ovsdb: add conditions utilities to support monitor_cond

Change ovsdb_condition to be a 3-element json array or a boolean value (see ovsdb-server
man page).
Conditions utilities will be used later for conditional monitoring.

Signed-off-by: Liran Schour <lirans@il.ibm.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>

ovsdb/condition.c

@@ -52,7 +52,7 @@ ovsdb_function_to_string(enum ovsdb_function function)
     return NULL;
 }
 
-static OVS_WARN_UNUSED_RESULT struct ovsdb_error *
+static struct ovsdb_error *
 ovsdb_clause_from_json(const struct ovsdb_table_schema *ts,
                        const struct json *json,
                        struct ovsdb_symbol_table *symtab,
@@ -64,6 +64,18 @@ ovsdb_clause_from_json(const struct ovsdb_table_schema *ts,
     const char *column_name;
     struct ovsdb_type type;
 
+    if (json->type == JSON_TRUE || json->type == JSON_FALSE) {
+        clause->function =
+            json->type == JSON_TRUE ? OVSDB_F_TRUE : OVSDB_F_FALSE;
+
+        /* Column and arg fields are not being used with boolean functions.
+         * Use dummy values */
+        clause->column = ovsdb_table_schema_get_column(ts, "_uuid");
+        clause->index = clause->column->index;
+        ovsdb_datum_init_default(&clause->arg, &clause->column->type);
+        return NULL;
+    }
+
     if (json->type != JSON_ARRAY
         || json->u.array.n != 3
         || json->u.array.elems[0]->type != JSON_STRING
@@ -79,6 +91,7 @@ ovsdb_clause_from_json(const struct ovsdb_table_schema *ts,
                                   "No column %s in table %s.",
                                   column_name, ts->name);
     }
+    clause->index = clause->column->index;
     type = clause->column->type;
 
     function_name = json_string(array->elems[1]);
@@ -109,7 +122,6 @@ ovsdb_clause_from_json(const struct ovsdb_table_schema *ts,
             return error;
         }
         break;
-
     case OVSDB_F_EQ:
     case OVSDB_F_NE:
         break;
@@ -126,6 +138,9 @@ ovsdb_clause_from_json(const struct ovsdb_table_schema *ts,
             type.n_min = 0;
         }
         break;
+    case OVSDB_F_TRUE:
+    case OVSDB_F_FALSE:
+        OVS_NOT_REACHED();
     }
     return ovsdb_datum_from_json(&clause->arg, &type, array->elems[2], symtab);
 }
@@ -164,6 +179,19 @@ compare_clauses_3way(const void *a_, const void *b_)
     }
 }
 
+static int
+compare_clauses_3way_with_data(const void *a_, const void *b_)
+{
+    const struct ovsdb_clause *a = a_;
+    const struct ovsdb_clause *b = b_;
+    int res;
+
+    res = compare_clauses_3way(a, b);
+    return res ? res : ovsdb_datum_compare_3way(&a->arg,
+                                                &b->arg,
+                                                &a->column->type);
+ }
+
 struct ovsdb_error *
 ovsdb_condition_from_json(const struct ovsdb_table_schema *ts,
                           const struct json *json,
@@ -190,7 +218,7 @@ ovsdb_condition_from_json(const struct ovsdb_table_schema *ts,
 
     /* A real database would have a query optimizer here. */
     qsort(cnd->clauses, cnd->n_clauses, sizeof *cnd->clauses,
-          compare_clauses_3way);
+          compare_clauses_3way_with_data);
 
     return NULL;
 }
@@ -198,10 +226,15 @@ ovsdb_condition_from_json(const struct ovsdb_table_schema *ts,
 static struct json *
 ovsdb_clause_to_json(const struct ovsdb_clause *clause)
 {
-    return json_array_create_3(
+    if (clause->function != OVSDB_F_TRUE &&
-        json_string_create(clause->column->name),
+        clause->function != OVSDB_F_FALSE) {
-        json_string_create(ovsdb_function_to_string(clause->function)),
+        return json_array_create_3(
-        ovsdb_datum_to_json(&clause->arg, &clause->column->type));
+                json_string_create(clause->column->name),
+                json_string_create(ovsdb_function_to_string(clause->function)),
+                ovsdb_datum_to_json(&clause->arg, &clause->column->type));
+    }
+
+    return json_boolean_create(clause->function == OVSDB_F_TRUE);
 }
 
 struct json *
@@ -218,13 +251,20 @@ ovsdb_condition_to_json(const struct ovsdb_condition *cnd)
 }
 
 static bool
-ovsdb_clause_evaluate(const struct ovsdb_row *row,
+ovsdb_clause_evaluate(const struct ovsdb_datum *fields,
-                      const struct ovsdb_clause *c)
+                      const struct ovsdb_clause *c,
+                      unsigned int index_map[])
 {
-    const struct ovsdb_datum *field = &row->fields[c->column->index];
+    const struct ovsdb_datum *field = &fields[index_map ?
+                                              index_map[c->column->index] :
+                                              c->column->index];
     const struct ovsdb_datum *arg = &c->arg;
     const struct ovsdb_type *type = &c->column->type;
 
+    if (c->function == OVSDB_F_TRUE ||
+        c->function == OVSDB_F_FALSE) {
+        return c->function == OVSDB_F_TRUE;
+    }
     if (ovsdb_type_is_optional_scalar(type) && field->n == 0) {
         switch (c->function) {
             case OVSDB_F_LT:
@@ -237,6 +277,9 @@ ovsdb_clause_evaluate(const struct ovsdb_row *row,
             case OVSDB_F_NE:
             case OVSDB_F_EXCLUDES:
                 return true;
+            case OVSDB_F_TRUE:
+            case OVSDB_F_FALSE:
+                OVS_NOT_REACHED();
         }
     } else if (ovsdb_type_is_scalar(type)
                || ovsdb_type_is_optional_scalar(type)) {
@@ -257,6 +300,9 @@ ovsdb_clause_evaluate(const struct ovsdb_row *row,
             return cmp >= 0;
         case OVSDB_F_GT:
             return cmp > 0;
+        case OVSDB_F_TRUE:
+        case OVSDB_F_FALSE:
+            OVS_NOT_REACHED();
         }
     } else {
         switch (c->function) {
@@ -272,6 +318,8 @@ ovsdb_clause_evaluate(const struct ovsdb_row *row,
         case OVSDB_F_LE:
         case OVSDB_F_GE:
         case OVSDB_F_GT:
+        case OVSDB_F_TRUE:
+        case OVSDB_F_FALSE:
             OVS_NOT_REACHED();
         }
     }
@@ -279,14 +327,24 @@ ovsdb_clause_evaluate(const struct ovsdb_row *row,
     OVS_NOT_REACHED();
 }
 
+static void
+ovsdb_clause_clone(struct ovsdb_clause *new, struct ovsdb_clause *old)
+{
+    new->function = old->function;
+    new->column = old->column;
+    ovsdb_datum_clone(&new->arg,
+                      &old->arg,
+                      &old->column->type);
+}
+
 bool
-ovsdb_condition_evaluate(const struct ovsdb_row *row,
+ovsdb_condition_match_every_clause(const struct ovsdb_row *row,
-                         const struct ovsdb_condition *cnd)
+                                   const struct ovsdb_condition *cnd)
 {
     size_t i;
 
     for (i = 0; i < cnd->n_clauses; i++) {
-        if (!ovsdb_clause_evaluate(row, &cnd->clauses[i])) {
+        if (!ovsdb_clause_evaluate(row->fields, &cnd->clauses[i], NULL)) {
             return false;
         }
     }
@@ -294,6 +352,25 @@ ovsdb_condition_evaluate(const struct ovsdb_row *row,
     return true;
 }
 
+/* Returns true if condition evaluation of one of the clauses is
+ * true. index_map[] is an optional array that if exists indicates a mapping
+ * between indexing row_datum to the indexes in ovsdb_column */
+bool
+ovsdb_condition_match_any_clause(const struct ovsdb_datum *row_datum,
+                                 const struct ovsdb_condition *cnd,
+                                 unsigned int index_map[])
+{
+    size_t i;
+
+    for (i = 0; i < cnd->n_clauses; i++) {
+        if (ovsdb_clause_evaluate(row_datum, &cnd->clauses[i], index_map)) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
 void
 ovsdb_condition_destroy(struct ovsdb_condition *cnd)
 {
@@ -303,4 +380,87 @@ ovsdb_condition_destroy(struct ovsdb_condition *cnd)
         ovsdb_clause_free(&cnd->clauses[i]);
     }
     free(cnd->clauses);
+    cnd->n_clauses = 0;
+}
+
+void
+ovsdb_condition_init(struct ovsdb_condition *cnd)
+{
+    cnd->clauses = NULL;
+    cnd->n_clauses = 0;
+}
+
+bool
+ovsdb_condition_empty(const struct ovsdb_condition *cnd)
+{
+    return cnd->n_clauses == 0;
+}
+
+int
+ovsdb_condition_cmp_3way(const struct ovsdb_condition *a,
+                         const struct ovsdb_condition *b)
+{
+    size_t i;
+    int res;
+
+    if (a->n_clauses != b->n_clauses) {
+        return a->n_clauses < b->n_clauses ? -1 : 1;
+    }
+
+    /* We assume clauses are sorted */
+    for (i = 0; i < a->n_clauses; i++) {
+        res = (compare_clauses_3way_with_data(&a->clauses[i], &b->clauses[i]));
+        if (res != 0) {
+            return res;
+        }
+    }
+
+    return 0;
+}
+
+void
+ovsdb_condition_clone(struct ovsdb_condition *to,
+                      const struct ovsdb_condition *from)
+{
+    size_t i;
+
+    to->clauses = xzalloc(from->n_clauses * sizeof *to->clauses);
+
+    for (i = 0; i < from->n_clauses; i++) {
+        ovsdb_clause_clone(&to->clauses[i], &from->clauses[i]);
+    }
+    to->n_clauses = from->n_clauses;
+}
+
+/* Return true if ovsdb_condition_match_any_clause() will return true on
+ * any row */
+bool
+ovsdb_condition_is_true(const struct ovsdb_condition *cond)
+{
+    return (!cond->n_clauses ||
+       (cond->n_clauses >= 1 && (cond->clauses[0].function == OVSDB_F_TRUE)) ||
+       (cond->n_clauses >= 2 && (cond->clauses[1].function == OVSDB_F_TRUE)));
+}
+
+bool
+ovsdb_condition_is_false(const struct ovsdb_condition *cond)
+{
+    return ((cond->n_clauses == 1) &&
+            (cond->clauses[0].function == OVSDB_F_FALSE));
+ }
+
+const struct ovsdb_column **
+ovsdb_condition_get_columns(const struct ovsdb_condition *cond,
+                            size_t *n_columns)
+{
+    const struct ovsdb_column **columns;
+    size_t i;
+
+    columns = xmalloc(cond->n_clauses * sizeof *columns);
+    for (i = 0; i < cond->n_clauses; i++) {
+        columns[i] = cond->clauses[i].column;
+    }
+    *n_columns = i;
+
+    return columns;
 }

ovsdb/condition.h

@@ -19,14 +19,18 @@
 #include <stddef.h>
 #include "compiler.h"
 #include "ovsdb-data.h"
+#include "bitmap.h"
 
 struct json;
 struct ovsdb_table_schema;
 struct ovsdb_row;
 
-/* These list is ordered in ascending order of the fraction of tables row that
+/* These list is ordered first with boolean functions and then in
- * they are (heuristically) expected to leave in query results. */
+ * ascending order of the fraction of tables row that they are
+ * (heuristically) expected to leave in query results. */
 #define OVSDB_FUNCTIONS                         \
+    OVSDB_FUNCTION(OVSDB_F_FALSE, "false")            \
+    OVSDB_FUNCTION(OVSDB_F_TRUE, "true")              \
     OVSDB_FUNCTION(OVSDB_F_EQ, "==")                  \
     OVSDB_FUNCTION(OVSDB_F_INCLUDES, "includes")      \
     OVSDB_FUNCTION(OVSDB_F_LE, "<=")                  \
@@ -40,6 +44,7 @@ enum ovsdb_function {
 #define OVSDB_FUNCTION(ENUM, NAME) ENUM,
     OVSDB_FUNCTIONS
 #undef OVSDB_FUNCTION
+    OVSDB_F_LAST = OVSDB_F_NE
 };
 
 struct ovsdb_error *ovsdb_function_from_string(const char *,
@@ -50,6 +55,7 @@ const char *ovsdb_function_to_string(enum ovsdb_function);
 struct ovsdb_clause {
     enum ovsdb_function function;
     const struct ovsdb_column *column;
+    unsigned int index;
     struct ovsdb_datum arg;
 };
 
@@ -58,15 +64,38 @@ struct ovsdb_condition {
     size_t n_clauses;
 };
 
-#define OVSDB_CONDITION_INITIALIZER { NULL, 0 }
+#define OVSDB_CONDITION_INITIALIZER { NULL, 0}
 
+void ovsdb_condition_init(struct ovsdb_condition *);
+bool ovsdb_condition_empty(const struct ovsdb_condition *);
 struct ovsdb_error *ovsdb_condition_from_json(
     const struct ovsdb_table_schema *,
     const struct json *, struct ovsdb_symbol_table *,
     struct ovsdb_condition *) OVS_WARN_UNUSED_RESULT;
 struct json *ovsdb_condition_to_json(const struct ovsdb_condition *);
 void ovsdb_condition_destroy(struct ovsdb_condition *);
-bool ovsdb_condition_evaluate(const struct ovsdb_row *,
+bool ovsdb_condition_match_every_clause(const struct ovsdb_row *,
-                              const struct ovsdb_condition *);
+                                        const struct ovsdb_condition *);
+bool ovsdb_condition_match_any_clause(const struct ovsdb_datum *,
+                                      const struct ovsdb_condition *,
+                                      unsigned int index_map[]);
+int ovsdb_condition_cmp_3way(const struct ovsdb_condition *a,
+                             const struct ovsdb_condition *b);
+void ovsdb_condition_clone(struct ovsdb_condition *to,
+                           const struct ovsdb_condition *from);
+bool ovsdb_condition_is_true(const struct ovsdb_condition *cond);
+bool ovsdb_condition_is_false(const struct ovsdb_condition *cond);
+const struct ovsdb_column **
+ovsdb_condition_get_columns(const struct ovsdb_condition *cond,
+                            size_t *n_columns);
+
+static inline bool
+ovsdb_condition_empty_or_match_any(const struct ovsdb_datum *row_datum,
+                                   const struct ovsdb_condition *cnd,
+                                   unsigned int index_map[])
+{
+    return (ovsdb_condition_empty(cnd) ||
+            ovsdb_condition_match_any_clause(row_datum, cnd, index_map));
+}
 
 #endif /* ovsdb/condition.h */

ovsdb/ovsdb-server.1.in

@@ -350,6 +350,12 @@ of 0 or 1 integer'' and ``set of 0 or 1 real''.  These conditions
 evaluate to false when the column is empty, and otherwise as described
 in RFC 7047 for integer and real types.
 .
+.IP
+<condition> is specified in Section 5.1 in the RFC with the following change:
+A condition can be either a 3-element JSON array as described in the RFC or a
+boolean value. In case of an empty array an implicit true boolean value will be
+considered.
+.
 .SH "BUGS"
 .
 In Open vSwitch before version 2.4, when \fBovsdb\-server\fR sent

ovsdb/query.c

@@ -34,7 +34,8 @@ ovsdb_query(struct ovsdb_table *table, const struct ovsdb_condition *cnd,
         const struct ovsdb_row *row;
 
         row = ovsdb_table_get_row(table, &cnd->clauses[0].arg.keys[0].uuid);
-        if (row && row->table == table && ovsdb_condition_evaluate(row, cnd)) {
+        if (row && row->table == table &&
+            ovsdb_condition_match_every_clause(row, cnd)) {
             output_row(row, aux);
         }
     } else {
@@ -42,7 +43,8 @@ ovsdb_query(struct ovsdb_table *table, const struct ovsdb_condition *cnd,
         const struct ovsdb_row *row, *next;
 
         HMAP_FOR_EACH_SAFE (row, next, hmap_node, &table->rows) {
-            if (ovsdb_condition_evaluate(row, cnd) && !output_row(row, aux)) {
+            if (ovsdb_condition_match_every_clause(row, cnd) &&
+                !output_row(row, aux)) {
                 break;
             }
         }

tests/ovsdb-condition.at

@@ -184,6 +184,18 @@ OVSDB_CHECK_POSITIVE([condition sorting],
       ["_uuid", "==", ["uuid", "d50e85c6-8ae7-4b16-b69e-4395928bd9be"]]]']],
   [[[["_uuid","==",["uuid","d50e85c6-8ae7-4b16-b69e-4395928bd9be"]],["i","==",1],["i","includes",2],["i","<=",3],["i","<",4],["i",">=",5],["i",">",6],["i","excludes",7],["i","!=",8]]]])
 
+OVSDB_CHECK_POSITIVE([boolean condition],
+  [[parse-conditions \
+    '{"columns": {"name": {"type": "string"}}}' \
+    '[true]']],
+  [[[true]]])
+
+OVSDB_CHECK_POSITIVE([boolean condition],
+  [[parse-conditions \
+    '{"columns": {"name": {"type": "string"}}}' \
+    '[false]']],
+  [[[false]]])
+
 OVSDB_CHECK_POSITIVE([evaluating null condition],
   [[evaluate-conditions \
     '{"columns": {"i": {"type": "integer"}}}' \
@@ -657,3 +669,32 @@ condition  5: --T-
 condition  6: -T--
 condition  7: T-TT
 condition  8: -T-T], [condition])
+
+OVSDB_CHECK_POSITIVE([evaluating false boolean condition],
+  [[evaluate-conditions-any \
+    '{"columns": {"i": {"type": "integer"}}}' \
+    '[[false,["i","==",1]]]' \
+    '[{"i": 0},
+      {"i": 1},
+      {"i": 2}']]],
+  [condition  0: -T-])
+
+OVSDB_CHECK_POSITIVE([evaluating true boolean condition],
+  [[evaluate-conditions-any \
+    '{"columns": {"i": {"type": "integer"}}}' \
+    '[[true,["i","==",1]]]' \
+    '[{"i": 0},
+      {"i": 1},
+      {"i": 2}']]],
+  [condition  0: TTT])
+
+OVSDB_CHECK_POSITIVE([compare condition],
+  [[compare-conditions \
+    '{"columns": {"i": {"type": "integer"}}}' \
+    '[[true,["i","==",1],["i","==",2],["i","==",3]],
+      [["i","==",1],["i","==",3],["i","==",2],true],
+      [["i","==",1]],
+      [["i",">=",1]]']]],
+  [condition 0-1: 0
+condition 1-2: 1
+condition 2-3: -1])

tests/test-ovsdb.c

@@ -166,6 +166,12 @@ usage(void)
            "    parse each CONDITION on TABLE, and re-serialize\n"
            "  evaluate-conditions TABLE [CONDITION,...] [ROW,...]\n"
            "    test CONDITIONS on TABLE against each ROW, print results\n"
+           "  evaluate-conditions-any TABLE [CONDITION,...] [ROW,...]\n"
+           "    test CONDITIONS to match any of the CONDITONS on TABLE\n"
+           "    against each ROW, print results\n"
+           "  compare-conditions TABLE [CONDITION,...]\n"
+           "    mutually compare all of the CONDITION, print results for\n"
+           "    each pair\n"
            "  parse-mutations TABLE MUTATION...\n"
            "    parse each MUTATION on TABLE, and re-serialize\n"
            "  execute-mutations TABLE [MUTATION,...] [ROW,...]\n"
@@ -856,8 +862,11 @@ do_parse_conditions(struct ovs_cmdl_context *ctx)
     exit(exit_code);
 }
 
+#define OVSDB_CONDITION_EVERY 0
+#define OVSDB_CONDITION_ANY 1
+
 static void
-do_evaluate_conditions(struct ovs_cmdl_context *ctx)
+do_evaluate_condition__(struct ovs_cmdl_context *ctx, int mode)
 {
     struct ovsdb_table_schema *ts;
     struct ovsdb_table *table;
@@ -905,7 +914,15 @@ do_evaluate_conditions(struct ovs_cmdl_context *ctx)
     for (i = 0; i < n_conditions; i++) {
         printf("condition %2"PRIuSIZE":", i);
         for (j = 0; j < n_rows; j++) {
-            bool result = ovsdb_condition_evaluate(rows[j], &conditions[i]);
+            bool result;
+            if (mode == OVSDB_CONDITION_EVERY) {
+                result = ovsdb_condition_match_every_clause(rows[j],
+                                                  &conditions[i]);
+            } else {
+                result = ovsdb_condition_match_any_clause(rows[j]->fields,
+                                                          &conditions[i],
+                                                          NULL);
+            }
             if (j % 5 == 0) {
                 putchar(' ');
             }
@@ -925,6 +942,61 @@ do_evaluate_conditions(struct ovs_cmdl_context *ctx)
     ovsdb_table_destroy(table); /* Also destroys 'ts'. */
 }
 
+static void
+do_evaluate_conditions(struct ovs_cmdl_context *ctx)
+{
+    do_evaluate_condition__(ctx, OVSDB_CONDITION_EVERY);
+}
+
+static void
+do_evaluate_conditions_any(struct ovs_cmdl_context *ctx)
+{
+    do_evaluate_condition__(ctx, OVSDB_CONDITION_ANY);
+}
+
+static void
+do_compare_conditions(struct ovs_cmdl_context *ctx)
+{
+    struct ovsdb_table_schema *ts;
+    struct ovsdb_table *table;
+    struct ovsdb_condition *conditions;
+    size_t n_conditions;
+    struct json *json;
+    size_t i;
+
+    /* Parse table schema, create table. */
+    json = unbox_json(parse_json(ctx->argv[1]));
+    check_ovsdb_error(ovsdb_table_schema_from_json(json, "mytable", &ts));
+    json_destroy(json);
+
+    table = ovsdb_table_create(ts);
+
+    /* Parse conditions. */
+    json = parse_json(ctx->argv[2]);
+    if (json->type != JSON_ARRAY) {
+        ovs_fatal(0, "CONDITION argument is not JSON array");
+    }
+    n_conditions = json->u.array.n;
+    conditions = xmalloc(n_conditions * sizeof *conditions);
+
+    for (i = 0; i < n_conditions; i++) {
+        check_ovsdb_error(ovsdb_condition_from_json(ts, json->u.array.elems[i],
+                                                    NULL, &conditions[i]));
+    }
+    json_destroy(json);
+
+    for (i = 0; i < n_conditions - 1; i++) {
+        int res = ovsdb_condition_cmp_3way(&conditions[i], &conditions[i + 1]);
+        printf("condition %"PRIuSIZE"-%"PRIuSIZE": %d\n", i, i + 1, res);
+    }
+
+    for (i = 0; i < n_conditions; i++) {
+        ovsdb_condition_destroy(&conditions[i]);
+    }
+    free(conditions);
+    ovsdb_table_destroy(table); /* Also destroys 'ts'. */
+}
+
 static void
 do_parse_mutations(struct ovs_cmdl_context *ctx)
 {
@@ -2311,6 +2383,8 @@ static struct ovs_cmdl_command all_commands[] = {
     { "compare-rows", NULL, 2, INT_MAX, do_compare_rows },
     { "parse-conditions", NULL, 2, INT_MAX, do_parse_conditions },
     { "evaluate-conditions", NULL, 3, 3, do_evaluate_conditions },
+    { "evaluate-conditions-any", NULL, 3, 3, do_evaluate_conditions_any },
+    { "compare-conditions", NULL, 2, 2, do_compare_conditions },
     { "parse-mutations", NULL, 2, INT_MAX, do_parse_mutations },
     { "execute-mutations", NULL, 3, 3, do_execute_mutations },
     { "query", NULL, 3, 3, do_query },