lib/dpkg/varbuf.h

   1 /*
   2  * libdpkg - Debian packaging suite library routines
   3  * varbuf.h - variable length expandable buffer handling
   4  *
   5  * Copyright © 1994, 1995 Ian Jackson <ijackson@chiark.greenend.org.uk>
   6  * Copyright © 2008-2015 Guillem Jover <guillem@debian.org>
   7  *
   8  * This is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  20  */
  21
  22 #ifndef LIBDPKG_VARBUF_H
  23 #define LIBDPKG_VARBUF_H
  24
  25 #include <stddef.h>
  26 #include <stdarg.h>
  27 #include <stdbool.h>
  28 #include <string.h>
  29
  30 #include <dpkg/macros.h>
  31
  32 DPKG_BEGIN_DECLS
  33
  34 /**
  35  * @defgroup varbuf Variable length buffers
  36  * @ingroup dpkg-public
  37  * @{
  38  */
  39
  40 /**
  41  * varbuf_init must be called exactly once before the use of each varbuf
  42  * (including before any call to varbuf_destroy), or the variable must be
  43  * initialized with VARBUF_INIT.
  44  *
  45  * However, varbufs allocated ‘static’ are properly initialized anyway and
  46  * do not need varbuf_init; multiple consecutive calls to varbuf_init before
  47  * any use are allowed.
  48  *
  49  * varbuf_destroy must be called after a varbuf is finished with, if anything
  50  * other than varbuf_init has been done. After this you are allowed but
  51  * not required to call varbuf_init again if you want to start using the
  52  * varbuf again.
  53  *
  54  * Callers using C++ need not worry about any of this.
  55  */
  56 struct varbuf {
  57         size_t used, size;
  58         char *buf;
  59
  60 #ifdef __cplusplus
  61         explicit varbuf(size_t _size = 0);
  62         ~varbuf();
  63         void init(size_t _size = 0);
  64         void reset();
  65         void destroy();
  66         int fmt(const char *_fmt, ...) DPKG_ATTR_PRINTF(2);
  67         int vfmt(const char *_fmt, va_list va) DPKG_ATTR_VPRINTF(2);
  68         void operator()(int c);
  69         void operator()(const char *s);
  70         const char *string();
  71 #endif
  72 };
  73
  74 #define VARBUF_INIT { 0, 0, NULL }
  75
  76 #define VARBUF_OBJECT (struct varbuf)VARBUF_INIT
  77
  78 struct varbuf *varbuf_new(size_t size);
  79 void varbuf_init(struct varbuf *v, size_t size);
  80 void varbuf_grow(struct varbuf *v, size_t need_size);
  81 void varbuf_trunc(struct varbuf *v, size_t used_size);
  82 char *varbuf_detach(struct varbuf *v);
  83 void varbuf_reset(struct varbuf *v);
  84 void varbuf_destroy(struct varbuf *v);
  85 void varbuf_free(struct varbuf *v);
  86
  87 const char *varbuf_str(struct varbuf *v);
  88
  89 void varbuf_set_varbuf(struct varbuf *v, struct varbuf *other);
  90 void varbuf_set_buf(struct varbuf *v, const void *buf, size_t size);
  91 #define varbuf_set_str(v, s) varbuf_set_buf(v, s, strlen(s))
  92 #define varbuf_set_strn(v, s, n) varbuf_set_buf(v, s, strnlen(s, n))
  93
  94 void varbuf_add_varbuf(struct varbuf *v, const struct varbuf *other);
  95 void varbuf_add_char(struct varbuf *v, int c);
  96 void varbuf_dup_char(struct varbuf *v, int c, size_t n);
  97 void varbuf_map_char(struct varbuf *v, int c_src, int c_dst);
  98 #define varbuf_add_str(v, s) varbuf_add_buf(v, s, strlen(s))
  99 #define varbuf_add_strn(v, s, n) varbuf_add_buf(v, s, strnlen(s, n))
 100 void varbuf_add_dir(struct varbuf *v, const char *dirname);
 101 void varbuf_add_buf(struct varbuf *v, const void *s, size_t size);
 102
 103 bool varbuf_has_prefix(struct varbuf *v, struct varbuf *prefix);
 104 bool varbuf_has_suffix(struct varbuf *v, struct varbuf *suffix);
 105 void varbuf_trim_varbuf_prefix(struct varbuf *v, struct varbuf *prefix);
 106 void varbuf_trim_char_prefix(struct varbuf *v, int prefix);
 107
 108 int varbuf_printf(struct varbuf *v, const char *fmt, ...) DPKG_ATTR_PRINTF(2);
 109 int varbuf_vprintf(struct varbuf *v, const char *fmt, va_list va)
 110         DPKG_ATTR_VPRINTF(2);
 111
 112 struct varbuf_state {
 113         struct varbuf *v;
 114         size_t used;
 115 };
 116
 117 void varbuf_snapshot(struct varbuf *v, struct varbuf_state *vs);
 118 void varbuf_rollback(struct varbuf_state *vs);
 119 size_t varbuf_rollback_len(struct varbuf_state *vs);
 120 const char *varbuf_rollback_start(struct varbuf_state *vs);
 121
 122 /** @} */
 123
 124 DPKG_END_DECLS
 125
 126 #ifdef __cplusplus
 127 inline
 128 varbuf::varbuf(size_t _size)
 129 {
 130         varbuf_init(this, _size);
 131 }
 132
 133 inline
 134 varbuf::~varbuf()
 135 {
 136         varbuf_destroy(this);
 137 }
 138
 139 inline void
 140 varbuf::init(size_t _size)
 141 {
 142         varbuf_init(this, _size);
 143 }
 144
 145 inline void
 146 varbuf::reset()
 147 {
 148         used = 0;
 149 }
 150
 151 inline void
 152 varbuf::destroy()
 153 {
 154         varbuf_destroy(this);
 155 }
 156
 157 inline int
 158 varbuf::fmt(const char *_fmt, ...)
 159 {
 160         va_list args;
 161         int rc;
 162
 163         va_start(args, _fmt);
 164         rc = varbuf_vprintf(this, _fmt, args);
 165         va_end(args);
 166
 167         return rc;
 168 }
 169
 170 inline int
 171 varbuf::vfmt(const char *_fmt, va_list va)
 172 {
 173         return varbuf_vprintf(this, _fmt, va);
 174 }
 175
 176 inline void
 177 varbuf::operator()(int c)
 178 {
 179         varbuf_add_char(this, c);
 180 }
 181
 182 inline void
 183 varbuf::operator()(const char *s)
 184 {
 185         varbuf_add_str(this, s);
 186 }
 187
 188 inline const char *
 189 varbuf::string()
 190 {
 191         return varbuf_str(this);
 192 }
 193 #endif
 194
 195 #endif /* LIBDPKG_VARBUF_H */