expression eval: Fix EEOP_JSON_CONSTRUCTOR and EEOP_JSONEXPR size.

The new expression step types increased the size of ExprEvalStep by ~4 for all
types of expression steps, slowing down expression evaluation noticeably. Move
them out of line.

There's other issues with these expression steps, but addressing them is
largely independent of this aspect.

Author: Andres Freund <andres@anarazel.de>
Reviewed-By: Andrew Dunstan <andrew@dunslane.net>
Discussion: https://postgr.es/m/20220616233130.rparivafipt6doj3@alap3.anarazel.de
Backpatch: 15-

1 files changed, 55 insertions, 49 deletions

diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index eaec697bb38..80c5e04dd5f 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -4510,39 +4510,40 @@ ExecEvalJsonConstructor(ExprState *state, ExprEvalStep *op,
 						ExprContext *econtext)
 {
 	Datum		res;
-	JsonConstructorExpr *ctor = op->d.json_constructor.constructor;
+	JsonConstructorExprState *jcstate = op->d.json_constructor.jcstate;
+	JsonConstructorExpr *ctor = jcstate->constructor;
 	bool		is_jsonb = ctor->returning->format->format_type == JS_FORMAT_JSONB;
 	bool		isnull = false;
 
 	if (ctor->type == JSCTOR_JSON_ARRAY)
 		res = (is_jsonb ?
 			   jsonb_build_array_worker :
-			   json_build_array_worker) (op->d.json_constructor.nargs,
-										 op->d.json_constructor.arg_values,
-										 op->d.json_constructor.arg_nulls,
-										 op->d.json_constructor.arg_types,
-										 op->d.json_constructor.constructor->absent_on_null);
+			   json_build_array_worker) (jcstate->nargs,
+										 jcstate->arg_values,
+										 jcstate->arg_nulls,
+										 jcstate->arg_types,
+										 ctor->absent_on_null);
 	else if (ctor->type == JSCTOR_JSON_OBJECT)
 		res = (is_jsonb ?
 			   jsonb_build_object_worker :
-			   json_build_object_worker) (op->d.json_constructor.nargs,
-										  op->d.json_constructor.arg_values,
-										  op->d.json_constructor.arg_nulls,
-										  op->d.json_constructor.arg_types,
-										  op->d.json_constructor.constructor->absent_on_null,
-										  op->d.json_constructor.constructor->unique);
+			   json_build_object_worker) (jcstate->nargs,
+										  jcstate->arg_values,
+										  jcstate->arg_nulls,
+										  jcstate->arg_types,
+										  ctor->absent_on_null,
+										  ctor->unique);
 	else if (ctor->type == JSCTOR_JSON_SCALAR)
 	{
-		if (op->d.json_constructor.arg_nulls[0])
+		if (jcstate->arg_nulls[0])
 		{
 			res = (Datum) 0;
 			isnull = true;
 		}
 		else
 		{
-			Datum		value = op->d.json_constructor.arg_values[0];
-			int			category = op->d.json_constructor.arg_type_cache[0].category;
-			Oid			outfuncid = op->d.json_constructor.arg_type_cache[0].outfuncid;
+			Datum		value = jcstate->arg_values[0];
+			int			category = jcstate->arg_type_cache[0].category;
+			Oid			outfuncid = jcstate->arg_type_cache[0].outfuncid;
 
 			if (is_jsonb)
 				res = to_jsonb_worker(value, category, outfuncid);
@@ -4552,14 +4553,14 @@ ExecEvalJsonConstructor(ExprState *state, ExprEvalStep *op,
 	}
 	else if (ctor->type == JSCTOR_JSON_PARSE)
 	{
-		if (op->d.json_constructor.arg_nulls[0])
+		if (jcstate->arg_nulls[0])
 		{
 			res = (Datum) 0;
 			isnull = true;
 		}
 		else
 		{
-			Datum		value = op->d.json_constructor.arg_values[0];
+			Datum		value = jcstate->arg_values[0];
 			text	   *js = DatumGetTextP(value);
 
 			if (is_jsonb)
@@ -4627,14 +4628,17 @@ ExecEvalJsonExprCoercion(ExprEvalStep *op, ExprContext *econtext,
 						 Datum res, bool *isNull, void *p, bool *error)
 {
 	ExprState  *estate = p;
+	JsonExprState *jsestate;
 
 	if (estate)					/* coerce using specified expression */
 		return ExecEvalExpr(estate, econtext, isNull);
 
-	if (op->d.jsonexpr.jsexpr->op != JSON_EXISTS_OP)
+	jsestate = op->d.jsonexpr.jsestate;
+
+	if (jsestate->jsexpr->op != JSON_EXISTS_OP)
 	{
-		JsonCoercion *coercion = op->d.jsonexpr.jsexpr->result_coercion;
-		JsonExpr   *jexpr = op->d.jsonexpr.jsexpr;
+		JsonCoercion *coercion = jsestate->jsexpr->result_coercion;
+		JsonExpr   *jexpr = jsestate->jsexpr;
 		Jsonb	   *jb = *isNull ? NULL : DatumGetJsonbP(res);
 
 		if ((coercion && coercion->via_io) ||
@@ -4644,25 +4648,25 @@ ExecEvalJsonExprCoercion(ExprEvalStep *op, ExprContext *econtext,
 			/* strip quotes and call typinput function */
 			char	   *str = *isNull ? NULL : JsonbUnquote(jb);
 
-			return InputFunctionCall(&op->d.jsonexpr.input.func, str,
-									 op->d.jsonexpr.input.typioparam,
+			return InputFunctionCall(&jsestate->input.func, str,
+									 jsestate->input.typioparam,
 									 jexpr->returning->typmod);
 		}
 		else if (coercion && coercion->via_populate)
 			return json_populate_type(res, JSONBOID,
 									  jexpr->returning->typid,
 									  jexpr->returning->typmod,
-									  &op->d.jsonexpr.cache,
+									  &jsestate->cache,
 									  econtext->ecxt_per_query_memory,
 									  isNull);
 	}
 
-	if (op->d.jsonexpr.result_expr)
+	if (jsestate->result_expr)
 	{
-		op->d.jsonexpr.res_expr->value = res;
-		op->d.jsonexpr.res_expr->isnull = *isNull;
+		jsestate->res_expr->value = res;
+		jsestate->res_expr->isnull = *isNull;
 
-		res = ExecEvalExpr(op->d.jsonexpr.result_expr, econtext, isNull);
+		res = ExecEvalExpr(jsestate->result_expr, econtext, isNull);
 	}
 
 	return res;
@@ -4895,7 +4899,8 @@ ExecEvalJsonExpr(ExprEvalStep *op, ExprContext *econtext,
 {
 	ExecEvalJsonExprContext *cxt = pcxt;
 	JsonPath   *path = cxt->path;
-	JsonExpr   *jexpr = op->d.jsonexpr.jsexpr;
+	JsonExprState *jsestate = op->d.jsonexpr.jsestate;
+	JsonExpr   *jexpr = jsestate->jsexpr;
 	ExprState  *estate = NULL;
 	bool		empty = false;
 	Datum		res = (Datum) 0;
@@ -4904,7 +4909,7 @@ ExecEvalJsonExpr(ExprEvalStep *op, ExprContext *econtext,
 	{
 		case JSON_QUERY_OP:
 			res = JsonPathQuery(item, path, jexpr->wrapper, &empty, error,
-								op->d.jsonexpr.args);
+								jsestate->args);
 			if (error && *error)
 			{
 				*resnull = true;
@@ -4917,7 +4922,7 @@ ExecEvalJsonExpr(ExprEvalStep *op, ExprContext *econtext,
 			{
 				struct JsonCoercionState *jcstate;
 				JsonbValue *jbv = JsonPathValue(item, path, &empty, error,
-												op->d.jsonexpr.args);
+												jsestate->args);
 
 				if (error && *error)
 					return (Datum) 0;
@@ -4940,8 +4945,8 @@ ExecEvalJsonExpr(ExprEvalStep *op, ExprContext *econtext,
 
 				/* Use coercion from SQL/JSON item type to the output type */
 				res = ExecPrepareJsonItemCoercion(jbv,
-												  op->d.jsonexpr.jsexpr->returning,
-												  &op->d.jsonexpr.coercions,
+												  jsestate->jsexpr->returning,
+												  &jsestate->coercions,
 												  &jcstate);
 
 				if (jcstate->coercion &&
@@ -4973,27 +4978,27 @@ ExecEvalJsonExpr(ExprEvalStep *op, ExprContext *econtext,
 
 				/* coerce using specific expression */
 				estate = jcstate->estate;
-				op->d.jsonexpr.coercion_expr->value = res;
-				op->d.jsonexpr.coercion_expr->isnull = *resnull;
+				jsestate->coercion_expr->value = res;
+				jsestate->coercion_expr->isnull = *resnull;
 				break;
 			}
 
 		case JSON_EXISTS_OP:
 			{
 				bool		exists = JsonPathExists(item, path,
-													op->d.jsonexpr.args,
+													jsestate->args,
 													error);
 
 				*resnull = error && *error;
 				res = BoolGetDatum(exists);
 
-				if (!op->d.jsonexpr.result_expr)
+				if (!jsestate->result_expr)
 					return res;
 
 				/* coerce using result expression */
-				estate = op->d.jsonexpr.result_expr;
-				op->d.jsonexpr.res_expr->value = res;
-				op->d.jsonexpr.res_expr->isnull = *resnull;
+				estate = jsestate->result_expr;
+				jsestate->res_expr->value = res;
+				jsestate->res_expr->isnull = *resnull;
 				break;
 			}
 
@@ -5029,11 +5034,11 @@ ExecEvalJsonExpr(ExprEvalStep *op, ExprContext *econtext,
 			 * Execute DEFAULT expression as a coercion expression, because
 			 * its result is already coerced to the target type.
 			 */
-			estate = op->d.jsonexpr.default_on_empty;
+			estate = jsestate->default_on_empty;
 		else
 			/* Execute ON EMPTY behavior */
 			res = ExecEvalJsonBehavior(econtext, jexpr->on_empty,
-									   op->d.jsonexpr.default_on_empty,
+									   jsestate->default_on_empty,
 									   resnull);
 	}
 
@@ -5066,7 +5071,8 @@ void
 ExecEvalJson(ExprState *state, ExprEvalStep *op, ExprContext *econtext)
 {
 	ExecEvalJsonExprContext cxt;
-	JsonExpr   *jexpr = op->d.jsonexpr.jsexpr;
+	JsonExprState *jsestate = op->d.jsonexpr.jsestate;
+	JsonExpr   *jexpr = jsestate->jsexpr;
 	Datum		item;
 	Datum		res = (Datum) 0;
 	JsonPath   *path;
@@ -5078,7 +5084,7 @@ ExecEvalJson(ExprState *state, ExprEvalStep *op, ExprContext *econtext)
 	*op->resnull = true;		/* until we get a result */
 	*op->resvalue = (Datum) 0;
 
-	if (op->d.jsonexpr.formatted_expr->isnull || op->d.jsonexpr.pathspec->isnull)
+	if (jsestate->formatted_expr->isnull || jsestate->pathspec->isnull)
 	{
 		/* execute domain checks for NULLs */
 		(void) ExecEvalJsonExprCoercion(op, econtext, res, op->resnull,
@@ -5088,11 +5094,11 @@ ExecEvalJson(ExprState *state, ExprEvalStep *op, ExprContext *econtext)
 		return;
 	}
 
-	item = op->d.jsonexpr.formatted_expr->value;
-	path = DatumGetJsonPathP(op->d.jsonexpr.pathspec->value);
+	item = jsestate->formatted_expr->value;
+	path = DatumGetJsonPathP(jsestate->pathspec->value);
 
 	/* reset JSON path variable contexts */
-	foreach(lc, op->d.jsonexpr.args)
+	foreach(lc, jsestate->args)
 	{
 		JsonPathVariableEvalContext *var = lfirst(lc);
 
@@ -5100,7 +5106,7 @@ ExecEvalJson(ExprState *state, ExprEvalStep *op, ExprContext *econtext)
 		var->evaluated = false;
 	}
 
-	needSubtrans = ExecEvalJsonNeedsSubTransaction(jexpr, &op->d.jsonexpr.coercions);
+	needSubtrans = ExecEvalJsonNeedsSubTransaction(jexpr, &jsestate->coercions);
 
 	cxt.path = path;
 	cxt.error = throwErrors ? NULL : &error;
@@ -5115,7 +5121,7 @@ ExecEvalJson(ExprState *state, ExprEvalStep *op, ExprContext *econtext)
 	{
 		/* Execute ON ERROR behavior */
 		res = ExecEvalJsonBehavior(econtext, jexpr->on_error,
-								   op->d.jsonexpr.default_on_error,
+								   jsestate->default_on_error,
 								   op->resnull);
 
 		/* result is already coerced in DEFAULT behavior case */