pg_subscription.c File Reference

#include "postgres.h"
#include "access/genam.h"
#include "access/heapam.h"
#include "access/htup_details.h"
#include "access/tableam.h"
#include "access/xact.h"
#include "catalog/indexing.h"
#include "catalog/pg_subscription.h"
#include "catalog/pg_subscription_rel.h"
#include "catalog/pg_type.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "storage/lmgr.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/pg_lsn.h"
#include "utils/rel.h"
#include "utils/syscache.h"

Include dependency graph for pg_subscription.c:

Go to the source code of this file.

Functions
static List *	textarray_to_stringlist (ArrayType *textarray)
Subscription *	GetSubscription (Oid subid, bool missing_ok)
int	CountDBSubscriptions (Oid dbid)
void	FreeSubscription (Subscription *sub)
void	DisableSubscription (Oid subid)
void	AddSubscriptionRelState (Oid subid, Oid relid, char state, XLogRecPtr sublsn)
void	UpdateSubscriptionRelState (Oid subid, Oid relid, char state, XLogRecPtr sublsn)
char	GetSubscriptionRelState (Oid subid, Oid relid, XLogRecPtr *sublsn)
void	RemoveSubscriptionRel (Oid subid, Oid relid)
bool	HasSubscriptionRelations (Oid subid)
List *	GetSubscriptionRelations (Oid subid, bool not_ready)

Function Documentation

AddSubscriptionRelState()

void AddSubscriptionRelState	(	Oid	subid,
		Oid	relid,
		char	state,
		XLogRecPtr	sublsn
	)

Definition at line 233 of file pg_subscription.c.

{
    Relation    rel;
    HeapTuple   tup;
    bool        nulls[Natts_pg_subscription_rel];
    Datum       values[Natts_pg_subscription_rel];
 
    LockSharedObject(SubscriptionRelationId, subid, 0, AccessShareLock);
 
    rel = table_open(SubscriptionRelRelationId, RowExclusiveLock);
 
    /* Try finding existing mapping. */
    tup = SearchSysCacheCopy2(SUBSCRIPTIONRELMAP,
                              ObjectIdGetDatum(relid),
                              ObjectIdGetDatum(subid));
    if (HeapTupleIsValid(tup))
        elog(ERROR, "subscription table %u in subscription %u already exists",
             relid, subid);
 
    /* Form the tuple. */
    memset(values, 0, sizeof(values));
    memset(nulls, false, sizeof(nulls));
    values[Anum_pg_subscription_rel_srsubid - 1] = ObjectIdGetDatum(subid);
    values[Anum_pg_subscription_rel_srrelid - 1] = ObjectIdGetDatum(relid);
    values[Anum_pg_subscription_rel_srsubstate - 1] = CharGetDatum(state);
    if (sublsn != InvalidXLogRecPtr)
        values[Anum_pg_subscription_rel_srsublsn - 1] = LSNGetDatum(sublsn);
    else
        nulls[Anum_pg_subscription_rel_srsublsn - 1] = true;
 
    tup = heap_form_tuple(RelationGetDescr(rel), values, nulls);
 
    /* Insert tuple into catalog. */
    CatalogTupleInsert(rel, tup);
 
    heap_freetuple(tup);
 
    /* Cleanup. */
    table_close(rel, NoLock);
}

References AccessShareLock, CatalogTupleInsert(), CharGetDatum(), elog(), ERROR, heap_form_tuple(), heap_freetuple(), HeapTupleIsValid, InvalidXLogRecPtr, LockSharedObject(), LSNGetDatum(), NoLock, ObjectIdGetDatum(), RelationGetDescr, RowExclusiveLock, SearchSysCacheCopy2, SUBSCRIPTIONRELMAP, table_close(), table_open(), and values.

Referenced by AlterSubscription_refresh(), and CreateSubscription().

CountDBSubscriptions()

int CountDBSubscriptions

(

Oid

dbid

)

Definition at line 124 of file pg_subscription.c.

{
    int         nsubs = 0;
    Relation    rel;
    ScanKeyData scankey;
    SysScanDesc scan;
    HeapTuple   tup;
 
    rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
    ScanKeyInit(&scankey,
                Anum_pg_subscription_subdbid,
                BTEqualStrategyNumber, F_OIDEQ,
                ObjectIdGetDatum(dbid));
 
    scan = systable_beginscan(rel, InvalidOid, false,
                              NULL, 1, &scankey);
 
    while (HeapTupleIsValid(tup = systable_getnext(scan)))
        nsubs++;
 
    systable_endscan(scan);
 
    table_close(rel, NoLock);
 
    return nsubs;
}

References BTEqualStrategyNumber, HeapTupleIsValid, InvalidOid, NoLock, ObjectIdGetDatum(), RowExclusiveLock, ScanKeyInit(), systable_beginscan(), systable_endscan(), systable_getnext(), table_close(), and table_open().

Referenced by dropdb().

DisableSubscription()

void DisableSubscription

(

Oid

subid

)

Definition at line 170 of file pg_subscription.c.

{
    Relation    rel;
    bool        nulls[Natts_pg_subscription];
    bool        replaces[Natts_pg_subscription];
    Datum       values[Natts_pg_subscription];
    HeapTuple   tup;
 
    /* Look up the subscription in the catalog */
    rel = table_open(SubscriptionRelationId, RowExclusiveLock);
    tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
 
    if (!HeapTupleIsValid(tup))
        elog(ERROR, "cache lookup failed for subscription %u", subid);
 
    LockSharedObject(SubscriptionRelationId, subid, 0, AccessShareLock);
 
    /* Form a new tuple. */
    memset(values, 0, sizeof(values));
    memset(nulls, false, sizeof(nulls));
    memset(replaces, false, sizeof(replaces));
 
    /* Set the subscription to disabled. */
    values[Anum_pg_subscription_subenabled - 1] = BoolGetDatum(false);
    replaces[Anum_pg_subscription_subenabled - 1] = true;
 
    /* Update the catalog */
    tup = heap_modify_tuple(tup, RelationGetDescr(rel), values, nulls,
                            replaces);
    CatalogTupleUpdate(rel, &tup->t_self, tup);
    heap_freetuple(tup);
 
    table_close(rel, NoLock);
}

References AccessShareLock, BoolGetDatum(), CatalogTupleUpdate(), elog(), ERROR, heap_freetuple(), heap_modify_tuple(), HeapTupleIsValid, LockSharedObject(), NoLock, ObjectIdGetDatum(), RelationGetDescr, RowExclusiveLock, SearchSysCacheCopy1, SUBSCRIPTIONOID, HeapTupleData::t_self, table_close(), table_open(), and values.

Referenced by DisableSubscriptionAndExit().

FreeSubscription()

void FreeSubscription

(

Subscription *

sub

)

Definition at line 156 of file pg_subscription.c.

{
    pfree(sub->name);
    pfree(sub->conninfo);
    if (sub->slotname)
        pfree(sub->slotname);
    list_free_deep(sub->publications);
    pfree(sub);
}

References Subscription::conninfo, list_free_deep(), Subscription::name, pfree(), Subscription::publications, and Subscription::slotname.

Referenced by maybe_reread_subscription().

GetSubscription()

Subscription* GetSubscription	(	Oid	subid,
		bool	missing_ok
	)

Definition at line 43 of file pg_subscription.c.

{
    HeapTuple   tup;
    Subscription *sub;
    Form_pg_subscription subform;
    Datum       datum;
    bool        isnull;
 
    tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
 
    if (!HeapTupleIsValid(tup))
    {
        if (missing_ok)
            return NULL;
 
        elog(ERROR, "cache lookup failed for subscription %u", subid);
    }
 
    subform = (Form_pg_subscription) GETSTRUCT(tup);
 
    sub = (Subscription *) palloc(sizeof(Subscription));
    sub->oid = subid;
    sub->dbid = subform->subdbid;
    sub->skiplsn = subform->subskiplsn;
    sub->name = pstrdup(NameStr(subform->subname));
    sub->owner = subform->subowner;
    sub->enabled = subform->subenabled;
    sub->binary = subform->subbinary;
    sub->stream = subform->substream;
    sub->twophasestate = subform->subtwophasestate;
    sub->disableonerr = subform->subdisableonerr;
    sub->passwordrequired = subform->subpasswordrequired;
    sub->runasowner = subform->subrunasowner;
 
    /* Get conninfo */
    datum = SysCacheGetAttrNotNull(SUBSCRIPTIONOID,
                                   tup,
                                   Anum_pg_subscription_subconninfo);
    sub->conninfo = TextDatumGetCString(datum);
 
    /* Get slotname */
    datum = SysCacheGetAttr(SUBSCRIPTIONOID,
                            tup,
                            Anum_pg_subscription_subslotname,
                            &isnull);
    if (!isnull)
        sub->slotname = pstrdup(NameStr(*DatumGetName(datum)));
    else
        sub->slotname = NULL;
 
    /* Get synccommit */
    datum = SysCacheGetAttrNotNull(SUBSCRIPTIONOID,
                                   tup,
                                   Anum_pg_subscription_subsynccommit);
    sub->synccommit = TextDatumGetCString(datum);
 
    /* Get publications */
    datum = SysCacheGetAttrNotNull(SUBSCRIPTIONOID,
                                   tup,
                                   Anum_pg_subscription_subpublications);
    sub->publications = textarray_to_stringlist(DatumGetArrayTypeP(datum));
 
    /* Get origin */
    datum = SysCacheGetAttrNotNull(SUBSCRIPTIONOID,
                                   tup,
                                   Anum_pg_subscription_suborigin);
    sub->origin = TextDatumGetCString(datum);
 
    /* Is the subscription owner a superuser? */
    sub->ownersuperuser = superuser_arg(sub->owner);
 
    ReleaseSysCache(tup);
 
    return sub;
}

References Subscription::binary, Subscription::conninfo, DatumGetArrayTypeP, DatumGetName(), Subscription::dbid, Subscription::disableonerr, elog(), Subscription::enabled, ERROR, GETSTRUCT, HeapTupleIsValid, Subscription::name, NameStr, ObjectIdGetDatum(), Subscription::oid, Subscription::origin, Subscription::owner, Subscription::ownersuperuser, palloc(), Subscription::passwordrequired, pstrdup(), Subscription::publications, ReleaseSysCache(), Subscription::runasowner, SearchSysCache1(), Subscription::skiplsn, Subscription::slotname, Subscription::stream, SUBSCRIPTIONOID, superuser_arg(), Subscription::synccommit, SysCacheGetAttr(), SysCacheGetAttrNotNull(), textarray_to_stringlist(), TextDatumGetCString, and Subscription::twophasestate.

Referenced by AlterSubscription(), InitializeLogRepWorker(), and maybe_reread_subscription().

GetSubscriptionRelations()

List* GetSubscriptionRelations	(	Oid	subid,
		bool	not_ready
	)

Definition at line 490 of file pg_subscription.c.

{
    List       *res = NIL;
    Relation    rel;
    HeapTuple   tup;
    int         nkeys = 0;
    ScanKeyData skey[2];
    SysScanDesc scan;
 
    rel = table_open(SubscriptionRelRelationId, AccessShareLock);
 
    ScanKeyInit(&skey[nkeys++],
                Anum_pg_subscription_rel_srsubid,
                BTEqualStrategyNumber, F_OIDEQ,
                ObjectIdGetDatum(subid));
 
    if (not_ready)
        ScanKeyInit(&skey[nkeys++],
                    Anum_pg_subscription_rel_srsubstate,
                    BTEqualStrategyNumber, F_CHARNE,
                    CharGetDatum(SUBREL_STATE_READY));
 
    scan = systable_beginscan(rel, InvalidOid, false,
                              NULL, nkeys, skey);
 
    while (HeapTupleIsValid(tup = systable_getnext(scan)))
    {
        Form_pg_subscription_rel subrel;
        SubscriptionRelState *relstate;
        Datum       d;
        bool        isnull;
 
        subrel = (Form_pg_subscription_rel) GETSTRUCT(tup);
 
        relstate = (SubscriptionRelState *) palloc(sizeof(SubscriptionRelState));
        relstate->relid = subrel->srrelid;
        relstate->state = subrel->srsubstate;
        d = SysCacheGetAttr(SUBSCRIPTIONRELMAP, tup,
                            Anum_pg_subscription_rel_srsublsn, &isnull);
        if (isnull)
            relstate->lsn = InvalidXLogRecPtr;
        else
            relstate->lsn = DatumGetLSN(d);
 
        res = lappend(res, relstate);
    }
 
    /* Cleanup */
    systable_endscan(scan);
    table_close(rel, AccessShareLock);
 
    return res;
}

References AccessShareLock, BTEqualStrategyNumber, CharGetDatum(), DatumGetLSN(), GETSTRUCT, HeapTupleIsValid, InvalidOid, InvalidXLogRecPtr, lappend(), SubscriptionRelState::lsn, NIL, ObjectIdGetDatum(), palloc(), SubscriptionRelState::relid, res, ScanKeyInit(), SubscriptionRelState::state, SUBSCRIPTIONRELMAP, SysCacheGetAttr(), systable_beginscan(), systable_endscan(), systable_getnext(), table_close(), and table_open().

Referenced by AlterSubscription_refresh(), DropSubscription(), and FetchTableStates().

GetSubscriptionRelState()

char GetSubscriptionRelState	(	Oid	subid,
		Oid	relid,
		XLogRecPtr *	sublsn
	)

Definition at line 330 of file pg_subscription.c.

{
    HeapTuple   tup;
    char        substate;
    bool        isnull;
    Datum       d;
    Relation    rel;
 
    /*
     * This is to avoid the race condition with AlterSubscription which tries
     * to remove this relstate.
     */
    rel = table_open(SubscriptionRelRelationId, AccessShareLock);
 
    /* Try finding the mapping. */
    tup = SearchSysCache2(SUBSCRIPTIONRELMAP,
                          ObjectIdGetDatum(relid),
                          ObjectIdGetDatum(subid));
 
    if (!HeapTupleIsValid(tup))
    {
        table_close(rel, AccessShareLock);
        *sublsn = InvalidXLogRecPtr;
        return SUBREL_STATE_UNKNOWN;
    }
 
    /* Get the state. */
    substate = ((Form_pg_subscription_rel) GETSTRUCT(tup))->srsubstate;
 
    /* Get the LSN */
    d = SysCacheGetAttr(SUBSCRIPTIONRELMAP, tup,
                        Anum_pg_subscription_rel_srsublsn, &isnull);
    if (isnull)
        *sublsn = InvalidXLogRecPtr;
    else
        *sublsn = DatumGetLSN(d);
 
    /* Cleanup */
    ReleaseSysCache(tup);
 
    table_close(rel, AccessShareLock);
 
    return substate;
}

References AccessShareLock, DatumGetLSN(), GETSTRUCT, HeapTupleIsValid, InvalidXLogRecPtr, ObjectIdGetDatum(), ReleaseSysCache(), SearchSysCache2(), SUBSCRIPTIONRELMAP, SysCacheGetAttr(), table_close(), and table_open().

Referenced by AlterSubscription_refresh(), logicalrep_rel_open(), LogicalRepSyncTableStart(), and wait_for_relation_state_change().

HasSubscriptionRelations()

bool HasSubscriptionRelations

(

Oid

subid

)

Definition at line 455 of file pg_subscription.c.

{
    Relation    rel;
    ScanKeyData skey[1];
    SysScanDesc scan;
    bool        has_subrels;
 
    rel = table_open(SubscriptionRelRelationId, AccessShareLock);
 
    ScanKeyInit(&skey[0],
                Anum_pg_subscription_rel_srsubid,
                BTEqualStrategyNumber, F_OIDEQ,
                ObjectIdGetDatum(subid));
 
    scan = systable_beginscan(rel, InvalidOid, false,
                              NULL, 1, skey);
 
    /* If even a single tuple exists then the subscription has tables. */
    has_subrels = HeapTupleIsValid(systable_getnext(scan));
 
    /* Cleanup */
    systable_endscan(scan);
    table_close(rel, AccessShareLock);
 
    return has_subrels;
}

References AccessShareLock, BTEqualStrategyNumber, HeapTupleIsValid, InvalidOid, ObjectIdGetDatum(), ScanKeyInit(), systable_beginscan(), systable_endscan(), systable_getnext(), table_close(), and table_open().

Referenced by FetchTableStates().

RemoveSubscriptionRel()

void RemoveSubscriptionRel	(	Oid	subid,
		Oid	relid
	)

Definition at line 380 of file pg_subscription.c.

{
    Relation    rel;
    TableScanDesc scan;
    ScanKeyData skey[2];
    HeapTuple   tup;
    int         nkeys = 0;
 
    rel = table_open(SubscriptionRelRelationId, RowExclusiveLock);
 
    if (OidIsValid(subid))
    {
        ScanKeyInit(&skey[nkeys++],
                    Anum_pg_subscription_rel_srsubid,
                    BTEqualStrategyNumber,
                    F_OIDEQ,
                    ObjectIdGetDatum(subid));
    }
 
    if (OidIsValid(relid))
    {
        ScanKeyInit(&skey[nkeys++],
                    Anum_pg_subscription_rel_srrelid,
                    BTEqualStrategyNumber,
                    F_OIDEQ,
                    ObjectIdGetDatum(relid));
    }
 
    /* Do the search and delete what we found. */
    scan = table_beginscan_catalog(rel, nkeys, skey);
    while (HeapTupleIsValid(tup = heap_getnext(scan, ForwardScanDirection)))
    {
        Form_pg_subscription_rel subrel;
 
        subrel = (Form_pg_subscription_rel) GETSTRUCT(tup);
 
        /*
         * We don't allow to drop the relation mapping when the table
         * synchronization is in progress unless the caller updates the
         * corresponding subscription as well. This is to ensure that we don't
         * leave tablesync slots or origins in the system when the
         * corresponding table is dropped.
         */
        if (!OidIsValid(subid) && subrel->srsubstate != SUBREL_STATE_READY)
        {
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                     errmsg("could not drop relation mapping for subscription \"%s\"",
                            get_subscription_name(subrel->srsubid, false)),
                     errdetail("Table synchronization for relation \"%s\" is in progress and is in state \"%c\".",
                               get_rel_name(relid), subrel->srsubstate),
 
            /*
             * translator: first %s is a SQL ALTER command and second %s is a
             * SQL DROP command
             */
                     errhint("Use %s to enable subscription if not already enabled or use %s to drop the subscription.",
                             "ALTER SUBSCRIPTION ... ENABLE",
                             "DROP SUBSCRIPTION ...")));
        }
 
        CatalogTupleDelete(rel, &tup->t_self);
    }
    table_endscan(scan);
 
    table_close(rel, RowExclusiveLock);
}

References BTEqualStrategyNumber, CatalogTupleDelete(), ereport, errcode(), errdetail(), errhint(), errmsg(), ERROR, ForwardScanDirection, get_rel_name(), get_subscription_name(), GETSTRUCT, heap_getnext(), HeapTupleIsValid, ObjectIdGetDatum(), OidIsValid, RowExclusiveLock, ScanKeyInit(), HeapTupleData::t_self, table_beginscan_catalog(), table_close(), table_endscan(), and table_open().

Referenced by AlterSubscription_refresh(), DropSubscription(), and heap_drop_with_catalog().

textarray_to_stringlist()

static List * textarray_to_stringlist ( ArrayType *  textarray )

static

Definition at line 211 of file pg_subscription.c.

{
    Datum      *elems;
    int         nelems,
                i;
    List       *res = NIL;
 
    deconstruct_array_builtin(textarray, TEXTOID, &elems, NULL, &nelems);
 
    if (nelems == 0)
        return NIL;
 
    for (i = 0; i < nelems; i++)
        res = lappend(res, makeString(TextDatumGetCString(elems[i])));
 
    return res;
}

References deconstruct_array_builtin(), i, lappend(), makeString(), NIL, res, and TextDatumGetCString.

Referenced by GetSubscription().

UpdateSubscriptionRelState()

void UpdateSubscriptionRelState	(	Oid	subid,
		Oid	relid,
		char	state,
		XLogRecPtr	sublsn
	)

Definition at line 279 of file pg_subscription.c.

{
    Relation    rel;
    HeapTuple   tup;
    bool        nulls[Natts_pg_subscription_rel];
    Datum       values[Natts_pg_subscription_rel];
    bool        replaces[Natts_pg_subscription_rel];
 
    LockSharedObject(SubscriptionRelationId, subid, 0, AccessShareLock);
 
    rel = table_open(SubscriptionRelRelationId, RowExclusiveLock);
 
    /* Try finding existing mapping. */
    tup = SearchSysCacheCopy2(SUBSCRIPTIONRELMAP,
                              ObjectIdGetDatum(relid),
                              ObjectIdGetDatum(subid));
    if (!HeapTupleIsValid(tup))
        elog(ERROR, "subscription table %u in subscription %u does not exist",
             relid, subid);
 
    /* Update the tuple. */
    memset(values, 0, sizeof(values));
    memset(nulls, false, sizeof(nulls));
    memset(replaces, false, sizeof(replaces));
 
    replaces[Anum_pg_subscription_rel_srsubstate - 1] = true;
    values[Anum_pg_subscription_rel_srsubstate - 1] = CharGetDatum(state);
 
    replaces[Anum_pg_subscription_rel_srsublsn - 1] = true;
    if (sublsn != InvalidXLogRecPtr)
        values[Anum_pg_subscription_rel_srsublsn - 1] = LSNGetDatum(sublsn);
    else
        nulls[Anum_pg_subscription_rel_srsublsn - 1] = true;
 
    tup = heap_modify_tuple(tup, RelationGetDescr(rel), values, nulls,
                            replaces);
 
    /* Update the catalog. */
    CatalogTupleUpdate(rel, &tup->t_self, tup);
 
    /* Cleanup. */
    table_close(rel, NoLock);
}

References AccessShareLock, CatalogTupleUpdate(), CharGetDatum(), elog(), ERROR, heap_modify_tuple(), HeapTupleIsValid, InvalidXLogRecPtr, LockSharedObject(), LSNGetDatum(), NoLock, ObjectIdGetDatum(), RelationGetDescr, RowExclusiveLock, SearchSysCacheCopy2, SUBSCRIPTIONRELMAP, HeapTupleData::t_self, table_close(), table_open(), and values.

Referenced by LogicalRepSyncTableStart(), process_syncing_tables_for_apply(), and process_syncing_tables_for_sync().