lib/svec.c

   1 /*
   2  * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include <config.h>
  18 #include "svec.h"
  19 #include <ctype.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include "openvswitch/dynamic-string.h"
  23 #include "random.h"
  24 #include "util.h"
  25 #include "openvswitch/vlog.h"
  26
  27 VLOG_DEFINE_THIS_MODULE(svec);
  28
  29 void
  30 svec_init(struct svec *svec)
  31 {
  32     svec->names = NULL;
  33     svec->n = 0;
  34     svec->allocated = 0;
  35 }
  36
  37 void
  38 svec_clone(struct svec *svec, const struct svec *other)
  39 {
  40     svec_init(svec);
  41     svec_append(svec, other);
  42 }
  43
  44 void
  45 svec_destroy(struct svec *svec)
  46 {
  47     svec_clear(svec);
  48     free(svec->names);
  49 }
  50
  51 void
  52 svec_clear(struct svec *svec)
  53 {
  54     size_t i;
  55
  56     for (i = 0; i < svec->n; i++) {
  57         free(svec->names[i]);
  58     }
  59     svec->n = 0;
  60 }
  61
  62 bool
  63 svec_is_empty(const struct svec *svec)
  64 {
  65     return svec->n == 0;
  66 }
  67
  68 void
  69 svec_add(struct svec *svec, const char *name)
  70 {
  71     svec_add_nocopy(svec, xstrdup(name));
  72 }
  73
  74 void
  75 svec_del(struct svec *svec, const char *name)
  76 {
  77     size_t offset;
  78
  79     offset = svec_find(svec, name);
  80     if (offset != SIZE_MAX) {
  81         free(svec->names[offset]);
  82         memmove(&svec->names[offset], &svec->names[offset + 1],
  83                 sizeof *svec->names * (svec->n - offset - 1));
  84         svec->n--;
  85     }
  86 }
  87
  88 static void
  89 svec_expand(struct svec *svec)
  90 {
  91     if (svec->n >= svec->allocated) {
  92         svec->names = x2nrealloc(svec->names, &svec->allocated,
  93                                  sizeof *svec->names);
  94     }
  95 }
  96
  97 void
  98 svec_add_nocopy(struct svec *svec, char *name)
  99 {
 100     svec_expand(svec);
 101     svec->names[svec->n++] = name;
 102 }
 103
 104 void
 105 svec_append(struct svec *svec, const struct svec *other)
 106 {
 107     size_t i;
 108     for (i = 0; i < other->n; i++) {
 109         svec_add(svec, other->names[i]);
 110     }
 111 }
 112
 113 void
 114 svec_terminate(struct svec *svec)
 115 {
 116     svec_expand(svec);
 117     svec->names[svec->n] = NULL;
 118 }
 119
 120 static int
 121 compare_strings(const void *a_, const void *b_)
 122 {
 123     char *const *a = a_;
 124     char *const *b = b_;
 125     return strcmp(*a, *b);
 126 }
 127
 128 void
 129 svec_sort(struct svec *svec)
 130 {
 131     if (svec->n) {
 132         qsort(svec->names, svec->n, sizeof *svec->names, compare_strings);
 133     }
 134 }
 135
 136 void
 137 svec_sort_unique(struct svec *svec)
 138 {
 139     svec_sort(svec);
 140     svec_unique(svec);
 141 }
 142
 143 void
 144 svec_unique(struct svec *svec)
 145 {
 146     ovs_assert(svec_is_sorted(svec));
 147     if (svec->n > 1) {
 148         /* This algorithm is lazy and sub-optimal, but it's "obviously correct"
 149          * and asymptotically optimal . */
 150         struct svec tmp;
 151         size_t i;
 152
 153         svec_init(&tmp);
 154         svec_add(&tmp, svec->names[0]);
 155         for (i = 1; i < svec->n; i++) {
 156             if (strcmp(svec->names[i - 1], svec->names[i])) {
 157                 svec_add(&tmp, svec->names[i]);
 158             }
 159         }
 160         svec_swap(&tmp, svec);
 161         svec_destroy(&tmp);
 162     }
 163 }
 164
 165 void
 166 svec_compact(struct svec *svec)
 167 {
 168     size_t i, j;
 169
 170     for (i = j = 0; i < svec->n; i++) {
 171         if (svec->names[i] != NULL) {
 172             svec->names[j++] = svec->names[i];
 173         }
 174     }
 175     svec->n = j;
 176 }
 177
 178 static void
 179 swap_strings(char **a, char **b)
 180 {
 181     char *tmp = *a;
 182     *a = *b;
 183     *b = tmp;
 184 }
 185
 186 void
 187 svec_shuffle(struct svec *svec)
 188 {
 189     for (size_t i = 0; i < svec->n; i++) {
 190         size_t j = i + random_range(svec->n - i);
 191         swap_strings(&svec->names[i], &svec->names[j]);
 192     }
 193 }
 194
 195 void
 196 svec_diff(const struct svec *a, const struct svec *b,
 197           struct svec *a_only, struct svec *both, struct svec *b_only)
 198 {
 199     size_t i, j;
 200
 201     ovs_assert(svec_is_sorted(a));
 202     ovs_assert(svec_is_sorted(b));
 203     if (a_only) {
 204         svec_init(a_only);
 205     }
 206     if (both) {
 207         svec_init(both);
 208     }
 209     if (b_only) {
 210         svec_init(b_only);
 211     }
 212     for (i = j = 0; i < a->n && j < b->n; ) {
 213         int cmp = strcmp(a->names[i], b->names[j]);
 214         if (cmp < 0) {
 215             if (a_only) {
 216                 svec_add(a_only, a->names[i]);
 217             }
 218             i++;
 219         } else if (cmp > 0) {
 220             if (b_only) {
 221                 svec_add(b_only, b->names[j]);
 222             }
 223             j++;
 224         } else {
 225             if (both) {
 226                 svec_add(both, a->names[i]);
 227             }
 228             i++;
 229             j++;
 230         }
 231     }
 232     if (a_only) {
 233         for (; i < a->n; i++) {
 234             svec_add(a_only, a->names[i]);
 235         }
 236     }
 237     if (b_only) {
 238         for (; j < b->n; j++) {
 239             svec_add(b_only, b->names[j]);
 240         }
 241     }
 242 }
 243
 244 bool
 245 svec_contains(const struct svec *svec, const char *name)
 246 {
 247     return svec_find(svec, name) != SIZE_MAX;
 248 }
 249
 250 size_t
 251 svec_find(const struct svec *svec, const char *name)
 252 {
 253     char **p;
 254
 255     ovs_assert(svec_is_sorted(svec));
 256     p = bsearch(&name, svec->names, svec->n, sizeof *svec->names,
 257                 compare_strings);
 258     return p ? p - svec->names : SIZE_MAX;
 259 }
 260
 261 bool
 262 svec_is_sorted(const struct svec *svec)
 263 {
 264     size_t i;
 265
 266     for (i = 1; i < svec->n; i++) {
 267         if (strcmp(svec->names[i - 1], svec->names[i]) > 0) {
 268             return false;
 269         }
 270     }
 271     return true;
 272 }
 273
 274 bool
 275 svec_is_unique(const struct svec *svec)
 276 {
 277     return svec_get_duplicate(svec) == NULL;
 278 }
 279
 280 const char *
 281 svec_get_duplicate(const struct svec *svec)
 282 {
 283     ovs_assert(svec_is_sorted(svec));
 284     if (svec->n > 1) {
 285         size_t i;
 286         for (i = 1; i < svec->n; i++) {
 287             if (!strcmp(svec->names[i - 1], svec->names[i])) {
 288                 return svec->names[i];
 289             }
 290         }
 291     }
 292     return NULL;
 293 }
 294
 295 void
 296 svec_swap(struct svec *a, struct svec *b)
 297 {
 298     struct svec tmp = *a;
 299     *a = *b;
 300     *b = tmp;
 301 }
 302
 303 void
 304 svec_print(const struct svec *svec, const char *title)
 305 {
 306     size_t i;
 307
 308     printf("%s:\n", title);
 309     for (i = 0; i < svec->n; i++) {
 310         printf("\"%s\"\n", svec->names[i]);
 311     }
 312 }
 313
 314 /* Breaks 'words' into words at white space, respecting shell-like quoting
 315  * conventions, and appends the words to 'svec'. */
 316 void
 317 svec_parse_words(struct svec *svec, const char *words)
 318 {
 319     struct ds word = DS_EMPTY_INITIALIZER;
 320     const char *p, *q;
 321
 322     for (p = words; *p != '\0'; p = q) {
 323         int quote = 0;
 324
 325         while (isspace((unsigned char) *p)) {
 326             p++;
 327         }
 328         if (*p == '\0') {
 329             break;
 330         }
 331
 332         ds_clear(&word);
 333         for (q = p; *q != '\0'; q++) {
 334             if (*q == quote) {
 335                 quote = 0;
 336             } else if (*q == '\'' || *q == '"') {
 337                 quote = *q;
 338             } else if (*q == '\\' && (!quote || quote == '"')) {
 339                 q++;
 340                 if (*q == '\0') {
 341                     VLOG_WARN("%s: ends in trailing backslash", words);
 342                     break;
 343                 }
 344                 ds_put_char(&word, *q);
 345             } else if (isspace((unsigned char) *q) && !quote) {
 346                 q++;
 347                 break;
 348             } else {
 349                 ds_put_char(&word, *q);
 350             }
 351         }
 352         svec_add(svec, ds_cstr(&word));
 353         if (quote) {
 354             VLOG_WARN("%s: word ends inside quoted string", words);
 355         }
 356     }
 357     ds_destroy(&word);
 358 }
 359
 360 bool
 361 svec_equal(const struct svec *a, const struct svec *b)
 362 {
 363     size_t i;
 364
 365     if (a->n != b->n) {
 366         return false;
 367     }
 368     for (i = 0; i < a->n; i++) {
 369         if (strcmp(a->names[i], b->names[i])) {
 370             return false;
 371         }
 372     }
 373     return true;
 374 }
 375
 376 char *
 377 svec_join(const struct svec *svec,
 378           const char *delimiter, const char *terminator)
 379 {
 380     struct ds ds;
 381     size_t i;
 382
 383     ds_init(&ds);
 384     for (i = 0; i < svec->n; i++) {
 385         if (i) {
 386             ds_put_cstr(&ds, delimiter);
 387         }
 388         ds_put_cstr(&ds, svec->names[i]);
 389     }
 390     ds_put_cstr(&ds, terminator);
 391     return ds_cstr(&ds);
 392 }
 393
 394 const char *
 395 svec_back(const struct svec *svec)
 396 {
 397     ovs_assert(svec->n);
 398     return svec->names[svec->n - 1];
 399 }
 400
 401 void
 402 svec_pop_back(struct svec *svec)
 403 {
 404     ovs_assert(svec->n);
 405     free(svec->names[--svec->n]);
 406 }