1 /* $NetBSD: mvect.c,v 1.4 2025/02/25 19:15:52 christos Exp $ */
2
3 /*++
4 /* NAME
5 /* mvect 3
6 /* SUMMARY
7 /* memory vector management
8 /* SYNOPSIS
9 /* #include <mvect.h>
10 /*
11 /* char *mvect_alloc(vector, elsize, nelm, init_fn, wipe_fn)
12 /* MVECT *vector;
13 /* ssize_t elsize;
14 /* ssize_t nelm;
15 /* void (*init_fn)(char *ptr, ssize_t count);
16 /* void (*wipe_fn)(char *ptr, ssize_t count);
17 /*
18 /* char *mvect_realloc(vector, nelm)
19 /* MVECT *vector;
20 /* ssize_t nelm;
21 /*
22 /* char *mvect_free(vector)
23 /* MVECT *vector;
24 /* DESCRIPTION
25 /* This module supports memory management for arrays of arbitrary
26 /* objects. It is up to the application to provide specific code
27 /* that initializes and uses object memory.
28 /*
29 /* mvect_alloc() initializes memory for a vector with elements
30 /* of \fIelsize\fR bytes, and with at least \fInelm\fR elements.
31 /* \fIinit_fn\fR is a null pointer, or a pointer to a function
32 /* that initializes \fIcount\fR vector elements.
33 /* \fIwipe_fn\fR is a null pointer, or a pointer to a function
34 /* that is complementary to \fIinit_fn\fR. This routine is called
35 /* by mvect_free(). The result of mvect_alloc() is a pointer to
36 /* the allocated vector.
37 /*
38 /* mvect_realloc() guarantees that the specified vector has space
39 /* for at least \fInelm\fR elements. The result is a pointer to the
40 /* allocated vector, which may change across calls.
41 /*
42 /* mvect_free() releases storage for the named vector. The result
43 /* is a convenient null pointer.
44 /* SEE ALSO
45 /* mymalloc(3) memory management
46 /* DIAGNOSTICS
47 /* Problems are reported via the msg(3) diagnostics routines:
48 /* the requested amount of memory is not available; improper use
49 /* is detected; other fatal errors.
50 /* LICENSE
51 /* .ad
52 /* .fi
53 /* The Secure Mailer license must be distributed with this software.
54 /* AUTHOR(S)
55 /* Wietse Venema
56 /* IBM T.J. Watson Research
57 /* P.O. Box 704
58 /* Yorktown Heights, NY 10598, USA
59 /*
60 /* Wietse Venema
61 /* Google, Inc.
62 /* 111 8th Avenue
63 /* New York, NY 10011, USA
64 /*--*/
65
66 /* System library. */
67
68 #include <sys_defs.h>
69
70 /* Utility library. */
71
72 #include "mymalloc.h"
73 #include "mvect.h"
74
75 /* mvect_alloc - allocate memory vector */
76
mvect_alloc(MVECT * vect,ssize_t elsize,ssize_t nelm,void (* init_fn)(char *,ssize_t),void (* wipe_fn)(char *,ssize_t))77 char *mvect_alloc(MVECT *vect, ssize_t elsize, ssize_t nelm,
78 void (*init_fn) (char *, ssize_t), void (*wipe_fn) (char *, ssize_t))
79 {
80 vect->init_fn = init_fn;
81 vect->wipe_fn = wipe_fn;
82 vect->nelm = 0;
83 vect->ptr = mymalloc(elsize * nelm);
84 vect->nelm = nelm;
85 vect->elsize = elsize;
86 if (vect->init_fn)
87 vect->init_fn(vect->ptr, vect->nelm);
88 return (vect->ptr);
89 }
90
91 /* mvect_realloc - adjust memory vector allocation */
92
mvect_realloc(MVECT * vect,ssize_t nelm)93 char *mvect_realloc(MVECT *vect, ssize_t nelm)
94 {
95 ssize_t old_len = vect->nelm;
96 ssize_t incr = nelm - old_len;
97 ssize_t new_nelm;
98
99 if (incr > 0) {
100 if (incr < old_len)
101 incr = old_len;
102 new_nelm = vect->nelm + incr;
103 vect->ptr = myrealloc(vect->ptr, vect->elsize * new_nelm);
104 vect->nelm = new_nelm;
105 if (vect->init_fn)
106 vect->init_fn(vect->ptr + old_len * vect->elsize, incr);
107 }
108 return (vect->ptr);
109 }
110
111 /* mvect_free - release memory vector storage */
112
mvect_free(MVECT * vect)113 char *mvect_free(MVECT *vect)
114 {
115 if (vect->wipe_fn)
116 vect->wipe_fn(vect->ptr, vect->nelm);
117 myfree(vect->ptr);
118 return (0);
119 }
120