/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Copyright by The HDF Group. * * Copyright by the Board of Trustees of the University of Illinois. * * All rights reserved. * * * * This file is part of HDF5. The full HDF5 copyright notice, including * * terms governing use, modification, and redistribution, is contained in * * the files COPYING and Copyright.html. COPYING can be found at the root * * of the source code distribution tree; Copyright.html can be found at the * * root level of an installed copy of the electronic HDF5 document set and * * is linked from the top-level documents page. It can also be found at * * http://hdfgroup.org/HDF5/doc/Copyright.html. If you do not have * * access to either file, you may request a copy from help@hdfgroup.org. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /* * This example creates a group in the file and dataset in the group. * Hard link to the group object is created and the dataset is accessed * under different names. * Iterator function is used to find the object names in the root group. * Note that the C++ API iterator function is not completed yet, thus * the C version is used in this example. */ #ifdef OLD_HEADER_FILENAME #include <iostream.h> #else #include <iostream> #endif #include <string> #ifndef H5_NO_NAMESPACE #ifndef H5_NO_STD using std::cout; using std::endl; #endif // H5_NO_STD #endif #include "H5Cpp.h" #ifndef H5_NO_NAMESPACE using namespace H5; #endif const H5std_string FILE_NAME( "Group.h5" ); const int RANK = 2; // Operator function extern "C" herr_t file_info(hid_t loc_id, const char *name, const H5L_info_t *linfo, void *opdata); int main(void) { hsize_t dims[2]; hsize_t cdims[2]; // Try block to detect exceptions raised by any of the calls inside it try { /* * Turn off the auto-printing when failure occurs so that we can * handle the errors appropriately */ Exception::dontPrint(); /* * Create the named file, truncating the existing one if any, * using default create and access property lists. */ H5File *file = new H5File( FILE_NAME, H5F_ACC_TRUNC ); /* * Create a group in the file */ Group* group = new Group( file->createGroup( "/Data" )); /* * Create dataset "Compressed Data" in the group using absolute * name. Dataset creation property list is modified to use * GZIP compression with the compression effort set to 6. * Note that compression can be used only when dataset is chunked. */ dims[0] = 1000; dims[1] = 20; cdims[0] = 20; cdims[1] = 20; DataSpace *dataspace = new DataSpace(RANK, dims); // create new dspace DSetCreatPropList ds_creatplist; // create dataset creation prop list ds_creatplist.setChunk( 2, cdims ); // then modify it for compression ds_creatplist.setDeflate( 6 ); /* * Create the first dataset. */ DataSet* dataset = new DataSet(file->createDataSet( "/Data/Compressed_Data", PredType::NATIVE_INT, *dataspace, ds_creatplist )); /* * Close the first dataset. */ delete dataset; delete dataspace; /* * Create the second dataset. */ dims[0] = 500; dims[1] = 20; dataspace = new DataSpace(RANK, dims); // create second dspace dataset = new DataSet(file->createDataSet("/Data/Float_Data", PredType::NATIVE_FLOAT, *dataspace)); delete dataset; delete dataspace; delete group; delete file; /* * Now reopen the file and group in the file. */ file = new H5File(FILE_NAME, H5F_ACC_RDWR); group = new Group(file->openGroup("Data")); /* * Access "Compressed_Data" dataset in the group. */ try { // to determine if the dataset exists in the group dataset = new DataSet( group->openDataSet( "Compressed_Data" )); } catch( GroupIException not_found_error ) { cout << " Dataset is not found." << endl; } cout << "dataset \"/Data/Compressed_Data\" is open" << endl; /* * Close the dataset. */ delete dataset; /* * Create hard link to the Data group. */ file->link( H5L_TYPE_HARD, "Data", "Data_new" ); /* * We can access "Compressed_Data" dataset using created * hard link "Data_new". */ try { // to determine if the dataset exists in the file dataset = new DataSet(file->openDataSet( "/Data_new/Compressed_Data" )); } catch( FileIException not_found_error ) { cout << " Dataset is not found." << endl; } cout << "dataset \"/Data_new/Compressed_Data\" is open" << endl; /* * Close the dataset. */ delete dataset; /* * Use iterator to see the names of the objects in the file * root directory. */ cout << endl << "Iterating over elements in the file" << endl; herr_t idx = H5Literate(file->getId(), H5_INDEX_NAME, H5_ITER_INC, NULL, file_info, NULL); cout << endl; /* * Unlink name "Data" and use iterator to see the names * of the objects in the file root direvtory. */ cout << "Unlinking..." << endl; try { // attempt to unlink the dataset file->unlink( "Data" ); } catch( FileIException unlink_error ) { cout << " unlink failed." << endl; } cout << "\"Data\" is unlinked" << endl; cout << endl << "Iterating over elements in the file again" << endl; idx = H5Literate(file->getId(), H5_INDEX_NAME, H5_ITER_INC, NULL, file_info, NULL); cout << endl; /* * Close the group and file. */ delete group; delete file; } // end of try block // catch failure caused by the H5File operations catch( FileIException error ) { error.printError(); return -1; } // catch failure caused by the DataSet operations catch( DataSetIException error ) { error.printError(); return -1; } // catch failure caused by the DataSpace operations catch( DataSpaceIException error ) { error.printError(); return -1; } // catch failure caused by the Attribute operations catch( AttributeIException error ) { error.printError(); return -1; } return 0; } /* * Operator function. */ herr_t file_info(hid_t loc_id, const char *name, const H5L_info_t *linfo, void *opdata) { hid_t group; /* * Open the group using its name. */ group = H5Gopen2(loc_id, name, H5P_DEFAULT); /* * Display group name. */ cout << "Name : " << name << endl; H5Gclose(group); return 0; }
1.6.2