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
|
/* 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
/* Handling of arrays that can grow dynamicly. */
#include <config.h>
#include <algorithm>
#include <drizzled/dynamic_array.h>
#include <drizzled/internal/my_sys.h>
using namespace std;
namespace drizzled {
/*
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->set_size(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
*/
static void insert_dynamic(DYNAMIC_ARRAY *array, void* element)
{
unsigned char* buffer;
if (array->size() == array->max_element)
buffer= alloc_dynamic(array);
else
{
buffer= array->buffer+(array->size() * array->size_of_element);
array->set_size(array->size() + 1);
}
memcpy(buffer,element, array->size_of_element);
}
void DYNAMIC_ARRAY::push_back(void* v)
{
insert_dynamic(this, v);
}
/*
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->size() == 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->size() * 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;
}
array->set_size(array->size() + 1);
return array->buffer + ((array->size() - 1) * 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->set_size(0);
else
if (array->buffer)
{
free(array->buffer);
array->buffer=0;
array->set_size(array->max_element=0);
}
}
} /* namespace drizzled */
|