H5Dget_space(dataset);
  if(file_space<0) {
    ::H5Dclose(dataset);
    a_size = 0;
    return false;
  }
 
  int dimn = H5Sget_simple_extent_ndims(file_space);
  if(dimn<0) {
    ::H5Sclose(file_space);
    ::H5Dclose(dataset);
    a_size = 0;
    return false;
  }
  if(dimn!=1) {
    ::H5Sclose(file_space);
    ::H5Dclose(dataset);
    a_size = 0;
    return false;
  }
  //printf("debug : read dimn %d\n",dimn);
 
  hsize_t dims[1];
 {if(H5Sget_simple_extent_dims(file_space,dims,NULL)<0) {
    ::H5Sclose(file_space);
    ::H5Dclose(dataset);
    a_size = 0;
    return false;
  }}
 
  ::H5Sclose(file_space);
  ::H5Dclose(dataset);
 
  a_size = dims[0];
  return true;
}
 
inline bool write_atb(hid_t a_id,const std::string& a_name,const std::string& a_data){
  // From H5LT.c/H5LTset_attribute_string.
  int has_attr = H5LT_find_attribute(a_id,a_name.c_str());
  if(has_attr==1)  {
    if(H5Adelete(a_id,a_name.c_str())<0) return false;
  }
 
  hid_t datatype = string_datatype(a_data.size()+1);
  if(datatype<0) return false;
 
  hid_t scalar = ::H5Screate(H5S_SCALAR);
  if(scalar<0) {
    ::H5Tclose(datatype);
    return false;
  }
 
  hid_t aid = tools_H5Acreate(a_id,a_name.c_str(),datatype,scalar,H5P_DEFAULT);
  if(aid<0) {
    ::H5Sclose(scalar);
    ::H5Tclose(datatype);
    return false;
  }
 
  if(H5Awrite(aid,datatype,a_data.c_str())<0) {
    ::H5Aclose(aid);
    ::H5Sclose(scalar);
    ::H5Tclose(datatype);
    return false;
  }
 
  ::H5Aclose(aid);
  ::H5Sclose(scalar);
  ::H5Tclose(datatype);
 
  return true;
}
 
inline bool write_bool(hid_t a_loc,const std::string& a_name,bool a_data) {
  hid_t scalar = ::H5Screate(H5S_SCALAR);
  if(scalar<0) return false;
 
  hid_t compact = ::H5Pcreate(H5P_DATASET_CREATE);
  if(compact<0) {
    ::H5Sclose(scalar);
    return false;
  }
  if(H5Pset_layout(compact,H5D_COMPACT)<0) {
    ::H5Pclose(compact);
    ::H5Sclose(scalar);
    return false;
  }
 
  hid_t dataset = tools_H5Dcreate(a_loc,a_name.c_str(),H5T_STD_U8XX(),scalar,compact);
  if(dataset<0) {
    ::H5Pclose(compact);
    ::H5Sclose(scalar);
    return false;
  }
 
  unsigned char data = a_data?1:0;
  if(::H5Dwrite(dataset,H5T_NATIVE_UCHAR,H5S_ALL,H5S_ALL,H5P_DEFAULT,&data)<0) {
    ::H5Pclose(compact);
    ::H5Sclose(scalar);
    ::H5Dclose(dataset);
    return false;
  }
 
  ::H5Pclose(compact);
  ::H5Sclose(scalar);
  ::H5Dclose(dataset);
  return true;
}
 
inline bool write_string(hid_t a_loc,const std::string& a_name,const std::string& a_string) {
  hid_t scalar = ::H5Screate(H5S_SCALAR);
  if(scalar<0) return false;
 
  hid_t compact = ::H5Pcreate(H5P_DATASET_CREATE);
  if(compact<0) {
    ::H5Sclose(scalar);
    return false;
  }
 
  if(H5Pset_layout(compact,H5D_COMPACT)<0) {
    ::H5Pclose(compact);
    ::H5Sclose(scalar);
    return false;
  }
 
  // From H5LTmakge_dataset_string.
  hid_t file_type = string_datatype(a_string.size()+1);
  if(file_type<0) {
    ::H5Pclose(compact);
    ::H5Sclose(scalar);
    return false;
  }
 
  hid_t dataset = tools_H5Dcreate(a_loc,a_name.c_str(),file_type,scalar,compact);
  if(dataset<0) {
    ::H5Pclose(compact);
    ::H5Sclose(scalar);
    ::H5Tclose(file_type);
    return false;
  }
 
  hid_t mem_type = file_type;
  if(H5Dwrite(dataset,mem_type,H5S_ALL,H5S_ALL,H5P_DEFAULT,a_string.c_str())<0) {
    ::H5Pclose(compact);
    ::H5Sclose(scalar);
    ::H5Dclose(dataset);
    ::H5Tclose(file_type);
    return false;
  }
 
  ::H5Pclose(compact);
  ::H5Sclose(scalar);
  ::H5Dclose(dataset);
  ::H5Tclose(file_type);
 
  return true;
}
 
inline bool write_string_dataset(hid_t a_loc,const std::string& a_name,
                                 unsigned int a_chunked,unsigned int a_compress,
                                 const std::string& a_string) {
  hid_t cpt = -1;
  if(a_compress || a_chunked) {
    cpt = ::H5Pcreate(H5P_DATASET_CREATE);
    if(cpt<0) return false;
    if(a_chunked) {
      if(H5Pset_layout(cpt,H5D_CHUNKED)<0) {
        ::H5Pclose(cpt);
        return false;
      }
      hsize_t cdims[1];
      cdims[0] = a_chunked;
      if(H5Pset_chunk(cpt,1,cdims)<0) {
        ::H5Pclose(cpt);
        return false;
      }
    } else {
      if(H5Pset_layout(cpt,H5D_COMPACT)<0) {
        ::H5Pclose(cpt);
        return false;
      }
    }
    if(a_compress) {
      if(H5Pset_deflate(cpt,a_compress>9?9:a_compress)<0) {
        ::H5Pclose(cpt);
        return false;
      }
    }
  } else {
    cpt = H5P_DEFAULT;
  }
 
  hid_t file_type = str_datatype(); //first input => H5T_VARIABLE.
  if(file_type<0) {
    if(cpt>=0) ::H5Pclose(cpt);
    return false;
  }
 
  hid_t file_space = -1;
 {hsize_t dims[1];
  dims[0] = 1;
  if(a_chunked) {
    hsize_t mx_dims[1];
    mx_dims[0] = H5S_UNLIMITED; //extendable.
    file_space = ::H5Screate_simple(1,dims,mx_dims);
  } else {
    file_space = ::H5Screate_simple(1,dims,NULL);
  }
  if(file_space<0) {if(cpt>=0) ::H5Pclose(cpt);::H5Tclose(file_type);return false;}}
 
  hid_t dataset = tools_H5Dcreate(a_loc,a_name.c_str(),file_type,file_space,cpt);
  if(cpt>=0) ::H5Pclose(cpt);
  ::H5Sclose(file_space);
  if(dataset<0) {
    ::H5Tclose(file_type);
    return false;
  }
 
  hid_t mem_type = file_type;
 
  const char* wdata[1];
  wdata[0] = a_string.c_str();
 
  if(H5Dwrite(dataset,mem_type,H5S_ALL,H5S_ALL,H5P_DEFAULT,wdata)<0) {
    ::H5Dclose(dataset);
    ::H5Tclose(file_type);
    return false;
  }
 
  ::H5Tclose(file_type);
  ::H5Dclose(dataset);
 
  return true;
}
 
inline bool write_string_dataset(hid_t a_loc,const std::string& a_name,
                                 const std::string& a_string,
                                 unsigned int a_chunked = 0,unsigned int a_compress = 0) {
  return hdf5::write_string_dataset(a_loc,a_name,a_chunked,a_compress,a_string);
}
 
inline bool write_append_string_dataset(hid_t a_dataset,const std::string& a_string) {
  hsize_t old_size = 0;
 
 {hid_t dataspace = H5Dget_space(a_dataset);
  if(dataspace<0) return false;
  hsize_t dims[1];
  if(H5Sget_simple_extent_dims(dataspace,dims,NULL)<0) {
    ::H5Sclose(dataspace);
    return false;
  }
  old_size = dims[0];
  ::H5Sclose(dataspace);}
 
 {hsize_t exts[1];
  exts[0] = old_size+1;
//  if(H5Dextend(dataset,exts)<0) {
  if(H5Dset_extent(a_dataset,exts)<0) return false;}
 
  hid_t file_space = H5Dget_space(a_dataset);
  if(file_space<0) return false;
 
 {hsize_t offset[1];
  offset[0] = old_size;
  hsize_t count[1];
  count[0] = 1;
  if(H5Sselect_hyperslab(file_space,H5S_SELECT_SET,offset,NULL,count,NULL)<0) {
    ::H5Sclose(file_space);
    return false;
  }}
 
  hsize_t dims[1];
  dims[0] = 1;
  hid_t mem_space = ::H5Screate_simple(1,dims,NULL);
  if(mem_space<0) {
    ::H5Sclose(file_space);
    return false;
  }
 
  hid_t mem_type = str_datatype();
  if(mem_type<0) {
    ::H5Sclose(mem_space);
    ::H5Sclose(file_space);
    return false;
  }
 
  const char* wdata[1];
  wdata[0] = a_string.c_str();
 
  if(H5Dwrite(a_dataset,mem_type,mem_space,file_space,H5P_DEFAULT,wdata)<0) {
    ::H5Tclose(mem_type);
    ::H5Sclose(mem_space);
    ::H5Sclose(file_space);
    return false;
  }
 
  ::H5Tclose(mem_type);
  ::H5Sclose(mem_space);
  ::H5Sclose(file_space);
 
  return true;
}
 
}}
 
#include <tools/buf2lines>
 
namespace tools {
namespace hdf5 {
 
inline bool write_array_string(hid_t a_loc,const std::string& a_name,const std::vector<std::string>& a_array) {
  hid_t scalar = ::H5Screate(H5S_SCALAR);
  if(scalar<0) return false;
 
  // From H5LTmake_dataset_string.
  size_t sz;
  char* buffer;
  if(!tools::strings2buf(a_array,sz,buffer)) {
    ::H5Sclose(scalar);
    return false;
  }
 
  hid_t file_type = string_datatype(sz);
  if(file_type<0) {
    delete [] buffer;
    ::H5Sclose(scalar);
    return false;
  }
 
  hid_t dataset = tools_H5Dcreate(a_loc,a_name.c_str(),file_type,scalar,H5P_DEFAULT);
  if(dataset<0) {
    delete [] buffer;
    ::H5Tclose(file_type);
    ::H5Sclose(scalar);
    return false;
  }
 
  hid_t mem_type = file_type;
  if(H5Dwrite(dataset,mem_type,H5S_ALL,H5S_ALL,H5P_DEFAULT,buffer)<0) {
    delete [] buffer;
    ::H5Dclose(dataset);
    ::H5Tclose(file_type);
    ::H5Sclose(scalar);
    return false;
  }
 
  delete [] buffer;
 
  ::H5Dclose(dataset);
  ::H5Tclose(file_type);
  ::H5Sclose(scalar);
  return true;
}
 
inline bool write_object(hid_t a_loc,const std::string& a_name,hid_t a_file_type,char* a_data) {
  unsigned int chunked = 0;
  unsigned int compress = 0;
 
  hid_t cpt = -1;
  if(compress || chunked) {
    cpt = ::H5Pcreate(H5P_DATASET_CREATE);
    if(cpt<0) return false;
    if(chunked) {
      if(H5Pset_layout(cpt,H5D_CHUNKED)<0) {
        ::H5Pclose(cpt);
        return false;
      }
      hsize_t cdims[1];
      cdims[0] = chunked;
      if(H5Pset_chunk(cpt,1,cdims)<0) {
        ::H5Pclose(cpt);
        return false;
      }
    } else {
      if(H5Pset_layout(cpt,H5D_COMPACT)<0) {
        ::H5Pclose(cpt);
        return false;
      }
    }
    if(compress) {
      if(H5Pset_deflate(cpt,compress>9?9:compress)<0) {
        ::H5Pclose(cpt);
        return false;
      }
    }
  } else {
    cpt = H5P_DEFAULT;
  }
 
  hsize_t dims[1];
  dims[0] = 1;
  hid_t simple = ::H5Screate_simple(1,dims,NULL);
  if(simple<0) {
    if(cpt>=0) ::H5Pclose(cpt);
    return false;
  }
 
  hid_t mem_type = compound_mem_type(a_file_type);
  if(mem_type<0) {
    ::H5Sclose(simple);
    if(cpt>=0) ::H5Pclose(cpt);
    return false;
  }
 
  hid_t dataset = tools_H5Dcreate(a_loc,a_name.c_str(),a_file_type,simple,cpt);
  if(dataset<0) {
    ::H5Tclose(mem_type);
    ::H5Sclose(simple);
    if(cpt>=0) ::H5Pclose(cpt);
    return false;
  }
 
  if(H5Dwrite(dataset,mem_type,H5S_ALL,H5S_ALL,H5P_DEFAULT,a_data)<0) {
    ::H5Dclose(dataset);
    ::H5Tclose(mem_type);
    ::H5Sclose(simple);
    if(cpt>=0) ::H5Pclose(cpt);
    return false;
  }
 
  ::H5Dclose(dataset);
  ::H5Tclose(mem_type);
  ::H5Sclose(simple);
  if(cpt>=0) ::H5Pclose(cpt);
 
  return true;
}
 
inline bool read_string(hid_t a_loc,const std::string& a_name,std::string& a_string) {
  // From H5LTread_dataset_string.
  hid_t dataset = tools_H5Dopen(a_loc,a_name.c_str());
  if(dataset<0) {
    a_string.clear();
    return false; // data set not found.
  }
 
  hid_t file_type = H5Dget_type(dataset);
  if(file_type<0) {
    ::H5Dclose(dataset);
    a_string.clear();
    return false;
  }
 
  H5T_class_t t_class = H5Tget_class(file_type);
  if(t_class!=H5T_STRING) {
    ::H5Tclose(file_type);
    ::H5Dclose(dataset);
    a_string.clear();
    return false;
  }
 
  size_t sz = H5Tget_size(file_type);
  ::H5Tclose(file_type);
  if(!sz) {
    ::H5Dclose(dataset);
    a_string.clear();
    return false;
  }
 
  // We could have use file_type since, for string,
  // file type is the same than memory type.
  hid_t mem_type = string_datatype(sz);
  if(mem_type<0) {
    ::H5Dclose(dataset);
    a_string.clear();
    return false;
  }
 
  char* buff = new char[sz];
  herr_t stat = H5Dread(dataset,mem_type,H5S_ALL,H5S_ALL,H5P_DEFAULT,buff);
  ::H5Tclose(mem_type);
  ::H5Dclose(dataset);
  if(stat<0) {
    delete [] buff;
    a_string.clear();
    return false;
  }
 
  size_t len = sz-1;
  a_string.resize(len,0);
  for(size_t index=0;index<len;index++) a_string[index] = buff[index];
 
  delete [] buff;
 
  return true;
}
 
inline bool read_sub_string(hid_t a_loc,const std::string& a_name,unsigned int a_offset,std::string& a_string) {
  hid_t dataset = tools_H5Dopen(a_loc,a_name.c_str());
  if(dataset<0) {
    a_string.clear();
    return false; // data set not found.
  }
 
  hid_t file_space = H5Dget_space(dataset);
  if(file_space<0) {
    ::H5Dclose(dataset);
    a_string.clear();
    return false;
  }
 
 {int dimn = H5Sget_simple_extent_ndims(file_space);
  if(dimn<0) {
    ::H5Sclose(file_space);
    ::H5Dclose(dataset);
    a_string.clear();
    return false;
  }
  if(dimn!=1) {
    ::H5Sclose(file_space);
    ::H5Dclose(dataset);
    a_string.clear();
    return false;
  }}
 
  hsize_t dims[1];
 {if(H5Sget_simple_extent_dims(file_space,dims,NULL)<0) {
    ::H5Sclose(file_space);
    ::H5Dclose(dataset);
    a_string.clear();
    return false;
  }}
 
 {unsigned int sz = (unsigned int)dims[0];
  if(!sz) {
    ::H5Sclose(file_space);
    ::H5Dclose(dataset);
    a_string.clear();
    return false; //Is it ok ?
  }
 
  //  abcdef
  //  012345
  int remain = sz-a_offset;
  if(remain<=0) {
    ::H5Sclose(file_space);
    ::H5Dclose(dataset);
    a_string.clear();
    return false;
  }}
 
 {hsize_t offset[1];
  offset[0] = a_offset;
  hsize_t count[1];
  count[0] = 1;
  if(H5Sselect_hyperslab(file_space,H5S_SELECT_SET,offset,NULL,count,NULL)<0) {
    ::H5Sclose(file_space);
    ::H5Dclose(dataset);
    a_string.clear();
    return false;
  }}
 
  dims[0] = 1;
  hid_t mem_space = ::H5Screate_simple(1,dims,NULL);
  if(mem_space<0) {
    ::H5Sclose(file_space);
    ::H5Dclose(dataset);
    a_string.clear();
    return false;
  }
 
  hid_t file_type = H5Dget_type(dataset);
  if(file_type<0) {
    ::H5Sclose(file_space);
    ::H5Dclose(dataset);
    a_string.clear();
    return false;
  }
 
  H5T_class_t t_class = H5Tget_class(file_type);
  if(t_class!=H5T_STRING) {
    ::H5Tclose(file_type);
    ::H5Sclose(file_space);
    ::H5Dclose(dataset);
    a_string.clear();
    return false;
  }
 
//size_t sz = H5Tget_size(file_type); //it gives the largest string size in the dataset.
//if(!sz) {
//  ::H5Tclose(file_type);
//  ::H5Sclose(file_space);
//  ::H5Dclose(dataset);
//  a_string.clear();
//  return false;
//}
 
  ::H5Tclose(file_type);
 
  hid_t mem_type = str_datatype();
  if(mem_type<0) {
    ::H5Sclose(file_space);
    ::H5Dclose(dataset);
    a_string.clear();
    return false;
  }
 
  char* rdata[1];
  herr_t stat = H5Dread(dataset,mem_type,mem_space,file_space,H5P_DEFAULT,rdata);
  if(stat<0) {
    ::H5Dvlen_reclaim(mem_type,mem_space, H5P_DEFAULT,rdata);
    ::H5Tclose(mem_type);
    ::H5Sclose(mem_space);
    ::H5Sclose(file_space);
    ::H5Dclose(dataset);
    a_string.clear();
    return false;
  }
 
  char* buff = rdata[0];
 
  size_t len = ::strlen(buff);
  a_string.resize(len,0);
  for(size_t index=0;index<len;index++) a_string[index] = buff[index];
 
  ::H5Dvlen_reclaim(mem_type,mem_space, H5P_DEFAULT,rdata);
 
  ::H5Tclose(mem_type);
  ::H5Sclose(mem_space);
  ::H5Sclose(file_space);
  ::H5Dclose(dataset);
 
  return true;
}
 
inline bool read_object(hid_t a_loc,const std::string& a_name,size_t& a_size,char*& a_data) {
  hid_t dataset = tools_H5Dopen(a_loc,a_name.c_str());
  if(dataset<0) {
    a_size = 0;
    a_data = 0;
    return false;
  }
 
  hid_t file_type = H5Dget_type(dataset);
  if(file_type<0) {
    ::H5Dclose(dataset);
    a_size = 0;
    a_data = 0;
    return false;
  }
 
  H5T_class_t t_class = H5Tget_class(file_type);
  if(t_class!=H5T_COMPOUND) {
    ::H5Tclose(file_type);
    ::H5Dclose(dataset);
    a_size = 0;
    a_data = 0;
    return false;
  }
 
  size_t sz = H5Tget_size(file_type);
  if(!sz) {
    ::H5Tclose(file_type);
    ::H5Dclose(dataset);
    a_size = 0;
    a_data = 0;
    return false;
  }
 
  hid_t mem_type = compound_mem_type(file_type);
  if(mem_type<0) {
    ::H5Tclose(file_type);
    ::H5Dclose(dataset);
    a_size = 0;
    a_data = 0;
    return false;
  }
 
  ::H5Tclose(file_type);
 
  hid_t dataspace = H5Dget_space(dataset);
  if(dataspace<0) {
    ::H5Tclose(mem_type);
    ::H5Dclose(dataset);
    a_size = 0;
    a_data = 0;
    return false;
  }
 
  hid_t scalar = ::H5Screate(H5S_SCALAR);
  if(scalar<0) {
    ::H5Sclose(dataspace);
    ::H5Tclose(mem_type);
    ::H5Dclose(dataset);
    a_size = 0;
    a_data = 0;
    return false;
  }
 
  char* buffer = new char[sz];
  if(H5Dread(dataset,mem_type,scalar,dataspace,H5P_DEFAULT,buffer)<0) {
    delete [] buffer;
    ::H5Sclose(scalar);
    ::H5Sclose(dataspace);
    ::H5Tclose(mem_type);
    ::H5Dclose(dataset);
    a_size = 0;
    a_data = 0;
    return false;
  }
 
  ::H5Sclose(scalar);
  ::H5Sclose(dataspace);
  ::H5Tclose(mem_type);
  ::H5Dclose(dataset);
 
  a_size = sz;
  a_data = buffer;
  return true;
}
 
inline bool read_array_string(hid_t a_loc,const std::string& a_name,std::vector<std::string>& a_array) {
  a_array.clear();
  hid_t dataset = tools_H5Dopen(a_loc,a_name.c_str());
  if(dataset<0) return false;
 
  hid_t file_type = H5Dget_type(dataset);
  if(file_type<0) {
    ::H5Dclose(dataset);
    return false;
  }
 
  H5T_class_t t_class = H5Tget_class(file_type);
  if(t_class!=H5T_STRING) {
    ::H5Tclose(file_type);
    ::H5Dclose(dataset);
    return false;
  }
 
  size_t sz = H5Tget_size(file_type);
  ::H5Tclose(file_type);
  if(!sz) {
    ::H5Dclose(dataset);
    return false;
  }
 
  // We could have use file_type since, for string,
  // file type is the same than memory type.
  hid_t mem_type = string_datatype(sz);
  if(mem_type<0) {
    ::H5Dclose(dataset);
    return false;
  }
 
  char* buffer = new char[sz];
  herr_t stat = H5Dread(dataset,mem_type,H5S_ALL,H5S_ALL,H5P_DEFAULT,buffer);
  ::H5Tclose(mem_type);
  ::H5Dclose(dataset);
  if(stat<0) {
    delete [] buffer;
    return false;
  }
 
  if(!tools::buf2strings(sz,buffer,a_array)) {
    delete [] buffer;
    return false;
  }
 
  delete [] buffer;
  return true;
}
 
}}
 
#endif