#include "funcapi.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
+#include "optimizer/planner.h"
+#include "parser/parse_coerce.h"
#include "parser/scansup.h"
#include "storage/proc.h"
#include "tcop/tcopprot.h"
bool *freevals; /* which arguments are pfree-able */
} PreparedParamsData;
+typedef struct
+{
+ /* NB: we assume this struct contains no padding bytes */
+ Oid srctype; /* source type for cast */
+ Oid dsttype; /* destination type for cast */
+ int32 dsttypmod; /* destination typmod for cast */
+} plpgsql_CastHashKey;
+
+typedef struct
+{
+ plpgsql_CastHashKey key; /* hash key --- MUST BE FIRST */
+ ExprState *cast_exprstate; /* cast expression, or NULL if no-op cast */
+} plpgsql_CastHashEntry;
+
/*
* All plpgsql function executions within a single transaction share the same
* executor EState for evaluating "simple" expressions. Each function call
static char *convert_value_to_string(PLpgSQL_execstate *estate,
Datum value, Oid valtype);
static Datum exec_cast_value(PLpgSQL_execstate *estate,
- Datum value, bool isnull,
+ Datum value, bool *isnull,
Oid valtype, int32 valtypmod,
- Oid reqtype, int32 reqtypmod,
- FmgrInfo *reqinput,
- Oid reqtypioparam);
-static Datum exec_simple_cast_value(PLpgSQL_execstate *estate,
- Datum value, bool isnull,
- Oid valtype, int32 valtypmod,
- Oid reqtype, int32 reqtypmod);
+ Oid reqtype, int32 reqtypmod);
+static ExprState *get_cast_expression(PLpgSQL_execstate *estate,
+ Oid srctype, Oid dsttype, int32 dsttypmod);
static void exec_init_tuple_store(PLpgSQL_execstate *estate);
static void exec_set_found(PLpgSQL_execstate *estate, bool state);
static void plpgsql_create_econtext(PLpgSQL_execstate *estate);
/* Cast value to proper type */
estate.retval = exec_cast_value(&estate,
estate.retval,
- fcinfo->isnull,
+ &fcinfo->isnull,
estate.rettype,
-1,
func->fn_rettype,
- -1,
- &(func->fn_retinput),
- func->fn_rettypioparam);
+ -1);
/*
* If the function's return type isn't by value, copy the value
* before the notnull check to be consistent with
* exec_assign_value.)
*/
- if (!var->datatype->typinput.fn_strict)
+ if (var->datatype->typtype == TYPTYPE_DOMAIN)
exec_assign_value(estate,
(PLpgSQL_datum *) var,
(Datum) 0,
*/
value = exec_eval_expr(estate, stmt->lower,
&isnull, &valtype, &valtypmod);
- value = exec_cast_value(estate, value, isnull,
+ value = exec_cast_value(estate, value, &isnull,
valtype, valtypmod,
var->datatype->typoid,
- var->datatype->atttypmod,
- &(var->datatype->typinput),
- var->datatype->typioparam);
+ var->datatype->atttypmod);
if (isnull)
ereport(ERROR,
(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
*/
value = exec_eval_expr(estate, stmt->upper,
&isnull, &valtype, &valtypmod);
- value = exec_cast_value(estate, value, isnull,
+ value = exec_cast_value(estate, value, &isnull,
valtype, valtypmod,
var->datatype->typoid,
- var->datatype->atttypmod,
- &(var->datatype->typinput),
- var->datatype->typioparam);
+ var->datatype->atttypmod);
if (isnull)
ereport(ERROR,
(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
{
value = exec_eval_expr(estate, stmt->step,
&isnull, &valtype, &valtypmod);
- value = exec_cast_value(estate, value, isnull,
+ value = exec_cast_value(estate, value, &isnull,
valtype, valtypmod,
var->datatype->typoid,
- var->datatype->atttypmod,
- &(var->datatype->typinput),
- var->datatype->typioparam);
+ var->datatype->atttypmod);
if (isnull)
ereport(ERROR,
(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
errmsg("wrong result type supplied in RETURN NEXT")));
/* coerce type if needed */
- retval = exec_simple_cast_value(estate,
- retval,
- isNull,
- var->datatype->typoid,
- var->datatype->atttypmod,
- tupdesc->attrs[0]->atttypid,
- tupdesc->attrs[0]->atttypmod);
+ retval = exec_cast_value(estate,
+ retval,
+ &isNull,
+ var->datatype->typoid,
+ var->datatype->atttypmod,
+ tupdesc->attrs[0]->atttypid,
+ tupdesc->attrs[0]->atttypmod);
tuplestore_putvalues(estate->tuple_store, tupdesc,
&retval, &isNull);
errmsg("wrong result type supplied in RETURN NEXT")));
/* coerce type if needed */
- retval = exec_simple_cast_value(estate,
- retval,
- isNull,
- rettype,
- rettypmod,
- tupdesc->attrs[0]->atttypid,
- tupdesc->attrs[0]->atttypmod);
+ retval = exec_cast_value(estate,
+ retval,
+ &isNull,
+ rettype,
+ rettypmod,
+ tupdesc->attrs[0]->atttypid,
+ tupdesc->attrs[0]->atttypmod);
tuplestore_putvalues(estate->tuple_store, tupdesc,
&retval, &isNull);
newvalue = exec_cast_value(estate,
value,
- isNull,
+ &isNull,
valtype,
valtypmod,
var->datatype->typoid,
- var->datatype->atttypmod,
- &(var->datatype->typinput),
- var->datatype->typioparam);
+ var->datatype->atttypmod);
if (isNull && var->notnull)
ereport(ERROR,
*/
atttype = rec->tupdesc->attrs[fno]->atttypid;
atttypmod = rec->tupdesc->attrs[fno]->atttypmod;
- values[fno] = exec_simple_cast_value(estate,
- value,
- isNull,
- valtype,
- valtypmod,
- atttype,
- atttypmod);
+ values[fno] = exec_cast_value(estate,
+ value,
+ &isNull,
+ valtype,
+ valtypmod,
+ atttype,
+ atttypmod);
nulls[fno] = isNull;
/*
estate->eval_tuptable = save_eval_tuptable;
/* Coerce source value to match array element type. */
- coerced_value = exec_simple_cast_value(estate,
- value,
- isNull,
- valtype,
- valtypmod,
- arrayelem->elemtypoid,
- arrayelem->arraytypmod);
+ coerced_value = exec_cast_value(estate,
+ value,
+ &isNull,
+ valtype,
+ valtypmod,
+ arrayelem->elemtypoid,
+ arrayelem->arraytypmod);
/*
* If the original array is null, cons up an empty array so
int32 exprtypmod;
exprdatum = exec_eval_expr(estate, expr, isNull, &exprtypeid, &exprtypmod);
- exprdatum = exec_simple_cast_value(estate, exprdatum, *isNull,
- exprtypeid, exprtypmod,
- INT4OID, -1);
+ exprdatum = exec_cast_value(estate, exprdatum, isNull,
+ exprtypeid, exprtypmod,
+ INT4OID, -1);
return DatumGetInt32(exprdatum);
}
int32 exprtypmod;
exprdatum = exec_eval_expr(estate, expr, isNull, &exprtypeid, &exprtypmod);
- exprdatum = exec_simple_cast_value(estate, exprdatum, *isNull,
- exprtypeid, exprtypmod,
- BOOLOID, -1);
+ exprdatum = exec_cast_value(estate, exprdatum, isNull,
+ exprtypeid, exprtypmod,
+ BOOLOID, -1);
return DatumGetBool(exprdatum);
}
* pass-by-reference) and so an exec_eval_cleanup() call is needed anyway.
*
* Note: not caching the conversion function lookup is bad for performance.
+ * However, this function isn't currently used in any places where an extra
+ * catalog lookup or two seems like a big deal.
* ----------
*/
static char *
/* ----------
* exec_cast_value Cast a value if required
*
+ * Note that *isnull is an input and also an output parameter. While it's
+ * unlikely that a cast operation would produce null from non-null or vice
+ * versa, that could happen in principle.
+ *
* Note: the estate's eval_econtext is used for temporary storage, and may
* also contain the result Datum if we have to do a conversion to a pass-
* by-reference data type. Be sure to do an exec_eval_cleanup() call when
*/
static Datum
exec_cast_value(PLpgSQL_execstate *estate,
- Datum value, bool isnull,
+ Datum value, bool *isnull,
Oid valtype, int32 valtypmod,
- Oid reqtype, int32 reqtypmod,
- FmgrInfo *reqinput,
- Oid reqtypioparam)
+ Oid reqtype, int32 reqtypmod)
{
/*
* If the type of the given value isn't what's requested, convert it.
if (valtype != reqtype ||
(valtypmod != reqtypmod && reqtypmod != -1))
{
- MemoryContext oldcontext;
+ ExprState *cast_expr;
- oldcontext = MemoryContextSwitchTo(estate->eval_econtext->ecxt_per_tuple_memory);
- if (!isnull)
+ cast_expr = get_cast_expression(estate, valtype, reqtype, reqtypmod);
+ if (cast_expr)
{
- char *extval;
+ ExprContext *econtext = estate->eval_econtext;
+ MemoryContext oldcontext;
- extval = convert_value_to_string(estate, value, valtype);
- value = InputFunctionCall(reqinput, extval,
- reqtypioparam, reqtypmod);
- }
- else
- {
- value = InputFunctionCall(reqinput, NULL,
- reqtypioparam, reqtypmod);
+ oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory);
+
+ econtext->caseValue_datum = value;
+ econtext->caseValue_isNull = *isnull;
+
+ value = ExecEvalExpr(cast_expr, econtext, isnull, NULL);
+
+ MemoryContextSwitchTo(oldcontext);
}
- MemoryContextSwitchTo(oldcontext);
}
return value;
}
/* ----------
- * exec_simple_cast_value Cast a value if required
+ * get_cast_expression Look up how to perform a type cast
*
- * As above, but need not supply details about target type. Note that this
- * is slower than exec_cast_value with cached type info, and so should be
- * avoided in heavily used code paths.
+ * Returns an expression evaluation tree based on a CaseTestExpr input,
+ * or NULL if the cast is a mere no-op relabeling.
+ *
+ * We cache the results of the lookup in a per-function hash table.
+ * It's tempting to consider using a session-wide hash table instead,
+ * but that introduces some corner-case questions that probably aren't
+ * worth dealing with; in particular that re-entrant use of an evaluation
+ * tree might occur. That would also set in stone the assumption that
+ * collation isn't important to a cast function.
* ----------
*/
-static Datum
-exec_simple_cast_value(PLpgSQL_execstate *estate,
- Datum value, bool isnull,
- Oid valtype, int32 valtypmod,
- Oid reqtype, int32 reqtypmod)
+static ExprState *
+get_cast_expression(PLpgSQL_execstate *estate,
+ Oid srctype, Oid dsttype, int32 dsttypmod)
{
- if (valtype != reqtype ||
- (valtypmod != reqtypmod && reqtypmod != -1))
+ HTAB *cast_hash = estate->func->cast_hash;
+ plpgsql_CastHashKey cast_key;
+ plpgsql_CastHashEntry *cast_entry;
+ bool found;
+ CaseTestExpr *placeholder;
+ Node *cast_expr;
+ ExprState *cast_exprstate;
+ MemoryContext oldcontext;
+
+ /* Create the cast-info hash table if we didn't already */
+ if (cast_hash == NULL)
{
- Oid typinput;
- Oid typioparam;
- FmgrInfo finfo_input;
-
- getTypeInputInfo(reqtype, &typinput, &typioparam);
-
- fmgr_info(typinput, &finfo_input);
-
- value = exec_cast_value(estate,
- value,
- isnull,
- valtype,
- valtypmod,
- reqtype,
- reqtypmod,
- &finfo_input,
- typioparam);
+ HASHCTL ctl;
+
+ memset(&ctl, 0, sizeof(ctl));
+ ctl.keysize = sizeof(plpgsql_CastHashKey);
+ ctl.entrysize = sizeof(plpgsql_CastHashEntry);
+ ctl.hcxt = estate->func->fn_cxt;
+ cast_hash = hash_create("PLpgSQL cast cache",
+ 16, /* start small and extend */
+ &ctl,
+ HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+ estate->func->cast_hash = cast_hash;
}
- return value;
-}
+ /* Look for existing entry */
+ cast_key.srctype = srctype;
+ cast_key.dsttype = dsttype;
+ cast_key.dsttypmod = dsttypmod;
+ cast_entry = (plpgsql_CastHashEntry *) hash_search(cast_hash,
+ (void *) &cast_key,
+ HASH_FIND, NULL);
+ if (cast_entry)
+ return cast_entry->cast_exprstate;
+
+ /* Construct expression tree for coercion in function's context */
+ oldcontext = MemoryContextSwitchTo(estate->func->fn_cxt);
+ /*
+ * We use a CaseTestExpr as the base of the coercion tree, since it's very
+ * cheap to insert the source value for that.
+ */
+ placeholder = makeNode(CaseTestExpr);
+ placeholder->typeId = srctype;
+ placeholder->typeMod = -1;
+ placeholder->collation = get_typcollation(srctype);
+ if (OidIsValid(estate->func->fn_input_collation) &&
+ OidIsValid(placeholder->collation))
+ placeholder->collation = estate->func->fn_input_collation;
+
+ /*
+ * Apply coercion. We use ASSIGNMENT coercion because that's the closest
+ * match to plpgsql's historical behavior; in particular, EXPLICIT
+ * coercion would allow silent truncation to a destination
+ * varchar/bpchar's length, which we do not want.
+ *
+ * If source type is UNKNOWN, coerce_to_target_type will fail (it only
+ * expects to see that for Const input nodes), so don't call it; we'll
+ * apply CoerceViaIO instead.
+ */
+ if (srctype != UNKNOWNOID)
+ cast_expr = coerce_to_target_type(NULL,
+ (Node *) placeholder, srctype,
+ dsttype, dsttypmod,
+ COERCION_ASSIGNMENT,
+ COERCE_IMPLICIT_CAST,
+ -1);
+ else
+ cast_expr = NULL;
+
+ /*
+ * If there's no cast path according to the parser, fall back to using an
+ * I/O coercion; this is semantically dubious but matches plpgsql's
+ * historical behavior. We would need something of the sort for UNKNOWN
+ * literals in any case.
+ */
+ if (cast_expr == NULL)
+ {
+ CoerceViaIO *iocoerce = makeNode(CoerceViaIO);
+
+ iocoerce->arg = (Expr *) placeholder;
+ iocoerce->resulttype = dsttype;
+ iocoerce->resultcollid = InvalidOid;
+ iocoerce->coerceformat = COERCE_IMPLICIT_CAST;
+ iocoerce->location = -1;
+ cast_expr = (Node *) iocoerce;
+ if (dsttypmod != -1)
+ cast_expr = coerce_to_target_type(NULL,
+ cast_expr, dsttype,
+ dsttype, dsttypmod,
+ COERCION_ASSIGNMENT,
+ COERCE_IMPLICIT_CAST,
+ -1);
+ }
+
+ /* Note: we don't bother labeling the expression tree with collation */
+
+ /* Detect whether we have a no-op (RelabelType) coercion */
+ if (IsA(cast_expr, RelabelType) &&
+ ((RelabelType *) cast_expr)->arg == (Expr *) placeholder)
+ cast_expr = NULL;
+
+ if (cast_expr)
+ {
+ /* ExecInitExpr assumes we've planned the expression */
+ cast_expr = (Node *) expression_planner((Expr *) cast_expr);
+ /* Create an expression eval state tree for it */
+ cast_exprstate = ExecInitExpr((Expr *) cast_expr, NULL);
+ }
+ else
+ cast_exprstate = NULL;
+
+ MemoryContextSwitchTo(oldcontext);
+
+ /*
+ * Now fill in a hashtable entry. If we fail anywhere up to/including
+ * this step, we've only leaked some memory in the function context, which
+ * isn't great but isn't disastrous either.
+ */
+ cast_entry = (plpgsql_CastHashEntry *) hash_search(cast_hash,
+ (void *) &cast_key,
+ HASH_ENTER, &found);
+ Assert(!found); /* wasn't there a moment ago */
+
+ cast_entry->cast_exprstate = cast_exprstate;
+
+ return cast_exprstate;
+}
/* ----------
* exec_simple_check_node - Recursively check if an expression
projects / postgresql.git / commitdiff