1 /*
2 * buffer.c
3 * dynamically-managed buffers
4 *
5 * Copyright (c) 2024 pkgconf authors (see AUTHORS).
6 *
7 * Permission to use, copy, modify, and/or distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * This software is provided 'as is' and without any warranty, express or
12 * implied. In no event shall the authors be liable for any damages arising
13 * from the use of this software.
14 */
15
16 #include <libpkgconf/stdinc.h>
17 #include <libpkgconf/libpkgconf.h>
18
19 /*
20 * !doc
21 *
22 * libpkgconf `buffer` module
23 * ==========================
24 *
25 * The libpkgconf `buffer` module contains the functions related to managing
26 * dynamically-allocated buffers.
27 */
28
29 static inline size_t
target_allocation_size(size_t target_size)30 target_allocation_size(size_t target_size)
31 {
32 return 4096 + (4096 * (target_size / 4096));
33 }
34
35 void
pkgconf_buffer_append(pkgconf_buffer_t * buffer,const char * text)36 pkgconf_buffer_append(pkgconf_buffer_t *buffer, const char *text)
37 {
38 size_t needed = strlen(text) + 1;
39 size_t newsize = pkgconf_buffer_len(buffer) + needed;
40
41 char *newbase = realloc(buffer->base, target_allocation_size(newsize));
42
43 /* XXX: silently failing here is antisocial */
44 if (newbase == NULL)
45 return;
46
47 char *newend = newbase + pkgconf_buffer_len(buffer);
48 pkgconf_strlcpy(newend, text, needed);
49
50 buffer->base = newbase;
51 buffer->end = newend + needed;
52 }
53
54 void
pkgconf_buffer_push_byte(pkgconf_buffer_t * buffer,char byte)55 pkgconf_buffer_push_byte(pkgconf_buffer_t *buffer, char byte)
56 {
57 size_t newsize = pkgconf_buffer_len(buffer) + 1;
58 char *newbase = realloc(buffer->base, target_allocation_size(newsize));
59
60 /* XXX: silently failing here remains antisocial */
61 if (newbase == NULL)
62 return;
63
64 char *newend = newbase + newsize;
65 *(newend - 1) = byte;
66 *newend = '\0';
67
68 buffer->base = newbase;
69 buffer->end = newend;
70 }
71
72 void
pkgconf_buffer_trim_byte(pkgconf_buffer_t * buffer)73 pkgconf_buffer_trim_byte(pkgconf_buffer_t *buffer)
74 {
75 size_t newsize = pkgconf_buffer_len(buffer) - 1;
76 char *newbase = realloc(buffer->base, target_allocation_size(newsize));
77
78 buffer->base = newbase;
79 buffer->end = newbase + newsize;
80 *(buffer->end) = '\0';
81 }
82
83 void
pkgconf_buffer_finalize(pkgconf_buffer_t * buffer)84 pkgconf_buffer_finalize(pkgconf_buffer_t *buffer)
85 {
86 free(buffer->base);
87 }
88