1 /*
2 * SysDB - src/core/store_expr.c
3 * Copyright (C) 2014 Sebastian 'tokkee' Harl <sh@tokkee.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
17 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
28 /*
29 * This module implements expressions which may be executed in the store.
30 */
32 #if HAVE_CONFIG_H
33 # include "config.h"
34 #endif /* HAVE_CONFIG_H */
36 #include "sysdb.h"
37 #include "core/store-private.h"
38 #include "core/data.h"
39 #include "core/object.h"
41 #include <assert.h>
42 #include <stdlib.h>
43 #include <string.h>
45 /*
46 * private data types
47 */
49 /* iterate through either a list of child nodes or arrays */
50 struct sdb_store_expr_iter {
51 sdb_store_obj_t *obj;
52 sdb_store_expr_t *expr;
54 sdb_avltree_iter_t *tree;
56 sdb_data_t array;
57 size_t array_idx;
59 sdb_store_matcher_t *filter;
60 };
62 /*
63 * private types
64 */
66 static int
67 expr_init(sdb_object_t *obj, va_list ap)
68 {
69 int type = va_arg(ap, int);
70 sdb_store_expr_t *left = va_arg(ap, sdb_store_expr_t *);
71 sdb_store_expr_t *right = va_arg(ap, sdb_store_expr_t *);
72 const sdb_data_t *value = va_arg(ap, const sdb_data_t *);
74 sdb_store_expr_t *expr = SDB_STORE_EXPR(obj);
76 if (type <= 0) {
77 if (! value)
78 return -1;
79 if ((type == TYPED_EXPR) && (! left))
80 return -1;
81 } else {
82 if (value)
83 return -1;
84 if ((! left) || (! right))
85 return -1;
86 }
88 if (value)
89 expr->data = *value;
91 sdb_object_ref(SDB_OBJ(left));
92 sdb_object_ref(SDB_OBJ(right));
94 expr->type = type;
95 expr->left = left;
96 expr->right = right;
98 /* unknown for now */
99 expr->data_type = -1;
100 return 0;
101 } /* expr_init */
103 static void
104 expr_destroy(sdb_object_t *obj)
105 {
106 sdb_store_expr_t *expr = SDB_STORE_EXPR(obj);
107 sdb_object_deref(SDB_OBJ(expr->left));
108 sdb_object_deref(SDB_OBJ(expr->right));
110 if (expr->data.type)
111 sdb_data_free_datum(&expr->data);
112 } /* expr_destroy */
114 static sdb_type_t expr_type = {
115 /* size = */ sizeof(sdb_store_expr_t),
116 /* init = */ expr_init,
117 /* destroy = */ expr_destroy,
118 };
120 /*
121 * public API
122 */
124 sdb_store_expr_t *
125 sdb_store_expr_create(int op, sdb_store_expr_t *left, sdb_store_expr_t *right)
126 {
127 sdb_data_t value = SDB_DATA_INIT;
128 sdb_store_expr_t *e;
130 if ((op < 0) || (SDB_DATA_CONCAT < op) || (! left) || (! right))
131 return NULL;
133 if (left->type || right->type) {
134 e = SDB_STORE_EXPR(sdb_object_create("store-expr", expr_type,
135 op, left, right, NULL));
136 e->data_type = sdb_data_expr_type(op, left->type, right->type);
137 return e;
138 }
139 /* else: both expressions are constant values; evaluate now */
141 if (sdb_data_expr_eval(op, &left->data, &right->data, &value))
142 return NULL;
143 e = SDB_STORE_EXPR(sdb_object_create("store-constvalue", expr_type,
144 0, NULL, NULL, &value));
145 e->data_type = value.type;
146 return e;
147 } /* sdb_store_expr_create */
149 sdb_store_expr_t *
150 sdb_store_expr_typed(int typ, sdb_store_expr_t *expr)
151 {
152 sdb_data_t value = { SDB_TYPE_INTEGER, { .integer = typ } };
153 sdb_store_expr_t *e;
155 if ((typ < SDB_HOST) || (SDB_ATTRIBUTE < typ))
156 return NULL;
158 e = SDB_STORE_EXPR(sdb_object_create("store-typedexpr", expr_type,
159 TYPED_EXPR, expr, NULL, &value));
160 e->data_type = expr->data_type;
161 return e;
162 } /* sdb_store_expr_typed */
164 sdb_store_expr_t *
165 sdb_store_expr_fieldvalue(int field)
166 {
167 sdb_data_t value = { SDB_TYPE_INTEGER, { .integer = field } };
168 sdb_store_expr_t *e;
170 if ((field < SDB_FIELD_NAME) || (SDB_FIELD_BACKEND < field))
171 return NULL;
172 e = SDB_STORE_EXPR(sdb_object_create("store-fieldvalue", expr_type,
173 FIELD_VALUE, NULL, NULL, &value));
174 e->data_type = SDB_FIELD_TYPE(field);
175 return e;
176 } /* sdb_store_expr_fieldvalue */
178 sdb_store_expr_t *
179 sdb_store_expr_attrvalue(const char *name)
180 {
181 sdb_data_t value = { SDB_TYPE_STRING, { .string = NULL} };
182 sdb_store_expr_t *expr;
184 value.data.string = strdup(name);
185 if (! value.data.string)
186 return NULL;
188 expr = SDB_STORE_EXPR(sdb_object_create("store-attrvalue", expr_type,
189 ATTR_VALUE, NULL, NULL, &value));
190 if (! expr)
191 free(value.data.string);
192 expr->data_type = -1;
193 return expr;
194 } /* sdb_store_expr_attrvalue */
196 sdb_store_expr_t *
197 sdb_store_expr_constvalue(const sdb_data_t *value)
198 {
199 sdb_data_t data = SDB_DATA_INIT;
200 sdb_store_expr_t *e;
202 if (sdb_data_copy(&data, value))
203 return NULL;
204 e = SDB_STORE_EXPR(sdb_object_create("store-constvalue", expr_type,
205 0, NULL, NULL, &data));
206 e->data_type = data.type;
207 return e;
208 } /* sdb_store_expr_constvalue */
210 int
211 sdb_store_expr_eval(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
212 sdb_data_t *res, sdb_store_matcher_t *filter)
213 {
214 sdb_data_t v1 = SDB_DATA_INIT, v2 = SDB_DATA_INIT;
215 int status = 0;
217 if ((! expr) || (! res))
218 return -1;
220 if (filter && obj && (! sdb_store_matcher_matches(filter, obj, NULL)))
221 obj = NULL; /* this object does not exist */
223 if (! expr->type)
224 return sdb_data_copy(res, &expr->data);
225 else if (expr->type == FIELD_VALUE)
226 return sdb_store_get_field(obj, (int)expr->data.data.integer, res);
227 else if (expr->type == ATTR_VALUE) {
228 status = sdb_store_get_attr(obj, expr->data.data.string, res, filter);
229 if ((status < 0) && obj) {
230 /* attribute does not exist => NULL */
231 status = 0;
232 res->type = SDB_TYPE_STRING;
233 res->data.string = NULL;
234 }
235 return status;
236 }
237 else if (expr->type == TYPED_EXPR) {
238 int typ = (int)expr->data.data.integer;
239 if (typ != obj->type) {
240 /* we support self-references and { service, metric } -> host */
241 if ((typ != SDB_HOST)
242 || ((obj->type != SDB_SERVICE)
243 && (obj->type != SDB_METRIC)))
244 return -1;
245 obj = obj->parent;
246 }
247 return sdb_store_expr_eval(expr->left, obj, res, filter);
248 }
250 if (sdb_store_expr_eval(expr->left, obj, &v1, filter))
251 return -1;
252 if (sdb_store_expr_eval(expr->right, obj, &v2, filter)) {
253 sdb_data_free_datum(&v1);
254 return -1;
255 }
257 if (sdb_data_expr_eval(expr->type, &v1, &v2, res))
258 status = -1;
259 sdb_data_free_datum(&v1);
260 sdb_data_free_datum(&v2);
261 return status;
262 } /* sdb_store_expr_eval */
264 bool
265 sdb_store_expr_iterable(sdb_store_expr_t *expr, int context)
266 {
267 if (expr->type == TYPED_EXPR) {
268 if ((context != SDB_HOST) && (context != SDB_SERVICE)
269 && (context != SDB_METRIC))
270 return 0;
271 if (context == expr->data.data.integer)
272 return 0;
273 if ((expr->data.data.integer != SDB_SERVICE)
274 && (expr->data.data.integer != SDB_METRIC)
275 && (expr->data.data.integer != SDB_ATTRIBUTE))
276 return 0;
277 if ((context == SDB_SERVICE)
278 && (expr->data.data.integer == SDB_METRIC))
279 return 0;
280 else if ((context == SDB_METRIC)
281 && (expr->data.data.integer == SDB_SERVICE))
282 return 0;
283 return 1;
284 }
285 else if (expr->type == FIELD_VALUE) {
286 if ((context != SDB_HOST) && (context != SDB_SERVICE)
287 && (context != SDB_METRIC) && (context != SDB_ATTRIBUTE))
288 return 0;
289 return expr->data.data.integer == SDB_FIELD_BACKEND;
290 }
291 else if (! expr->type) {
292 return !!(expr->data.type & SDB_TYPE_ARRAY);
293 }
294 return 0;
295 } /* sdb_store_expr_iterable */
297 sdb_store_expr_iter_t *
298 sdb_store_expr_iter(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
299 sdb_store_matcher_t *filter)
300 {
301 sdb_store_expr_iter_t *iter;
302 sdb_avltree_iter_t *tree = NULL;
303 sdb_data_t array = SDB_DATA_INIT;
305 if ((! expr) || (! obj))
306 return NULL;
308 if (expr->type == TYPED_EXPR) {
309 if (obj->type == SDB_HOST) {
310 if (expr->data.data.integer == SDB_SERVICE)
311 tree = sdb_avltree_get_iter(HOST(obj)->services);
312 else if (expr->data.data.integer == SDB_METRIC)
313 tree = sdb_avltree_get_iter(HOST(obj)->metrics);
314 else if (expr->data.data.integer == SDB_ATTRIBUTE)
315 tree = sdb_avltree_get_iter(HOST(obj)->attributes);
316 }
317 else if (obj->type == SDB_SERVICE) {
318 if (expr->data.data.integer == SDB_ATTRIBUTE)
319 tree = sdb_avltree_get_iter(SVC(obj)->attributes);
320 }
321 else if (obj->type == SDB_METRIC) {
322 if (expr->data.data.integer == SDB_ATTRIBUTE)
323 tree = sdb_avltree_get_iter(METRIC(obj)->attributes);
324 }
325 }
326 else if (expr->type == FIELD_VALUE) {
327 if (expr->data.data.integer == SDB_FIELD_BACKEND) {
328 /* while scanning the store, we hold a read lock, so it's safe to
329 * access the data without copying */
330 array.type = SDB_TYPE_ARRAY | SDB_TYPE_STRING;
331 array.data.array.length = obj->backends_num;
332 array.data.array.values = obj->backends;
333 }
334 }
335 else if (! expr->type) {
336 if (expr->data.type & SDB_TYPE_ARRAY)
337 array = expr->data;
338 }
339 else
340 return NULL;
342 if ((! tree) && (array.type == SDB_TYPE_NULL))
343 return NULL;
345 iter = calloc(1, sizeof(*iter));
346 if (! iter)
347 return NULL;
349 sdb_object_ref(SDB_OBJ(obj));
350 sdb_object_ref(SDB_OBJ(expr));
351 sdb_object_ref(SDB_OBJ(filter));
353 iter->obj = obj;
354 iter->expr = expr;
355 iter->tree = tree;
356 iter->array = array;
357 iter->filter = filter;
358 return iter;
359 } /* sdb_store_expr_iter */
361 void
362 sdb_store_expr_iter_destroy(sdb_store_expr_iter_t *iter)
363 {
364 sdb_data_t null = SDB_DATA_INIT;
366 if (! iter)
367 return;
369 if (iter->tree)
370 sdb_avltree_iter_destroy(iter->tree);
371 iter->tree = NULL;
373 iter->array = null;
374 iter->array_idx = 0;
376 sdb_object_deref(SDB_OBJ(iter->obj));
377 sdb_object_deref(SDB_OBJ(iter->expr));
378 sdb_object_deref(SDB_OBJ(iter->filter));
379 free(iter);
380 } /* sdb_store_expr_iter_destroy */
382 bool
383 sdb_store_expr_iter_has_next(sdb_store_expr_iter_t *iter)
384 {
385 if (! iter)
386 return 0;
388 if (iter->tree)
389 return sdb_avltree_iter_has_next(iter->tree);
390 return iter->array_idx < iter->array.data.array.length;
391 } /* sdb_store_expr_iter_has_next */
393 sdb_data_t
394 sdb_store_expr_iter_get_next(sdb_store_expr_iter_t *iter)
395 {
396 sdb_data_t null = SDB_DATA_INIT;
397 sdb_data_t ret = SDB_DATA_INIT;
398 sdb_data_t tmp = SDB_DATA_INIT;
400 if (! iter)
401 return null;
403 if (iter->tree) {
404 sdb_store_obj_t *child;
406 while (42) {
407 child = STORE_OBJ(sdb_avltree_iter_get_next(iter->tree));
408 if (! child)
409 break;
410 if (iter->filter
411 && (! sdb_store_matcher_matches(iter->filter, child, NULL)))
412 continue;
414 if (sdb_store_expr_eval(iter->expr, child, &ret, iter->filter))
415 return null;
416 break;
417 }
419 /* Skip over any filtered objects */
420 if (iter->filter)
421 while ((child = STORE_OBJ(sdb_avltree_iter_peek_next(iter->tree))))
422 if (sdb_store_matcher_matches(iter->filter, child, NULL))
423 break;
425 return ret;
426 }
428 if (iter->array_idx >= iter->array.data.array.length)
429 return null;
431 ++iter->array_idx;
432 if (sdb_data_array_get(&iter->array, iter->array_idx - 1, &ret))
433 return null;
434 if (sdb_data_copy(&tmp, &ret))
435 return null;
436 ret = tmp;
437 return ret;
438 } /* sdb_store_expr_iter_get_next */
440 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */