From b6e1157e7d339c4e20d68448125a4cef42b1ac9d Mon Sep 17 00:00:00 2001 From: Amit Langote Date: Fri, 7 Jul 2023 20:21:58 +0900 Subject: [PATCH] Don't include CaseTestExpr in JsonValueExpr.formatted_expr MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit A CaseTestExpr is currently being put into JsonValueExpr.formatted_expr as placeholder for the result of evaluating JsonValueExpr.raw_expr, which in turn is evaluated separately. Though, there's no need for this indirection if raw_expr itself can be embedded into formatted_expr and evaluated as part of evaluating the latter, especially as there is no special reason to evaluate it separately. So this commit makes it so. As a result, JsonValueExpr.raw_expr no longer needs to be evaluated in ExecInterpExpr(), eval_const_exprs_mutator() etc. and is now only used for displaying the original "unformatted" expression in ruleutils.c. While at it, this also removes the function makeCaseTestExpr(), because the code in makeJsonConstructorExpr() looks more readable without it IMO and isn't used by anyone else either. Finally, a note is added in the comment above CaseTestExpr's definition that JsonConstructorExpr is also using it. Reviewed-by: Álvaro Herrera Discussion: https://postgr.es/m/CA+HiwqE4XTdfb1nW=Ojoy_tQSRhYt-q_kb6i5d4xcKyrLC1Nbg@mail.gmail.com --- src/backend/executor/execExpr.c | 17 ++--------- src/backend/nodes/makefuncs.c | 4 +++ src/backend/optimizer/util/clauses.c | 23 ++++----------- src/backend/parser/parse_expr.c | 43 ++++++++++++++-------------- src/include/nodes/primnodes.h | 7 ++++- 5 files changed, 39 insertions(+), 55 deletions(-) diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c index e6e616865c2..bf3a08c5f08 100644 --- a/src/backend/executor/execExpr.c +++ b/src/backend/executor/execExpr.c @@ -2294,21 +2294,8 @@ ExecInitExprRec(Expr *node, ExprState *state, { JsonValueExpr *jve = (JsonValueExpr *) node; - ExecInitExprRec(jve->raw_expr, state, resv, resnull); - - if (jve->formatted_expr) - { - Datum *innermost_caseval = state->innermost_caseval; - bool *innermost_isnull = state->innermost_casenull; - - state->innermost_caseval = resv; - state->innermost_casenull = resnull; - - ExecInitExprRec(jve->formatted_expr, state, resv, resnull); - - state->innermost_caseval = innermost_caseval; - state->innermost_casenull = innermost_isnull; - } + Assert(jve->formatted_expr != NULL); + ExecInitExprRec(jve->formatted_expr, state, resv, resnull); break; } diff --git a/src/backend/nodes/makefuncs.c b/src/backend/nodes/makefuncs.c index 39e1884cf43..c6c310d2531 100644 --- a/src/backend/nodes/makefuncs.c +++ b/src/backend/nodes/makefuncs.c @@ -853,6 +853,10 @@ makeJsonValueExpr(Expr *expr, JsonFormat *format) JsonValueExpr *jve = makeNode(JsonValueExpr); jve->raw_expr = expr; + + /* + * Set after checking the format, if needed, in transformJsonValueExpr(). + */ jve->formatted_expr = NULL; jve->format = format; diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c index 7f453b04f8b..da258968b8c 100644 --- a/src/backend/optimizer/util/clauses.c +++ b/src/backend/optimizer/util/clauses.c @@ -2827,25 +2827,12 @@ eval_const_expressions_mutator(Node *node, case T_JsonValueExpr: { JsonValueExpr *jve = (JsonValueExpr *) node; - Node *raw; + Node *formatted; - raw = eval_const_expressions_mutator((Node *) jve->raw_expr, - context); - if (raw && IsA(raw, Const)) - { - Node *formatted; - Node *save_case_val = context->case_val; - - context->case_val = raw; - - formatted = eval_const_expressions_mutator((Node *) jve->formatted_expr, - context); - - context->case_val = save_case_val; - - if (formatted && IsA(formatted, Const)) - return formatted; - } + formatted = eval_const_expressions_mutator((Node *) jve->formatted_expr, + context); + if (formatted && IsA(formatted, Const)) + return formatted; break; } diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index 5bf790cf0fe..26344743e40 100644 --- a/src/backend/parser/parse_expr.c +++ b/src/backend/parser/parse_expr.c @@ -3202,21 +3202,6 @@ makeJsonByteaToTextConversion(Node *expr, JsonFormat *format, int location) return (Node *) fexpr; } -/* - * Make a CaseTestExpr node. - */ -static Node * -makeCaseTestExpr(Node *expr) -{ - CaseTestExpr *placeholder = makeNode(CaseTestExpr); - - placeholder->typeId = exprType(expr); - placeholder->typeMod = exprTypmod(expr); - placeholder->collation = exprCollation(expr); - - return (Node *) placeholder; -} - /* * Transform JSON value expression using specified input JSON format or * default format otherwise. @@ -3268,11 +3253,8 @@ transformJsonValueExpr(ParseState *pstate, char *constructName, if (format != JS_FORMAT_DEFAULT) { Oid targettype = format == JS_FORMAT_JSONB ? JSONBOID : JSONOID; - Node *orig = makeCaseTestExpr(expr); Node *coerced; - expr = orig; - if (exprtype != BYTEAOID && typcategory != TYPCATEGORY_STRING) ereport(ERROR, errcode(ERRCODE_DATATYPE_MISMATCH), @@ -3310,7 +3292,7 @@ transformJsonValueExpr(ParseState *pstate, char *constructName, coerced = (Node *) fexpr; } - if (coerced == orig) + if (coerced == expr) expr = rawexpr; else { @@ -3537,8 +3519,22 @@ makeJsonConstructorExpr(ParseState *pstate, JsonConstructorType type, jsctor->absent_on_null = absent_on_null; jsctor->location = location; + /* + * Coerce to the RETURNING type and format, if needed. We abuse + * CaseTestExpr here as placeholder to pass the result of either evaluating + * 'fexpr' or whatever is produced by ExecEvalJsonConstructor() that is of + * type JSON or JSONB to the coercion function. + */ if (fexpr) - placeholder = makeCaseTestExpr((Node *) fexpr); + { + CaseTestExpr *cte = makeNode(CaseTestExpr); + + cte->typeId = exprType((Node *) fexpr); + cte->typeMod = exprTypmod((Node *) fexpr); + cte->collation = exprCollation((Node *) fexpr); + + placeholder = (Node *) cte; + } else { CaseTestExpr *cte = makeNode(CaseTestExpr); @@ -3636,6 +3632,11 @@ transformJsonArrayQueryConstructor(ParseState *pstate, colref->location = ctor->location; agg->arg = makeJsonValueExpr((Expr *) colref, ctor->format); + /* + * No formatting necessary, so set formatted_expr to be the same as + * raw_expr. + */ + agg->arg->formatted_expr = agg->arg->raw_expr; agg->absent_on_null = ctor->absent_on_null; agg->constructor = makeNode(JsonAggConstructor); agg->constructor->agg_order = NIL; @@ -3900,7 +3901,7 @@ transformJsonParseArg(ParseState *pstate, Node *jsexpr, JsonFormat *format, { JsonValueExpr *jve; - expr = makeCaseTestExpr(raw_expr); + expr = raw_expr; expr = makeJsonByteaToTextConversion(expr, format, exprLocation(expr)); *exprtype = TEXTOID; diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h index 792a743f72e..0d2df069b3b 100644 --- a/src/include/nodes/primnodes.h +++ b/src/include/nodes/primnodes.h @@ -1264,6 +1264,8 @@ typedef struct CaseWhen * see build_coercion_expression(). * * Nested FieldStore/SubscriptingRef assignment expressions in INSERT/UPDATE; * see transformAssignmentIndirection(). + * * Placeholder for intermediate results in some SQL/JSON expression nodes, + * such as JsonConstructorExpr. * * The uses in CaseExpr and ArrayCoerceExpr are safe only to the extent that * there is not any other CaseExpr or ArrayCoerceExpr between the value source @@ -1593,12 +1595,15 @@ typedef struct JsonReturning /* * JsonValueExpr - * representation of JSON value expression (expr [FORMAT JsonFormat]) + * + * Note that raw_expr is only there for displaying and is not evaluated by + * ExecInterpExpr() and eval_const_exprs_mutator(). */ typedef struct JsonValueExpr { NodeTag type; Expr *raw_expr; /* raw expression */ - Expr *formatted_expr; /* formatted expression or NULL */ + Expr *formatted_expr; /* formatted expression */ JsonFormat *format; /* FORMAT clause, if specified */ } JsonValueExpr; -- 2.39.5