*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/optimizer/util/predtest.c,v 1.4 2005/10/15 02:49:21 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/optimizer/util/predtest.c,v 1.5 2005/11/27 22:15:42 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "executor/executor.h"
#include "optimizer/clauses.h"
#include "optimizer/predtest.h"
+#include "utils/array.h"
#include "utils/catcache.h"
#include "utils/lsyscache.h"
#include "utils/syscache.h"
+/*
+ * To avoid redundant coding in predicate_implied_by_recurse and
+ * predicate_refuted_by_recurse, we need to abstract out the notion of
+ * iterating over the components of an expression that is logically an AND
+ * or OR structure. There are multiple sorts of expression nodes that can
+ * be treated as ANDs or ORs, and we don't want to code each one separately.
+ * Hence, these types and support routines.
+ */
+typedef enum
+{
+ CLASS_ATOM, /* expression that's not AND or OR */
+ CLASS_AND, /* expression with AND semantics */
+ CLASS_OR /* expression with OR semantics */
+} PredClass;
+
+typedef struct PredIterInfoData *PredIterInfo;
+
+typedef struct PredIterInfoData
+{
+ /* node-type-specific iteration state */
+ void *state;
+ /* initialize to do the iteration */
+ void (*startup_fn) (Node *clause, PredIterInfo info);
+ /* next-component iteration function */
+ Node *(*next_fn) (PredIterInfo info);
+ /* release resources when done with iteration */
+ void (*cleanup_fn) (PredIterInfo info);
+} PredIterInfoData;
+
+#define iterate_begin(item, clause, info) \
+ do { \
+ Node *item; \
+ (info).startup_fn((clause), &(info)); \
+ while ((item = (info).next_fn(&(info))) != NULL)
+
+#define iterate_end(info) \
+ (info).cleanup_fn(&(info)); \
+ } while (0)
+
+
static bool predicate_implied_by_recurse(Node *clause, Node *predicate);
static bool predicate_refuted_by_recurse(Node *clause, Node *predicate);
+static PredClass predicate_classify(Node *clause, PredIterInfo info);
+static void list_startup_fn(Node *clause, PredIterInfo info);
+static Node *list_next_fn(PredIterInfo info);
+static void list_cleanup_fn(PredIterInfo info);
+static void boolexpr_startup_fn(Node *clause, PredIterInfo info);
+static void arrayconst_startup_fn(Node *clause, PredIterInfo info);
+static Node *arrayconst_next_fn(PredIterInfo info);
+static void arrayconst_cleanup_fn(PredIterInfo info);
+static void arrayexpr_startup_fn(Node *clause, PredIterInfo info);
+static Node *arrayexpr_next_fn(PredIterInfo info);
+static void arrayexpr_cleanup_fn(PredIterInfo info);
static bool predicate_implied_by_simple_clause(Expr *predicate, Node *clause);
static bool predicate_refuted_by_simple_clause(Expr *predicate, Node *clause);
static bool btree_predicate_proof(Expr *predicate, Node *clause,
bool
predicate_implied_by(List *predicate_list, List *restrictinfo_list)
{
- ListCell *item;
-
if (predicate_list == NIL)
return true; /* no predicate: implication is vacuous */
if (restrictinfo_list == NIL)
return false; /* no restriction: implication must fail */
- /*
- * In all cases where the predicate is an AND-clause,
- * predicate_implied_by_recurse() will prefer to iterate over the
- * predicate's components. So we can just do that to start with here, and
- * eliminate the need for predicate_implied_by_recurse() to handle a bare
- * List on the predicate side.
- *
- * Logic is: restriction must imply each of the AND'ed predicate items.
- */
- foreach(item, predicate_list)
- {
- if (!predicate_implied_by_recurse((Node *) restrictinfo_list,
- lfirst(item)))
- return false;
- }
- return true;
+ /* Otherwise, away we go ... */
+ return predicate_implied_by_recurse((Node *) restrictinfo_list,
+ (Node *) predicate_list);
}
/*
if (restrictinfo_list == NIL)
return false; /* no restriction: refutation must fail */
- /*
- * Unlike the implication case, predicate_refuted_by_recurse needs to be
- * able to see the top-level AND structure on both sides --- otherwise it
- * will fail to handle the case where one restriction clause is an OR that
- * can refute the predicate AND as a whole, but not each predicate clause
- * separately.
- */
+ /* Otherwise, away we go ... */
return predicate_refuted_by_recurse((Node *) restrictinfo_list,
(Node *) predicate_list);
}
* This is still not an exhaustive test, but it handles most normal cases
* under the assumption that both inputs have been AND/OR flattened.
*
- * A bare List node on the restriction side is interpreted as an AND clause,
- * in order to handle the top-level restriction List properly. However we
- * need not consider a List on the predicate side since predicate_implied_by()
- * already expanded it.
- *
* We have to be prepared to handle RestrictInfo nodes in the restrictinfo
* tree, though not in the predicate tree.
*----------
static bool
predicate_implied_by_recurse(Node *clause, Node *predicate)
{
- ListCell *item;
+ PredIterInfoData clause_info;
+ PredIterInfoData pred_info;
+ PredClass pclass;
+ bool result;
- Assert(clause != NULL);
/* skip through RestrictInfo */
+ Assert(clause != NULL);
if (IsA(clause, RestrictInfo))
- {
clause = (Node *) ((RestrictInfo *) clause)->clause;
- Assert(clause != NULL);
- Assert(!IsA(clause, RestrictInfo));
- }
- Assert(predicate != NULL);
- /*
- * Since a restriction List clause is handled the same as an AND clause,
- * we can avoid duplicate code like this:
- */
- if (and_clause(clause))
- clause = (Node *) ((BoolExpr *) clause)->args;
+ pclass = predicate_classify(predicate, &pred_info);
- if (IsA(clause, List))
- {
- if (and_clause(predicate))
- {
- /* AND-clause => AND-clause if A implies each of B's items */
- foreach(item, ((BoolExpr *) predicate)->args)
- {
- if (!predicate_implied_by_recurse(clause, lfirst(item)))
- return false;
- }
- return true;
- }
- else if (or_clause(predicate))
- {
- /* AND-clause => OR-clause if A implies any of B's items */
- /* Needed to handle (x AND y) => ((x AND y) OR z) */
- foreach(item, ((BoolExpr *) predicate)->args)
- {
- if (predicate_implied_by_recurse(clause, lfirst(item)))
- return true;
- }
- /* Also check if any of A's items implies B */
- /* Needed to handle ((x OR y) AND z) => (x OR y) */
- foreach(item, (List *) clause)
- {
- if (predicate_implied_by_recurse(lfirst(item), predicate))
- return true;
- }
- return false;
- }
- else
- {
- /* AND-clause => atom if any of A's items implies B */
- foreach(item, (List *) clause)
- {
- if (predicate_implied_by_recurse(lfirst(item), predicate))
- return true;
- }
- return false;
- }
- }
- else if (or_clause(clause))
+ switch (predicate_classify(clause, &clause_info))
{
- if (or_clause(predicate))
- {
- /*
- * OR-clause => OR-clause if each of A's items implies any of B's
- * items. Messy but can't do it any more simply.
- */
- foreach(item, ((BoolExpr *) clause)->args)
- {
- Node *citem = lfirst(item);
- ListCell *item2;
-
- foreach(item2, ((BoolExpr *) predicate)->args)
- {
- if (predicate_implied_by_recurse(citem, lfirst(item2)))
- break;
- }
- if (item2 == NULL)
- return false; /* doesn't imply any of B's */
- }
- return true;
- }
- else
- {
- /* OR-clause => AND-clause if each of A's items implies B */
- /* OR-clause => atom if each of A's items implies B */
- foreach(item, ((BoolExpr *) clause)->args)
+ case CLASS_AND:
+ switch (pclass)
{
- if (!predicate_implied_by_recurse(lfirst(item), predicate))
- return false;
+ case CLASS_AND:
+ /*
+ * AND-clause => AND-clause if A implies each of B's items
+ */
+ result = true;
+ iterate_begin(pitem, predicate, pred_info)
+ {
+ if (!predicate_implied_by_recurse(clause, pitem))
+ {
+ result = false;
+ break;
+ }
+ }
+ iterate_end(pred_info);
+ return result;
+
+ case CLASS_OR:
+ /*
+ * AND-clause => OR-clause if A implies any of B's items
+ *
+ * Needed to handle (x AND y) => ((x AND y) OR z)
+ */
+ result = false;
+ iterate_begin(pitem, predicate, pred_info)
+ {
+ if (predicate_implied_by_recurse(clause, pitem))
+ {
+ result = true;
+ break;
+ }
+ }
+ iterate_end(pred_info);
+ if (result)
+ return result;
+ /*
+ * Also check if any of A's items implies B
+ *
+ * Needed to handle ((x OR y) AND z) => (x OR y)
+ */
+ iterate_begin(citem, clause, clause_info)
+ {
+ if (predicate_implied_by_recurse(citem, predicate))
+ {
+ result = true;
+ break;
+ }
+ }
+ iterate_end(clause_info);
+ return result;
+
+ case CLASS_ATOM:
+ /*
+ * AND-clause => atom if any of A's items implies B
+ */
+ result = false;
+ iterate_begin(citem, clause, clause_info)
+ {
+ if (predicate_implied_by_recurse(citem, predicate))
+ {
+ result = true;
+ break;
+ }
+ }
+ iterate_end(clause_info);
+ return result;
}
- return true;
- }
- }
- else
- {
- if (and_clause(predicate))
- {
- /* atom => AND-clause if A implies each of B's items */
- foreach(item, ((BoolExpr *) predicate)->args)
+ break;
+
+ case CLASS_OR:
+ switch (pclass)
{
- if (!predicate_implied_by_recurse(clause, lfirst(item)))
- return false;
+ case CLASS_OR:
+ /*
+ * OR-clause => OR-clause if each of A's items implies any
+ * of B's items. Messy but can't do it any more simply.
+ */
+ result = true;
+ iterate_begin(citem, clause, clause_info)
+ {
+ bool presult = false;
+
+ iterate_begin(pitem, predicate, pred_info)
+ {
+ if (predicate_implied_by_recurse(citem, pitem))
+ {
+ presult = true;
+ break;
+ }
+ }
+ iterate_end(pred_info);
+ if (!presult)
+ {
+ result = false; /* doesn't imply any of B's */
+ break;
+ }
+ }
+ iterate_end(clause_info);
+ return result;
+
+ case CLASS_AND:
+ case CLASS_ATOM:
+ /*
+ * OR-clause => AND-clause if each of A's items implies B
+ *
+ * OR-clause => atom if each of A's items implies B
+ */
+ result = true;
+ iterate_begin(citem, clause, clause_info)
+ {
+ if (!predicate_implied_by_recurse(citem, predicate))
+ {
+ result = false;
+ break;
+ }
+ }
+ iterate_end(clause_info);
+ return result;
}
- return true;
- }
- else if (or_clause(predicate))
- {
- /* atom => OR-clause if A implies any of B's items */
- foreach(item, ((BoolExpr *) predicate)->args)
+ break;
+
+ case CLASS_ATOM:
+ switch (pclass)
{
- if (predicate_implied_by_recurse(clause, lfirst(item)))
- return true;
+ case CLASS_AND:
+ /*
+ * atom => AND-clause if A implies each of B's items
+ */
+ result = true;
+ iterate_begin(pitem, predicate, pred_info)
+ {
+ if (!predicate_implied_by_recurse(clause, pitem))
+ {
+ result = false;
+ break;
+ }
+ }
+ iterate_end(pred_info);
+ return result;
+
+ case CLASS_OR:
+ /*
+ * atom => OR-clause if A implies any of B's items
+ */
+ result = false;
+ iterate_begin(pitem, predicate, pred_info)
+ {
+ if (predicate_implied_by_recurse(clause, pitem))
+ {
+ result = true;
+ break;
+ }
+ }
+ iterate_end(pred_info);
+ return result;
+
+ case CLASS_ATOM:
+ /*
+ * atom => atom is the base case
+ */
+ return
+ predicate_implied_by_simple_clause((Expr *) predicate,
+ clause);
}
- return false;
- }
- else
- {
- /* atom => atom is the base case */
- return predicate_implied_by_simple_clause((Expr *) predicate,
- clause);
- }
+ break;
}
+
+ /* can't get here */
+ elog(ERROR, "predicate_classify returned a bogus value");
+ return false;
}
/*----------
* OR-expr A R=> AND-expr B iff: each of A's components R=> any of B's
* OR-expr A R=> OR-expr B iff: A R=> each of B's components
*
- * Other comments are as for predicate_implied_by_recurse(), except that
- * we have to handle a top-level AND list on both sides.
+ * Other comments are as for predicate_implied_by_recurse().
*----------
*/
static bool
predicate_refuted_by_recurse(Node *clause, Node *predicate)
{
- ListCell *item;
+ PredIterInfoData clause_info;
+ PredIterInfoData pred_info;
+ PredClass pclass;
+ bool result;
- Assert(clause != NULL);
/* skip through RestrictInfo */
+ Assert(clause != NULL);
if (IsA(clause, RestrictInfo))
- {
clause = (Node *) ((RestrictInfo *) clause)->clause;
- Assert(clause != NULL);
- Assert(!IsA(clause, RestrictInfo));
- }
- Assert(predicate != NULL);
-
- /*
- * Since a restriction List clause is handled the same as an AND clause,
- * we can avoid duplicate code like this:
- */
- if (and_clause(clause))
- clause = (Node *) ((BoolExpr *) clause)->args;
- /* Ditto for predicate AND-clause and List */
- if (and_clause(predicate))
- predicate = (Node *) ((BoolExpr *) predicate)->args;
+ pclass = predicate_classify(predicate, &pred_info);
- if (IsA(clause, List))
+ switch (predicate_classify(clause, &clause_info))
{
- if (IsA(predicate, List))
- {
- /* AND-clause R=> AND-clause if A refutes any of B's items */
- /* Needed to handle (x AND y) R=> ((!x OR !y) AND z) */
- foreach(item, (List *) predicate)
- {
- if (predicate_refuted_by_recurse(clause, lfirst(item)))
- return true;
- }
- /* Also check if any of A's items refutes B */
- /* Needed to handle ((x OR y) AND z) R=> (!x AND !y) */
- foreach(item, (List *) clause)
+ case CLASS_AND:
+ switch (pclass)
{
- if (predicate_refuted_by_recurse(lfirst(item), predicate))
- return true;
+ case CLASS_AND:
+ /*
+ * AND-clause R=> AND-clause if A refutes any of B's items
+ *
+ * Needed to handle (x AND y) R=> ((!x OR !y) AND z)
+ */
+ result = false;
+ iterate_begin(pitem, predicate, pred_info)
+ {
+ if (predicate_refuted_by_recurse(clause, pitem))
+ {
+ result = true;
+ break;
+ }
+ }
+ iterate_end(pred_info);
+ if (result)
+ return result;
+ /*
+ * Also check if any of A's items refutes B
+ *
+ * Needed to handle ((x OR y) AND z) R=> (!x AND !y)
+ */
+ iterate_begin(citem, clause, clause_info)
+ {
+ if (predicate_refuted_by_recurse(citem, predicate))
+ {
+ result = true;
+ break;
+ }
+ }
+ iterate_end(clause_info);
+ return result;
+
+ case CLASS_OR:
+ /*
+ * AND-clause R=> OR-clause if A refutes each of B's items
+ */
+ result = true;
+ iterate_begin(pitem, predicate, pred_info)
+ {
+ if (!predicate_refuted_by_recurse(clause, pitem))
+ {
+ result = false;
+ break;
+ }
+ }
+ iterate_end(pred_info);
+ return result;
+
+ case CLASS_ATOM:
+ /*
+ * AND-clause R=> atom if any of A's items refutes B
+ */
+ result = false;
+ iterate_begin(citem, clause, clause_info)
+ {
+ if (predicate_refuted_by_recurse(citem, predicate))
+ {
+ result = true;
+ break;
+ }
+ }
+ iterate_end(clause_info);
+ return result;
}
- return false;
- }
- else if (or_clause(predicate))
- {
- /* AND-clause R=> OR-clause if A refutes each of B's items */
- foreach(item, ((BoolExpr *) predicate)->args)
+ break;
+
+ case CLASS_OR:
+ switch (pclass)
{
- if (!predicate_refuted_by_recurse(clause, lfirst(item)))
- return false;
+ case CLASS_OR:
+ /*
+ * OR-clause R=> OR-clause if A refutes each of B's items
+ */
+ result = true;
+ iterate_begin(pitem, predicate, pred_info)
+ {
+ if (!predicate_refuted_by_recurse(clause, pitem))
+ {
+ result = false;
+ break;
+ }
+ }
+ iterate_end(pred_info);
+ return result;
+
+ case CLASS_AND:
+ /*
+ * OR-clause R=> AND-clause if each of A's items refutes
+ * any of B's items.
+ */
+ result = true;
+ iterate_begin(citem, clause, clause_info)
+ {
+ bool presult = false;
+
+ iterate_begin(pitem, predicate, pred_info)
+ {
+ if (predicate_refuted_by_recurse(citem, pitem))
+ {
+ presult = true;
+ break;
+ }
+ }
+ iterate_end(pred_info);
+ if (!presult)
+ {
+ result = false; /* citem refutes nothing */
+ break;
+ }
+ }
+ iterate_end(clause_info);
+ return result;
+
+ case CLASS_ATOM:
+ /*
+ * OR-clause R=> atom if each of A's items refutes B
+ */
+ result = true;
+ iterate_begin(citem, clause, clause_info)
+ {
+ if (!predicate_refuted_by_recurse(citem, predicate))
+ {
+ result = false;
+ break;
+ }
+ }
+ iterate_end(clause_info);
+ return result;
}
- return true;
- }
- else
- {
- /* AND-clause R=> atom if any of A's items refutes B */
- foreach(item, (List *) clause)
+ break;
+
+ case CLASS_ATOM:
+ switch (pclass)
{
- if (predicate_refuted_by_recurse(lfirst(item), predicate))
- return true;
+ case CLASS_AND:
+ /*
+ * atom R=> AND-clause if A refutes any of B's items
+ */
+ result = false;
+ iterate_begin(pitem, predicate, pred_info)
+ {
+ if (predicate_refuted_by_recurse(clause, pitem))
+ {
+ result = true;
+ break;
+ }
+ }
+ iterate_end(pred_info);
+ return result;
+
+ case CLASS_OR:
+ /*
+ * atom R=> OR-clause if A refutes each of B's items
+ */
+ result = true;
+ iterate_begin(pitem, predicate, pred_info)
+ {
+ if (!predicate_refuted_by_recurse(clause, pitem))
+ {
+ result = false;
+ break;
+ }
+ }
+ iterate_end(pred_info);
+ return result;
+
+ case CLASS_ATOM:
+ /*
+ * atom R=> atom is the base case
+ */
+ return
+ predicate_refuted_by_simple_clause((Expr *) predicate,
+ clause);
}
- return false;
- }
+ break;
}
- else if (or_clause(clause))
+
+ /* can't get here */
+ elog(ERROR, "predicate_classify returned a bogus value");
+ return false;
+}
+
+
+/*
+ * predicate_classify
+ * Classify an expression node as AND-type, OR-type, or neither (an atom).
+ *
+ * If the expression is classified as AND- or OR-type, then *info is filled
+ * in with the functions needed to iterate over its components.
+ */
+static PredClass
+predicate_classify(Node *clause, PredIterInfo info)
+{
+ /* Caller should not pass us NULL, nor a RestrictInfo clause */
+ Assert(clause != NULL);
+ Assert(!IsA(clause, RestrictInfo));
+
+ /*
+ * If we see a List, assume it's an implicit-AND list; this is the
+ * correct semantics for lists of RestrictInfo nodes.
+ */
+ if (IsA(clause, List))
{
- if (or_clause(predicate))
- {
- /* OR-clause R=> OR-clause if A refutes each of B's items */
- foreach(item, ((BoolExpr *) predicate)->args)
- {
- if (!predicate_refuted_by_recurse(clause, lfirst(item)))
- return false;
- }
- return true;
- }
- else if (IsA(predicate, List))
- {
- /*
- * OR-clause R=> AND-clause if each of A's items refutes any of
- * B's items.
- */
- foreach(item, ((BoolExpr *) clause)->args)
- {
- Node *citem = lfirst(item);
- ListCell *item2;
-
- foreach(item2, (List *) predicate)
- {
- if (predicate_refuted_by_recurse(citem, lfirst(item2)))
- break;
- }
- if (item2 == NULL)
- return false; /* citem refutes nothing */
- }
- return true;
- }
- else
- {
- /* OR-clause R=> atom if each of A's items refutes B */
- foreach(item, ((BoolExpr *) clause)->args)
- {
- if (!predicate_refuted_by_recurse(lfirst(item), predicate))
- return false;
- }
- return true;
- }
+ info->startup_fn = list_startup_fn;
+ info->next_fn = list_next_fn;
+ info->cleanup_fn = list_cleanup_fn;
+ return CLASS_AND;
}
- else
+
+ /* Handle normal AND and OR boolean clauses */
+ if (and_clause(clause))
{
- if (IsA(predicate, List))
- {
- /* atom R=> AND-clause if A refutes any of B's items */
- foreach(item, (List *) predicate)
- {
- if (predicate_refuted_by_recurse(clause, lfirst(item)))
- return true;
- }
- return false;
- }
- else if (or_clause(predicate))
+ info->startup_fn = boolexpr_startup_fn;
+ info->next_fn = list_next_fn;
+ info->cleanup_fn = list_cleanup_fn;
+ return CLASS_AND;
+ }
+ if (or_clause(clause))
+ {
+ info->startup_fn = boolexpr_startup_fn;
+ info->next_fn = list_next_fn;
+ info->cleanup_fn = list_cleanup_fn;
+ return CLASS_OR;
+ }
+
+ /* Handle ScalarArrayOpExpr */
+ if (IsA(clause, ScalarArrayOpExpr))
+ {
+ ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause;
+ Node *arraynode = (Node *) lsecond(saop->args);
+
+ /*
+ * We can break this down into an AND or OR structure, but only if
+ * we know how to iterate through expressions for the array's
+ * elements. We can do that if the array operand is a non-null
+ * constant or a simple ArrayExpr.
+ */
+ if (arraynode && IsA(arraynode, Const) &&
+ !((Const *) arraynode)->constisnull)
{
- /* atom R=> OR-clause if A refutes each of B's items */
- foreach(item, ((BoolExpr *) predicate)->args)
- {
- if (!predicate_refuted_by_recurse(clause, lfirst(item)))
- return false;
- }
- return true;
+ info->startup_fn = arrayconst_startup_fn;
+ info->next_fn = arrayconst_next_fn;
+ info->cleanup_fn = arrayconst_cleanup_fn;
+ return saop->useOr ? CLASS_OR : CLASS_AND;
}
- else
+ if (arraynode && IsA(arraynode, ArrayExpr) &&
+ !((ArrayExpr *) arraynode)->multidims)
{
- /* atom R=> atom is the base case */
- return predicate_refuted_by_simple_clause((Expr *) predicate,
- clause);
+ info->startup_fn = arrayexpr_startup_fn;
+ info->next_fn = arrayexpr_next_fn;
+ info->cleanup_fn = arrayexpr_cleanup_fn;
+ return saop->useOr ? CLASS_OR : CLASS_AND;
}
}
+
+ /* None of the above, so it's an atom */
+ return CLASS_ATOM;
+}
+
+/*
+ * PredIterInfo routines for iterating over regular Lists. The iteration
+ * state variable is the next ListCell to visit.
+ */
+static void
+list_startup_fn(Node *clause, PredIterInfo info)
+{
+ info->state = (void *) list_head((List *) clause);
+}
+
+static Node *
+list_next_fn(PredIterInfo info)
+{
+ ListCell *l = (ListCell *) info->state;
+ Node *n;
+
+ if (l == NULL)
+ return NULL;
+ n = lfirst(l);
+ info->state = (void *) lnext(l);
+ return n;
+}
+
+static void
+list_cleanup_fn(PredIterInfo info)
+{
+ /* Nothing to clean up */
+}
+
+/*
+ * BoolExpr needs its own startup function, but can use list_next_fn and
+ * list_cleanup_fn.
+ */
+static void
+boolexpr_startup_fn(Node *clause, PredIterInfo info)
+{
+ info->state = (void *) list_head(((BoolExpr *) clause)->args);
+}
+
+/*
+ * PredIterInfo routines for iterating over a ScalarArrayOpExpr with a
+ * constant array operand.
+ */
+typedef struct
+{
+ OpExpr opexpr;
+ Const constexpr;
+ int next_elem;
+ int num_elems;
+ Datum *elem_values;
+ bool *elem_nulls;
+} ArrayConstIterState;
+
+static void
+arrayconst_startup_fn(Node *clause, PredIterInfo info)
+{
+ ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause;
+ ArrayConstIterState *state;
+ Const *arrayconst;
+ ArrayType *arrayval;
+ int16 elmlen;
+ bool elmbyval;
+ char elmalign;
+
+ /* Create working state struct */
+ state = (ArrayConstIterState *) palloc(sizeof(ArrayConstIterState));
+ info->state = (void *) state;
+
+ /* Deconstruct the array literal */
+ arrayconst = (Const *) lsecond(saop->args);
+ arrayval = DatumGetArrayTypeP(arrayconst->constvalue);
+ get_typlenbyvalalign(ARR_ELEMTYPE(arrayval),
+ &elmlen, &elmbyval, &elmalign);
+ deconstruct_array(arrayval,
+ ARR_ELEMTYPE(arrayval),
+ elmlen, elmbyval, elmalign,
+ &state->elem_values, &state->elem_nulls,
+ &state->num_elems);
+
+ /* Set up a dummy OpExpr to return as the per-item node */
+ state->opexpr.xpr.type = T_OpExpr;
+ state->opexpr.opno = saop->opno;
+ state->opexpr.opfuncid = saop->opfuncid;
+ state->opexpr.opresulttype = BOOLOID;
+ state->opexpr.opretset = false;
+ state->opexpr.args = list_copy(saop->args);
+
+ /* Set up a dummy Const node to hold the per-element values */
+ state->constexpr.xpr.type = T_Const;
+ state->constexpr.consttype = ARR_ELEMTYPE(arrayval);
+ state->constexpr.constlen = elmlen;
+ state->constexpr.constbyval = elmbyval;
+ lsecond(state->opexpr.args) = &state->constexpr;
+
+ /* Initialize iteration state */
+ state->next_elem = 0;
+}
+
+static Node *
+arrayconst_next_fn(PredIterInfo info)
+{
+ ArrayConstIterState *state = (ArrayConstIterState *) info->state;
+
+ if (state->next_elem >= state->num_elems)
+ return NULL;
+ state->constexpr.constvalue = state->elem_values[state->next_elem];
+ state->constexpr.constisnull = state->elem_nulls[state->next_elem];
+ state->next_elem++;
+ return (Node *) &(state->opexpr);
+}
+
+static void
+arrayconst_cleanup_fn(PredIterInfo info)
+{
+ ArrayConstIterState *state = (ArrayConstIterState *) info->state;
+
+ pfree(state->elem_values);
+ pfree(state->elem_nulls);
+ list_free(state->opexpr.args);
+ pfree(state);
+}
+
+/*
+ * PredIterInfo routines for iterating over a ScalarArrayOpExpr with a
+ * one-dimensional ArrayExpr array operand.
+ */
+typedef struct
+{
+ OpExpr opexpr;
+ ListCell *next;
+} ArrayExprIterState;
+
+static void
+arrayexpr_startup_fn(Node *clause, PredIterInfo info)
+{
+ ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause;
+ ArrayExprIterState *state;
+ ArrayExpr *arrayexpr;
+
+ /* Create working state struct */
+ state = (ArrayExprIterState *) palloc(sizeof(ArrayExprIterState));
+ info->state = (void *) state;
+
+ /* Set up a dummy OpExpr to return as the per-item node */
+ state->opexpr.xpr.type = T_OpExpr;
+ state->opexpr.opno = saop->opno;
+ state->opexpr.opfuncid = saop->opfuncid;
+ state->opexpr.opresulttype = BOOLOID;
+ state->opexpr.opretset = false;
+ state->opexpr.args = list_copy(saop->args);
+
+ /* Initialize iteration variable to first member of ArrayExpr */
+ arrayexpr = (ArrayExpr *) lsecond(saop->args);
+ state->next = list_head(arrayexpr->elements);
+}
+
+static Node *
+arrayexpr_next_fn(PredIterInfo info)
+{
+ ArrayExprIterState *state = (ArrayExprIterState *) info->state;
+
+ if (state->next == NULL)
+ return NULL;
+ lsecond(state->opexpr.args) = lfirst(state->next);
+ state->next = lnext(state->next);
+ return (Node *) &(state->opexpr);
+}
+
+static void
+arrayexpr_cleanup_fn(PredIterInfo info)
+{
+ ArrayExprIterState *state = (ArrayExprIterState *) info->state;
+
+ list_free(state->opexpr.args);
+ pfree(state);
}
projects / postgresql / commitdiff