1 /* Copyright (c) 2009, 2010, 2011 Nicira, Inc.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
18 #include "condition.h"
24 #include "ovsdb-error.h"
29 ovsdb_function_from_string(const char *name, enum ovsdb_function *function)
31 #define OVSDB_FUNCTION(ENUM, NAME) \
32 if (!strcmp(name, NAME)) { \
39 return ovsdb_syntax_error(NULL, "unknown function",
40 "No function named %s.", name);
44 ovsdb_function_to_string(enum ovsdb_function function)
47 #define OVSDB_FUNCTION(ENUM, NAME) case ENUM: return NAME;
55 static struct ovsdb_error *
56 ovsdb_clause_from_json(const struct ovsdb_table_schema *ts,
57 const struct json *json,
58 struct ovsdb_symbol_table *symtab,
59 struct ovsdb_clause *clause)
61 const struct json_array *array;
62 struct ovsdb_error *error;
63 const char *function_name;
64 const char *column_name;
65 struct ovsdb_type type;
67 if (json->type == JSON_TRUE || json->type == JSON_FALSE) {
69 json->type == JSON_TRUE ? OVSDB_F_TRUE : OVSDB_F_FALSE;
71 /* Column and arg fields are not being used with boolean functions.
73 clause->column = ovsdb_table_schema_get_column(ts, "_uuid");
74 clause->index = clause->column->index;
75 ovsdb_datum_init_default(&clause->arg, &clause->column->type);
79 if (json->type != JSON_ARRAY
80 || json->u.array.n != 3
81 || json->u.array.elems[0]->type != JSON_STRING
82 || json->u.array.elems[1]->type != JSON_STRING) {
83 return ovsdb_syntax_error(json, NULL, "Parse error in condition.");
85 array = json_array(json);
87 column_name = json_string(array->elems[0]);
88 clause->column = ovsdb_table_schema_get_column(ts, column_name);
89 if (!clause->column) {
90 return ovsdb_syntax_error(json, "unknown column",
91 "No column %s in table %s.",
92 column_name, ts->name);
94 clause->index = clause->column->index;
95 type = clause->column->type;
97 function_name = json_string(array->elems[1]);
98 error = ovsdb_function_from_string(function_name, &clause->function);
103 /* Type-check and relax restrictions on 'type' if appropriate. */
104 switch (clause->function) {
109 /* Allow these operators for types with n_min == 0, n_max == 1.
110 * (They will always be "false" if the value is missing.) */
111 if (!(ovsdb_type_is_scalar(&type)
112 || ovsdb_type_is_optional_scalar(&type))
113 || (type.key.type != OVSDB_TYPE_INTEGER
114 && type.key.type != OVSDB_TYPE_REAL)) {
115 char *s = ovsdb_type_to_english(&type);
116 error = ovsdb_syntax_error(
117 json, NULL, "Type mismatch: \"%s\" operator may not be "
118 "applied to column %s of type %s.",
119 ovsdb_function_to_string(clause->function),
120 clause->column->name, s);
129 case OVSDB_F_EXCLUDES:
130 if (!ovsdb_type_is_scalar(&type)) {
132 type.n_max = UINT_MAX;
136 case OVSDB_F_INCLUDES:
137 if (!ovsdb_type_is_scalar(&type)) {
145 return ovsdb_datum_from_json(&clause->arg, &type, array->elems[2], symtab);
149 ovsdb_clause_free(struct ovsdb_clause *clause)
151 ovsdb_datum_destroy(&clause->arg, &clause->column->type);
155 compare_clauses_3way(const void *a_, const void *b_)
157 const struct ovsdb_clause *a = a_;
158 const struct ovsdb_clause *b = b_;
160 if (a->function != b->function) {
161 /* Bring functions to the front based on the fraction of table rows
162 * that they are (heuristically) expected to leave in the query
163 * results. Note that "enum ovsdb_function" is intentionally ordered
164 * to make this trivial. */
165 return a->function < b->function ? -1 : 1;
166 } else if (a->column->index != b->column->index) {
167 if (a->column->index < OVSDB_N_STD_COLUMNS
168 || b->column->index < OVSDB_N_STD_COLUMNS) {
169 /* Bring the standard columns and in particular the UUID column
170 * (since OVSDB_COL_UUID has value 0) to the front. We have an
171 * index on the UUID column, so that makes our queries cheaper. */
172 return a->column->index < b->column->index ? -1 : 1;
174 /* Order clauses predictably to make testing easier. */
175 return strcmp(a->column->name, b->column->name);
183 compare_clauses_3way_with_data(const void *a_, const void *b_)
185 const struct ovsdb_clause *a = a_;
186 const struct ovsdb_clause *b = b_;
189 res = compare_clauses_3way(a, b);
190 return res ? res : ovsdb_datum_compare_3way(&a->arg,
195 struct ovsdb_o_column {
196 const struct ovsdb_column *column;
197 struct hmap o_clauses;
200 struct ovsdb_o_clause {
201 struct ovsdb_datum *arg;
202 struct hmap_node hmap_node;
206 ovsdb_condition_optimize(struct ovsdb_condition *cnd)
211 if (!cnd->optimized) {
215 for(i = 0; i < cnd->n_clauses; i++) {
216 struct ovsdb_clause *clause = &cnd->clauses[i];
218 if (clause->function != OVSDB_F_EQ) {
222 struct ovsdb_o_clause *o_clause = xzalloc(sizeof *o_clause);
223 struct ovsdb_o_column *o_column =
224 shash_find_data(&cnd->o_columns, clause->column->name);
227 o_column = xzalloc(sizeof *o_column);
228 o_column->column = clause->column;
229 hmap_init(&o_column->o_clauses);
230 shash_add(&cnd->o_columns, clause->column->name, o_column);
232 o_clause->arg = &clause->arg;
233 hash = ovsdb_datum_hash(&clause->arg, &clause->column->type, 0);
234 hmap_insert(&o_column->o_clauses, &o_clause->hmap_node, hash);
239 ovsdb_condition_optimize_destroy(struct ovsdb_condition *cnd)
241 struct shash_node *node, *next;
243 SHASH_FOR_EACH_SAFE (node, next, &cnd->o_columns) {
244 struct ovsdb_o_column *o_column = node->data;
245 struct ovsdb_o_clause *c, *c_next;
247 HMAP_FOR_EACH_SAFE(c, c_next, hmap_node, &o_column->o_clauses) {
248 hmap_remove(&o_column->o_clauses, &c->hmap_node);
251 hmap_destroy(&o_column->o_clauses);
252 shash_delete(&cnd->o_columns, node);
255 shash_destroy(&cnd->o_columns);
259 ovsdb_condition_from_json(const struct ovsdb_table_schema *ts,
260 const struct json *json,
261 struct ovsdb_symbol_table *symtab,
262 struct ovsdb_condition *cnd)
264 const struct json_array *array = json_array(json);
267 ovsdb_condition_init(cnd);
268 cnd->clauses = xmalloc(array->n * sizeof *cnd->clauses);
270 for (i = 0; i < array->n; i++) {
271 struct ovsdb_error *error;
272 error = ovsdb_clause_from_json(ts, array->elems[i], symtab,
275 ovsdb_condition_destroy(cnd);
281 if (cnd->clauses[i].function > OVSDB_F_EQ) {
282 cnd->optimized = false;
286 /* A real database would have a query optimizer here. */
287 qsort(cnd->clauses, cnd->n_clauses, sizeof *cnd->clauses,
288 compare_clauses_3way_with_data);
290 ovsdb_condition_optimize(cnd);
296 ovsdb_clause_to_json(const struct ovsdb_clause *clause)
298 if (clause->function != OVSDB_F_TRUE &&
299 clause->function != OVSDB_F_FALSE) {
300 return json_array_create_3(
301 json_string_create(clause->column->name),
302 json_string_create(ovsdb_function_to_string(clause->function)),
303 ovsdb_datum_to_json(&clause->arg, &clause->column->type));
306 return json_boolean_create(clause->function == OVSDB_F_TRUE);
310 ovsdb_condition_to_json(const struct ovsdb_condition *cnd)
312 struct json **clauses;
315 clauses = xmalloc(cnd->n_clauses * sizeof *clauses);
316 for (i = 0; i < cnd->n_clauses; i++) {
317 clauses[i] = ovsdb_clause_to_json(&cnd->clauses[i]);
319 return json_array_create(clauses, cnd->n_clauses);
323 ovsdb_clause_evaluate(const struct ovsdb_datum *fields,
324 const struct ovsdb_clause *c,
325 unsigned int index_map[])
327 const struct ovsdb_datum *field = &fields[index_map ?
328 index_map[c->column->index] :
330 const struct ovsdb_datum *arg = &c->arg;
331 const struct ovsdb_type *type = &c->column->type;
333 if (c->function == OVSDB_F_TRUE ||
334 c->function == OVSDB_F_FALSE) {
335 return c->function == OVSDB_F_TRUE;
337 if (ovsdb_type_is_optional_scalar(type) && field->n == 0) {
338 switch (c->function) {
344 case OVSDB_F_INCLUDES:
347 case OVSDB_F_EXCLUDES:
353 } else if (ovsdb_type_is_scalar(type)
354 || ovsdb_type_is_optional_scalar(type)) {
355 int cmp = ovsdb_atom_compare_3way(&field->keys[0], &arg->keys[0],
357 switch (c->function) {
363 case OVSDB_F_INCLUDES:
366 case OVSDB_F_EXCLUDES:
377 switch (c->function) {
379 return ovsdb_datum_equals(field, arg, type);
381 return !ovsdb_datum_equals(field, arg, type);
382 case OVSDB_F_INCLUDES:
383 return ovsdb_datum_includes_all(arg, field, type);
384 case OVSDB_F_EXCLUDES:
385 return ovsdb_datum_excludes_all(arg, field, type);
400 ovsdb_clause_clone(struct ovsdb_clause *new, struct ovsdb_clause *old)
402 new->function = old->function;
403 new->column = old->column;
404 ovsdb_datum_clone(&new->arg,
410 ovsdb_condition_match_every_clause(const struct ovsdb_row *row,
411 const struct ovsdb_condition *cnd)
415 for (i = 0; i < cnd->n_clauses; i++) {
416 if (!ovsdb_clause_evaluate(row->fields, &cnd->clauses[i], NULL)) {
425 ovsdb_condition_match_any_clause_optimized(const struct ovsdb_datum *row_datum,
426 const struct ovsdb_condition *cnd,
427 unsigned int index_map[])
429 if (ovsdb_condition_is_true(cnd)) {
433 struct shash_node *node;
434 SHASH_FOR_EACH (node, &cnd->o_columns) {
435 struct ovsdb_o_column *o_column = node->data;
436 const struct ovsdb_column *column = o_column->column;
437 const struct ovsdb_datum *arg = &row_datum[index_map ?
438 index_map[column->index] :
440 uint32_t hash = ovsdb_datum_hash(arg, &column->type, 0);
441 struct ovsdb_o_clause *o_clause;
443 HMAP_FOR_EACH_WITH_HASH(o_clause, hmap_node, hash, &o_column->o_clauses) {
444 if (ovsdb_datum_equals(arg, o_clause->arg, &column->type)) {
452 /* Returns true if condition evaluation of one of the clauses is
453 * true. index_map[] is an optional array that if exists indicates a mapping
454 * between indexing row_datum to the indexes in ovsdb_column */
456 ovsdb_condition_match_any_clause(const struct ovsdb_datum *row_datum,
457 const struct ovsdb_condition *cnd,
458 unsigned int index_map[])
462 if (cnd->optimized) {
463 return ovsdb_condition_match_any_clause_optimized(row_datum, cnd,
467 for (i = 0; i < cnd->n_clauses; i++) {
468 if (ovsdb_clause_evaluate(row_datum, &cnd->clauses[i], index_map)) {
477 ovsdb_condition_destroy(struct ovsdb_condition *cnd)
481 for (i = 0; i < cnd->n_clauses; i++) {
482 ovsdb_clause_free(&cnd->clauses[i]);
487 ovsdb_condition_optimize_destroy(cnd);
491 ovsdb_condition_init(struct ovsdb_condition *cnd)
495 cnd->optimized = true;
496 shash_init(&cnd->o_columns);
500 ovsdb_condition_empty(const struct ovsdb_condition *cnd)
502 return cnd->n_clauses == 0;
506 ovsdb_condition_cmp_3way(const struct ovsdb_condition *a,
507 const struct ovsdb_condition *b)
512 if (a->n_clauses != b->n_clauses) {
513 return a->n_clauses < b->n_clauses ? -1 : 1;
516 /* We assume clauses are sorted */
517 for (i = 0; i < a->n_clauses; i++) {
518 res = (compare_clauses_3way_with_data(&a->clauses[i], &b->clauses[i]));
528 ovsdb_condition_clone(struct ovsdb_condition *to,
529 const struct ovsdb_condition *from)
533 ovsdb_condition_init(to);
535 to->clauses = xzalloc(from->n_clauses * sizeof *to->clauses);
537 for (i = 0; i < from->n_clauses; i++) {
538 ovsdb_clause_clone(&to->clauses[i], &from->clauses[i]);
540 to->n_clauses = from->n_clauses;
541 to->optimized = from->optimized;
543 ovsdb_condition_optimize(to);
547 /* Return true if ovsdb_condition_match_any_clause() will return true on
550 ovsdb_condition_is_true(const struct ovsdb_condition *cond)
552 return (!cond->n_clauses ||
553 (cond->n_clauses >= 1 && (cond->clauses[0].function == OVSDB_F_TRUE)) ||
554 (cond->n_clauses >= 2 && (cond->clauses[1].function == OVSDB_F_TRUE)));
558 ovsdb_condition_is_false(const struct ovsdb_condition *cond)
560 return ((cond->n_clauses == 1) &&
561 (cond->clauses[0].function == OVSDB_F_FALSE));
564 const struct ovsdb_column **
565 ovsdb_condition_get_columns(const struct ovsdb_condition *cond,
568 const struct ovsdb_column **columns;
571 columns = xmalloc(cond->n_clauses * sizeof *columns);
572 for (i = 0; i < cond->n_clauses; i++) {
573 columns[i] = cond->clauses[i].column;