xref: /lighttpd1.4/src/array.c (revision dbdab5db)
1 #include "first.h"
2 
3 #include "array.h"
4 #include "buffer.h"
5 
6 #include <string.h>
7 #include <stdio.h>
8 #include <stdlib.h>
9 #include <limits.h>
10 
11 #include <errno.h>
12 #include <assert.h>
13 
14 #define ARRAY_NOT_FOUND ((size_t)(-1))
15 
16 array *array_init(void) {
17 	array *a;
18 
19 	a = calloc(1, sizeof(*a));
20 	force_assert(a);
21 
22 	return a;
23 }
24 
25 array *array_init_array(array *src) {
26 	size_t i;
27 	array *a = array_init();
28 
29 	if (0 == src->size) return a;
30 
31 	a->used = src->used;
32 	a->size = src->size;
33 	a->unique_ndx = src->unique_ndx;
34 
35 	a->data = malloc(sizeof(*src->data) * src->size);
36 	force_assert(NULL != a->data);
37 	for (i = 0; i < src->size; i++) {
38 		if (src->data[i]) a->data[i] = src->data[i]->copy(src->data[i]);
39 		else a->data[i] = NULL;
40 	}
41 
42 	a->sorted = malloc(sizeof(*src->sorted) * src->size);
43 	force_assert(NULL != a->sorted);
44 	memcpy(a->sorted, src->sorted, sizeof(*src->sorted) * src->size);
45 	return a;
46 }
47 
48 void array_free(array *a) {
49 	size_t i;
50 	if (!a) return;
51 
52 	for (i = 0; i < a->size; i++) {
53 		if (a->data[i]) a->data[i]->free(a->data[i]);
54 	}
55 
56 	if (a->data) free(a->data);
57 	if (a->sorted) free(a->sorted);
58 
59 	free(a);
60 }
61 
62 void array_reset(array *a) {
63 	size_t i;
64 	if (!a) return;
65 
66 	for (i = 0; i < a->used; i++) {
67 		a->data[i]->reset(a->data[i]);
68 	}
69 
70 	a->used = 0;
71 	a->unique_ndx = 0;
72 }
73 
74 data_unset *array_pop(array *a) {
75 	data_unset *du;
76 
77 	force_assert(a->used != 0);
78 
79 	a->used --;
80 	du = a->data[a->used];
81 	force_assert(a->sorted[a->used] == a->used); /* only works on "simple" lists */
82 	a->data[a->used] = NULL;
83 
84 	return du;
85 }
86 
87 /* returns index of element or ARRAY_NOT_FOUND
88  * if rndx != NULL it stores the position in a->sorted[] where the key needs
89  * to be inserted
90  */
91 static size_t array_get_index(array *a, const char *key, size_t keylen, size_t *rndx) {
92 	/* invariant: [lower-1] < key < [upper]
93 	 * "virtual elements": [-1] = -INFTY, [a->used] = +INFTY
94 	 * also an invariant: 0 <= lower <= upper <= a->used
95 	 */
96 	size_t lower = 0, upper = a->used;
97 	force_assert(upper <= SSIZE_MAX); /* (lower + upper) can't overflow */
98 
99 	while (lower != upper) {
100 		size_t probe = (lower + upper) / 2;
101 		int cmp = buffer_caseless_compare(key, keylen, CONST_BUF_LEN(a->data[a->sorted[probe]]->key));
102 		assert(lower < upper); /* from loop invariant (lower <= upper) + (lower != upper) */
103 		assert((lower <= probe) && (probe < upper)); /* follows from lower < upper */
104 
105 		if (cmp == 0) {
106 			/* found */
107 			if (rndx) *rndx = probe;
108 			return a->sorted[probe];
109 		} else if (cmp < 0) {
110 			/* key < [probe] */
111 			upper = probe; /* still: lower <= upper */
112 		} else {
113 			/* key > [probe] */
114 			lower = probe + 1; /* still: lower <= upper */
115 		}
116 	}
117 
118 	/* not found: [lower-1] < key < [upper] = [lower] ==> insert at [lower] */
119 	if (rndx) *rndx = lower;
120 	return ARRAY_NOT_FOUND;
121 }
122 
123 data_unset *array_get_element(array *a, const char *key) {
124 	size_t ndx;
125 	force_assert(NULL != key);
126 
127 	if (ARRAY_NOT_FOUND != (ndx = array_get_index(a, key, strlen(key), NULL))) {
128 		/* found, return it */
129 		return a->data[ndx];
130 	}
131 
132 	return NULL;
133 }
134 
135 data_unset *array_extract_element(array *a, const char *key) {
136 	size_t ndx, pos;
137 	force_assert(NULL != key);
138 
139 	if (ARRAY_NOT_FOUND != (ndx = array_get_index(a, key, strlen(key), &pos))) {
140 		/* found */
141 		const size_t last_ndx = a->used - 1;
142 		data_unset *entry = a->data[ndx];
143 
144 		/* now we need to swap it with the last element (if it isn't already the last element) */
145 		if (ndx != last_ndx) {
146 			/* to swap we also need to modify the index in a->sorted - find pos of last_elem there */
147 			size_t last_elem_pos;
148 			/* last element must be present at the expected position */
149 			force_assert(last_ndx == array_get_index(a, CONST_BUF_LEN(a->data[last_ndx]->key), &last_elem_pos));
150 
151 			/* move entry from last_ndx to ndx */
152 			a->data[ndx] = a->data[last_ndx];
153 			a->data[last_ndx] = NULL;
154 
155 			/* fix index entry for moved entry */
156 			a->sorted[last_elem_pos] = ndx;
157 		} else {
158 			a->data[ndx] = NULL;
159 		}
160 
161 		/* remove entry in a->sorted: move everything after pos one step to the left */
162 		if (pos != last_ndx) {
163 			memmove(a->sorted + pos, a->sorted + pos + 1, (last_ndx - pos) * sizeof(*a->sorted));
164 		}
165 		a->sorted[last_ndx] = ARRAY_NOT_FOUND;
166 		--a->used;
167 
168 		return entry;
169 	}
170 
171 	return NULL;
172 }
173 
174 data_unset *array_get_unused_element(array *a, data_type_t t) {
175 	data_unset *ds = NULL;
176 	unsigned int i;
177 
178 	for (i = a->used; i < a->size; i++) {
179 		if (a->data[i] && a->data[i]->type == t) {
180 			ds = a->data[i];
181 
182 			/* make empty slot at a->used for next insert */
183 			a->data[i] = a->data[a->used];
184 			a->data[a->used] = NULL;
185 
186 			return ds;
187 		}
188 	}
189 
190 	return NULL;
191 }
192 
193 void array_set_key_value(array *hdrs, const char *key, size_t key_len, const char *value, size_t val_len) {
194 	data_string *ds_dst;
195 
196 	if (NULL != (ds_dst = (data_string *)array_get_element(hdrs, key))) {
197 		buffer_copy_string_len(ds_dst->value, value, val_len);
198 		return;
199 	}
200 
201 	if (NULL == (ds_dst = (data_string *)array_get_unused_element(hdrs, TYPE_STRING))) {
202 		ds_dst = data_string_init();
203 	}
204 
205 	buffer_copy_string_len(ds_dst->key, key, key_len);
206 	buffer_copy_string_len(ds_dst->value, value, val_len);
207 	array_insert_unique(hdrs, (data_unset *)ds_dst);
208 }
209 
210 /* if entry already exists return pointer to existing entry, otherwise insert entry and return NULL */
211 static data_unset **array_find_or_insert(array *a, data_unset *entry) {
212 	size_t ndx, pos, j;
213 
214 	/* generate unique index if neccesary */
215 	if (buffer_is_empty(entry->key) || entry->is_index_key) {
216 		buffer_copy_int(entry->key, a->unique_ndx++);
217 		entry->is_index_key = 1;
218 		force_assert(0 != a->unique_ndx); /* must not wrap or we'll get problems */
219 	}
220 
221 	/* try to find the entry */
222 	if (ARRAY_NOT_FOUND != (ndx = array_get_index(a, CONST_BUF_LEN(entry->key), &pos))) {
223 		/* found collision, return it */
224 		return &a->data[ndx];
225 	}
226 
227 	/* insert */
228 
229 	/* there couldn't possibly be enough memory to store so many entries */
230 	force_assert(a->used + 1 <= SSIZE_MAX);
231 
232 	if (a->size == 0) {
233 		a->size   = 16;
234 		a->data   = malloc(sizeof(*a->data)     * a->size);
235 		a->sorted = malloc(sizeof(*a->sorted)   * a->size);
236 		force_assert(a->data);
237 		force_assert(a->sorted);
238 		for (j = a->used; j < a->size; j++) a->data[j] = NULL;
239 	} else if (a->size == a->used) {
240 		a->size  += 16;
241 		a->data   = realloc(a->data,   sizeof(*a->data)   * a->size);
242 		a->sorted = realloc(a->sorted, sizeof(*a->sorted) * a->size);
243 		force_assert(a->data);
244 		force_assert(a->sorted);
245 		for (j = a->used; j < a->size; j++) a->data[j] = NULL;
246 	}
247 
248 	ndx = a->used;
249 
250 	/* make sure there is nothing here */
251 	if (a->data[ndx]) a->data[ndx]->free(a->data[ndx]);
252 
253 	a->data[a->used++] = entry;
254 
255 	/* move everything one step to the right */
256 	if (pos != ndx) {
257 		memmove(a->sorted + (pos + 1), a->sorted + (pos), (ndx - pos) * sizeof(*a->sorted));
258 	}
259 
260 	/* insert */
261 	a->sorted[pos] = ndx;
262 
263 	return NULL;
264 }
265 
266 /* replace or insert data (free existing entry) */
267 void array_replace(array *a, data_unset *entry) {
268 	data_unset **old;
269 
270 	force_assert(NULL != entry);
271 	if (NULL != (old = array_find_or_insert(a, entry))) {
272 		force_assert(*old != entry);
273 		(*old)->free(*old);
274 		*old = entry;
275 	}
276 }
277 
278 void array_insert_unique(array *a, data_unset *entry) {
279 	data_unset **old;
280 
281 	force_assert(NULL != entry);
282 	if (NULL != (old = array_find_or_insert(a, entry))) {
283 		force_assert((*old)->type == entry->type);
284 		entry->insert_dup(*old, entry);
285 	}
286 }
287 
288 void array_print_indent(int depth) {
289 	int i;
290 	for (i = 0; i < depth; i ++) {
291 		fprintf(stdout, "    ");
292 	}
293 }
294 
295 size_t array_get_max_key_length(array *a) {
296 	size_t maxlen, i;
297 
298 	maxlen = 0;
299 	for (i = 0; i < a->used; i ++) {
300 		data_unset *du = a->data[i];
301 		size_t len = strlen(du->key->ptr);
302 
303 		if (len > maxlen) {
304 			maxlen = len;
305 		}
306 	}
307 	return maxlen;
308 }
309 
310 int array_print(array *a, int depth) {
311 	size_t i;
312 	size_t maxlen;
313 	int oneline = 1;
314 
315 	if (a->used > 5) {
316 		oneline = 0;
317 	}
318 	for (i = 0; i < a->used && oneline; i++) {
319 		data_unset *du = a->data[i];
320 		if (!du->is_index_key) {
321 			oneline = 0;
322 			break;
323 		}
324 		switch (du->type) {
325 			case TYPE_INTEGER:
326 			case TYPE_STRING:
327 			case TYPE_COUNT:
328 				break;
329 			default:
330 				oneline = 0;
331 				break;
332 		}
333 	}
334 	if (oneline) {
335 		fprintf(stdout, "(");
336 		for (i = 0; i < a->used; i++) {
337 			data_unset *du = a->data[i];
338 			if (i != 0) {
339 				fprintf(stdout, ", ");
340 			}
341 			du->print(du, depth + 1);
342 		}
343 		fprintf(stdout, ")");
344 		return 0;
345 	}
346 
347 	maxlen = array_get_max_key_length(a);
348 	fprintf(stdout, "(\n");
349 	for (i = 0; i < a->used; i++) {
350 		data_unset *du = a->data[i];
351 		array_print_indent(depth + 1);
352 		if (!du->is_index_key) {
353 			int j;
354 
355 			if (i && (i % 5) == 0) {
356 				fprintf(stdout, "# %zd\n", i);
357 				array_print_indent(depth + 1);
358 			}
359 			fprintf(stdout, "\"%s\"", du->key->ptr);
360 			for (j = maxlen - strlen(du->key->ptr); j > 0; j --) {
361 				fprintf(stdout, " ");
362 			}
363 			fprintf(stdout, " => ");
364 		}
365 		du->print(du, depth + 1);
366 		fprintf(stdout, ",\n");
367 	}
368 	if (!(i && (i - 1 % 5) == 0)) {
369 		array_print_indent(depth + 1);
370 		fprintf(stdout, "# %zd\n", i);
371 	}
372 	array_print_indent(depth);
373 	fprintf(stdout, ")");
374 
375 	return 0;
376 }
377 
378 #ifdef DEBUG_ARRAY
379 int main (int argc, char **argv) {
380 	array *a;
381 	data_string *ds;
382 	data_count *dc;
383 
384 	UNUSED(argc);
385 	UNUSED(argv);
386 
387 	a = array_init();
388 
389 	ds = data_string_init();
390 	buffer_copy_string_len(ds->key, CONST_STR_LEN("abc"));
391 	buffer_copy_string_len(ds->value, CONST_STR_LEN("alfrag"));
392 
393 	array_insert_unique(a, (data_unset *)ds);
394 
395 	ds = data_string_init();
396 	buffer_copy_string_len(ds->key, CONST_STR_LEN("abc"));
397 	buffer_copy_string_len(ds->value, CONST_STR_LEN("hameplman"));
398 
399 	array_insert_unique(a, (data_unset *)ds);
400 
401 	ds = data_string_init();
402 	buffer_copy_string_len(ds->key, CONST_STR_LEN("123"));
403 	buffer_copy_string_len(ds->value, CONST_STR_LEN("alfrag"));
404 
405 	array_insert_unique(a, (data_unset *)ds);
406 
407 	dc = data_count_init();
408 	buffer_copy_string_len(dc->key, CONST_STR_LEN("def"));
409 
410 	array_insert_unique(a, (data_unset *)dc);
411 
412 	dc = data_count_init();
413 	buffer_copy_string_len(dc->key, CONST_STR_LEN("def"));
414 
415 	array_insert_unique(a, (data_unset *)dc);
416 
417 	array_print(a, 0);
418 
419 	array_free(a);
420 
421 	fprintf(stderr, "%d\n",
422 	       buffer_caseless_compare(CONST_STR_LEN("Content-Type"), CONST_STR_LEN("Content-type")));
423 
424 	return 0;
425 }
426 #endif
427