Thread
-
[PATCH v20220922 02/13] FIXUP 0001-catalog-support-for-session-variables
Julien Rouhaud <julien.rouhaud@free.fr> — 2022-09-13T08:06:59Z
--- src/backend/catalog/dependency.c | 2 +- src/backend/catalog/pg_variable.c | 250 +++++++++++++++++------- src/backend/commands/session_variable.c | 120 ++---------- src/backend/tcop/utility.c | 2 +- src/include/catalog/pg_variable.h | 20 +- src/include/commands/session_variable.h | 4 +- 6 files changed, 207 insertions(+), 191 deletions(-) diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c index 6255c2c72f..d8d512973d 100644 --- a/src/backend/catalog/dependency.c +++ b/src/backend/catalog/dependency.c @@ -1513,7 +1513,7 @@ doDeletion(const ObjectAddress *object, int flags) break; case OCLASS_VARIABLE: - RemoveSessionVariable(object->objectId); + DropVariable(object->objectId); break; /* diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c index a844e5c217..f4a06c47a3 100644 --- a/src/backend/catalog/pg_variable.c +++ b/src/backend/catalog/pg_variable.c @@ -16,7 +16,6 @@ #include "access/heapam.h" #include "access/htup_details.h" - #include "catalog/catalog.h" #include "catalog/dependency.h" #include "catalog/indexing.h" @@ -26,82 +25,47 @@ #include "catalog/pg_namespace.h" #include "catalog/pg_type.h" #include "catalog/pg_variable.h" +#include "commands/session_variable.h" +#include "miscadmin.h" +#include "parser/parse_coerce.h" +#include "parser/parse_collate.h" +#include "parser/parse_expr.h" +#include "parser/parse_type.h" #include "storage/lmgr.h" #include "utils/builtins.h" #include "utils/lsyscache.h" #include "utils/pg_lsn.h" #include "utils/syscache.h" -/* - * Fetch attributes (without acl) of session variable from the syscache. - * We don't work with acl directly, so we don't need to read it here. - * Skip deserialization of defexpr when fast_only is true. - */ -void -initVariable(Variable *var, Oid varid, bool fast_only) -{ - HeapTuple tup; - Form_pg_variable varform; - Datum defexpr_datum; - bool defexpr_isnull; - - tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid)); - if (!HeapTupleIsValid(tup)) - elog(ERROR, "cache lookup failed for session variable %u", varid); +static ObjectAddress create_variable(const char *varName, + Oid varNamespace, + Oid varType, + int32 varTypmod, + Oid varOwner, + Oid varCollation, + Node *varDefexpr, + VariableEOXAction eoxaction, + bool is_not_null, + bool if_not_exists, + bool is_immutable); - varform = (Form_pg_variable) GETSTRUCT(tup); - - var->oid = varid; - var->create_lsn = varform->create_lsn; - var->name = pstrdup(NameStr(varform->varname)); - var->namespaceid = varform->varnamespace; - var->typid = varform->vartype; - var->typmod = varform->vartypmod; - var->owner = varform->varowner; - var->collation = varform->varcollation; - var->is_immutable = varform->varisimmutable; - var->is_not_null = varform->varisnotnull; - var->eoxaction = varform->vareoxaction; - - /* Get defexpr */ - defexpr_datum = SysCacheGetAttr(VARIABLEOID, - tup, - Anum_pg_variable_vardefexpr, - &defexpr_isnull); - - var->has_defexpr = !defexpr_isnull; - - /* - * Deserialize defexpr only when it is requested. We need to deserialize - * Node with default expression, only when we read from session variable, - * and this session variable has not assigned value, and this session - * variable has default expression. For other cases, we skip skip this - * operation. - */ - if (!fast_only && !defexpr_isnull) - var->defexpr = stringToNode(TextDatumGetCString(defexpr_datum)); - else - var->defexpr = NULL; - - ReleaseSysCache(tup); -} /* - * Create entry in pg_variable table + * Creates entry in pg_variable table */ -ObjectAddress -VariableCreate(const char *varName, - Oid varNamespace, - Oid varType, - int32 varTypmod, - Oid varOwner, - Oid varCollation, - Node *varDefexpr, - VariableEOXAction eoxaction, - bool is_not_null, - bool if_not_exists, - bool is_immutable) +static ObjectAddress +create_variable(const char *varName, + Oid varNamespace, + Oid varType, + int32 varTypmod, + Oid varOwner, + Oid varCollation, + Node *varDefexpr, + VariableEOXAction eoxaction, + bool is_not_null, + bool if_not_exists, + bool is_immutable) { Acl *varacl; NameData varname; @@ -235,10 +199,102 @@ VariableCreate(const char *varName, } /* - * Remove variable specified by id from pg_variable + * Creates a new variable + * + * Used by CREATE VARIABLE command + */ +ObjectAddress +CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt) +{ + Oid namespaceid; + AclResult aclresult; + Oid typid; + int32 typmod; + Oid varowner = GetUserId(); + Oid collation; + Oid typcollation; + ObjectAddress variable; + + Node *cooked_default = NULL; + + /* + * Check consistency of arguments + */ + if (stmt->eoxaction == VARIABLE_EOX_DROP + && stmt->variable->relpersistence != RELPERSISTENCE_TEMP) + ereport(ERROR, + (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), + errmsg("ON COMMIT DROP can only be used on temporary variables"))); + + if (stmt->is_not_null && stmt->is_immutable && !stmt->defexpr) + ereport(ERROR, + (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), + errmsg("IMMUTABLE NOT NULL variable requires default expression"))); + + namespaceid = + RangeVarGetAndCheckCreationNamespace(stmt->variable, NoLock, NULL); + + typenameTypeIdAndMod(pstate, stmt->typeName, &typid, &typmod); + typcollation = get_typcollation(typid); + + aclresult = pg_type_aclcheck(typid, GetUserId(), ACL_USAGE); + if (aclresult != ACLCHECK_OK) + aclcheck_error_type(aclresult, typid); + + if (stmt->collClause) + collation = LookupCollation(pstate, + stmt->collClause->collname, + stmt->collClause->location); + else + collation = typcollation;; + + /* Complain if COLLATE is applied to an uncollatable type */ + if (OidIsValid(collation) && !OidIsValid(typcollation)) + ereport(ERROR, + (errcode(ERRCODE_DATATYPE_MISMATCH), + errmsg("collations are not supported by type %s", + format_type_be(typid)), + parser_errposition(pstate, stmt->collClause->location))); + + if (stmt->defexpr) + { + cooked_default = transformExpr(pstate, stmt->defexpr, + EXPR_KIND_VARIABLE_DEFAULT); + + cooked_default = coerce_to_specific_type(pstate, + cooked_default, typid, "DEFAULT"); + assign_expr_collations(pstate, cooked_default); + } + + variable = create_variable(stmt->variable->relname, + namespaceid, + typid, + typmod, + varowner, + collation, + cooked_default, + stmt->eoxaction, + stmt->is_not_null, + stmt->if_not_exists, + stmt->is_immutable); + + elog(DEBUG1, "record for session variable \"%s\" (oid:%d) was created in pg_variable", + stmt->variable->relname, variable.objectId); + + /* We want SessionVariableCreatePostprocess to see the catalog changes. */ + CommandCounterIncrement(); + + SessionVariableCreatePostprocess(variable.objectId, stmt->eoxaction); + + return variable; +} + +/* + * Drop variable by OID, and register the needed session variable + * cleanup. */ void -VariableDrop(Oid varid) +DropVariable(Oid varid) { Relation rel; HeapTuple tup; @@ -255,4 +311,62 @@ VariableDrop(Oid varid) ReleaseSysCache(tup); table_close(rel, RowExclusiveLock); + + /* Do the necessary cleanup if needed in local memory */ + SessionVariableDropPostprocess(varid); +} + +/* + * Fetch attributes (without acl) of session variable from the syscache. + * We don't work with acl directly, so we don't need to read it here. + * Skip deserialization of defexpr when fast_only is true. + */ +void +InitVariable(Variable *var, Oid varid, bool fast_only) +{ + HeapTuple tup; + Form_pg_variable varform; + Datum defexpr_datum; + bool defexpr_isnull; + + tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid)); + + if (!HeapTupleIsValid(tup)) + elog(ERROR, "cache lookup failed for session variable %u", varid); + + varform = (Form_pg_variable) GETSTRUCT(tup); + + var->oid = varid; + var->create_lsn = varform->create_lsn; + var->name = pstrdup(NameStr(varform->varname)); + var->namespaceid = varform->varnamespace; + var->typid = varform->vartype; + var->typmod = varform->vartypmod; + var->owner = varform->varowner; + var->collation = varform->varcollation; + var->is_immutable = varform->varisimmutable; + var->is_not_null = varform->varisnotnull; + var->eoxaction = varform->vareoxaction; + + /* Get defexpr */ + defexpr_datum = SysCacheGetAttr(VARIABLEOID, + tup, + Anum_pg_variable_vardefexpr, + &defexpr_isnull); + + var->has_defexpr = !defexpr_isnull; + + /* + * Deserialize defexpr only when it is requested. We need to deserialize + * Node with default expression, only when we read from session variable, + * and this session variable has not assigned value, and this session + * variable has default expression. For other cases, we skip skip this + * operation. + */ + if (!fast_only && !defexpr_isnull) + var->defexpr = stringToNode(TextDatumGetCString(defexpr_datum)); + else + var->defexpr = NULL; + + ReleaseSysCache(tup); } diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c index 4ac6ecf730..3eafc05f89 100644 --- a/src/backend/commands/session_variable.c +++ b/src/backend/commands/session_variable.c @@ -13,7 +13,7 @@ *------------------------------------------------------------------------- */ #include "postgres.h" -#include "miscadmin.h" + #include "access/heapam.h" #include "catalog/dependency.h" #include "catalog/indexing.h" @@ -21,10 +21,7 @@ #include "catalog/pg_variable.h" #include "commands/session_variable.h" #include "funcapi.h" -#include "parser/parse_coerce.h" -#include "parser/parse_collate.h" -#include "parser/parse_expr.h" -#include "parser/parse_type.h" +#include "miscadmin.h" #include "utils/builtins.h" #include "utils/lsyscache.h" #include "utils/memutils.h" @@ -58,123 +55,40 @@ static List *xact_drop_actions = NIL; static void register_session_variable_xact_action(Oid varid, SVariableXActAction action); static void unregister_session_variable_xact_action(Oid varid, SVariableXActAction action); -/* - * Routines used for manipulation with session variables from - * SQL level - */ /* - * Creates new variable - entry in pg_catalog.pg_variable table + * Do the necessary work to setup local memory management of a new + * variable. * - * Used by CREATE VARIABLE command + * Caller should already have created the necessary entry in catalog + * and made them visible. */ -ObjectAddress -DefineSessionVariable(ParseState *pstate, CreateSessionVarStmt *stmt) +void +SessionVariableCreatePostprocess(Oid varid, char eoxaction) { - Oid namespaceid; - AclResult aclresult; - Oid typid; - int32 typmod; - Oid varowner = GetUserId(); - Oid collation; - Oid typcollation; - ObjectAddress variable; - - Node *cooked_default = NULL; - - /* - * Check consistency of arguments - */ - if (stmt->eoxaction == VARIABLE_EOX_DROP - && stmt->variable->relpersistence != RELPERSISTENCE_TEMP) - ereport(ERROR, - (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), - errmsg("ON COMMIT DROP can only be used on temporary variables"))); - - if (stmt->is_not_null && stmt->is_immutable && !stmt->defexpr) - ereport(ERROR, - (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), - errmsg("IMMUTABLE NOT NULL variable requires default expression"))); - - namespaceid = - RangeVarGetAndCheckCreationNamespace(stmt->variable, NoLock, NULL); - - typenameTypeIdAndMod(pstate, stmt->typeName, &typid, &typmod); - typcollation = get_typcollation(typid); - - aclresult = pg_type_aclcheck(typid, GetUserId(), ACL_USAGE); - if (aclresult != ACLCHECK_OK) - aclcheck_error_type(aclresult, typid); - - if (stmt->collClause) - collation = LookupCollation(pstate, - stmt->collClause->collname, - stmt->collClause->location); - else - collation = typcollation;; - - /* Complain if COLLATE is applied to an uncollatable type */ - if (OidIsValid(collation) && !OidIsValid(typcollation)) - ereport(ERROR, - (errcode(ERRCODE_DATATYPE_MISMATCH), - errmsg("collations are not supported by type %s", - format_type_be(typid)), - parser_errposition(pstate, stmt->collClause->location))); - - if (stmt->defexpr) - { - cooked_default = transformExpr(pstate, stmt->defexpr, - EXPR_KIND_VARIABLE_DEFAULT); - - cooked_default = coerce_to_specific_type(pstate, - cooked_default, typid, "DEFAULT"); - assign_expr_collations(pstate, cooked_default); - } - - variable = VariableCreate(stmt->variable->relname, - namespaceid, - typid, - typmod, - varowner, - collation, - cooked_default, - stmt->eoxaction, - stmt->is_not_null, - stmt->if_not_exists, - stmt->is_immutable); - - elog(DEBUG1, "record for session variable \"%s\" (oid:%d) was created in pg_variable", - stmt->variable->relname, variable.objectId); - /* * For temporary variables, we need to create a new end of xact action to * ensure deletion from catalog. */ - if (stmt->eoxaction == VARIABLE_EOX_DROP) + if (eoxaction == VARIABLE_EOX_DROP) { - Assert(isTempNamespace(namespaceid)); + Assert(isTempNamespace(get_session_variable_namespace(varid))); - register_session_variable_xact_action(variable.objectId, - SVAR_ON_COMMIT_DROP); + register_session_variable_xact_action(varid, SVAR_ON_COMMIT_DROP); } - - return variable; } /* - * Drop variable by OID. This routine doesn't try to remove - * the value of session variable immediately. It will be - * removed on transaction end in sync_sessionvars_xact_callback - * routine. This routine manipulate just with system catalog. + * Handle the local memory cleanup for a DROP VARIABLE command. + * + * Caller should take care of removing the pg_variable entry first. */ void -RemoveSessionVariable(Oid varid) +SessionVariableDropPostprocess(Oid varid) { - VariableDrop(varid); - /* - * We removed entry from catalog already, we must not do it again at end - * of xact time + * The entry was removed from catalog already, we must not do it + * again at end of xact time. */ unregister_session_variable_xact_action(varid, SVAR_ON_COMMIT_DROP); } diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c index 58f5c2b69c..0bba0ed480 100644 --- a/src/backend/tcop/utility.c +++ b/src/backend/tcop/utility.c @@ -1396,7 +1396,7 @@ ProcessUtilitySlow(ParseState *pstate, break; case T_CreateSessionVarStmt: - address = DefineSessionVariable(pstate, (CreateSessionVarStmt *) parsetree); + address = CreateVariable(pstate, (CreateSessionVarStmt *) parsetree); break; /* diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h index e75222f90c..cde36b0cea 100644 --- a/src/include/catalog/pg_variable.h +++ b/src/include/catalog/pg_variable.h @@ -112,21 +112,9 @@ typedef struct Variable Node *defexpr; } Variable; -extern void initVariable(Variable *var, - Oid varid, - bool fast_only); -extern ObjectAddress VariableCreate(const char *varName, - Oid varNamespace, - Oid varType, - int32 varTypmod, - Oid varOwner, - Oid varCollation, - Node *varDefexpr, - VariableEOXAction eoxaction, - bool is_not_null, - bool if_not_exists, - bool is_immutable); - -extern void VariableDrop(Oid varid); +extern ObjectAddress CreateVariable(ParseState *pstate, + CreateSessionVarStmt *stmt); +extern void DropVariable(Oid varid); +extern void InitVariable(Variable *var, Oid varid, bool fast_only); #endif /* PG_VARIABLE_H */ diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h index 0daf6f41ec..51934e8d1a 100644 --- a/src/include/commands/session_variable.h +++ b/src/include/commands/session_variable.h @@ -24,8 +24,8 @@ #include "utils/queryenvironment.h" extern void ResetSessionVariables(void); -extern void RemoveSessionVariable(Oid varid); -extern ObjectAddress DefineSessionVariable(ParseState *pstate, CreateSessionVarStmt *stmt); +extern void SessionVariableCreatePostprocess(Oid varid, char eoxaction); +extern void SessionVariableDropPostprocess(Oid varid); extern Datum CopySessionVariable(Oid varid, bool *isNull, Oid *typid); extern Datum CopySessionVariableWithTypeCheck(Oid varid, bool *isNull, Oid expected_typid); -- 2.37.0 --z3ntqfnlkpftg4xg Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename="v20220922-0003-session-variables.patch"