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pglogical_dependency.c
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pglogical_dependency.c
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/*-------------------------------------------------------------------------
*
* pglogical_dependency.c
* pglogical dependenct handling
*
* Most of the code here is taken from dependency.c as the dependency
* handling in postgres is sadly not extensible.
*
* See
*
* git diff REL_10_STABLE..REL_11_STABLE -- src/backend/catalog/dependency.c
*
* for version comparisons, but you can't apply directly as you must
* keep old-version compatibility.
*
* IDENTIFICATION
* pglogical_functions.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#if PG_VERSION_NUM >= 120000
#include "access/heapam.h"
#endif
#include "access/htup_details.h"
#include "access/xact.h"
#include "catalog/dependency.h"
#include "catalog/heap.h"
#include "catalog/index.h"
#include "catalog/objectaccess.h"
#include "catalog/pg_am.h"
#include "catalog/pg_amop.h"
#include "catalog/pg_amproc.h"
#include "catalog/pg_attrdef.h"
#include "catalog/pg_authid.h"
#include "catalog/pg_cast.h"
#include "catalog/pg_collation.h"
#if PG_VERSION_NUM < 110000
#include "catalog/pg_collation_fn.h"
#endif
#include "catalog/pg_constraint.h"
#include "catalog/pg_conversion.h"
#if PG_VERSION_NUM < 110000
#include "catalog/pg_conversion_fn.h"
#endif
#include "catalog/pg_database.h"
#include "catalog/pg_default_acl.h"
#include "catalog/pg_event_trigger.h"
#include "catalog/pg_extension.h"
#include "catalog/pg_foreign_data_wrapper.h"
#include "catalog/pg_foreign_server.h"
#include "catalog/pg_language.h"
#include "catalog/pg_largeobject.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_opclass.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_opfamily.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_rewrite.h"
#include "catalog/pg_tablespace.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_ts_config.h"
#include "catalog/pg_ts_dict.h"
#include "catalog/pg_ts_parser.h"
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
#include "commands/comment.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
#include "commands/extension.h"
#include "commands/proclang.h"
#include "commands/schemacmds.h"
#include "commands/seclabel.h"
#include "commands/trigger.h"
#include "commands/typecmds.h"
#include "nodes/nodeFuncs.h"
#include "parser/parsetree.h"
#include "rewrite/rewriteRemove.h"
#include "storage/lmgr.h"
#include "utils/fmgroids.h"
#include "utils/guc.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/syscache.h"
#if PG_VERSION_NUM < 120000
#include "utils/tqual.h"
#endif
#include "pglogical_dependency.h"
#include "pglogical_sync.h"
#include "pglogical_repset.h"
#include "pglogical.h"
#define CATALOG_REPSET_RELATION "depend"
typedef struct FormData_pglogical_depend
{
/*
* Identification of the dependent (referencing) object.
*
* These fields are all zeroes for a DEPENDENCY_PIN entry.
*/
Oid classid; /* OID of table containing object */
Oid objid; /* OID of object itself */
int32 objsubid; /* column number, or 0 if not used */
/*
* Identification of the independent (referenced) object.
*/
Oid refclassid; /* OID of table containing object */
Oid refobjid; /* OID of object itself */
int32 refobjsubid; /* column number, or 0 if not used */
/*
* Precise semantics of the relationship are specified by the deptype
* field. See DependencyType in catalog/dependency.h.
*/
char deptype; /* see codes in dependency.h */
} FormData_pglogical_depend;
typedef FormData_pglogical_depend *Form_pglogical_depend;
#define Natts_pglogical_depend 7
#define Anum_pglogical_depend_classid 1
#define Anum_pglogical_depend_objid 2
#define Anum_pglogical_depend_objsubid 3
#define Anum_pglogical_depend_refclassid 4
#define Anum_pglogical_depend_refobjid 5
#define Anum_pglogical_depend_refobjsubid 6
#define Anum_pglogical_depend_deptype 7
static Oid
get_pglogical_depend_rel_oid(void);
/*
* Deletion processing requires additional state for each ObjectAddress that
* it's planning to delete. For simplicity and code-sharing we make the
* ObjectAddresses code support arrays with or without this extra state.
*/
typedef struct
{
int flags; /* bitmask, see bit definitions below */
ObjectAddress dependee; /* object whose deletion forced this one */
} ObjectAddressExtra;
/* ObjectAddressExtra flag bits */
#define DEPFLAG_ORIGINAL 0x0001 /* an original deletion target */
#define DEPFLAG_NORMAL 0x0002 /* reached via normal dependency */
#define DEPFLAG_AUTO 0x0004 /* reached via auto dependency */
#define DEPFLAG_INTERNAL 0x0008 /* reached via internal dependency */
#define DEPFLAG_EXTENSION 0x0010 /* reached via extension dependency */
#define DEPFLAG_REVERSE 0x0020 /* reverse internal/extension link */
/* expansible list of ObjectAddresses */
struct ObjectAddresses
{
ObjectAddress *refs; /* => palloc'd array */
ObjectAddressExtra *extras; /* => palloc'd array, or NULL if not used */
int numrefs; /* current number of references */
int maxrefs; /* current size of palloc'd array(s) */
};
/* typedef ObjectAddresses appears in dependency.h */
/* threaded list of ObjectAddresses, for recursion detection */
typedef struct ObjectAddressStack
{
const ObjectAddress *object; /* object being visited */
int flags; /* its current flag bits */
struct ObjectAddressStack *next; /* next outer stack level */
} ObjectAddressStack;
/* for find_expr_references_walker */
typedef struct
{
ObjectAddresses *addrs; /* addresses being accumulated */
List *rtables; /* list of rangetables to resolve Vars */
} find_expr_references_context;
/*
* This constant table maps ObjectClasses to the corresponding catalog OIDs.
* See also getObjectClass().
*/
static const Oid object_classes[] = {
RelationRelationId, /* OCLASS_CLASS */
ProcedureRelationId, /* OCLASS_PROC */
TypeRelationId, /* OCLASS_TYPE */
CastRelationId, /* OCLASS_CAST */
CollationRelationId, /* OCLASS_COLLATION */
ConstraintRelationId, /* OCLASS_CONSTRAINT */
ConversionRelationId, /* OCLASS_CONVERSION */
AttrDefaultRelationId, /* OCLASS_DEFAULT */
LanguageRelationId, /* OCLASS_LANGUAGE */
LargeObjectRelationId, /* OCLASS_LARGEOBJECT */
OperatorRelationId, /* OCLASS_OPERATOR */
OperatorClassRelationId, /* OCLASS_OPCLASS */
OperatorFamilyRelationId, /* OCLASS_OPFAMILY */
AccessMethodRelationId, /* OCLASS_AM */
AccessMethodOperatorRelationId, /* OCLASS_AMOP */
AccessMethodProcedureRelationId, /* OCLASS_AMPROC */
RewriteRelationId, /* OCLASS_REWRITE */
TriggerRelationId, /* OCLASS_TRIGGER */
NamespaceRelationId, /* OCLASS_SCHEMA */
TSParserRelationId, /* OCLASS_TSPARSER */
TSDictionaryRelationId, /* OCLASS_TSDICT */
TSTemplateRelationId, /* OCLASS_TSTEMPLATE */
TSConfigRelationId, /* OCLASS_TSCONFIG */
AuthIdRelationId, /* OCLASS_ROLE */
DatabaseRelationId, /* OCLASS_DATABASE */
TableSpaceRelationId, /* OCLASS_TBLSPACE */
ForeignDataWrapperRelationId, /* OCLASS_FDW */
ForeignServerRelationId, /* OCLASS_FOREIGN_SERVER */
UserMappingRelationId, /* OCLASS_USER_MAPPING */
DefaultAclRelationId, /* OCLASS_DEFACL */
ExtensionRelationId, /* OCLASS_EXTENSION */
EventTriggerRelationId, /* OCLASS_EVENT_TRIGGER */
// PolicyRelationId, /* OCLASS_POLICY */
// TransformRelationId /* OCLASS_TRANSFORM */
};
static void findDependentObjects(const ObjectAddress *object,
int flags,
ObjectAddressStack *stack,
ObjectAddresses *targetObjects,
const ObjectAddresses *pendingObjects,
Relation *depRel);
static void reportDependentObjects(const ObjectAddresses *targetObjects,
DropBehavior behavior,
int msglevel,
const ObjectAddress *origObject);
static void PGLAcquireDeletionLock(const ObjectAddress *object, int flags);
static void PGLReleaseDeletionLock(const ObjectAddress *object);
static bool find_expr_references_walker(Node *node,
find_expr_references_context *context);
static void eliminate_duplicate_dependencies(ObjectAddresses *addrs);
static int object_address_comparator(const void *a, const void *b);
static void add_object_address(ObjectClass oclass, Oid objectId, int32 subId,
ObjectAddresses *addrs);
static void add_exact_object_address_extra(const ObjectAddress *object,
const ObjectAddressExtra *extra,
ObjectAddresses *addrs);
static bool object_address_present_add_flags(const ObjectAddress *object,
int flags,
ObjectAddresses *addrs);
static bool stack_address_present_add_flags(const ObjectAddress *object,
int flags,
ObjectAddressStack *stack);
static void deleteOneObjectDepencencyRecord(const ObjectAddress *object, Relation *depRel);
static void deleteOneObject(const ObjectAddress *object, Relation *depRel);
static void doDeletion(const ObjectAddress *object);
static char *pglogical_getObjectDescription(const ObjectAddress *object);
/*
* Go through the objects given running the final actions on them, and execute
* the actual deletion.
*/
static void
deleteObjectsInList(ObjectAddresses *targetObjects, Relation *depRel)
{
int i;
/*
* Delete all the objects in the proper order.
*/
for (i = 0; i < targetObjects->numrefs; i++)
{
ObjectAddress *thisobj = targetObjects->refs + i;
deleteOneObject(thisobj, depRel);
}
}
/*
* Record a dependency between 2 objects via their respective objectAddress.
* The first argument is the dependent object, the second the one it
* references.
*
* This simply creates an entry in pglogical_depend, without any other processing.
*/
void
pglogical_recordDependencyOn(const ObjectAddress *depender,
const ObjectAddress *referenced,
DependencyType behavior)
{
pglogical_recordMultipleDependencies(depender, referenced, 1, behavior);
}
/*
* Record multiple dependencies (of the same kind) for a single dependent
* object. This has a little less overhead than recording each separately.
*/
void
pglogical_recordMultipleDependencies(const ObjectAddress *depender,
const ObjectAddress *referenced,
int nreferenced,
DependencyType behavior)
{
Relation dependDesc;
HeapTuple tup;
int i;
bool nulls[Natts_pglogical_depend];
Datum values[Natts_pglogical_depend];
if (nreferenced <= 0)
return; /* nothing to do */
dependDesc = table_open(get_pglogical_depend_rel_oid(),
RowExclusiveLock);
memset(nulls, false, sizeof(nulls));
for (i = 0; i < nreferenced; i++, referenced++)
{
/*
* Record the Dependency. Note we don't bother to check for
* duplicate dependencies; there's no harm in them.
*/
values[Anum_pglogical_depend_classid - 1] = ObjectIdGetDatum(depender->classId);
values[Anum_pglogical_depend_objid - 1] = ObjectIdGetDatum(depender->objectId);
values[Anum_pglogical_depend_objsubid - 1] = Int32GetDatum(depender->objectSubId);
values[Anum_pglogical_depend_refclassid - 1] = ObjectIdGetDatum(referenced->classId);
values[Anum_pglogical_depend_refobjid - 1] = ObjectIdGetDatum(referenced->objectId);
values[Anum_pglogical_depend_refobjsubid - 1] = Int32GetDatum(referenced->objectSubId);
values[Anum_pglogical_depend_deptype - 1] = CharGetDatum((char) behavior);
tup = heap_form_tuple(dependDesc->rd_att, values, nulls);
CatalogTupleInsert(dependDesc, tup);
heap_freetuple(tup);
}
table_close(dependDesc, RowExclusiveLock);
}
/*
* findDependentObjects - find all objects that depend on 'object'
*
* For every object that depends on the starting object, acquire a deletion
* lock on the object, add it to targetObjects (if not already there),
* and recursively find objects that depend on it. An object's dependencies
* will be placed into targetObjects before the object itself; this means
* that the finished list's order represents a safe deletion order.
*
* The caller must already have a deletion lock on 'object' itself,
* but must not have added it to targetObjects. (Note: there are corner
* cases where we won't add the object either, and will also release the
* caller-taken lock. This is a bit ugly, but the API is set up this way
* to allow easy rechecking of an object's liveness after we lock it. See
* notes within the function.)
*
* When dropping a whole object (subId = 0), we find dependencies for
* its sub-objects too.
*
* object: the object to add to targetObjects and find dependencies on
* flags: flags to be ORed into the object's targetObjects entry
* stack: list of objects being visited in current recursion; topmost item
* is the object that we recursed from (NULL for external callers)
* targetObjects: list of objects that are scheduled to be deleted
* pendingObjects: list of other objects slated for destruction, but
* not necessarily in targetObjects yet (can be NULL if none)
* *depRel: already opened pglogical_depend relation
*/
static void
findDependentObjects(const ObjectAddress *object,
int flags,
ObjectAddressStack *stack,
ObjectAddresses *targetObjects,
const ObjectAddresses *pendingObjects,
Relation *depRel)
{
ScanKeyData key[3];
int nkeys;
SysScanDesc scan;
HeapTuple tup;
ObjectAddress otherObject;
ObjectAddressStack mystack;
ObjectAddressExtra extra;
/*
* If the target object is already being visited in an outer recursion
* level, just report the current flags back to that level and exit. This
* is needed to avoid infinite recursion in the face of circular
* dependencies.
*
* The stack check alone would result in dependency loops being broken at
* an arbitrary point, ie, the first member object of the loop to be
* visited is the last one to be deleted. This is obviously unworkable.
* However, the check for internal dependency below guarantees that we
* will not break a loop at an internal dependency: if we enter the loop
* at an "owned" object we will switch and start at the "owning" object
* instead. We could probably hack something up to avoid breaking at an
* auto dependency, too, if we had to. However there are no known cases
* where that would be necessary.
*/
if (stack_address_present_add_flags(object, flags, stack))
return;
/*
* It's also possible that the target object has already been completely
* processed and put into targetObjects. If so, again we just add the
* specified flags to its entry and return.
*
* (Note: in these early-exit cases we could release the caller-taken
* lock, since the object is presumably now locked multiple times; but it
* seems not worth the cycles.)
*/
if (object_address_present_add_flags(object, flags, targetObjects))
return;
/*
* The target object might be internally dependent on some other object
* (its "owner"), and/or be a member of an extension (also considered its
* owner). If so, and if we aren't recursing from the owning object, we
* have to transform this deletion request into a deletion request of the
* owning object. (We'll eventually recurse back to this object, but the
* owning object has to be visited first so it will be deleted after.) The
* way to find out about this is to scan the pglogical_depend entries that show
* what this object depends on.
*/
ScanKeyInit(&key[0],
Anum_pglogical_depend_classid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(object->classId));
ScanKeyInit(&key[1],
Anum_pglogical_depend_objid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(object->objectId));
if (object->objectSubId != 0)
{
ScanKeyInit(&key[2],
Anum_pglogical_depend_objsubid,
BTEqualStrategyNumber, F_INT4EQ,
Int32GetDatum(object->objectSubId));
nkeys = 3;
}
else
nkeys = 2;
scan = systable_beginscan(*depRel, InvalidOid, false,
NULL, nkeys, key);
while (HeapTupleIsValid(tup = systable_getnext(scan)))
{
Form_pglogical_depend foundDep = (Form_pglogical_depend) GETSTRUCT(tup);
otherObject.classId = foundDep->refclassid;
otherObject.objectId = foundDep->refobjid;
otherObject.objectSubId = foundDep->refobjsubid;
switch (foundDep->deptype)
{
case DEPENDENCY_NORMAL:
case DEPENDENCY_AUTO:
#if PG_VERSION_NUM >= 90600
case DEPENDENCY_AUTO_EXTENSION:
#endif
/* no problem */
break;
#if PG_VERSION_NUM >= 110000 && PG_VERSION_NUM < 120000
case DEPENDENCY_INTERNAL_AUTO:
#endif
case DEPENDENCY_INTERNAL:
case DEPENDENCY_EXTENSION:
/*
* This object is part of the internal implementation of
* another object, or is part of the extension that is the
* other object. We have three cases:
*
* 1. At the outermost recursion level, we normally disallow
* the DROP. (We just ereport here, rather than proceeding,
* since no other dependencies are likely to be interesting.)
* However, there are exceptions.
*/
if (stack == NULL)
{
char *otherObjDesc;
/*
* Exception 1a: if the owning object is listed in
* pendingObjects, just release the caller's lock and
* return. We'll eventually complete the DROP when we
* reach that entry in the pending list.
*/
if (pendingObjects &&
object_address_present(&otherObject, pendingObjects))
{
systable_endscan(scan);
/* need to release caller's lock; see notes below */
PGLReleaseDeletionLock(object);
return;
}
/*
* Exception 1b: if the owning object is the extension
* currently being created/altered, it's okay to continue
* with the deletion. This allows dropping of an
* extension's objects within the extension's scripts, as
* well as corner cases such as dropping a transient
* object created within such a script.
*
* Note that pglogical currently does not care about
* extension dependencies and CurrentExtensionObject is
* not PGDLLIMPORTed so we relax this and just skip any
* extension dependencies.
*/
if (creating_extension &&
otherObject.classId == ExtensionRelationId /*&&
otherObject.objectId == CurrentExtensionObject*/)
break;
/* No exception applies, so throw the error */
otherObjDesc = pglogical_getObjectDescription(&otherObject);
ereport(ERROR,
(errcode(ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST),
errmsg("cannot drop %s because %s requires it",
pglogical_getObjectDescription(object),
otherObjDesc),
errhint("You can drop %s instead.",
otherObjDesc)));
}
/*
* 2. When recursing from the other end of this dependency,
* it's okay to continue with the deletion. This holds when
* recursing from a whole object that includes the nominal
* other end as a component, too. Since there can be more
* than one "owning" object, we have to allow matches that are
* more than one level down in the stack.
*/
if (stack_address_present_add_flags(&otherObject, 0, stack))
break;
/*
* 3. Not all the owning objects have been visited, so
* transform this deletion request into a delete of this
* owning object.
*
* For INTERNAL_AUTO dependencies, we don't enforce this; in
* other words, we don't follow the links back to the owning
* object.
*/
#if PG_VERSION_NUM >= 110000 && PG_VERSION_NUM < 120000
if (foundDep->deptype == DEPENDENCY_INTERNAL_AUTO)
break;
#endif
/*
* First, release caller's lock on this object and get
* deletion lock on the owning object. (We must release
* caller's lock to avoid deadlock against a concurrent
* deletion of the owning object.)
*/
PGLReleaseDeletionLock(object);
PGLAcquireDeletionLock(&otherObject, 0);
/*
* The owning object might have been deleted while we waited
* to lock it; if so, neither it nor the current object are
* interesting anymore. We test this by checking the
* pglogical_depend entry (see notes below).
*/
if (!systable_recheck_tuple(scan, tup))
{
systable_endscan(scan);
PGLReleaseDeletionLock(&otherObject);
return;
}
/*
* Okay, recurse to the owning object instead of proceeding.
*
* We do not need to stack the current object; we want the
* traversal order to be as if the original reference had
* linked to the owning object instead of this one.
*
* The dependency type is a "reverse" dependency: we need to
* delete the owning object if this one is to be deleted, but
* this linkage is never a reason for an automatic deletion.
*/
findDependentObjects(&otherObject,
DEPFLAG_REVERSE,
stack,
targetObjects,
pendingObjects,
depRel);
/* And we're done here. */
systable_endscan(scan);
return;
#if PG_VERSION_NUM < 150000
case DEPENDENCY_PIN:
/*
* Should not happen; PIN dependencies should have zeroes in
* the depender fields...
*/
elog(ERROR, "incorrect use of PIN dependency with %s",
pglogical_getObjectDescription(object));
break;
#endif
default:
elog(ERROR, "unrecognized dependency type '%c' for %s",
foundDep->deptype, pglogical_getObjectDescription(object));
break;
}
}
systable_endscan(scan);
/*
* Now recurse to any dependent objects. We must visit them first since
* they have to be deleted before the current object.
*/
mystack.object = object; /* set up a new stack level */
mystack.flags = flags;
mystack.next = stack;
ScanKeyInit(&key[0],
Anum_pglogical_depend_refclassid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(object->classId));
ScanKeyInit(&key[1],
Anum_pglogical_depend_refobjid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(object->objectId));
if (object->objectSubId != 0)
{
ScanKeyInit(&key[2],
Anum_pglogical_depend_refobjsubid,
BTEqualStrategyNumber, F_INT4EQ,
Int32GetDatum(object->objectSubId));
nkeys = 3;
}
else
nkeys = 2;
scan = systable_beginscan(*depRel, InvalidOid, false,
NULL, nkeys, key);
while (HeapTupleIsValid(tup = systable_getnext(scan)))
{
Form_pglogical_depend foundDep = (Form_pglogical_depend) GETSTRUCT(tup);
int subflags;
otherObject.classId = foundDep->classid;
otherObject.objectId = foundDep->objid;
otherObject.objectSubId = foundDep->objsubid;
/*
* Must lock the dependent object before recursing to it.
*/
PGLAcquireDeletionLock(&otherObject, 0);
/*
* The dependent object might have been deleted while we waited to
* lock it; if so, we don't need to do anything more with it. We can
* test this cheaply and independently of the object's type by seeing
* if the pglogical_depend tuple we are looking at is still live. (If the
* object got deleted, the tuple would have been deleted too.)
*/
if (!systable_recheck_tuple(scan, tup))
{
/* release the now-useless lock */
PGLReleaseDeletionLock(&otherObject);
/* and continue scanning for dependencies */
continue;
}
/* Recurse, passing flags indicating the dependency type */
switch (foundDep->deptype)
{
case DEPENDENCY_NORMAL:
subflags = DEPFLAG_NORMAL;
break;
case DEPENDENCY_AUTO:
#if PG_VERSION_NUM >= 90600
case DEPENDENCY_AUTO_EXTENSION:
subflags = DEPFLAG_AUTO;
break;
#endif
case DEPENDENCY_INTERNAL:
#if PG_VERSION_NUM >= 110000 && PG_VERSION_NUM < 120000
case DEPENDENCY_INTERNAL_AUTO:
#endif
subflags = DEPFLAG_INTERNAL;
break;
case DEPENDENCY_EXTENSION:
subflags = DEPFLAG_EXTENSION;
break;
#if PG_VERSION_NUM < 150000
case DEPENDENCY_PIN:
/*
* For a PIN dependency we just ereport immediately; there
* won't be any others to report.
*/
ereport(ERROR,
(errcode(ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST),
errmsg("cannot drop %s because it is required by the database system",
pglogical_getObjectDescription(object))));
subflags = 0; /* keep compiler quiet */
break;
#endif
default:
elog(ERROR, "unrecognized dependency type '%c' for %s",
foundDep->deptype, pglogical_getObjectDescription(object));
subflags = 0; /* keep compiler quiet */
break;
}
findDependentObjects(&otherObject,
subflags,
&mystack,
targetObjects,
pendingObjects,
depRel);
}
systable_endscan(scan);
/*
* Finally, we can add the target object to targetObjects. Be careful to
* include any flags that were passed back down to us from inner recursion
* levels.
*/
extra.flags = mystack.flags;
if (stack)
extra.dependee = *stack->object;
else
memset(&extra.dependee, 0, sizeof(extra.dependee));
add_exact_object_address_extra(object, &extra, targetObjects);
}
/*
* reportDependentObjects - report about dependencies, and fail if RESTRICT
*
* Tell the user about dependent objects that we are going to delete
* (or would need to delete, but are prevented by RESTRICT mode);
* then error out if there are any and it's not CASCADE mode.
*
* targetObjects: list of objects that are scheduled to be deleted
* behavior: RESTRICT or CASCADE
* msglevel: elog level for non-error report messages
* origObject: base object of deletion, or NULL if not available
* (the latter case occurs in DROP OWNED)
*/
static void
reportDependentObjects(const ObjectAddresses *targetObjects,
DropBehavior behavior,
int msglevel,
const ObjectAddress *origObject)
{
bool ok = true;
StringInfoData clientdetail;
StringInfoData logdetail;
int numReportedClient = 0;
int numNotReportedClient = 0;
int i;
int my_client_min_messages;
int my_log_min_messages;
/*
* This is cludge for Windows (Postgres des not define the GUC variables
* as PGDDLIMPORT)
*/
my_client_min_messages = atoi(GetConfigOptionByName("client_min_messages",
NULL, false));
my_log_min_messages = atoi(GetConfigOptionByName("log_min_messages",
NULL, false));
/*
* If no error is to be thrown, and the msglevel is too low to be shown to
* either client or server log, there's no need to do any of the work.
*
* Note: this code doesn't know all there is to be known about elog
* levels, but it works for NOTICE and DEBUG2, which are the only values
* msglevel can currently have. We also assume we are running in a normal
* operating environment.
*/
if (behavior == DROP_CASCADE &&
msglevel < my_client_min_messages &&
(msglevel < my_log_min_messages || my_log_min_messages == LOG))
return;
/*
* We limit the number of dependencies reported to the client to
* MAX_REPORTED_DEPS, since client software may not deal well with
* enormous error strings. The server log always gets a full report.
*/
#define MAX_REPORTED_DEPS 100
initStringInfo(&clientdetail);
initStringInfo(&logdetail);
/*
* We process the list back to front (ie, in dependency order not deletion
* order), since this makes for a more understandable display.
*/
for (i = targetObjects->numrefs - 1; i >= 0; i--)
{
const ObjectAddress *obj = &targetObjects->refs[i];
const ObjectAddressExtra *extra = &targetObjects->extras[i];
char *objDesc;
/* Ignore the original deletion target(s) */
if (extra->flags & DEPFLAG_ORIGINAL)
continue;
objDesc = pglogical_getObjectDescription(obj);
/*
* If, at any stage of the recursive search, we reached the object via
* an AUTO, INTERNAL, or EXTENSION dependency, then it's okay to
* delete it even in RESTRICT mode.
*/
if (extra->flags & (DEPFLAG_AUTO |
DEPFLAG_INTERNAL |
DEPFLAG_EXTENSION))
{
/*
* auto-cascades are reported at DEBUG2, not msglevel. We don't
* try to combine them with the regular message because the
* results are too confusing when client_min_messages and
* log_min_messages are different.
*/
ereport(DEBUG2,
(errmsg("drop auto-cascades to %s",
objDesc)));
}
else if (behavior == DROP_RESTRICT)
{
char *otherDesc = pglogical_getObjectDescription(&extra->dependee);
if (numReportedClient < MAX_REPORTED_DEPS)
{
/* separate entries with a newline */
if (clientdetail.len != 0)
appendStringInfoChar(&clientdetail, '\n');
appendStringInfo(&clientdetail, _("%s depends on %s"),
objDesc, otherDesc);
numReportedClient++;
}
else
numNotReportedClient++;
/* separate entries with a newline */
if (logdetail.len != 0)
appendStringInfoChar(&logdetail, '\n');
appendStringInfo(&logdetail, _("%s depends on %s"),
objDesc, otherDesc);
pfree(otherDesc);
ok = false;
}
else
{
if (numReportedClient < MAX_REPORTED_DEPS)
{
/* separate entries with a newline */
if (clientdetail.len != 0)
appendStringInfoChar(&clientdetail, '\n');
appendStringInfo(&clientdetail, _("drop cascades to %s"),
objDesc);
numReportedClient++;
}
else
numNotReportedClient++;
/* separate entries with a newline */
if (logdetail.len != 0)
appendStringInfoChar(&logdetail, '\n');
appendStringInfo(&logdetail, _("drop cascades to %s"),
objDesc);
}
pfree(objDesc);
}
if (numNotReportedClient > 0)
appendStringInfo(&clientdetail, ngettext("\nand %d other object "
"(see server log for list)",
"\nand %d other objects "
"(see server log for list)",
numNotReportedClient),
numNotReportedClient);
if (!ok)
{
if (origObject)
ereport(ERROR,
(errcode(ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST),
errmsg("cannot drop %s because other objects depend on it",
pglogical_getObjectDescription(origObject)),
errdetail("%s", clientdetail.data),
errdetail_log("%s", logdetail.data),
errhint("Use DROP ... CASCADE to drop the dependent objects too.")));
else
ereport(ERROR,
(errcode(ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST),
errmsg("cannot drop desired object(s) because other objects depend on them"),
errdetail("%s", clientdetail.data),
errdetail_log("%s", logdetail.data),
errhint("Use DROP ... CASCADE to drop the dependent objects too.")));
}
else if (numReportedClient > 1)
{
ereport(msglevel,
/* translator: %d always has a value larger than 1 */
(errmsg_plural("drop cascades to %d other object",
"drop cascades to %d other objects",
numReportedClient + numNotReportedClient,
numReportedClient + numNotReportedClient),
errdetail("%s", clientdetail.data),
errdetail_log("%s", logdetail.data)));
}
else if (numReportedClient == 1)
{
/* we just use the single item as-is */
ereport(msglevel,
(errmsg_internal("%s", clientdetail.data)));
}
pfree(clientdetail.data);
pfree(logdetail.data);
}
/*
* PGLAcquireDeletionLock - acquire a suitable lock for deleting an object
*
* We use LockRelation for relations, LockDatabaseObject for everything
* else. Note that dependency.c is not concerned with deleting any kind of
* shared-across-databases object, so we have no need for LockSharedObject.
*/
static void
PGLAcquireDeletionLock(const ObjectAddress *object, int flags)
{
if (object->classId == RelationRelationId)
{
/*
* In DROP INDEX CONCURRENTLY, take only ShareUpdateExclusiveLock on
* the index for the moment. index_drop() will promote the lock once
* it's safe to do so. In all other cases we need full exclusive
* lock.
*/
if (flags & PERFORM_DELETION_CONCURRENTLY)
LockRelationOid(object->objectId, ShareUpdateExclusiveLock);
else
LockRelationOid(object->objectId, AccessExclusiveLock);
}
else
{
/* assume we should lock the whole object not a sub-object */
LockDatabaseObject(object->classId, object->objectId, 0,
AccessExclusiveLock);
}
}
/*
* PGLReleaseDeletionLock - release an object deletion lock
*/
static void
PGLReleaseDeletionLock(const ObjectAddress *object)
{
if (object->classId == RelationRelationId)
UnlockRelationOid(object->objectId, AccessExclusiveLock);
else
/* assume we should lock the whole object not a sub-object */
UnlockDatabaseObject(object->classId, object->objectId, 0,
AccessExclusiveLock);
}
/*
* recordDependencyOnSingleRelExpr - find expression dependencies
*
* As above, but only one relation is expected to be referenced (with
* varno = 1 and varlevelsup = 0). Pass the relation OID instead of a
* range table. An additional frammish is that dependencies on that
* relation (or its component columns) will be marked with 'self_behavior',
* whereas 'behavior' is used for everything else.
*
* NOTE: the caller should ensure that a whole-table dependency on the
* specified relation is created separately, if one is needed. In particular,
* a whole-row Var "relation.*" will not cause this routine to emit any
* dependency item. This is appropriate behavior for subexpressions of an
* ordinary query, so other cases need to cope as necessary.
*/
void
pglogical_recordDependencyOnSingleRelExpr(const ObjectAddress *depender,
Node *expr, Oid relId,
DependencyType behavior,
DependencyType self_behavior)
{