hashtable.c 22 KB

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  1. /*
  2. * This implementation is based on code from uClibc-0.9.30.3 but was
  3. * modified and extended for use within U-Boot.
  4. *
  5. * Copyright (C) 2010 Wolfgang Denk <wd@denx.de>
  6. *
  7. * Original license header:
  8. *
  9. * Copyright (C) 1993, 1995, 1996, 1997, 2002 Free Software Foundation, Inc.
  10. * This file is part of the GNU C Library.
  11. * Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1993.
  12. *
  13. * The GNU C Library is free software; you can redistribute it and/or
  14. * modify it under the terms of the GNU Lesser General Public
  15. * License as published by the Free Software Foundation; either
  16. * version 2.1 of the License, or (at your option) any later version.
  17. *
  18. * The GNU C Library is distributed in the hope that it will be useful,
  19. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  21. * Lesser General Public License for more details.
  22. *
  23. * You should have received a copy of the GNU Lesser General Public
  24. * License along with the GNU C Library; if not, write to the Free
  25. * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  26. * 02111-1307 USA.
  27. */
  28. #include <errno.h>
  29. #include <malloc.h>
  30. #ifdef USE_HOSTCC /* HOST build */
  31. # include <string.h>
  32. # include <assert.h>
  33. # include <ctype.h>
  34. # ifndef debug
  35. # ifdef DEBUG
  36. # define debug(fmt,args...) printf(fmt ,##args)
  37. # else
  38. # define debug(fmt,args...)
  39. # endif
  40. # endif
  41. #else /* U-Boot build */
  42. # include <common.h>
  43. # include <linux/string.h>
  44. # include <linux/ctype.h>
  45. #endif
  46. #ifndef CONFIG_ENV_MIN_ENTRIES /* minimum number of entries */
  47. #define CONFIG_ENV_MIN_ENTRIES 64
  48. #endif
  49. #ifndef CONFIG_ENV_MAX_ENTRIES /* maximum number of entries */
  50. #define CONFIG_ENV_MAX_ENTRIES 512
  51. #endif
  52. #include "search.h"
  53. /*
  54. * [Aho,Sethi,Ullman] Compilers: Principles, Techniques and Tools, 1986
  55. * [Knuth] The Art of Computer Programming, part 3 (6.4)
  56. */
  57. /*
  58. * The reentrant version has no static variables to maintain the state.
  59. * Instead the interface of all functions is extended to take an argument
  60. * which describes the current status.
  61. */
  62. typedef struct _ENTRY {
  63. int used;
  64. ENTRY entry;
  65. } _ENTRY;
  66. /*
  67. * hcreate()
  68. */
  69. /*
  70. * For the used double hash method the table size has to be a prime. To
  71. * correct the user given table size we need a prime test. This trivial
  72. * algorithm is adequate because
  73. * a) the code is (most probably) called a few times per program run and
  74. * b) the number is small because the table must fit in the core
  75. * */
  76. static int isprime(unsigned int number)
  77. {
  78. /* no even number will be passed */
  79. unsigned int div = 3;
  80. while (div * div < number && number % div != 0)
  81. div += 2;
  82. return number % div != 0;
  83. }
  84. /*
  85. * Before using the hash table we must allocate memory for it.
  86. * Test for an existing table are done. We allocate one element
  87. * more as the found prime number says. This is done for more effective
  88. * indexing as explained in the comment for the hsearch function.
  89. * The contents of the table is zeroed, especially the field used
  90. * becomes zero.
  91. */
  92. int hcreate_r(size_t nel, struct hsearch_data *htab)
  93. {
  94. /* Test for correct arguments. */
  95. if (htab == NULL) {
  96. __set_errno(EINVAL);
  97. return 0;
  98. }
  99. /* There is still another table active. Return with error. */
  100. if (htab->table != NULL)
  101. return 0;
  102. /* Change nel to the first prime number not smaller as nel. */
  103. nel |= 1; /* make odd */
  104. while (!isprime(nel))
  105. nel += 2;
  106. htab->size = nel;
  107. htab->filled = 0;
  108. /* allocate memory and zero out */
  109. htab->table = (_ENTRY *) calloc(htab->size + 1, sizeof(_ENTRY));
  110. if (htab->table == NULL)
  111. return 0;
  112. /* everything went alright */
  113. return 1;
  114. }
  115. /*
  116. * hdestroy()
  117. */
  118. /*
  119. * After using the hash table it has to be destroyed. The used memory can
  120. * be freed and the local static variable can be marked as not used.
  121. */
  122. void hdestroy_r(struct hsearch_data *htab, int do_apply)
  123. {
  124. int i;
  125. /* Test for correct arguments. */
  126. if (htab == NULL) {
  127. __set_errno(EINVAL);
  128. return;
  129. }
  130. /* free used memory */
  131. for (i = 1; i <= htab->size; ++i) {
  132. if (htab->table[i].used > 0) {
  133. ENTRY *ep = &htab->table[i].entry;
  134. if (do_apply && htab->apply != NULL) {
  135. /* deletion is always forced */
  136. htab->apply(ep->key, ep->data, NULL, H_FORCE);
  137. }
  138. free((void *)ep->key);
  139. free(ep->data);
  140. }
  141. }
  142. free(htab->table);
  143. /* the sign for an existing table is an value != NULL in htable */
  144. htab->table = NULL;
  145. }
  146. /*
  147. * hsearch()
  148. */
  149. /*
  150. * This is the search function. It uses double hashing with open addressing.
  151. * The argument item.key has to be a pointer to an zero terminated, most
  152. * probably strings of chars. The function for generating a number of the
  153. * strings is simple but fast. It can be replaced by a more complex function
  154. * like ajw (see [Aho,Sethi,Ullman]) if the needs are shown.
  155. *
  156. * We use an trick to speed up the lookup. The table is created by hcreate
  157. * with one more element available. This enables us to use the index zero
  158. * special. This index will never be used because we store the first hash
  159. * index in the field used where zero means not used. Every other value
  160. * means used. The used field can be used as a first fast comparison for
  161. * equality of the stored and the parameter value. This helps to prevent
  162. * unnecessary expensive calls of strcmp.
  163. *
  164. * This implementation differs from the standard library version of
  165. * this function in a number of ways:
  166. *
  167. * - While the standard version does not make any assumptions about
  168. * the type of the stored data objects at all, this implementation
  169. * works with NUL terminated strings only.
  170. * - Instead of storing just pointers to the original objects, we
  171. * create local copies so the caller does not need to care about the
  172. * data any more.
  173. * - The standard implementation does not provide a way to update an
  174. * existing entry. This version will create a new entry or update an
  175. * existing one when both "action == ENTER" and "item.data != NULL".
  176. * - Instead of returning 1 on success, we return the index into the
  177. * internal hash table, which is also guaranteed to be positive.
  178. * This allows us direct access to the found hash table slot for
  179. * example for functions like hdelete().
  180. */
  181. /*
  182. * hstrstr_r - return index to entry whose key and/or data contains match
  183. */
  184. int hstrstr_r(const char *match, int last_idx, ENTRY ** retval,
  185. struct hsearch_data *htab)
  186. {
  187. unsigned int idx;
  188. for (idx = last_idx + 1; idx < htab->size; ++idx) {
  189. if (htab->table[idx].used <= 0)
  190. continue;
  191. if (strstr(htab->table[idx].entry.key, match) ||
  192. strstr(htab->table[idx].entry.data, match)) {
  193. *retval = &htab->table[idx].entry;
  194. return idx;
  195. }
  196. }
  197. __set_errno(ESRCH);
  198. *retval = NULL;
  199. return 0;
  200. }
  201. int hmatch_r(const char *match, int last_idx, ENTRY ** retval,
  202. struct hsearch_data *htab)
  203. {
  204. unsigned int idx;
  205. size_t key_len = strlen(match);
  206. for (idx = last_idx + 1; idx < htab->size; ++idx) {
  207. if (htab->table[idx].used <= 0)
  208. continue;
  209. if (!strncmp(match, htab->table[idx].entry.key, key_len)) {
  210. *retval = &htab->table[idx].entry;
  211. return idx;
  212. }
  213. }
  214. __set_errno(ESRCH);
  215. *retval = NULL;
  216. return 0;
  217. }
  218. int hsearch_r(ENTRY item, ACTION action, ENTRY ** retval,
  219. struct hsearch_data *htab)
  220. {
  221. unsigned int hval;
  222. unsigned int count;
  223. unsigned int len = strlen(item.key);
  224. unsigned int idx;
  225. unsigned int first_deleted = 0;
  226. /* Compute an value for the given string. Perhaps use a better method. */
  227. hval = len;
  228. count = len;
  229. while (count-- > 0) {
  230. hval <<= 4;
  231. hval += item.key[count];
  232. }
  233. /*
  234. * First hash function:
  235. * simply take the modul but prevent zero.
  236. */
  237. hval %= htab->size;
  238. if (hval == 0)
  239. ++hval;
  240. /* The first index tried. */
  241. idx = hval;
  242. if (htab->table[idx].used) {
  243. /*
  244. * Further action might be required according to the
  245. * action value.
  246. */
  247. unsigned hval2;
  248. if (htab->table[idx].used == -1
  249. && !first_deleted)
  250. first_deleted = idx;
  251. if (htab->table[idx].used == hval
  252. && strcmp(item.key, htab->table[idx].entry.key) == 0) {
  253. /* Overwrite existing value? */
  254. if ((action == ENTER) && (item.data != NULL)) {
  255. free(htab->table[idx].entry.data);
  256. htab->table[idx].entry.data =
  257. strdup(item.data);
  258. if (!htab->table[idx].entry.data) {
  259. __set_errno(ENOMEM);
  260. *retval = NULL;
  261. return 0;
  262. }
  263. }
  264. /* return found entry */
  265. *retval = &htab->table[idx].entry;
  266. return idx;
  267. }
  268. /*
  269. * Second hash function:
  270. * as suggested in [Knuth]
  271. */
  272. hval2 = 1 + hval % (htab->size - 2);
  273. do {
  274. /*
  275. * Because SIZE is prime this guarantees to
  276. * step through all available indices.
  277. */
  278. if (idx <= hval2)
  279. idx = htab->size + idx - hval2;
  280. else
  281. idx -= hval2;
  282. /*
  283. * If we visited all entries leave the loop
  284. * unsuccessfully.
  285. */
  286. if (idx == hval)
  287. break;
  288. /* If entry is found use it. */
  289. if ((htab->table[idx].used == hval)
  290. && strcmp(item.key, htab->table[idx].entry.key) == 0) {
  291. /* Overwrite existing value? */
  292. if ((action == ENTER) && (item.data != NULL)) {
  293. free(htab->table[idx].entry.data);
  294. htab->table[idx].entry.data =
  295. strdup(item.data);
  296. if (!htab->table[idx].entry.data) {
  297. __set_errno(ENOMEM);
  298. *retval = NULL;
  299. return 0;
  300. }
  301. }
  302. /* return found entry */
  303. *retval = &htab->table[idx].entry;
  304. return idx;
  305. }
  306. }
  307. while (htab->table[idx].used);
  308. }
  309. /* An empty bucket has been found. */
  310. if (action == ENTER) {
  311. /*
  312. * If table is full and another entry should be
  313. * entered return with error.
  314. */
  315. if (htab->filled == htab->size) {
  316. __set_errno(ENOMEM);
  317. *retval = NULL;
  318. return 0;
  319. }
  320. /*
  321. * Create new entry;
  322. * create copies of item.key and item.data
  323. */
  324. if (first_deleted)
  325. idx = first_deleted;
  326. htab->table[idx].used = hval;
  327. htab->table[idx].entry.key = strdup(item.key);
  328. htab->table[idx].entry.data = strdup(item.data);
  329. if (!htab->table[idx].entry.key ||
  330. !htab->table[idx].entry.data) {
  331. __set_errno(ENOMEM);
  332. *retval = NULL;
  333. return 0;
  334. }
  335. ++htab->filled;
  336. /* return new entry */
  337. *retval = &htab->table[idx].entry;
  338. return 1;
  339. }
  340. __set_errno(ESRCH);
  341. *retval = NULL;
  342. return 0;
  343. }
  344. /*
  345. * hdelete()
  346. */
  347. /*
  348. * The standard implementation of hsearch(3) does not provide any way
  349. * to delete any entries from the hash table. We extend the code to
  350. * do that.
  351. */
  352. int hdelete_r(const char *key, struct hsearch_data *htab, int do_apply)
  353. {
  354. ENTRY e, *ep;
  355. int idx;
  356. debug("hdelete: DELETE key \"%s\"\n", key);
  357. e.key = (char *)key;
  358. if ((idx = hsearch_r(e, FIND, &ep, htab)) == 0) {
  359. __set_errno(ESRCH);
  360. return 0; /* not found */
  361. }
  362. /* free used ENTRY */
  363. debug("hdelete: DELETING key \"%s\"\n", key);
  364. if (do_apply && htab->apply != NULL)
  365. htab->apply(ep->key, ep->data, NULL, H_FORCE);
  366. free((void *)ep->key);
  367. free(ep->data);
  368. htab->table[idx].used = -1;
  369. --htab->filled;
  370. return 1;
  371. }
  372. /*
  373. * hexport()
  374. */
  375. /*
  376. * Export the data stored in the hash table in linearized form.
  377. *
  378. * Entries are exported as "name=value" strings, separated by an
  379. * arbitrary (non-NUL, of course) separator character. This allows to
  380. * use this function both when formatting the U-Boot environment for
  381. * external storage (using '\0' as separator), but also when using it
  382. * for the "printenv" command to print all variables, simply by using
  383. * as '\n" as separator. This can also be used for new features like
  384. * exporting the environment data as text file, including the option
  385. * for later re-import.
  386. *
  387. * The entries in the result list will be sorted by ascending key
  388. * values.
  389. *
  390. * If the separator character is different from NUL, then any
  391. * separator characters and backslash characters in the values will
  392. * be escaped by a preceeding backslash in output. This is needed for
  393. * example to enable multi-line values, especially when the output
  394. * shall later be parsed (for example, for re-import).
  395. *
  396. * There are several options how the result buffer is handled:
  397. *
  398. * *resp size
  399. * -----------
  400. * NULL 0 A string of sufficient length will be allocated.
  401. * NULL >0 A string of the size given will be
  402. * allocated. An error will be returned if the size is
  403. * not sufficient. Any unused bytes in the string will
  404. * be '\0'-padded.
  405. * !NULL 0 The user-supplied buffer will be used. No length
  406. * checking will be performed, i. e. it is assumed that
  407. * the buffer size will always be big enough. DANGEROUS.
  408. * !NULL >0 The user-supplied buffer will be used. An error will
  409. * be returned if the size is not sufficient. Any unused
  410. * bytes in the string will be '\0'-padded.
  411. */
  412. static int cmpkey(const void *p1, const void *p2)
  413. {
  414. ENTRY *e1 = *(ENTRY **) p1;
  415. ENTRY *e2 = *(ENTRY **) p2;
  416. return (strcmp(e1->key, e2->key));
  417. }
  418. ssize_t hexport_r(struct hsearch_data *htab, const char sep,
  419. char **resp, size_t size,
  420. int argc, char * const argv[])
  421. {
  422. ENTRY *list[htab->size];
  423. char *res, *p;
  424. size_t totlen;
  425. int i, n;
  426. /* Test for correct arguments. */
  427. if ((resp == NULL) || (htab == NULL)) {
  428. __set_errno(EINVAL);
  429. return (-1);
  430. }
  431. debug("EXPORT table = %p, htab.size = %d, htab.filled = %d, "
  432. "size = %zu\n", htab, htab->size, htab->filled, size);
  433. /*
  434. * Pass 1:
  435. * search used entries,
  436. * save addresses and compute total length
  437. */
  438. for (i = 1, n = 0, totlen = 0; i <= htab->size; ++i) {
  439. if (htab->table[i].used > 0) {
  440. ENTRY *ep = &htab->table[i].entry;
  441. int arg, found = 0;
  442. for (arg = 0; arg < argc; ++arg) {
  443. if (strcmp(argv[arg], ep->key) == 0) {
  444. found = 1;
  445. break;
  446. }
  447. }
  448. if ((argc > 0) && (found == 0))
  449. continue;
  450. list[n++] = ep;
  451. totlen += strlen(ep->key) + 2;
  452. if (sep == '\0') {
  453. totlen += strlen(ep->data);
  454. } else { /* check if escapes are needed */
  455. char *s = ep->data;
  456. while (*s) {
  457. ++totlen;
  458. /* add room for needed escape chars */
  459. if ((*s == sep) || (*s == '\\'))
  460. ++totlen;
  461. ++s;
  462. }
  463. }
  464. totlen += 2; /* for '=' and 'sep' char */
  465. }
  466. }
  467. #ifdef DEBUG
  468. /* Pass 1a: print unsorted list */
  469. printf("Unsorted: n=%d\n", n);
  470. for (i = 0; i < n; ++i) {
  471. printf("\t%3d: %p ==> %-10s => %s\n",
  472. i, list[i], list[i]->key, list[i]->data);
  473. }
  474. #endif
  475. /* Sort list by keys */
  476. qsort(list, n, sizeof(ENTRY *), cmpkey);
  477. /* Check if the user supplied buffer size is sufficient */
  478. if (size) {
  479. if (size < totlen + 1) { /* provided buffer too small */
  480. printf("Env export buffer too small: %zu, "
  481. "but need %zu\n", size, totlen + 1);
  482. __set_errno(ENOMEM);
  483. return (-1);
  484. }
  485. } else {
  486. size = totlen + 1;
  487. }
  488. /* Check if the user provided a buffer */
  489. if (*resp) {
  490. /* yes; clear it */
  491. res = *resp;
  492. memset(res, '\0', size);
  493. } else {
  494. /* no, allocate and clear one */
  495. *resp = res = calloc(1, size);
  496. if (res == NULL) {
  497. __set_errno(ENOMEM);
  498. return (-1);
  499. }
  500. }
  501. /*
  502. * Pass 2:
  503. * export sorted list of result data
  504. */
  505. for (i = 0, p = res; i < n; ++i) {
  506. const char *s;
  507. s = list[i]->key;
  508. while (*s)
  509. *p++ = *s++;
  510. *p++ = '=';
  511. s = list[i]->data;
  512. while (*s) {
  513. if ((*s == sep) || (*s == '\\'))
  514. *p++ = '\\'; /* escape */
  515. *p++ = *s++;
  516. }
  517. *p++ = sep;
  518. }
  519. *p = '\0'; /* terminate result */
  520. return size;
  521. }
  522. /*
  523. * himport()
  524. */
  525. /*
  526. * Check whether variable 'name' is amongst vars[],
  527. * and remove all instances by setting the pointer to NULL
  528. */
  529. static int drop_var_from_set(const char *name, int nvars, char * vars[])
  530. {
  531. int i = 0;
  532. int res = 0;
  533. /* No variables specified means process all of them */
  534. if (nvars == 0)
  535. return 1;
  536. for (i = 0; i < nvars; i++) {
  537. if (vars[i] == NULL)
  538. continue;
  539. /* If we found it, delete all of them */
  540. if (!strcmp(name, vars[i])) {
  541. vars[i] = NULL;
  542. res = 1;
  543. }
  544. }
  545. if (!res)
  546. debug("Skipping non-listed variable %s\n", name);
  547. return res;
  548. }
  549. /*
  550. * Import linearized data into hash table.
  551. *
  552. * This is the inverse function to hexport(): it takes a linear list
  553. * of "name=value" pairs and creates hash table entries from it.
  554. *
  555. * Entries without "value", i. e. consisting of only "name" or
  556. * "name=", will cause this entry to be deleted from the hash table.
  557. *
  558. * The "flag" argument can be used to control the behaviour: when the
  559. * H_NOCLEAR bit is set, then an existing hash table will kept, i. e.
  560. * new data will be added to an existing hash table; otherwise, old
  561. * data will be discarded and a new hash table will be created.
  562. *
  563. * The separator character for the "name=value" pairs can be selected,
  564. * so we both support importing from externally stored environment
  565. * data (separated by NUL characters) and from plain text files
  566. * (entries separated by newline characters).
  567. *
  568. * To allow for nicely formatted text input, leading white space
  569. * (sequences of SPACE and TAB chars) is ignored, and entries starting
  570. * (after removal of any leading white space) with a '#' character are
  571. * considered comments and ignored.
  572. *
  573. * [NOTE: this means that a variable name cannot start with a '#'
  574. * character.]
  575. *
  576. * When using a non-NUL separator character, backslash is used as
  577. * escape character in the value part, allowing for example for
  578. * multi-line values.
  579. *
  580. * In theory, arbitrary separator characters can be used, but only
  581. * '\0' and '\n' have really been tested.
  582. */
  583. int himport_r(struct hsearch_data *htab,
  584. const char *env, size_t size, const char sep, int flag,
  585. int nvars, char * const vars[], int do_apply)
  586. {
  587. char *data, *sp, *dp, *name, *value;
  588. char *localvars[nvars];
  589. int i;
  590. /* Test for correct arguments. */
  591. if (htab == NULL) {
  592. __set_errno(EINVAL);
  593. return 0;
  594. }
  595. /* we allocate new space to make sure we can write to the array */
  596. if ((data = malloc(size)) == NULL) {
  597. debug("himport_r: can't malloc %zu bytes\n", size);
  598. __set_errno(ENOMEM);
  599. return 0;
  600. }
  601. memcpy(data, env, size);
  602. dp = data;
  603. /* make a local copy of the list of variables */
  604. if (nvars)
  605. memcpy(localvars, vars, sizeof(vars[0]) * nvars);
  606. if ((flag & H_NOCLEAR) == 0) {
  607. /* Destroy old hash table if one exists */
  608. debug("Destroy Hash Table: %p table = %p\n", htab,
  609. htab->table);
  610. if (htab->table)
  611. hdestroy_r(htab, do_apply);
  612. }
  613. /*
  614. * Create new hash table (if needed). The computation of the hash
  615. * table size is based on heuristics: in a sample of some 70+
  616. * existing systems we found an average size of 39+ bytes per entry
  617. * in the environment (for the whole key=value pair). Assuming a
  618. * size of 8 per entry (= safety factor of ~5) should provide enough
  619. * safety margin for any existing environment definitions and still
  620. * allow for more than enough dynamic additions. Note that the
  621. * "size" argument is supposed to give the maximum enviroment size
  622. * (CONFIG_ENV_SIZE). This heuristics will result in
  623. * unreasonably large numbers (and thus memory footprint) for
  624. * big flash environments (>8,000 entries for 64 KB
  625. * envrionment size), so we clip it to a reasonable value.
  626. * On the other hand we need to add some more entries for free
  627. * space when importing very small buffers. Both boundaries can
  628. * be overwritten in the board config file if needed.
  629. */
  630. if (!htab->table) {
  631. int nent = CONFIG_ENV_MIN_ENTRIES + size / 8;
  632. if (nent > CONFIG_ENV_MAX_ENTRIES)
  633. nent = CONFIG_ENV_MAX_ENTRIES;
  634. debug("Create Hash Table: N=%d\n", nent);
  635. if (hcreate_r(nent, htab) == 0) {
  636. free(data);
  637. return 0;
  638. }
  639. }
  640. /* Parse environment; allow for '\0' and 'sep' as separators */
  641. do {
  642. ENTRY e, *rv;
  643. /* skip leading white space */
  644. while (isblank(*dp))
  645. ++dp;
  646. /* skip comment lines */
  647. if (*dp == '#') {
  648. while (*dp && (*dp != sep))
  649. ++dp;
  650. ++dp;
  651. continue;
  652. }
  653. /* parse name */
  654. for (name = dp; *dp != '=' && *dp && *dp != sep; ++dp)
  655. ;
  656. /* deal with "name" and "name=" entries (delete var) */
  657. if (*dp == '\0' || *(dp + 1) == '\0' ||
  658. *dp == sep || *(dp + 1) == sep) {
  659. if (*dp == '=')
  660. *dp++ = '\0';
  661. *dp++ = '\0'; /* terminate name */
  662. debug("DELETE CANDIDATE: \"%s\"\n", name);
  663. if (!drop_var_from_set(name, nvars, localvars))
  664. continue;
  665. if (hdelete_r(name, htab, do_apply) == 0)
  666. debug("DELETE ERROR ##############################\n");
  667. continue;
  668. }
  669. *dp++ = '\0'; /* terminate name */
  670. /* parse value; deal with escapes */
  671. for (value = sp = dp; *dp && (*dp != sep); ++dp) {
  672. if ((*dp == '\\') && *(dp + 1))
  673. ++dp;
  674. *sp++ = *dp;
  675. }
  676. *sp++ = '\0'; /* terminate value */
  677. ++dp;
  678. /* Skip variables which are not supposed to be processed */
  679. if (!drop_var_from_set(name, nvars, localvars))
  680. continue;
  681. /* enter into hash table */
  682. e.key = name;
  683. e.data = value;
  684. /* if there is an apply function, check what it has to say */
  685. if (do_apply && htab->apply != NULL) {
  686. debug("searching before calling cb function"
  687. " for %s\n", name);
  688. /*
  689. * Search for variable in existing env, so to pass
  690. * its previous value to the apply callback
  691. */
  692. hsearch_r(e, FIND, &rv, htab);
  693. debug("previous value was %s\n", rv ? rv->data : "");
  694. if (htab->apply(name, rv ? rv->data : NULL,
  695. value, flag)) {
  696. debug("callback function refused to set"
  697. " variable %s, skipping it!\n", name);
  698. continue;
  699. }
  700. }
  701. hsearch_r(e, ENTER, &rv, htab);
  702. if (rv == NULL) {
  703. printf("himport_r: can't insert \"%s=%s\" into hash table\n",
  704. name, value);
  705. return 0;
  706. }
  707. debug("INSERT: table %p, filled %d/%d rv %p ==> name=\"%s\" value=\"%s\"\n",
  708. htab, htab->filled, htab->size,
  709. rv, name, value);
  710. } while ((dp < data + size) && *dp); /* size check needed for text */
  711. /* without '\0' termination */
  712. debug("INSERT: free(data = %p)\n", data);
  713. free(data);
  714. /* process variables which were not considered */
  715. for (i = 0; i < nvars; i++) {
  716. if (localvars[i] == NULL)
  717. continue;
  718. /*
  719. * All variables which were not deleted from the variable list
  720. * were not present in the imported env
  721. * This could mean two things:
  722. * a) if the variable was present in current env, we delete it
  723. * b) if the variable was not present in current env, we notify
  724. * it might be a typo
  725. */
  726. if (hdelete_r(localvars[i], htab, do_apply) == 0)
  727. printf("WARNING: '%s' neither in running nor in imported env!\n", localvars[i]);
  728. else
  729. printf("WARNING: '%s' not in imported env, deleting it!\n", localvars[i]);
  730. }
  731. debug("INSERT: done\n");
  732. return 1; /* everything OK */
  733. }