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
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
|
/* Copyright (C) 2000 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/* Handling of arrays that can grow dynamicly. */
#include "config.h"
#include "drizzled/internal/my_sys.h"
#include "drizzled/internal/m_string.h"
#include <algorithm>
using namespace std;
namespace drizzled
{
static bool allocate_dynamic(DYNAMIC_ARRAY *array, uint32_t max_elements);
/*
Initiate dynamic array
SYNOPSIS
init_dynamic_array2()
array Pointer to an array
element_size Size of element
init_buffer Initial buffer pointer
init_alloc Number of initial elements
alloc_increment Increment for adding new elements
DESCRIPTION
init_dynamic_array() initiates array and allocate space for
init_alloc eilements.
Array is usable even if space allocation failed.
Static buffers must begin immediately after the array structure.
RETURN VALUE
true malloc() failed
false Ok
*/
bool init_dynamic_array2(DYNAMIC_ARRAY *array, uint32_t element_size,
void *init_buffer, uint32_t init_alloc,
uint32_t alloc_increment)
{
if (!alloc_increment)
{
alloc_increment=max((8192-MALLOC_OVERHEAD)/element_size,16U);
if (init_alloc > 8 && alloc_increment > init_alloc * 2)
alloc_increment=init_alloc*2;
}
if (!init_alloc)
{
init_alloc=alloc_increment;
init_buffer= 0;
}
array->elements=0;
array->max_element=init_alloc;
array->alloc_increment=alloc_increment;
array->size_of_element=element_size;
if ((array->buffer= (unsigned char*) init_buffer))
return(false);
if (!(array->buffer=(unsigned char*) malloc(element_size*init_alloc)))
{
array->max_element=0;
return(true);
}
return(false);
}
/*
Insert element at the end of array. Allocate memory if needed.
SYNOPSIS
insert_dynamic()
array
element
RETURN VALUE
true Insert failed
false Ok
*/
bool insert_dynamic(DYNAMIC_ARRAY *array, unsigned char* element)
{
unsigned char* buffer;
if (array->elements == array->max_element)
{ /* Call only when nessesary */
if (!(buffer=alloc_dynamic(array)))
return true;
}
else
{
buffer=array->buffer+(array->elements * array->size_of_element);
array->elements++;
}
memcpy(buffer,element,(size_t) array->size_of_element);
return false;
}
/*
Alloc space for next element(s)
SYNOPSIS
alloc_dynamic()
array
DESCRIPTION
alloc_dynamic() checks if there is empty space for at least
one element if not tries to allocate space for alloc_increment
elements at the end of array.
RETURN VALUE
pointer Pointer to empty space for element
0 Error
*/
unsigned char *alloc_dynamic(DYNAMIC_ARRAY *array)
{
if (array->elements == array->max_element)
{
char *new_ptr;
if (array->buffer == (unsigned char *)(array + 1))
{
/*
In this senerio, the buffer is statically preallocated,
so we have to create an all-new malloc since we overflowed
*/
if (!(new_ptr= (char *) malloc((array->max_element+
array->alloc_increment) *
array->size_of_element)))
return 0;
memcpy(new_ptr, array->buffer,
array->elements * array->size_of_element);
}
else if (!(new_ptr= (char*) realloc(array->buffer,
(array->max_element+
array->alloc_increment)*
array->size_of_element)))
return 0;
array->buffer= (unsigned char*) new_ptr;
array->max_element+=array->alloc_increment;
}
return array->buffer+(array->elements++ * array->size_of_element);
}
/*
Pop last element from array.
SYNOPSIS
pop_dynamic()
array
RETURN VALUE
pointer Ok
0 Array is empty
*/
unsigned char *pop_dynamic(DYNAMIC_ARRAY *array)
{
if (array->elements)
return array->buffer+(--array->elements * array->size_of_element);
return 0;
}
/*
Replace element in array with given element and index
SYNOPSIS
set_dynamic()
array
element Element to be inserted
idx Index where element is to be inserted
DESCRIPTION
set_dynamic() replaces element in array.
If idx > max_element insert new element. Allocate memory if needed.
RETURN VALUE
true Idx was out of range and allocation of new memory failed
false Ok
*/
bool set_dynamic(DYNAMIC_ARRAY *array, unsigned char* element, uint32_t idx)
{
if (idx >= array->elements)
{
if (idx >= array->max_element && allocate_dynamic(array, idx))
return true;
memset(array->buffer+array->elements*array->size_of_element, 0,
(idx - array->elements)*array->size_of_element);
array->elements=idx+1;
}
memcpy(array->buffer+(idx * array->size_of_element),element,
(size_t) array->size_of_element);
return false;
}
/*
Ensure that dynamic array has enough elements
SYNOPSIS
allocate_dynamic()
array
max_elements Numbers of elements that is needed
NOTES
Any new allocated element are NOT initialized
RETURN VALUE
false Ok
true Allocation of new memory failed
*/
static bool allocate_dynamic(DYNAMIC_ARRAY *array, uint32_t max_elements)
{
if (max_elements >= array->max_element)
{
uint32_t size;
unsigned char *new_ptr;
size= (max_elements + array->alloc_increment)/array->alloc_increment;
size*= array->alloc_increment;
if (array->buffer == (unsigned char *)(array + 1))
{
/*
In this senerio, the buffer is statically preallocated,
so we have to create an all-new malloc since we overflowed
*/
if (!(new_ptr= (unsigned char *) malloc(size *
array->size_of_element)))
return 0;
memcpy(new_ptr, array->buffer,
array->elements * array->size_of_element);
}
else
if (!(new_ptr=(unsigned char*) realloc(array->buffer,
size* array->size_of_element)))
return true;
array->buffer= new_ptr;
array->max_element= size;
}
return false;
}
/*
Get an element from array by given index
SYNOPSIS
get_dynamic()
array
unsigned char* Element to be returned. If idx > elements contain zeroes.
idx Index of element wanted.
*/
void get_dynamic(DYNAMIC_ARRAY *array, unsigned char* element, uint32_t idx)
{
if (idx >= array->elements)
{
memset(element, 0, array->size_of_element);
return;
}
memcpy(element,array->buffer+idx*array->size_of_element,
(size_t) array->size_of_element);
}
/*
Empty array by freeing all memory
SYNOPSIS
delete_dynamic()
array Array to be deleted
*/
void delete_dynamic(DYNAMIC_ARRAY *array)
{
/*
Just mark as empty if we are using a static buffer
*/
if (array->buffer == (unsigned char *)(array + 1))
array->elements= 0;
else
if (array->buffer)
{
free(array->buffer);
array->buffer=0;
array->elements=array->max_element=0;
}
}
} /* namespace drizzled */
|