xref: /lighttpd1.4/src/array.c (revision ae9f354b)
1 #include "first.h"
2 
3 #include "array.h"
4 #include "buffer.h"
5 
6 #include <string.h>
7 #include <stdlib.h>
8 #include <limits.h>
9 
10 #include <errno.h>
11 #include <assert.h>
12 
13 #define ARRAY_NOT_FOUND ((size_t)(-1))
14 
15 array *array_init(void) {
16 	array *a;
17 
18 	a = calloc(1, sizeof(*a));
19 	force_assert(a);
20 
21 	return a;
22 }
23 
24 array *array_init_array(array *src) {
25 	size_t i;
26 	array *a = array_init();
27 
28 	if (0 == src->size) return a;
29 
30 	a->used = src->used;
31 	a->size = src->size;
32 	a->unique_ndx = src->unique_ndx;
33 
34 	a->data = malloc(sizeof(*src->data) * src->size);
35 	force_assert(NULL != a->data);
36 	for (i = 0; i < src->size; i++) {
37 		if (src->data[i]) a->data[i] = src->data[i]->copy(src->data[i]);
38 		else a->data[i] = NULL;
39 	}
40 
41 	a->sorted = malloc(sizeof(*src->sorted) * src->size);
42 	force_assert(NULL != a->sorted);
43 	memcpy(a->sorted, src->sorted, sizeof(*src->sorted) * src->size);
44 	return a;
45 }
46 
47 void array_free(array *a) {
48 	size_t i;
49 	if (!a) return;
50 
51 	for (i = 0; i < a->size; i++) {
52 		if (a->data[i]) a->data[i]->free(a->data[i]);
53 	}
54 
55 	if (a->data) free(a->data);
56 	if (a->sorted) free(a->sorted);
57 
58 	free(a);
59 }
60 
61 void array_reset(array *a) {
62 	size_t i;
63 	if (!a) return;
64 
65 	for (i = 0; i < a->used; i++) {
66 		a->data[i]->reset(a->data[i]);
67 	}
68 
69 	a->used = 0;
70 	a->unique_ndx = 0;
71 }
72 
73 data_unset *array_pop(array *a) {
74 	data_unset *du;
75 
76 	force_assert(a->used != 0);
77 
78 	a->used --;
79 	du = a->data[a->used];
80 	force_assert(a->sorted[a->used] == a->used); /* only works on "simple" lists */
81 	a->data[a->used] = NULL;
82 
83 	return du;
84 }
85 
86 /* returns index of element or ARRAY_NOT_FOUND
87  * if rndx != NULL it stores the position in a->sorted[] where the key needs
88  * to be inserted
89  */
90 static size_t array_get_index(const array *a, const char *key, size_t keylen, size_t *rndx) {
91 	/* invariant: [lower-1] < key < [upper]
92 	 * "virtual elements": [-1] = -INFTY, [a->used] = +INFTY
93 	 * also an invariant: 0 <= lower <= upper <= a->used
94 	 */
95 	size_t lower = 0, upper = a->used;
96 	force_assert(upper <= SSIZE_MAX); /* (lower + upper) can't overflow */
97 
98 	while (lower != upper) {
99 		size_t probe = (lower + upper) / 2;
100 		int cmp = buffer_caseless_compare(key, keylen, CONST_BUF_LEN(a->data[a->sorted[probe]]->key));
101 		assert(lower < upper); /* from loop invariant (lower <= upper) + (lower != upper) */
102 		assert((lower <= probe) && (probe < upper)); /* follows from lower < upper */
103 
104 		if (cmp == 0) {
105 			/* found */
106 			if (rndx) *rndx = probe;
107 			return a->sorted[probe];
108 		} else if (cmp < 0) {
109 			/* key < [probe] */
110 			upper = probe; /* still: lower <= upper */
111 		} else {
112 			/* key > [probe] */
113 			lower = probe + 1; /* still: lower <= upper */
114 		}
115 	}
116 
117 	/* not found: [lower-1] < key < [upper] = [lower] ==> insert at [lower] */
118 	if (rndx) *rndx = lower;
119 	return ARRAY_NOT_FOUND;
120 }
121 
122 data_unset *array_get_element_klen(const array *a, const char *key, size_t klen) {
123 	size_t ndx;
124 	force_assert(NULL != key);
125 
126 	if (ARRAY_NOT_FOUND != (ndx = array_get_index(a, key, klen, NULL))) {
127 		/* found, return it */
128 		return a->data[ndx];
129 	}
130 
131 	return NULL;
132 }
133 
134 data_unset *array_extract_element_klen(array *a, const char *key, size_t klen) {
135 	size_t ndx, pos;
136 	force_assert(NULL != key);
137 
138 	if (ARRAY_NOT_FOUND != (ndx = array_get_index(a, key, klen, &pos))) {
139 		/* found */
140 		const size_t last_ndx = a->used - 1;
141 		data_unset *entry = a->data[ndx];
142 
143 		/* now we need to swap it with the last element (if it isn't already the last element) */
144 		if (ndx != last_ndx) {
145 			/* to swap we also need to modify the index in a->sorted - find pos of last_elem there */
146 			size_t last_elem_pos;
147 			/* last element must be present at the expected position */
148 			force_assert(last_ndx == array_get_index(a, CONST_BUF_LEN(a->data[last_ndx]->key), &last_elem_pos));
149 
150 			/* move entry from last_ndx to ndx */
151 			a->data[ndx] = a->data[last_ndx];
152 			a->data[last_ndx] = NULL;
153 
154 			/* fix index entry for moved entry */
155 			a->sorted[last_elem_pos] = ndx;
156 		} else {
157 			a->data[ndx] = NULL;
158 		}
159 
160 		/* remove entry in a->sorted: move everything after pos one step to the left */
161 		if (pos != last_ndx) {
162 			memmove(a->sorted + pos, a->sorted + pos + 1, (last_ndx - pos) * sizeof(*a->sorted));
163 		}
164 		a->sorted[last_ndx] = ARRAY_NOT_FOUND;
165 		--a->used;
166 
167 		return entry;
168 	}
169 
170 	return NULL;
171 }
172 
173 static data_unset *array_get_unused_element(array *a, data_type_t t) {
174 	data_unset *ds = NULL;
175 	unsigned int i;
176 
177 	for (i = a->used; i < a->size; i++) {
178 		if (a->data[i] && a->data[i]->type == t) {
179 			ds = a->data[i];
180 
181 			/* make empty slot at a->used for next insert */
182 			a->data[i] = a->data[a->used];
183 			a->data[a->used] = NULL;
184 
185 			return ds;
186 		}
187 	}
188 
189 	return NULL;
190 }
191 
192 void array_set_key_value(array *hdrs, const char *key, size_t key_len, const char *value, size_t val_len) {
193 	data_string *ds;
194 
195 	if (NULL != (ds = (data_string *)array_get_element_klen(hdrs, key, key_len))) {
196 		buffer_copy_string_len(ds->value, value, val_len);
197 		return;
198 	}
199 
200 	array_insert_key_value(hdrs, key, key_len, value, val_len);
201 }
202 
203 void array_insert_key_value(array *hdrs, const char *key, size_t key_len, const char *value, size_t val_len) {
204 	data_string *ds;
205 
206 	if (NULL == (ds = (data_string *)array_get_unused_element(hdrs, TYPE_STRING))) {
207 		ds = data_string_init();
208 	}
209 
210 	buffer_copy_string_len(ds->key, key, key_len);
211 	buffer_copy_string_len(ds->value, value, val_len);
212 	array_insert_unique(hdrs, (data_unset *)ds);
213 }
214 
215 void array_insert_value(array *hdrs, const char *value, size_t val_len) {
216 	data_string *ds;
217 
218 	if (NULL == (ds = (data_string *)array_get_unused_element(hdrs, TYPE_STRING))) {
219 		ds = data_string_init();
220 	}
221 
222 	buffer_copy_string_len(ds->value, value, val_len);
223 	array_insert_unique(hdrs, (data_unset *)ds);
224 }
225 
226 /* if entry already exists return pointer to existing entry, otherwise insert entry and return NULL */
227 static data_unset **array_find_or_insert(array *a, data_unset *entry) {
228 	size_t ndx, pos, j;
229 
230 	/* generate unique index if neccesary */
231 	if (buffer_is_empty(entry->key) || entry->is_index_key) {
232 		buffer_copy_int(entry->key, a->unique_ndx++);
233 		entry->is_index_key = 1;
234 		force_assert(0 != a->unique_ndx); /* must not wrap or we'll get problems */
235 	}
236 
237 	/* try to find the entry */
238 	if (ARRAY_NOT_FOUND != (ndx = array_get_index(a, CONST_BUF_LEN(entry->key), &pos))) {
239 		/* found collision, return it */
240 		return &a->data[ndx];
241 	}
242 
243 	/* insert */
244 
245 	/* there couldn't possibly be enough memory to store so many entries */
246 	force_assert(a->used + 1 <= SSIZE_MAX);
247 
248 	if (a->size == 0) {
249 		a->size   = 16;
250 		a->data   = malloc(sizeof(*a->data)     * a->size);
251 		a->sorted = malloc(sizeof(*a->sorted)   * a->size);
252 		force_assert(a->data);
253 		force_assert(a->sorted);
254 		for (j = a->used; j < a->size; j++) a->data[j] = NULL;
255 	} else if (a->size == a->used) {
256 		a->size  += 16;
257 		a->data   = realloc(a->data,   sizeof(*a->data)   * a->size);
258 		a->sorted = realloc(a->sorted, sizeof(*a->sorted) * a->size);
259 		force_assert(a->data);
260 		force_assert(a->sorted);
261 		for (j = a->used; j < a->size; j++) a->data[j] = NULL;
262 	}
263 
264 	ndx = a->used;
265 
266 	/* make sure there is nothing here */
267 	if (a->data[ndx]) a->data[ndx]->free(a->data[ndx]);
268 
269 	a->data[a->used++] = entry;
270 
271 	/* move everything one step to the right */
272 	if (pos != ndx) {
273 		memmove(a->sorted + (pos + 1), a->sorted + (pos), (ndx - pos) * sizeof(*a->sorted));
274 	}
275 
276 	/* insert */
277 	a->sorted[pos] = ndx;
278 
279 	return NULL;
280 }
281 
282 /* replace or insert data (free existing entry) */
283 void array_replace(array *a, data_unset *entry) {
284 	data_unset **old;
285 
286 	force_assert(NULL != entry);
287 	if (NULL != (old = array_find_or_insert(a, entry))) {
288 		force_assert(*old != entry);
289 		(*old)->free(*old);
290 		*old = entry;
291 	}
292 }
293 
294 void array_insert_unique(array *a, data_unset *entry) {
295 	data_unset **old;
296 
297 	force_assert(NULL != entry);
298 	if (NULL != (old = array_find_or_insert(a, entry))) {
299 		force_assert((*old)->type == entry->type);
300 		entry->insert_dup(*old, entry);
301 	}
302 }
303 
304 int array_is_vlist(array *a) {
305 	for (size_t i = 0; i < a->used; ++i) {
306 		data_unset *du = a->data[i];
307 		if (!du->is_index_key || du->type != TYPE_STRING) return 0;
308 	}
309 	return 1;
310 }
311 
312 int array_is_kvany(array *a) {
313 	for (size_t i = 0; i < a->used; ++i) {
314 		data_unset *du = a->data[i];
315 		if (du->is_index_key) return 0;
316 	}
317 	return 1;
318 }
319 
320 int array_is_kvarray(array *a) {
321 	for (size_t i = 0; i < a->used; ++i) {
322 		data_unset *du = a->data[i];
323 		if (du->is_index_key || du->type != TYPE_ARRAY) return 0;
324 	}
325 	return 1;
326 }
327 
328 int array_is_kvstring(array *a) {
329 	for (size_t i = 0; i < a->used; ++i) {
330 		data_unset *du = a->data[i];
331 		if (du->is_index_key || du->type != TYPE_STRING) return 0;
332 	}
333 	return 1;
334 }
335 
336 /* array_match_*() routines follow very similar pattern, but operate on slightly
337  * different data: array key/value, prefix/suffix match, case-insensitive or not
338  * While these could be combined into fewer routines with flags to modify the
339  * behavior, the interface distinctions are useful to add clarity to the code,
340  * and the specialized routines run slightly faster */
341 
342 data_unset *
343 array_match_key_prefix_klen (const array * const a, const char * const s, const size_t slen)
344 {
345     for (size_t i = 0; i < a->used; ++i) {
346         const buffer * const key = a->data[i]->key;
347         const size_t klen = buffer_string_length(key);
348         if (klen <= slen && 0 == memcmp(s, key->ptr, klen))
349             return a->data[i];
350     }
351     return NULL;
352 }
353 
354 data_unset *
355 array_match_key_prefix_nc_klen (const array * const a, const char * const s, const size_t slen)
356 {
357     for (size_t i = 0; i < a->used; ++i) {
358         const buffer * const key = a->data[i]->key;
359         const size_t klen = buffer_string_length(key);
360         if (klen <= slen && 0 == strncasecmp(s, key->ptr, klen))
361             return a->data[i];
362     }
363     return NULL;
364 }
365 
366 data_unset *
367 array_match_key_prefix (const array * const a, const buffer * const b)
368 {
369     return array_match_key_prefix_klen(a, CONST_BUF_LEN(b));
370 }
371 
372 data_unset *
373 array_match_key_prefix_nc (const array * const a, const buffer * const b)
374 {
375     return array_match_key_prefix_nc_klen(a, CONST_BUF_LEN(b));
376 }
377 
378 const buffer *
379 array_match_value_prefix (const array * const a, const buffer * const b)
380 {
381     const size_t blen = buffer_string_length(b);
382 
383     for (size_t i = 0; i < a->used; ++i) {
384         const buffer * const value = ((data_string *)a->data[i])->value;
385         const size_t vlen = buffer_string_length(value);
386         if (vlen <= blen && 0 == memcmp(b->ptr, value->ptr, vlen))
387             return value;
388     }
389     return NULL;
390 }
391 
392 const buffer *
393 array_match_value_prefix_nc (const array * const a, const buffer * const b)
394 {
395     const size_t blen = buffer_string_length(b);
396 
397     for (size_t i = 0; i < a->used; ++i) {
398         const buffer * const value = ((data_string *)a->data[i])->value;
399         const size_t vlen = buffer_string_length(value);
400         if (vlen <= blen && 0 == strncasecmp(b->ptr, value->ptr, vlen))
401             return value;
402     }
403     return NULL;
404 }
405 
406 data_unset *
407 array_match_key_suffix (const array * const a, const buffer * const b)
408 {
409     const size_t blen = buffer_string_length(b);
410     const char * const end = b->ptr + blen;
411 
412     for (size_t i = 0; i < a->used; ++i) {
413         const buffer * const key = a->data[i]->key;
414         const size_t klen = buffer_string_length(key);
415         if (klen <= blen && 0 == memcmp(end - klen, key->ptr, klen))
416             return a->data[i];
417     }
418     return NULL;
419 }
420 
421 data_unset *
422 array_match_key_suffix_nc (const array * const a, const buffer * const b)
423 {
424     const size_t blen = buffer_string_length(b);
425     const char * const end = b->ptr + blen;
426 
427     for (size_t i = 0; i < a->used; ++i) {
428         const buffer * const key = a->data[i]->key;
429         const size_t klen = buffer_string_length(key);
430         if (klen <= blen && 0 == strncasecmp(end - klen, key->ptr, klen))
431             return a->data[i];
432     }
433     return NULL;
434 }
435 
436 const buffer *
437 array_match_value_suffix (const array * const a, const buffer * const b)
438 {
439     const size_t blen = buffer_string_length(b);
440     const char * const end = b->ptr + blen;
441 
442     for (size_t i = 0; i < a->used; ++i) {
443         const buffer * const value = ((data_string *)a->data[i])->value;
444         const size_t vlen = buffer_string_length(value);
445         if (vlen <= blen && 0 == memcmp(end - vlen, value->ptr, vlen))
446             return value;
447     }
448     return NULL;
449 }
450 
451 const buffer *
452 array_match_value_suffix_nc (const array * const a, const buffer * const b)
453 {
454     const size_t blen = buffer_string_length(b);
455     const char * const end = b->ptr + blen;
456 
457     for (size_t i = 0; i < a->used; ++i) {
458         const buffer * const value = ((data_string *)a->data[i])->value;
459         const size_t vlen = buffer_string_length(value);
460         if (vlen <= blen && 0 == strncasecmp(end - vlen, value->ptr, vlen))
461             return value;
462     }
463     return NULL;
464 }
465 
466 data_unset *
467 array_match_path_or_ext (const array * const a, const buffer * const b)
468 {
469     const size_t blen = buffer_string_length(b);
470 
471     for (size_t i = 0; i < a->used; ++i) {
472         /* check extension in the form "^/path" or ".ext$" */
473         const buffer * const key = a->data[i]->key;
474         const size_t klen = buffer_string_length(key);
475         if (klen <= blen
476             && 0 == memcmp((*(key->ptr) == '/' ? b->ptr : b->ptr + blen - klen),
477                            key->ptr, klen))
478             return a->data[i];
479     }
480     return NULL;
481 }
482 
483 
484 
485 
486 
487 #include <stdio.h>
488 
489 void array_print_indent(int depth) {
490 	int i;
491 	for (i = 0; i < depth; i ++) {
492 		fprintf(stdout, "    ");
493 	}
494 }
495 
496 size_t array_get_max_key_length(array *a) {
497 	size_t maxlen, i;
498 
499 	maxlen = 0;
500 	for (i = 0; i < a->used; i ++) {
501 		data_unset *du = a->data[i];
502 		size_t len = buffer_string_length(du->key);
503 
504 		if (len > maxlen) {
505 			maxlen = len;
506 		}
507 	}
508 	return maxlen;
509 }
510 
511 int array_print(array *a, int depth) {
512 	size_t i;
513 	size_t maxlen;
514 	int oneline = 1;
515 
516 	if (a->used > 5) {
517 		oneline = 0;
518 	}
519 	for (i = 0; i < a->used && oneline; i++) {
520 		data_unset *du = a->data[i];
521 		if (!du->is_index_key) {
522 			oneline = 0;
523 			break;
524 		}
525 		switch (du->type) {
526 			case TYPE_INTEGER:
527 			case TYPE_STRING:
528 				break;
529 			default:
530 				oneline = 0;
531 				break;
532 		}
533 	}
534 	if (oneline) {
535 		fprintf(stdout, "(");
536 		for (i = 0; i < a->used; i++) {
537 			data_unset *du = a->data[i];
538 			if (i != 0) {
539 				fprintf(stdout, ", ");
540 			}
541 			du->print(du, depth + 1);
542 		}
543 		fprintf(stdout, ")");
544 		return 0;
545 	}
546 
547 	maxlen = array_get_max_key_length(a);
548 	fprintf(stdout, "(\n");
549 	for (i = 0; i < a->used; i++) {
550 		data_unset *du = a->data[i];
551 		array_print_indent(depth + 1);
552 		if (!du->is_index_key) {
553 			int j;
554 
555 			if (i && (i % 5) == 0) {
556 				fprintf(stdout, "# %zu\n", i);
557 				array_print_indent(depth + 1);
558 			}
559 			fprintf(stdout, "\"%s\"", du->key->ptr);
560 			for (j = maxlen - buffer_string_length(du->key); j > 0; j--) {
561 				fprintf(stdout, " ");
562 			}
563 			fprintf(stdout, " => ");
564 		}
565 		du->print(du, depth + 1);
566 		fprintf(stdout, ",\n");
567 	}
568 	if (!(i && (i - 1 % 5) == 0)) {
569 		array_print_indent(depth + 1);
570 		fprintf(stdout, "# %zu\n", i);
571 	}
572 	array_print_indent(depth);
573 	fprintf(stdout, ")");
574 
575 	return 0;
576 }
577 
578 #ifdef DEBUG_ARRAY
579 int main (int argc, char **argv) {
580 	array *a;
581 	data_string *ds;
582 
583 	UNUSED(argc);
584 	UNUSED(argv);
585 
586 	a = array_init();
587 
588 	ds = data_string_init();
589 	buffer_copy_string_len(ds->key, CONST_STR_LEN("abc"));
590 	buffer_copy_string_len(ds->value, CONST_STR_LEN("alfrag"));
591 
592 	array_insert_unique(a, (data_unset *)ds);
593 
594 	ds = data_string_init();
595 	buffer_copy_string_len(ds->key, CONST_STR_LEN("abc"));
596 	buffer_copy_string_len(ds->value, CONST_STR_LEN("hameplman"));
597 
598 	array_insert_unique(a, (data_unset *)ds);
599 
600 	ds = data_string_init();
601 	buffer_copy_string_len(ds->key, CONST_STR_LEN("123"));
602 	buffer_copy_string_len(ds->value, CONST_STR_LEN("alfrag"));
603 
604 	array_insert_unique(a, (data_unset *)ds);
605 
606 	array_print(a, 0);
607 
608 	array_free(a);
609 
610 	fprintf(stderr, "%d\n",
611 	       buffer_caseless_compare(CONST_STR_LEN("Content-Type"), CONST_STR_LEN("Content-type")));
612 
613 	return 0;
614 }
615 #endif
616