lib/buffer.c

   1 /*
   2  * No copyright is claimed.  This code is in the public domain; do with
   3  * it what you wish.
   4  *
   5  * Written by Karel Zak <kzak@redhat.com>
   6  */
   7 #include "buffer.h"
   8 #include "mbsalign.h"
   9 #include "strutils.h"
  10
  11 void ul_buffer_reset_data(struct ul_buffer *buf)
  12 {
  13         if (buf->begin)
  14                 memset(buf->begin, 0, buf->sz);
  15         buf->end = buf->begin;
  16
  17         if (buf->ptrs && buf->nptrs)
  18                 memset(buf->ptrs, 0, buf->nptrs * sizeof(char *));
  19 }
  20
  21 void ul_buffer_free_data(struct ul_buffer *buf)
  22 {
  23         assert(buf);
  24
  25         free(buf->begin);
  26         buf->begin = NULL;
  27         buf->end = NULL;
  28         buf->sz = 0;
  29
  30         free(buf->ptrs);
  31         buf->ptrs = NULL;
  32         buf->nptrs = 0;
  33
  34         free(buf->encoded);
  35         buf->encoded = NULL;
  36         buf->encoded_sz = 0;
  37 }
  38
  39 void ul_buffer_set_chunksize(struct ul_buffer *buf, size_t sz)
  40 {
  41         buf->chunksize = sz;
  42 }
  43
  44 int ul_buffer_is_empty(struct ul_buffer *buf)
  45 {
  46         return buf->begin == buf->end;
  47 }
  48
  49 int ul_buffer_save_pointer(struct ul_buffer *buf, unsigned short ptr_idx)
  50 {
  51         if (ptr_idx >= buf->nptrs) {
  52                 char **tmp = reallocarray(buf->ptrs, ptr_idx + 1, sizeof(char *));
  53
  54                 if (!tmp)
  55                         return -EINVAL;
  56                 buf->ptrs = tmp;
  57                 buf->nptrs = ptr_idx + 1;
  58         }
  59
  60         buf->ptrs[ptr_idx] = buf->end;
  61         return 0;
  62 }
  63
  64
  65 char *ul_buffer_get_pointer(struct ul_buffer *buf, unsigned short ptr_idx)
  66 {
  67         if (ptr_idx < buf->nptrs)
  68                 return buf->ptrs[ptr_idx];
  69         return NULL;
  70 }
  71
  72 /* returns length from begin to the pointer */
  73 size_t ul_buffer_get_pointer_length(struct ul_buffer *buf, unsigned short ptr_idx)
  74 {
  75         char *ptr = ul_buffer_get_pointer(buf, ptr_idx);
  76
  77         if (ptr && ptr > buf->begin)
  78                 return ptr - buf->begin;
  79         return 0;
  80 }
  81
  82 /* returns width of data in safe encoding (from the begin to the pointer) */
  83 size_t ul_buffer_get_safe_pointer_width(struct ul_buffer *buf, unsigned short ptr_idx)
  84 {
  85         size_t len = ul_buffer_get_pointer_length(buf, ptr_idx);
  86
  87         if (!len)
  88                 return 0;
  89
  90         return mbs_safe_nwidth(buf->begin, len, NULL);
  91 }
  92
  93 void ul_buffer_refer_string(struct ul_buffer *buf, char *str)
  94 {
  95         if (buf->sz)
  96                 ul_buffer_free_data(buf);
  97         buf->begin = str;
  98         buf->sz = str ? strlen(str) : 0;
  99         buf->end = buf->begin ? buf->begin + buf->sz : buf->begin;
 100 }
 101
 102 int ul_buffer_alloc_data(struct ul_buffer *buf, size_t sz)
 103 {
 104         char *tmp;
 105         size_t len = 0;
 106
 107         assert(buf);
 108
 109         if (sz <= buf->sz)
 110                 return 0;
 111
 112         if (buf->end && buf->begin)
 113                 len = buf->end - buf->begin;
 114
 115         if (buf->chunksize)
 116                 sz = ((sz + buf->chunksize) / buf->chunksize) * buf->chunksize + 1;
 117
 118         tmp = realloc(buf->begin, sz);
 119         if (!tmp)
 120                 return -ENOMEM;
 121
 122         buf->begin = tmp;
 123         buf->end = buf->begin + len;
 124         buf->sz = sz;
 125
 126         memset(buf->end, '\0', sz - len);
 127
 128         return 0;
 129 }
 130
 131 int ul_buffer_append_data(struct ul_buffer *buf, const char *data, size_t sz)
 132 {
 133         size_t maxsz = 0;
 134
 135         if (!buf)
 136                 return -EINVAL;
 137         if (!data)
 138                 return 0;
 139
 140         if (buf->begin && buf->end)
 141                 maxsz = buf->sz - (buf->end - buf->begin);
 142         if (maxsz <= sz + 1) {
 143                 int rc = ul_buffer_alloc_data(buf, buf->sz + sz + 1);
 144                 if (rc)
 145                         return rc;
 146         }
 147         if (!buf->end)
 148                 return -EINVAL; /* make static analyzers happy */
 149
 150         buf->end = mempcpy(buf->end, data, sz);
 151         *buf->end = '\0';       /* make sure it's terminated */
 152         return 0;
 153 }
 154
 155 int ul_buffer_append_string(struct ul_buffer *buf, const char *str)
 156 {
 157         if (!str)
 158                 return 0;
 159
 160         return ul_buffer_append_data(buf, str, strlen(str));
 161 }
 162
 163 int ul_buffer_append_ntimes(struct ul_buffer *buf, size_t n, const char *str)
 164 {
 165         size_t i;
 166         size_t len = strlen(str);
 167
 168         for (i = 0; len && i < n; i++) {
 169                 int rc = ul_buffer_append_data(buf, str, len);
 170                 if (rc)
 171                         return rc;
 172         }
 173         return 0;
 174 }
 175
 176 int ul_buffer_set_data(struct ul_buffer *buf, const char *data, size_t sz)
 177 {
 178         ul_buffer_reset_data(buf);
 179         return ul_buffer_append_data(buf, data, sz);
 180 }
 181
 182 char *ul_buffer_get_data(struct ul_buffer *buf, size_t *sz, size_t *width)
 183 {
 184         if (sz)
 185                 *sz = buf->end - buf->begin;
 186         if (width)
 187                 *width = buf->begin && *buf->begin ? mbs_width(buf->begin) : 0;
 188         return buf->begin;
 189 }
 190
 191 /* size of allocated area (!= size of stored data */
 192 size_t ul_buffer_get_bufsiz(struct ul_buffer *buf)
 193 {
 194         return buf->sz;
 195 }
 196
 197 /* encode data by mbs_safe_encode() to avoid control and non-printable chars */
 198 char *ul_buffer_get_safe_data(struct ul_buffer *buf, size_t *sz, size_t *width, const char *safechars)
 199 {
 200         char *data = ul_buffer_get_data(buf, NULL, NULL);
 201         size_t encsz, wsz = 0;
 202         char *res = NULL;
 203
 204         if (!data)
 205                 goto nothing;
 206
 207         encsz = mbs_safe_encode_size(buf->sz) + 1;
 208         if (encsz > buf->encoded_sz) {
 209                 char *tmp = realloc(buf->encoded, encsz);
 210                 if (!tmp)
 211                         goto nothing;
 212                 buf->encoded = tmp;
 213                 buf->encoded_sz = encsz;
 214         }
 215
 216         res = mbs_safe_encode_to_buffer(data, &wsz, buf->encoded, safechars);
 217         if (!res || !wsz || wsz == (size_t) -1)
 218                 goto nothing;
 219
 220         if (width)
 221                 *width = wsz;
 222         if (sz)
 223                 *sz = strlen(res);
 224         return res;
 225 nothing:
 226         if (width)
 227                 *width = 0;
 228         if (sz)
 229                 *sz = 0;
 230         return NULL;
 231 }
 232
 233
 234 #ifdef TEST_PROGRAM_BUFFER
 235
 236 enum {
 237         PTR_AAA  = 0,
 238         PTR_BBB,
 239 };
 240
 241 int main(void)
 242 {
 243         struct ul_buffer buf = UL_INIT_BUFFER;
 244         char *str;
 245         size_t sz = 0;
 246
 247         ul_buffer_set_chunksize(&buf, 16);
 248
 249         ul_buffer_append_string(&buf, "AAA");
 250         ul_buffer_append_data(&buf, "=", 1);
 251         ul_buffer_append_string(&buf, "aaa");
 252         ul_buffer_save_pointer(&buf, PTR_AAA);
 253
 254         ul_buffer_append_data(&buf, ",", 1);
 255         ul_buffer_append_string(&buf, "BBB");
 256         ul_buffer_append_string(&buf, "=");
 257         ul_buffer_append_string(&buf, "bbb");
 258         ul_buffer_save_pointer(&buf, PTR_BBB);
 259
 260         str = ul_buffer_get_data(&buf, &sz, NULL);
 261         printf("data [%zu] '%s'\n", sz, str);
 262
 263         printf(" pointer data len: AAA=%zu, BBB=%zu\n",
 264                         ul_buffer_get_pointer_length(&buf, PTR_AAA),
 265                         ul_buffer_get_pointer_length(&buf, PTR_BBB));
 266         printf(" pointer data width: AAA=%zu, BBB=%zu\n",
 267                         ul_buffer_get_safe_pointer_width(&buf, PTR_AAA),
 268                         ul_buffer_get_safe_pointer_width(&buf, PTR_BBB));
 269
 270         ul_buffer_reset_data(&buf);
 271         ul_buffer_append_string(&buf, "This is really long string to test the buffer function.");
 272         ul_buffer_save_pointer(&buf, PTR_AAA);
 273         ul_buffer_append_string(&buf, " YES!");
 274         str = ul_buffer_get_data(&buf, &sz, NULL);
 275         printf("data [%zu] '%s'\n", sz, str);
 276         printf(" pointer data len: AAA=%zu\n", ul_buffer_get_pointer_length(&buf, PTR_AAA));
 277
 278         ul_buffer_free_data(&buf);
 279         str = strdup("foo");
 280         ul_buffer_refer_string(&buf, str);
 281         ul_buffer_append_data(&buf, ",", 1);
 282         ul_buffer_append_string(&buf, "bar");
 283         str = ul_buffer_get_data(&buf, &sz, NULL);
 284         printf("data [%zu] '%s'\n", sz, str);
 285
 286         ul_buffer_free_data(&buf);
 287
 288         return EXIT_SUCCESS;
 289 }
 290 #endif /* TEST_PROGRAM_BUFFER */