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ovsdb: add conditions utilities to support monitor_cond
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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 <[email protected]>
Signed-off-by: Ben Pfaff <[email protected]>
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@liranschour @blp
liranschour authored and blp committed Jul 19, 2016
1 parent ec1eadc commit ae9cab3
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Showing 6 changed files with 334 additions and 22 deletions.
186 changes: 173 additions & 13 deletions ovsdb/condition.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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,
Expand All @@ -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
Expand All @@ -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]);
Expand Down Expand Up @@ -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;
Expand All @@ -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);
}
Expand Down Expand Up @@ -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,
Expand All @@ -190,18 +218,23 @@ 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;
}

static struct json *
ovsdb_clause_to_json(const struct ovsdb_clause *clause)
{
return json_array_create_3(
json_string_create(clause->column->name),
json_string_create(ovsdb_function_to_string(clause->function)),
ovsdb_datum_to_json(&clause->arg, &clause->column->type));
if (clause->function != OVSDB_F_TRUE &&
clause->function != OVSDB_F_FALSE) {
return json_array_create_3(
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 *
Expand All @@ -218,13 +251,20 @@ ovsdb_condition_to_json(const struct ovsdb_condition *cnd)
}

static bool
ovsdb_clause_evaluate(const struct ovsdb_row *row,
const struct ovsdb_clause *c)
ovsdb_clause_evaluate(const struct ovsdb_datum *fields,
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:
Expand All @@ -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)) {
Expand All @@ -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) {
Expand All @@ -272,28 +318,59 @@ 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();
}
}

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,
const struct ovsdb_condition *cnd)
ovsdb_condition_match_every_clause(const struct ovsdb_row *row,
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;
}
}

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)
{
Expand All @@ -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;
}
39 changes: 34 additions & 5 deletions ovsdb/condition.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
* they are (heuristically) expected to leave in query results. */
/* These list is ordered first with boolean functions and then in
* 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, "<=") \
Expand All @@ -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 *,
Expand All @@ -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;
};

Expand All @@ -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 *,
const struct ovsdb_condition *);
bool ovsdb_condition_match_every_clause(const struct ovsdb_row *,
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 */
6 changes: 6 additions & 0 deletions ovsdb/ovsdb-server.1.in
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down
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