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
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
|
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* Copyright by The HDF Group. *
* 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 COPYING file, which can be found at the root of the source code *
* distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases. *
* If you do not have access to either file, you may request a copy from *
* help@hdfgroup.org. *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/* Purpose: A virtual object layer (VOL) connector that uses JSON to
* store HDF5 data and metadata.
*
* The JSON representation is taken from hdf5-json, though
* that code can't be directly used because it's in Python.
* (https://github.com/HDFGroup/hdf5-json)
*/
#include "hdf5.h"
#include "H5PLextern.h"
#include "json_vol_connector.h"
/* XXX: Note that we're going to have to guard most of the JSON VOL
* connector content with #ifdefs in the final product...
*/
/* The Jansson JSON parser */
#include <jansson.h>
/* libuuid for generating UUIDs */
#include <uuid/uuid.h>
#define SUCCEED 0
#define FAIL (-1)
/* Callbacks */
/* File */
static void *jvc_file_create(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id, hid_t dxpl_id, void **req);
static void *jvc_file_open(const char *name, unsigned flags, hid_t fapl_id, hid_t dxpl_id, void **req);
static herr_t jvc_file_close(void *file, hid_t dxpl_id, void **req);
/* The VOL class struct */
static const H5VL_class_t json_vol_g = {
JSON_VOL_CONNECTOR_VERSION, /* version */
JSON_VOL_CONNECTOR_VALUE, /* value */
JSON_VOL_CONNECTOR_NAME, /* name */
0, /* capability flags */
NULL, /* initialize */
NULL, /* terminate */
{ /* info_cls */
(size_t)0, /* info size */
NULL, /* info copy */
NULL, /* info compare */
NULL, /* info free */
NULL, /* info to str */
NULL /* str to info */
},
{ /* wrap_cls */
NULL, /* get_object */
NULL, /* get_wrap_ctx */
NULL, /* wrap_object */
NULL /* free_wrap_ctx */
},
{ /* attribute_cls */
NULL, /* create */
NULL, /* open */
NULL, /* read */
NULL, /* write */
NULL, /* get */
NULL, /* specific */
NULL, /* optional */
NULL /* close */
},
{ /* dataset_cls */
NULL, /* create */
NULL, /* open */
NULL, /* read */
NULL, /* write */
NULL, /* get */
NULL, /* specific */
NULL, /* optional */
NULL /* close */
},
{ /* datatype_cls */
NULL, /* commit */
NULL, /* open */
NULL, /* get_size */
NULL, /* specific */
NULL, /* optional */
NULL /* close */
},
{ /* file_cls */
jvc_file_create, /* create */
jvc_file_open, /* open */
NULL, /* get */
NULL, /* specific */
NULL, /* optional */
jvc_file_close /* close */
},
{ /* group_cls */
NULL, /* create */
NULL, /* open */
NULL, /* get */
NULL, /* specific */
NULL, /* optional */
NULL /* close */
},
{ /* link_cls */
NULL, /* create */
NULL, /* copy */
NULL, /* move */
NULL, /* get */
NULL, /* specific */
NULL /* optional */
},
{ /* object_cls */
NULL, /* open */
NULL, /* copy */
NULL, /* get */
NULL, /* specific */
NULL /* optional */
},
{ /* request_cls */
NULL, /* wait */
NULL, /* notify */
NULL, /* cancel */
NULL, /* specific */
NULL, /* optional */
NULL /* free */
},
NULL /* optional */
};
/* These two functions are necessary to load this plugin using
* the HDF5 library.
*/
H5PL_type_t H5PLget_plugin_type(void) {return H5PL_TYPE_VOL;}
const void *H5PLget_plugin_info(void) {return &json_vol_g;}
/******************/
/* IMPLEMENTATION */
/******************/
typedef struct json_vol_file_t {
FILE *fp; /* File pointer to JSON file */
json_t *root; /* Root of the JSON tree */
json_t *groups; /* JSON array of groups */
} json_vol_file_t;
#if 0
/* Helper functions */
static herr_t
jvc_helper_create_group(json_vol_file_t *jfile, char *group_name)
{
return SUCCEED;
} /* end jvc_helper_create_group() */
#endif
/* File callback implementation */
static void *
jvc_file_create(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id, hid_t dxpl_id, void **req)
{
json_vol_file_t *jfile = NULL;
/* Set up */
if(NULL == (jfile = (json_vol_file_t *)calloc((size_t)1, sizeof(json_vol_file_t))))
goto error;
/* Create the file */
if(NULL == (jfile->fp = fopen(name, "w")))
goto error;
/* Create the JSON root */
jfile->root = json_object();
/* Add the groups array */
jfile->groups = json_array();
json_object_set_new(jfile->root, "groups", jfile->groups);
return (void *)jfile;
error:
if(jfile->fp)
fclose(jfile->fp);
if(jfile)
free(jfile);
return NULL;
} /* end jvc_file_create() */
static void *
jvc_file_open(const char *name, unsigned flags, hid_t fapl_id, hid_t dxpl_id, void **req)
{
json_vol_file_t *jfile = NULL;
char *json_in = NULL;
long int file_size;
json_error_t jerror;
/* Set up */
if(NULL == (jfile = (json_vol_file_t *)calloc((size_t)1, sizeof(json_vol_file_t))))
goto error;
/* Open the file and get the size */
if(NULL == (jfile->fp = fopen(name, "r")))
goto error;
fseek(jfile->fp, 0, SEEK_END);
file_size = ftell(jfile->fp);
fseek(jfile->fp, 0, SEEK_SET);
/* Create the JSON root */
if(NULL == (json_in = (char *)malloc((size_t)(file_size + 1) * sizeof(char))))
goto error;
fread(json_in, (size_t)file_size, 1, jfile->fp);
jfile->root = json_loads(json_in, 0, &jerror);
/* Will still need to parse out the groups array */
free(json_in);
return (void *)jfile;
error:
if(json_in)
free(json_in);
if(jfile->fp)
fclose(jfile->fp);
if(jfile)
free(jfile);
return NULL;
} /* end jvc_file_open() */
static herr_t
jvc_file_close(void *file, hid_t dxpl_id, void **req)
{
json_vol_file_t *jfile = (json_vol_file_t *)file;
/* Dump the JSON string to the file */
fprintf(jfile->fp, "%s", json_dumps(jfile->root, 0));
/* Close the file */
if(EOF == fclose(jfile->fp))
goto error;
/* Decrement the reference count on the JSON root, closing it */
json_decref(jfile->root);
/* Tear down */
free(jfile);
return SUCCEED;
error:
return FAIL;
} /* end jvc_file_close() */
|
