summaryrefslogtreecommitdiffstats
path: root/src/H5Fcore.c
blob: 4f8e21639a3242888e9147f57cb42caafb64667d (plain)
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
259
260
261
262
263
264
265
266
267
268
/*
 * Copyright (C) 1997 NCSA
 *		      All rights reserved.
 *
 * Programmer: Robb Matzke <matzke@llnl.gov>
 *	       Wednesday, October 22, 1997
 *
 * Purpose:    This file implements an in-core temporary file.	It's intended
 *	       for storing small temporary files such as wrappers generated
 *	       on the fly.
 *
 * Note:       This is mostly an exercise to help clean up parts of the H5F
 *	       package since this driver is quite different than the other
 *	       low level drivers we have so far.
 *
 */
#include <H5private.h>
#include <H5Eprivate.h>
#include <H5Fprivate.h>
#include <H5MMprivate.h>

#define H5F_CORE_DEV	0xffff	/*pseudo dev for core until we fix things */

#define PABLO_MASK	H5F_core
static hbool_t		interface_initialize_g = FALSE;
#define INTERFACE_INIT NULL

static hbool_t H5F_core_access(const char *name,
			       const H5F_access_t *access_parms, int mode,
			       H5F_search_t *key/*out*/);
static H5F_low_t *H5F_core_open(const char *name,
				const H5F_access_t *access_parms, uintn flags,
				H5F_search_t *key/*out*/);
static herr_t H5F_core_close(H5F_low_t *lf, const H5F_access_t *access_parms);
static herr_t H5F_core_read(H5F_low_t *lf, const H5F_access_t *access_parms,
			    const haddr_t *addr, size_t size, uint8 *buf);
static herr_t H5F_core_write(H5F_low_t *lf, const H5F_access_t *access_parms,
			     const haddr_t *addr, size_t size,
			     const uint8 *buf);

const H5F_low_class_t	H5F_LOW_CORE_g[1] = {{
    H5F_core_access,	    /* access method			    */
    H5F_core_open,	    /* open method			    */
    H5F_core_close,	    /* close method			    */
    H5F_core_read,	    /* read method			    */
    H5F_core_write,	    /* write method			    */
    NULL,		    /* flush method			    */
    NULL,		    /* extend method			    */
}};


/*-------------------------------------------------------------------------
 * Function:	H5F_core_access
 *
 * Purpose:	Determines if the specified file already exists.  This driver
 *		doesn't use names, so every call to H5F_core_open() would
 *		create a new file.  Therefore, this function always returns
 *		false and KEY is never initialized.
 *
 * Return:	Success:	FALSE
 *
 *		Failure:	FAIL
 *
 * Programmer:	Robb Matzke
 *		Friday, October 24, 1997
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static hbool_t
H5F_core_access(const char __unused__*name,
		const H5F_access_t __unused__ *access_parms,
		int __unused__ mode, H5F_search_t __unused__ *key/*out*/)
{
    FUNC_ENTER(H5F_core_access, FAIL);
    FUNC_LEAVE(FALSE);
}


/*-------------------------------------------------------------------------
 * Function:	H5F_core_open
 *
 * Purpose:	Opens a temporary file which will exist only in memory.	 The
 *		NAME argument is unused.  The FLAGS are a bit field with
 *		the possible values defined in H5F_low_open().
 *
 * Errors:
 *		IO	  CANTOPENFILE	Must creat file with write access. 
 *
 * Return:	Success:	Low-level file pointer
 *
 *		Failure:	NULL
 *
 * Programmer:	Robb Matzke
 *		Wednesday, October 22, 1997
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static H5F_low_t *
H5F_core_open(const char __unused__ *name,
	      const H5F_access_t __unused__ *access_parms,
	      uintn flags, H5F_search_t *key/*out*/)
{
    H5F_low_t		   *lf = NULL;
    static ino_t	    ino = 0;

    FUNC_ENTER(H5F_core_open, NULL);

    if (0 == (flags & H5F_ACC_RDWR) || 0 == (flags & H5F_ACC_CREAT)) {
	HRETURN_ERROR(H5E_IO, H5E_CANTOPENFILE, NULL,
		      "must creat file with write access");
    }
    
    lf = H5MM_xcalloc(1, sizeof(H5F_low_t));
    lf->u.core.mem = NULL;
    lf->u.core.alloc = 0;
    lf->u.core.size = 0;
    H5F_addr_reset(&(lf->eof));

    if (key) {
	key->dev = H5F_CORE_DEV;
	key->ino = ino++;
    }
    
    FUNC_LEAVE(lf);
}


/*-------------------------------------------------------------------------
 * Function:	H5F_core_close
 *
 * Purpose:	Closes a file.
 *
 * Errors:
 *
 * Return:	Success:	SUCCEED
 *
 *		Failure:	FAIL
 *
 * Programmer:	Robb Matzke
 *		Wednesday, October 22, 1997
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5F_core_close(H5F_low_t *lf, const H5F_access_t __unused__ *access_parms)
{
    FUNC_ENTER(H5F_core_close, FAIL);

    lf->u.core.mem = H5MM_xfree(lf->u.core.mem);
    lf->u.core.size = 0;
    lf->u.core.alloc = 0;

    FUNC_LEAVE(SUCCEED);
}


/*-------------------------------------------------------------------------
 * Function:	H5F_core_read
 *
 * Purpose:	Reads SIZE bytes beginning at address ADDR in file LF and
 *		places them in buffer BUF.  Reading past the logical or
 *		physical end of the file returns zeros instead of failing.
 *
 * Errors:
 *
 * Return:	Success:	SUCCEED
 *
 *		Failure:	FAIL
 *
 * Programmer:	Robb Matzke
 *		Wednesday, October 22, 1997
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5F_core_read(H5F_low_t *lf, const H5F_access_t __unused__ *access_parms,
	      const haddr_t *addr, size_t size, uint8 *buf)
{
    size_t		n;
    size_t		eof;

    FUNC_ENTER(H5F_core_read, FAIL);

    assert(lf);
    assert(addr && H5F_addr_defined(addr));
    assert(buf);

    eof = MIN(lf->eof.offset, lf->u.core.size);

    if (addr->offset >= eof) {
	HDmemset(buf, 0, size);
    } else {
	n = MIN(size, eof-addr->offset);
	HDmemcpy(buf, lf->u.core.mem + addr->offset, n);
	HDmemset(buf+n, 0, size-n);
    }

    FUNC_LEAVE(SUCCEED);
}


/*-------------------------------------------------------------------------
 * Function:	H5F_core_write
 *
 * Purpose:	Writes SIZE bytes from the beginning of BUF into file LF at
 *		file address ADDR.  The file is extended as necessary to
 *		accommodate the new data.
 *
 * Errors:
 *
 * Return:	Success:	SUCCEED
 *
 *		Failure:	FAIL
 *
 * Programmer:	Robb Matzke
 *		Wednesday, October 22, 1997
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5F_core_write(H5F_low_t *lf, const H5F_access_t *access_parms,
	       const haddr_t *addr, size_t size, const uint8 *buf)
{
    size_t		need_more;
    size_t		increment = 1;
    

    FUNC_ENTER(H5F_core_write, FAIL);

    assert(lf);
    assert(addr && H5F_addr_defined(addr));
    assert(buf);
    assert (!access_parms || H5F_LOW_CORE==access_parms->driver);

    /*
     * Allocate more space.  We always allocate a multiple of the increment
     * size, which is either defined in the file access property list or
     * which defaults to one.
     */
    if (addr->offset + size > lf->u.core.alloc) {
	if (access_parms) increment = access_parms->u.core.increment;
	need_more = addr->offset+size - lf->u.core.alloc;
	need_more = increment*((need_more+increment-1)/increment);

	lf->u.core.alloc = lf->u.core.alloc + need_more;
	lf->u.core.mem = H5MM_xrealloc(lf->u.core.mem, lf->u.core.alloc);
    }
    
    /* Move the physical EOF marker */
    if (addr->offset + size > lf->u.core.size) {
	lf->u.core.size = addr->offset + size;
    }
    
    /* Copy data */
    HDmemcpy(lf->u.core.mem+addr->offset, buf, size);

    FUNC_LEAVE(SUCCEED);
}