1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
|
//
// 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.
//
#include <string>
#ifndef H5_NO_NAMESPACE
using namespace std;
#endif
#ifdef OLD_HEADER_FILENAME
#include <iostream.h>
#else
#include <iostream>
#endif
#include "H5Cpp.h"
#ifndef H5_NO_NAMESPACE
using namespace H5;
#endif
const string FILE_NAME( "Group.h5" );
const int RANK = 2;
// Operator function
extern "C" herr_t file_info(hid_t loc_id, const char *name, 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
{
// 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( RANK, dims ); // create the new dataspace
// for the dataset
DSetCreatPropList ds_creatplist; // create dataset creation prop list
ds_creatplist.setChunk( 2, cdims ); // then modify it for compression
ds_creatplist.setDeflate( 6 );
DataSet* dataset = new DataSet( file->createDataSet( "/Data/Compressed_Data", PredType::NATIVE_INT, dataspace, ds_creatplist ));
//
// Close the dataset and the file.
//
delete dataset;
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( H5G_LINK_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 = H5Giterate(file->getId(), "/", 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 = H5Giterate(file->getId(), "/", NULL, file_info, NULL);
cout << endl;
// Close the file.
delete file;
} // end of try block
// catch failure caused by the H5File operations
catch( FileIException error )
{
error.printError();
}
// catch failure caused by the DataSet operations
catch( DataSetIException error )
{
error.printError();
}
// catch failure caused by the DataSpace operations
catch( DataSpaceIException error )
{
error.printError();
}
// catch failure caused by the Attribute operations
catch( AttributeIException error )
{
error.printError();
}
return 0;
}
//
// Operator function.
//
herr_t
file_info(hid_t loc_id, const char *name, void *opdata)
{
hid_t group;
//
// Open the group using its name.
//
group = H5Gopen(loc_id, name);
//
// Display group name.
//
cout << "Name : " << name << endl;
H5Gclose(group);
return 0;
}
|
