1 /* sane - Scanner Access Now Easy.
2    Copyright (C) 1997 Geoffrey T. Dairiki
3    This file is part of the SANE package.
4 
5    This program is free software; you can redistribute it and/or
6    modify it under the terms of the GNU General Public License as
7    published by the Free Software Foundation; either version 2 of the
8    License, or (at your option) any later version.
9 
10    This program is distributed in the hope that it will be useful, but
11    WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    General Public License for more details.
14 
15    You should have received a copy of the GNU General Public License
16    along with this program.  If not, see <https://www.gnu.org/licenses/>.
17 
18    As a special exception, the authors of SANE give permission for
19    additional uses of the libraries contained in this release of SANE.
20 
21    The exception is that, if you link a SANE library with other files
22    to produce an executable, this does not by itself cause the
23    resulting executable to be covered by the GNU General Public
24    License.  Your use of that executable is in no way restricted on
25    account of linking the SANE library code into it.
26 
27    This exception does not, however, invalidate any other reasons why
28    the executable file might be covered by the GNU General Public
29    License.
30 
31    If you submit changes to SANE to the maintainers to be included in
32    a subsequent release, you agree by submitting the changes that
33    those changes may be distributed with this exception intact.
34 
35    If you write modifications of your own for SANE, it is your choice
36    whether to permit this exception to apply to your modifications.
37    If you do not wish that, delete this exception notice.
38 
39    This file is part of a SANE backend for HP Scanners supporting
40    HP Scanner Control Language (SCL).
41 */
42 /*
43 #define STUBS
44 extern int sanei_debug_hp;*/
45 #define DEBUG_DECLARE_ONLY
46 #include "../include/sane/config.h"
47 
48 #include <stdlib.h>
49 #include <string.h>
50 #include "../include/lassert.h"
51 
52 #include "hp.h"
53 
54 typedef struct hp_alloc_s  Alloc;
55 
56 struct hp_alloc_s
57 {
58     Alloc *	prev;
59     Alloc *	next;
60     hp_byte_t	buf[1];
61 };
62 
63 static Alloc  head[] = {{ head, head, {0} }};
64 
65 #define DATA_OFFSET	  (head->buf - (hp_byte_t *)head)
66 #define VOID_TO_ALLOCP(p) ((Alloc *)((hp_byte_t *)(p) - DATA_OFFSET))
67 #define ALLOCSIZE(sz) 	  (sz + DATA_OFFSET)
68 
69 
70 void *
sanei_hp_alloc(size_t sz)71 sanei_hp_alloc (size_t sz)
72 {
73   Alloc * new = malloc(ALLOCSIZE(sz));
74 
75   if (!new)
76       return 0;
77   (new->next = head->next)->prev = new;
78   (new->prev = head)->next = new;
79   return new->buf;
80 }
81 
82 void *
sanei_hp_allocz(size_t sz)83 sanei_hp_allocz (size_t sz)
84 {
85   void * new = sanei_hp_alloc(sz);
86 
87   if (!new)
88       return 0;
89   memset(new, 0, sz);
90   return new;
91 }
92 
93 void *
sanei_hp_memdup(const void * src,size_t sz)94 sanei_hp_memdup (const void * src, size_t sz)
95 {
96   char * new = sanei_hp_alloc(sz);
97   if (!new)
98       return 0;
99   return memcpy(new, src, sz);
100 }
101 
102 char *
sanei_hp_strdup(const char * str)103 sanei_hp_strdup (const char * str)
104 {
105   return sanei_hp_memdup(str, strlen(str) + 1);
106 }
107 
108 void *
sanei_hp_realloc(void * ptr,size_t sz)109 sanei_hp_realloc (void * ptr, size_t sz)
110 {
111   if (ptr)
112     {
113       Alloc * old = VOID_TO_ALLOCP(ptr);
114       Alloc  copy = *old;
115       Alloc * new = realloc(old, ALLOCSIZE(sz));
116       if (!new)
117 	  return 0;
118       if (new != old)
119 	  (new->prev = copy.prev)->next = (new->next = copy.next)->prev = new;
120       return new->buf;
121     }
122   else
123       return sanei_hp_alloc(sz);
124 }
125 
126 void
sanei_hp_free(void * ptr)127 sanei_hp_free (void * ptr)
128 {
129   Alloc * old = VOID_TO_ALLOCP(ptr);
130 
131   assert(old && old != head);
132   (old->next->prev = old->prev)->next = old->next;
133   old->next = old->prev = 0;	/* so we can puke on multiple free's */
134   free(old);
135 }
136 
137 void
sanei_hp_free_all(void)138 sanei_hp_free_all (void)
139 {
140   Alloc * ptr;
141   Alloc * next;
142 
143   for (ptr = head->next; ptr != head; ptr = next)
144     {
145       next = ptr->next;
146       free(ptr);
147     }
148   head->next = head->prev = head;
149 }
150