Adding upstream version 14.5.upstream/14.5upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1346 insertions, 0 deletions

diff --git a/src/backend/replication/pgoutput/pgoutput.c b/src/backend/replication/pgoutput/pgoutput.c
new file mode 100644
index 0000000..ff9cf5d
--- /dev/null
+++ b/src/backend/replication/pgoutput/pgoutput.c
@@ -0,0 +1,1346 @@
+/*-------------------------------------------------------------------------
+ *
+ * pgoutput.c
+ *		Logical Replication output plugin
+ *
+ * Copyright (c) 2012-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *		  src/backend/replication/pgoutput/pgoutput.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/tupconvert.h"
+#include "catalog/partition.h"
+#include "catalog/pg_publication.h"
+#include "commands/defrem.h"
+#include "fmgr.h"
+#include "replication/logical.h"
+#include "replication/logicalproto.h"
+#include "replication/origin.h"
+#include "replication/pgoutput.h"
+#include "utils/int8.h"
+#include "utils/inval.h"
+#include "utils/lsyscache.h"
+#include "utils/memutils.h"
+#include "utils/syscache.h"
+#include "utils/varlena.h"
+
+PG_MODULE_MAGIC;
+
+extern void _PG_output_plugin_init(OutputPluginCallbacks *cb);
+
+static void pgoutput_startup(LogicalDecodingContext *ctx,
+							 OutputPluginOptions *opt, bool is_init);
+static void pgoutput_shutdown(LogicalDecodingContext *ctx);
+static void pgoutput_begin_txn(LogicalDecodingContext *ctx,
+							   ReorderBufferTXN *txn);
+static void pgoutput_commit_txn(LogicalDecodingContext *ctx,
+								ReorderBufferTXN *txn, XLogRecPtr commit_lsn);
+static void pgoutput_change(LogicalDecodingContext *ctx,
+							ReorderBufferTXN *txn, Relation rel,
+							ReorderBufferChange *change);
+static void pgoutput_truncate(LogicalDecodingContext *ctx,
+							  ReorderBufferTXN *txn, int nrelations, Relation relations[],
+							  ReorderBufferChange *change);
+static void pgoutput_message(LogicalDecodingContext *ctx,
+							 ReorderBufferTXN *txn, XLogRecPtr message_lsn,
+							 bool transactional, const char *prefix,
+							 Size sz, const char *message);
+static bool pgoutput_origin_filter(LogicalDecodingContext *ctx,
+								   RepOriginId origin_id);
+static void pgoutput_stream_start(struct LogicalDecodingContext *ctx,
+								  ReorderBufferTXN *txn);
+static void pgoutput_stream_stop(struct LogicalDecodingContext *ctx,
+								 ReorderBufferTXN *txn);
+static void pgoutput_stream_abort(struct LogicalDecodingContext *ctx,
+								  ReorderBufferTXN *txn,
+								  XLogRecPtr abort_lsn);
+static void pgoutput_stream_commit(struct LogicalDecodingContext *ctx,
+								   ReorderBufferTXN *txn,
+								   XLogRecPtr commit_lsn);
+
+static bool publications_valid;
+static bool in_streaming;
+
+static List *LoadPublications(List *pubnames);
+static void publication_invalidation_cb(Datum arg, int cacheid,
+										uint32 hashvalue);
+static void send_relation_and_attrs(Relation relation, TransactionId xid,
+									LogicalDecodingContext *ctx);
+static void update_replication_progress(LogicalDecodingContext *ctx);
+
+/*
+ * Entry in the map used to remember which relation schemas we sent.
+ *
+ * The schema_sent flag determines if the current schema record for the
+ * relation (and for its ancestor if publish_as_relid is set) was already
+ * sent to the subscriber (in which case we don't need to send it again).
+ *
+ * The schema cache on downstream is however updated only at commit time,
+ * and with streamed transactions the commit order may be different from
+ * the order the transactions are sent in. Also, the (sub) transactions
+ * might get aborted so we need to send the schema for each (sub) transaction
+ * so that we don't lose the schema information on abort. For handling this,
+ * we maintain the list of xids (streamed_txns) for those we have already sent
+ * the schema.
+ *
+ * For partitions, 'pubactions' considers not only the table's own
+ * publications, but also those of all of its ancestors.
+ */
+typedef struct RelationSyncEntry
+{
+	Oid			relid;			/* relation oid */
+
+	bool		schema_sent;
+	List	   *streamed_txns;	/* streamed toplevel transactions with this
+								 * schema */
+
+	bool		replicate_valid;
+	PublicationActions pubactions;
+
+	/*
+	 * OID of the relation to publish changes as.  For a partition, this may
+	 * be set to one of its ancestors whose schema will be used when
+	 * replicating changes, if publish_via_partition_root is set for the
+	 * publication.
+	 */
+	Oid			publish_as_relid;
+
+	/*
+	 * Map used when replicating using an ancestor's schema to convert tuples
+	 * from partition's type to the ancestor's; NULL if publish_as_relid is
+	 * same as 'relid' or if unnecessary due to partition and the ancestor
+	 * having identical TupleDesc.
+	 */
+	TupleConversionMap *map;
+} RelationSyncEntry;
+
+/* Map used to remember which relation schemas we sent. */
+static HTAB *RelationSyncCache = NULL;
+
+static void init_rel_sync_cache(MemoryContext decoding_context);
+static void cleanup_rel_sync_cache(TransactionId xid, bool is_commit);
+static RelationSyncEntry *get_rel_sync_entry(PGOutputData *data, Oid relid);
+static void rel_sync_cache_relation_cb(Datum arg, Oid relid);
+static void rel_sync_cache_publication_cb(Datum arg, int cacheid,
+										  uint32 hashvalue);
+static void set_schema_sent_in_streamed_txn(RelationSyncEntry *entry,
+											TransactionId xid);
+static bool get_schema_sent_in_streamed_txn(RelationSyncEntry *entry,
+											TransactionId xid);
+
+/*
+ * Specify output plugin callbacks
+ */
+void
+_PG_output_plugin_init(OutputPluginCallbacks *cb)
+{
+	AssertVariableIsOfType(&_PG_output_plugin_init, LogicalOutputPluginInit);
+
+	cb->startup_cb = pgoutput_startup;
+	cb->begin_cb = pgoutput_begin_txn;
+	cb->change_cb = pgoutput_change;
+	cb->truncate_cb = pgoutput_truncate;
+	cb->message_cb = pgoutput_message;
+	cb->commit_cb = pgoutput_commit_txn;
+	cb->filter_by_origin_cb = pgoutput_origin_filter;
+	cb->shutdown_cb = pgoutput_shutdown;
+
+	/* transaction streaming */
+	cb->stream_start_cb = pgoutput_stream_start;
+	cb->stream_stop_cb = pgoutput_stream_stop;
+	cb->stream_abort_cb = pgoutput_stream_abort;
+	cb->stream_commit_cb = pgoutput_stream_commit;
+	cb->stream_change_cb = pgoutput_change;
+	cb->stream_message_cb = pgoutput_message;
+	cb->stream_truncate_cb = pgoutput_truncate;
+}
+
+static void
+parse_output_parameters(List *options, PGOutputData *data)
+{
+	ListCell   *lc;
+	bool		protocol_version_given = false;
+	bool		publication_names_given = false;
+	bool		binary_option_given = false;
+	bool		messages_option_given = false;
+	bool		streaming_given = false;
+
+	data->binary = false;
+	data->streaming = false;
+	data->messages = false;
+
+	foreach(lc, options)
+	{
+		DefElem    *defel = (DefElem *) lfirst(lc);
+
+		Assert(defel->arg == NULL || IsA(defel->arg, String));
+
+		/* Check each param, whether or not we recognize it */
+		if (strcmp(defel->defname, "proto_version") == 0)
+		{
+			int64		parsed;
+
+			if (protocol_version_given)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+			protocol_version_given = true;
+
+			if (!scanint8(strVal(defel->arg), true, &parsed))
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						 errmsg("invalid proto_version")));
+
+			if (parsed > PG_UINT32_MAX || parsed < 0)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						 errmsg("proto_version \"%s\" out of range",
+								strVal(defel->arg))));
+
+			data->protocol_version = (uint32) parsed;
+		}
+		else if (strcmp(defel->defname, "publication_names") == 0)
+		{
+			if (publication_names_given)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+			publication_names_given = true;
+
+			if (!SplitIdentifierString(strVal(defel->arg), ',',
+									   &data->publication_names))
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_NAME),
+						 errmsg("invalid publication_names syntax")));
+		}
+		else if (strcmp(defel->defname, "binary") == 0)
+		{
+			if (binary_option_given)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+			binary_option_given = true;
+
+			data->binary = defGetBoolean(defel);
+		}
+		else if (strcmp(defel->defname, "messages") == 0)
+		{
+			if (messages_option_given)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+			messages_option_given = true;
+
+			data->messages = defGetBoolean(defel);
+		}
+		else if (strcmp(defel->defname, "streaming") == 0)
+		{
+			if (streaming_given)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+			streaming_given = true;
+
+			data->streaming = defGetBoolean(defel);
+		}
+		else
+			elog(ERROR, "unrecognized pgoutput option: %s", defel->defname);
+	}
+}
+
+/*
+ * Initialize this plugin
+ */
+static void
+pgoutput_startup(LogicalDecodingContext *ctx, OutputPluginOptions *opt,
+				 bool is_init)
+{
+	PGOutputData *data = palloc0(sizeof(PGOutputData));
+
+	/* Create our memory context for private allocations. */
+	data->context = AllocSetContextCreate(ctx->context,
+										  "logical replication output context",
+										  ALLOCSET_DEFAULT_SIZES);
+
+	ctx->output_plugin_private = data;
+
+	/* This plugin uses binary protocol. */
+	opt->output_type = OUTPUT_PLUGIN_BINARY_OUTPUT;
+
+	/*
+	 * This is replication start and not slot initialization.
+	 *
+	 * Parse and validate options passed by the client.
+	 */
+	if (!is_init)
+	{
+		/* Parse the params and ERROR if we see any we don't recognize */
+		parse_output_parameters(ctx->output_plugin_options, data);
+
+		/* Check if we support requested protocol */
+		if (data->protocol_version > LOGICALREP_PROTO_MAX_VERSION_NUM)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("client sent proto_version=%d but we only support protocol %d or lower",
+							data->protocol_version, LOGICALREP_PROTO_MAX_VERSION_NUM)));
+
+		if (data->protocol_version < LOGICALREP_PROTO_MIN_VERSION_NUM)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("client sent proto_version=%d but we only support protocol %d or higher",
+							data->protocol_version, LOGICALREP_PROTO_MIN_VERSION_NUM)));
+
+		if (list_length(data->publication_names) < 1)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("publication_names parameter missing")));
+
+		/*
+		 * Decide whether to enable streaming. It is disabled by default, in
+		 * which case we just update the flag in decoding context. Otherwise
+		 * we only allow it with sufficient version of the protocol, and when
+		 * the output plugin supports it.
+		 */
+		if (!data->streaming)
+			ctx->streaming = false;
+		else if (data->protocol_version < LOGICALREP_PROTO_STREAM_VERSION_NUM)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("requested proto_version=%d does not support streaming, need %d or higher",
+							data->protocol_version, LOGICALREP_PROTO_STREAM_VERSION_NUM)));
+		else if (!ctx->streaming)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("streaming requested, but not supported by output plugin")));
+
+		/* Also remember we're currently not streaming any transaction. */
+		in_streaming = false;
+
+		/* Init publication state. */
+		data->publications = NIL;
+		publications_valid = false;
+		CacheRegisterSyscacheCallback(PUBLICATIONOID,
+									  publication_invalidation_cb,
+									  (Datum) 0);
+
+		/* Initialize relation schema cache. */
+		init_rel_sync_cache(CacheMemoryContext);
+	}
+	else
+	{
+		/* Disable the streaming during the slot initialization mode. */
+		ctx->streaming = false;
+	}
+}
+
+/*
+ * BEGIN callback
+ */
+static void
+pgoutput_begin_txn(LogicalDecodingContext *ctx, ReorderBufferTXN *txn)
+{
+	bool		send_replication_origin = txn->origin_id != InvalidRepOriginId;
+
+	OutputPluginPrepareWrite(ctx, !send_replication_origin);
+	logicalrep_write_begin(ctx->out, txn);
+
+	if (send_replication_origin)
+	{
+		char	   *origin;
+
+		/*----------
+		 * XXX: which behaviour do we want here?
+		 *
+		 * Alternatives:
+		 *	- don't send origin message if origin name not found
+		 *	  (that's what we do now)
+		 *	- throw error - that will break replication, not good
+		 *	- send some special "unknown" origin
+		 *----------
+		 */
+		if (replorigin_by_oid(txn->origin_id, true, &origin))
+		{
+			/* Message boundary */
+			OutputPluginWrite(ctx, false);
+			OutputPluginPrepareWrite(ctx, true);
+			logicalrep_write_origin(ctx->out, origin, txn->origin_lsn);
+		}
+
+	}
+
+	OutputPluginWrite(ctx, true);
+}
+
+/*
+ * COMMIT callback
+ */
+static void
+pgoutput_commit_txn(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
+					XLogRecPtr commit_lsn)
+{
+	update_replication_progress(ctx);
+
+	OutputPluginPrepareWrite(ctx, true);
+	logicalrep_write_commit(ctx->out, txn, commit_lsn);
+	OutputPluginWrite(ctx, true);
+}
+
+/*
+ * Write the current schema of the relation and its ancestor (if any) if not
+ * done yet.
+ */
+static void
+maybe_send_schema(LogicalDecodingContext *ctx,
+				  ReorderBufferTXN *txn, ReorderBufferChange *change,
+				  Relation relation, RelationSyncEntry *relentry)
+{
+	bool		schema_sent;
+	TransactionId xid = InvalidTransactionId;
+	TransactionId topxid = InvalidTransactionId;
+
+	/*
+	 * Remember XID of the (sub)transaction for the change. We don't care if
+	 * it's top-level transaction or not (we have already sent that XID in
+	 * start of the current streaming block).
+	 *
+	 * If we're not in a streaming block, just use InvalidTransactionId and
+	 * the write methods will not include it.
+	 */
+	if (in_streaming)
+		xid = change->txn->xid;
+
+	if (change->txn->toptxn)
+		topxid = change->txn->toptxn->xid;
+	else
+		topxid = xid;
+
+	/*
+	 * Do we need to send the schema? We do track streamed transactions
+	 * separately, because those may be applied later (and the regular
+	 * transactions won't see their effects until then) and in an order that
+	 * we don't know at this point.
+	 *
+	 * XXX There is a scope of optimization here. Currently, we always send
+	 * the schema first time in a streaming transaction but we can probably
+	 * avoid that by checking 'relentry->schema_sent' flag. However, before
+	 * doing that we need to study its impact on the case where we have a mix
+	 * of streaming and non-streaming transactions.
+	 */
+	if (in_streaming)
+		schema_sent = get_schema_sent_in_streamed_txn(relentry, topxid);
+	else
+		schema_sent = relentry->schema_sent;
+
+	/* Nothing to do if we already sent the schema. */
+	if (schema_sent)
+		return;
+
+	/*
+	 * Nope, so send the schema.  If the changes will be published using an
+	 * ancestor's schema, not the relation's own, send that ancestor's schema
+	 * before sending relation's own (XXX - maybe sending only the former
+	 * suffices?).  This is also a good place to set the map that will be used
+	 * to convert the relation's tuples into the ancestor's format, if needed.
+	 */
+	if (relentry->publish_as_relid != RelationGetRelid(relation))
+	{
+		Relation	ancestor = RelationIdGetRelation(relentry->publish_as_relid);
+		TupleDesc	indesc = RelationGetDescr(relation);
+		TupleDesc	outdesc = RelationGetDescr(ancestor);
+		MemoryContext oldctx;
+
+		/* Map must live as long as the session does. */
+		oldctx = MemoryContextSwitchTo(CacheMemoryContext);
+
+		/*
+		 * Make copies of the TupleDescs that will live as long as the map
+		 * does before putting into the map.
+		 */
+		indesc = CreateTupleDescCopy(indesc);
+		outdesc = CreateTupleDescCopy(outdesc);
+		relentry->map = convert_tuples_by_name(indesc, outdesc);
+		if (relentry->map == NULL)
+		{
+			/* Map not necessary, so free the TupleDescs too. */
+			FreeTupleDesc(indesc);
+			FreeTupleDesc(outdesc);
+		}
+
+		MemoryContextSwitchTo(oldctx);
+		send_relation_and_attrs(ancestor, xid, ctx);
+		RelationClose(ancestor);
+	}
+
+	send_relation_and_attrs(relation, xid, ctx);
+
+	if (in_streaming)
+		set_schema_sent_in_streamed_txn(relentry, topxid);
+	else
+		relentry->schema_sent = true;
+}
+
+/*
+ * Sends a relation
+ */
+static void
+send_relation_and_attrs(Relation relation, TransactionId xid,
+						LogicalDecodingContext *ctx)
+{
+	TupleDesc	desc = RelationGetDescr(relation);
+	int			i;
+
+	/*
+	 * Write out type info if needed.  We do that only for user-created types.
+	 * We use FirstGenbkiObjectId as the cutoff, so that we only consider
+	 * objects with hand-assigned OIDs to be "built in", not for instance any
+	 * function or type defined in the information_schema. This is important
+	 * because only hand-assigned OIDs can be expected to remain stable across
+	 * major versions.
+	 */
+	for (i = 0; i < desc->natts; i++)
+	{
+		Form_pg_attribute att = TupleDescAttr(desc, i);
+
+		if (att->attisdropped || att->attgenerated)
+			continue;
+
+		if (att->atttypid < FirstGenbkiObjectId)
+			continue;
+
+		OutputPluginPrepareWrite(ctx, false);
+		logicalrep_write_typ(ctx->out, xid, att->atttypid);
+		OutputPluginWrite(ctx, false);
+	}
+
+	OutputPluginPrepareWrite(ctx, false);
+	logicalrep_write_rel(ctx->out, xid, relation);
+	OutputPluginWrite(ctx, false);
+}
+
+/*
+ * Sends the decoded DML over wire.
+ *
+ * This is called both in streaming and non-streaming modes.
+ */
+static void
+pgoutput_change(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
+				Relation relation, ReorderBufferChange *change)
+{
+	PGOutputData *data = (PGOutputData *) ctx->output_plugin_private;
+	MemoryContext old;
+	RelationSyncEntry *relentry;
+	TransactionId xid = InvalidTransactionId;
+	Relation	ancestor = NULL;
+
+	update_replication_progress(ctx);
+
+	if (!is_publishable_relation(relation))
+		return;
+
+	/*
+	 * Remember the xid for the change in streaming mode. We need to send xid
+	 * with each change in the streaming mode so that subscriber can make
+	 * their association and on aborts, it can discard the corresponding
+	 * changes.
+	 */
+	if (in_streaming)
+		xid = change->txn->xid;
+
+	relentry = get_rel_sync_entry(data, RelationGetRelid(relation));
+
+	/* First check the table filter */
+	switch (change->action)
+	{
+		case REORDER_BUFFER_CHANGE_INSERT:
+			if (!relentry->pubactions.pubinsert)
+				return;
+			break;
+		case REORDER_BUFFER_CHANGE_UPDATE:
+			if (!relentry->pubactions.pubupdate)
+				return;
+			break;
+		case REORDER_BUFFER_CHANGE_DELETE:
+			if (!relentry->pubactions.pubdelete)
+				return;
+			break;
+		default:
+			Assert(false);
+	}
+
+	/* Avoid leaking memory by using and resetting our own context */
+	old = MemoryContextSwitchTo(data->context);
+
+	maybe_send_schema(ctx, txn, change, relation, relentry);
+
+	/* Send the data */
+	switch (change->action)
+	{
+		case REORDER_BUFFER_CHANGE_INSERT:
+			{
+				HeapTuple	tuple = &change->data.tp.newtuple->tuple;
+
+				/* Switch relation if publishing via root. */
+				if (relentry->publish_as_relid != RelationGetRelid(relation))
+				{
+					Assert(relation->rd_rel->relispartition);
+					ancestor = RelationIdGetRelation(relentry->publish_as_relid);
+					relation = ancestor;
+					/* Convert tuple if needed. */
+					if (relentry->map)
+						tuple = execute_attr_map_tuple(tuple, relentry->map);
+				}
+
+				OutputPluginPrepareWrite(ctx, true);
+				logicalrep_write_insert(ctx->out, xid, relation, tuple,
+										data->binary);
+				OutputPluginWrite(ctx, true);
+				break;
+			}
+		case REORDER_BUFFER_CHANGE_UPDATE:
+			{
+				HeapTuple	oldtuple = change->data.tp.oldtuple ?
+				&change->data.tp.oldtuple->tuple : NULL;
+				HeapTuple	newtuple = &change->data.tp.newtuple->tuple;
+
+				/* Switch relation if publishing via root. */
+				if (relentry->publish_as_relid != RelationGetRelid(relation))
+				{
+					Assert(relation->rd_rel->relispartition);
+					ancestor = RelationIdGetRelation(relentry->publish_as_relid);
+					relation = ancestor;
+					/* Convert tuples if needed. */
+					if (relentry->map)
+					{
+						if (oldtuple)
+							oldtuple = execute_attr_map_tuple(oldtuple,
+															  relentry->map);
+						newtuple = execute_attr_map_tuple(newtuple,
+														  relentry->map);
+					}
+				}
+
+				OutputPluginPrepareWrite(ctx, true);
+				logicalrep_write_update(ctx->out, xid, relation, oldtuple,
+										newtuple, data->binary);
+				OutputPluginWrite(ctx, true);
+				break;
+			}
+		case REORDER_BUFFER_CHANGE_DELETE:
+			if (change->data.tp.oldtuple)
+			{
+				HeapTuple	oldtuple = &change->data.tp.oldtuple->tuple;
+
+				/* Switch relation if publishing via root. */
+				if (relentry->publish_as_relid != RelationGetRelid(relation))
+				{
+					Assert(relation->rd_rel->relispartition);
+					ancestor = RelationIdGetRelation(relentry->publish_as_relid);
+					relation = ancestor;
+					/* Convert tuple if needed. */
+					if (relentry->map)
+						oldtuple = execute_attr_map_tuple(oldtuple, relentry->map);
+				}
+
+				OutputPluginPrepareWrite(ctx, true);
+				logicalrep_write_delete(ctx->out, xid, relation, oldtuple,
+										data->binary);
+				OutputPluginWrite(ctx, true);
+			}
+			else
+				elog(DEBUG1, "didn't send DELETE change because of missing oldtuple");
+			break;
+		default:
+			Assert(false);
+	}
+
+	if (RelationIsValid(ancestor))
+	{
+		RelationClose(ancestor);
+		ancestor = NULL;
+	}
+
+	/* Cleanup */
+	MemoryContextSwitchTo(old);
+	MemoryContextReset(data->context);
+}
+
+static void
+pgoutput_truncate(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
+				  int nrelations, Relation relations[], ReorderBufferChange *change)
+{
+	PGOutputData *data = (PGOutputData *) ctx->output_plugin_private;
+	MemoryContext old;
+	RelationSyncEntry *relentry;
+	int			i;
+	int			nrelids;
+	Oid		   *relids;
+	TransactionId xid = InvalidTransactionId;
+
+	update_replication_progress(ctx);
+
+	/* Remember the xid for the change in streaming mode. See pgoutput_change. */
+	if (in_streaming)
+		xid = change->txn->xid;
+
+	old = MemoryContextSwitchTo(data->context);
+
+	relids = palloc0(nrelations * sizeof(Oid));
+	nrelids = 0;
+
+	for (i = 0; i < nrelations; i++)
+	{
+		Relation	relation = relations[i];
+		Oid			relid = RelationGetRelid(relation);
+
+		if (!is_publishable_relation(relation))
+			continue;
+
+		relentry = get_rel_sync_entry(data, relid);
+
+		if (!relentry->pubactions.pubtruncate)
+			continue;
+
+		/*
+		 * Don't send partitions if the publication wants to send only the
+		 * root tables through it.
+		 */
+		if (relation->rd_rel->relispartition &&
+			relentry->publish_as_relid != relid)
+			continue;
+
+		relids[nrelids++] = relid;
+		maybe_send_schema(ctx, txn, change, relation, relentry);
+	}
+
+	if (nrelids > 0)
+	{
+		OutputPluginPrepareWrite(ctx, true);
+		logicalrep_write_truncate(ctx->out,
+								  xid,
+								  nrelids,
+								  relids,
+								  change->data.truncate.cascade,
+								  change->data.truncate.restart_seqs);
+		OutputPluginWrite(ctx, true);
+	}
+
+	MemoryContextSwitchTo(old);
+	MemoryContextReset(data->context);
+}
+
+static void
+pgoutput_message(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
+				 XLogRecPtr message_lsn, bool transactional, const char *prefix, Size sz,
+				 const char *message)
+{
+	PGOutputData *data = (PGOutputData *) ctx->output_plugin_private;
+	TransactionId xid = InvalidTransactionId;
+
+	update_replication_progress(ctx);
+
+	if (!data->messages)
+		return;
+
+	/*
+	 * Remember the xid for the message in streaming mode. See
+	 * pgoutput_change.
+	 */
+	if (in_streaming)
+		xid = txn->xid;
+
+	OutputPluginPrepareWrite(ctx, true);
+	logicalrep_write_message(ctx->out,
+							 xid,
+							 message_lsn,
+							 transactional,
+							 prefix,
+							 sz,
+							 message);
+	OutputPluginWrite(ctx, true);
+}
+
+/*
+ * Currently we always forward.
+ */
+static bool
+pgoutput_origin_filter(LogicalDecodingContext *ctx,
+					   RepOriginId origin_id)
+{
+	return false;
+}
+
+/*
+ * Shutdown the output plugin.
+ *
+ * Note, we don't need to clean the data->context as it's child context
+ * of the ctx->context so it will be cleaned up by logical decoding machinery.
+ */
+static void
+pgoutput_shutdown(LogicalDecodingContext *ctx)
+{
+	if (RelationSyncCache)
+	{
+		hash_destroy(RelationSyncCache);
+		RelationSyncCache = NULL;
+	}
+}
+
+/*
+ * Load publications from the list of publication names.
+ */
+static List *
+LoadPublications(List *pubnames)
+{
+	List	   *result = NIL;
+	ListCell   *lc;
+
+	foreach(lc, pubnames)
+	{
+		char	   *pubname = (char *) lfirst(lc);
+		Publication *pub = GetPublicationByName(pubname, false);
+
+		result = lappend(result, pub);
+	}
+
+	return result;
+}
+
+/*
+ * Publication cache invalidation callback.
+ */
+static void
+publication_invalidation_cb(Datum arg, int cacheid, uint32 hashvalue)
+{
+	publications_valid = false;
+
+	/*
+	 * Also invalidate per-relation cache so that next time the filtering info
+	 * is checked it will be updated with the new publication settings.
+	 */
+	rel_sync_cache_publication_cb(arg, cacheid, hashvalue);
+}
+
+/*
+ * START STREAM callback
+ */
+static void
+pgoutput_stream_start(struct LogicalDecodingContext *ctx,
+					  ReorderBufferTXN *txn)
+{
+	bool		send_replication_origin = txn->origin_id != InvalidRepOriginId;
+
+	/* we can't nest streaming of transactions */
+	Assert(!in_streaming);
+
+	/*
+	 * If we already sent the first stream for this transaction then don't
+	 * send the origin id in the subsequent streams.
+	 */
+	if (rbtxn_is_streamed(txn))
+		send_replication_origin = false;
+
+	OutputPluginPrepareWrite(ctx, !send_replication_origin);
+	logicalrep_write_stream_start(ctx->out, txn->xid, !rbtxn_is_streamed(txn));
+
+	if (send_replication_origin)
+	{
+		char	   *origin;
+
+		if (replorigin_by_oid(txn->origin_id, true, &origin))
+		{
+			/* Message boundary */
+			OutputPluginWrite(ctx, false);
+			OutputPluginPrepareWrite(ctx, true);
+			logicalrep_write_origin(ctx->out, origin, InvalidXLogRecPtr);
+		}
+	}
+
+	OutputPluginWrite(ctx, true);
+
+	/* we're streaming a chunk of transaction now */
+	in_streaming = true;
+}
+
+/*
+ * STOP STREAM callback
+ */
+static void
+pgoutput_stream_stop(struct LogicalDecodingContext *ctx,
+					 ReorderBufferTXN *txn)
+{
+	/* we should be streaming a trasanction */
+	Assert(in_streaming);
+
+	OutputPluginPrepareWrite(ctx, true);
+	logicalrep_write_stream_stop(ctx->out);
+	OutputPluginWrite(ctx, true);
+
+	/* we've stopped streaming a transaction */
+	in_streaming = false;
+}
+
+/*
+ * Notify downstream to discard the streamed transaction (along with all
+ * it's subtransactions, if it's a toplevel transaction).
+ */
+static void
+pgoutput_stream_abort(struct LogicalDecodingContext *ctx,
+					  ReorderBufferTXN *txn,
+					  XLogRecPtr abort_lsn)
+{
+	ReorderBufferTXN *toptxn;
+
+	/*
+	 * The abort should happen outside streaming block, even for streamed
+	 * transactions. The transaction has to be marked as streamed, though.
+	 */
+	Assert(!in_streaming);
+
+	/* determine the toplevel transaction */
+	toptxn = (txn->toptxn) ? txn->toptxn : txn;
+
+	Assert(rbtxn_is_streamed(toptxn));
+
+	OutputPluginPrepareWrite(ctx, true);
+	logicalrep_write_stream_abort(ctx->out, toptxn->xid, txn->xid);
+	OutputPluginWrite(ctx, true);
+
+	cleanup_rel_sync_cache(toptxn->xid, false);
+}
+
+/*
+ * Notify downstream to apply the streamed transaction (along with all
+ * it's subtransactions).
+ */
+static void
+pgoutput_stream_commit(struct LogicalDecodingContext *ctx,
+					   ReorderBufferTXN *txn,
+					   XLogRecPtr commit_lsn)
+{
+	/*
+	 * The commit should happen outside streaming block, even for streamed
+	 * transactions. The transaction has to be marked as streamed, though.
+	 */
+	Assert(!in_streaming);
+	Assert(rbtxn_is_streamed(txn));
+
+	update_replication_progress(ctx);
+
+	OutputPluginPrepareWrite(ctx, true);
+	logicalrep_write_stream_commit(ctx->out, txn, commit_lsn);
+	OutputPluginWrite(ctx, true);
+
+	cleanup_rel_sync_cache(txn->xid, true);
+}
+
+/*
+ * Initialize the relation schema sync cache for a decoding session.
+ *
+ * The hash table is destroyed at the end of a decoding session. While
+ * relcache invalidations still exist and will still be invoked, they
+ * will just see the null hash table global and take no action.
+ */
+static void
+init_rel_sync_cache(MemoryContext cachectx)
+{
+	HASHCTL		ctl;
+
+	if (RelationSyncCache != NULL)
+		return;
+
+	/* Make a new hash table for the cache */
+	ctl.keysize = sizeof(Oid);
+	ctl.entrysize = sizeof(RelationSyncEntry);
+	ctl.hcxt = cachectx;
+
+	RelationSyncCache = hash_create("logical replication output relation cache",
+									128, &ctl,
+									HASH_ELEM | HASH_CONTEXT | HASH_BLOBS);
+
+	Assert(RelationSyncCache != NULL);
+
+	CacheRegisterRelcacheCallback(rel_sync_cache_relation_cb, (Datum) 0);
+	CacheRegisterSyscacheCallback(PUBLICATIONRELMAP,
+								  rel_sync_cache_publication_cb,
+								  (Datum) 0);
+}
+
+/*
+ * We expect relatively small number of streamed transactions.
+ */
+static bool
+get_schema_sent_in_streamed_txn(RelationSyncEntry *entry, TransactionId xid)
+{
+	ListCell   *lc;
+
+	foreach(lc, entry->streamed_txns)
+	{
+		if (xid == (uint32) lfirst_int(lc))
+			return true;
+	}
+
+	return false;
+}
+
+/*
+ * Add the xid in the rel sync entry for which we have already sent the schema
+ * of the relation.
+ */
+static void
+set_schema_sent_in_streamed_txn(RelationSyncEntry *entry, TransactionId xid)
+{
+	MemoryContext oldctx;
+
+	oldctx = MemoryContextSwitchTo(CacheMemoryContext);
+
+	entry->streamed_txns = lappend_int(entry->streamed_txns, xid);
+
+	MemoryContextSwitchTo(oldctx);
+}
+
+/*
+ * Find or create entry in the relation schema cache.
+ *
+ * This looks up publications that the given relation is directly or
+ * indirectly part of (the latter if it's really the relation's ancestor that
+ * is part of a publication) and fills up the found entry with the information
+ * about which operations to publish and whether to use an ancestor's schema
+ * when publishing.
+ */
+static RelationSyncEntry *
+get_rel_sync_entry(PGOutputData *data, Oid relid)
+{
+	RelationSyncEntry *entry;
+	bool		found;
+	MemoryContext oldctx;
+
+	Assert(RelationSyncCache != NULL);
+
+	/* Find cached relation info, creating if not found */
+	entry = (RelationSyncEntry *) hash_search(RelationSyncCache,
+											  (void *) &relid,
+											  HASH_ENTER, &found);
+	Assert(entry != NULL);
+
+	/* Not found means schema wasn't sent */
+	if (!found)
+	{
+		/* immediately make a new entry valid enough to satisfy callbacks */
+		entry->schema_sent = false;
+		entry->streamed_txns = NIL;
+		entry->replicate_valid = false;
+		entry->pubactions.pubinsert = entry->pubactions.pubupdate =
+			entry->pubactions.pubdelete = entry->pubactions.pubtruncate = false;
+		entry->publish_as_relid = InvalidOid;
+		entry->map = NULL;		/* will be set by maybe_send_schema() if
+								 * needed */
+	}
+
+	/* Validate the entry */
+	if (!entry->replicate_valid)
+	{
+		List	   *pubids = GetRelationPublications(relid);
+		ListCell   *lc;
+		Oid			publish_as_relid = relid;
+		int			publish_ancestor_level = 0;
+		bool		am_partition = get_rel_relispartition(relid);
+		char		relkind = get_rel_relkind(relid);
+
+		/* Reload publications if needed before use. */
+		if (!publications_valid)
+		{
+			oldctx = MemoryContextSwitchTo(CacheMemoryContext);
+			if (data->publications)
+				list_free_deep(data->publications);
+
+			data->publications = LoadPublications(data->publication_names);
+			MemoryContextSwitchTo(oldctx);
+			publications_valid = true;
+		}
+
+		/*
+		 * Build publication cache. We can't use one provided by relcache as
+		 * relcache considers all publications given relation is in, but here
+		 * we only need to consider ones that the subscriber requested.
+		 */
+		foreach(lc, data->publications)
+		{
+			Publication *pub = lfirst(lc);
+			bool		publish = false;
+
+			/*
+			 * Under what relid should we publish changes in this publication?
+			 * We'll use the top-most relid across all publications. Also track
+			 * the ancestor level for this publication.
+			 */
+			Oid			pub_relid = relid;
+			int			ancestor_level = 0;
+
+			/*
+			 * If this is a FOR ALL TABLES publication, pick the partition root
+			 * and set the ancestor level accordingly.
+			 */
+			if (pub->alltables)
+			{
+				publish = true;
+				if (pub->pubviaroot && am_partition)
+				{
+					List	   *ancestors = get_partition_ancestors(relid);
+
+					pub_relid = llast_oid(ancestors);
+					ancestor_level = list_length(ancestors);
+				}
+			}
+
+			if (!publish)
+			{
+				bool		ancestor_published = false;
+
+				/*
+				 * For a partition, check if any of the ancestors are
+				 * published.  If so, note down the topmost ancestor that is
+				 * published via this publication, which will be used as the
+				 * relation via which to publish the partition's changes.
+				 */
+				if (am_partition)
+				{
+					List	   *ancestors = get_partition_ancestors(relid);
+					ListCell   *lc2;
+					int			level = 0;
+
+					/*
+					 * Find the "topmost" ancestor that is in this
+					 * publication.
+					 */
+					foreach(lc2, ancestors)
+					{
+						Oid			ancestor = lfirst_oid(lc2);
+
+						level++;
+
+						if (list_member_oid(GetRelationPublications(ancestor),
+											pub->oid))
+						{
+							ancestor_published = true;
+							if (pub->pubviaroot)
+							{
+								pub_relid = ancestor;
+								ancestor_level = level;
+							}
+						}
+					}
+				}
+
+				if (list_member_oid(pubids, pub->oid) || ancestor_published)
+					publish = true;
+			}
+
+			/*
+			 * Don't publish changes for partitioned tables, because
+			 * publishing those of its partitions suffices, unless partition
+			 * changes won't be published due to pubviaroot being set.
+			 */
+			if (publish &&
+				(relkind != RELKIND_PARTITIONED_TABLE || pub->pubviaroot))
+			{
+				entry->pubactions.pubinsert |= pub->pubactions.pubinsert;
+				entry->pubactions.pubupdate |= pub->pubactions.pubupdate;
+				entry->pubactions.pubdelete |= pub->pubactions.pubdelete;
+				entry->pubactions.pubtruncate |= pub->pubactions.pubtruncate;
+
+				/*
+				 * We want to publish the changes as the top-most ancestor
+				 * across all publications. So we need to check if the
+				 * already calculated level is higher than the new one. If
+				 * yes, we can ignore the new value (as it's a child).
+				 * Otherwise the new value is an ancestor, so we keep it.
+				 */
+				if (publish_ancestor_level > ancestor_level)
+					continue;
+
+				/* The new value is an ancestor, so let's keep it. */
+				publish_as_relid = pub_relid;
+				publish_ancestor_level = ancestor_level;
+			}
+		}
+
+		list_free(pubids);
+
+		entry->publish_as_relid = publish_as_relid;
+		entry->replicate_valid = true;
+	}
+
+	return entry;
+}
+
+/*
+ * Cleanup list of streamed transactions and update the schema_sent flag.
+ *
+ * When a streamed transaction commits or aborts, we need to remove the
+ * toplevel XID from the schema cache. If the transaction aborted, the
+ * subscriber will simply throw away the schema records we streamed, so
+ * we don't need to do anything else.
+ *
+ * If the transaction is committed, the subscriber will update the relation
+ * cache - so tweak the schema_sent flag accordingly.
+ */
+static void
+cleanup_rel_sync_cache(TransactionId xid, bool is_commit)
+{
+	HASH_SEQ_STATUS hash_seq;
+	RelationSyncEntry *entry;
+	ListCell   *lc;
+
+	Assert(RelationSyncCache != NULL);
+
+	hash_seq_init(&hash_seq, RelationSyncCache);
+	while ((entry = hash_seq_search(&hash_seq)) != NULL)
+	{
+		/*
+		 * We can set the schema_sent flag for an entry that has committed xid
+		 * in the list as that ensures that the subscriber would have the
+		 * corresponding schema and we don't need to send it unless there is
+		 * any invalidation for that relation.
+		 */
+		foreach(lc, entry->streamed_txns)
+		{
+			if (xid == (uint32) lfirst_int(lc))
+			{
+				if (is_commit)
+					entry->schema_sent = true;
+
+				entry->streamed_txns =
+					foreach_delete_current(entry->streamed_txns, lc);
+				break;
+			}
+		}
+	}
+}
+
+/*
+ * Relcache invalidation callback
+ */
+static void
+rel_sync_cache_relation_cb(Datum arg, Oid relid)
+{
+	RelationSyncEntry *entry;
+
+	/*
+	 * We can get here if the plugin was used in SQL interface as the
+	 * RelSchemaSyncCache is destroyed when the decoding finishes, but there
+	 * is no way to unregister the relcache invalidation callback.
+	 */
+	if (RelationSyncCache == NULL)
+		return;
+
+	/*
+	 * Nobody keeps pointers to entries in this hash table around outside
+	 * logical decoding callback calls - but invalidation events can come in
+	 * *during* a callback if we access the relcache in the callback. Because
+	 * of that we must mark the cache entry as invalid but not remove it from
+	 * the hash while it could still be referenced, then prune it at a later
+	 * safe point.
+	 *
+	 * Getting invalidations for relations that aren't in the table is
+	 * entirely normal, since there's no way to unregister for an invalidation
+	 * event. So we don't care if it's found or not.
+	 */
+	entry = (RelationSyncEntry *) hash_search(RelationSyncCache, &relid,
+											  HASH_FIND, NULL);
+
+	/*
+	 * Reset schema sent status as the relation definition may have changed.
+	 * Also free any objects that depended on the earlier definition.
+	 */
+	if (entry != NULL)
+	{
+		entry->schema_sent = false;
+		list_free(entry->streamed_txns);
+		entry->streamed_txns = NIL;
+		if (entry->map)
+		{
+			/*
+			 * Must free the TupleDescs contained in the map explicitly,
+			 * because free_conversion_map() doesn't.
+			 */
+			FreeTupleDesc(entry->map->indesc);
+			FreeTupleDesc(entry->map->outdesc);
+			free_conversion_map(entry->map);
+		}
+		entry->map = NULL;
+	}
+}
+
+/*
+ * Publication relation map syscache invalidation callback
+ */
+static void
+rel_sync_cache_publication_cb(Datum arg, int cacheid, uint32 hashvalue)
+{
+	HASH_SEQ_STATUS status;
+	RelationSyncEntry *entry;
+
+	/*
+	 * We can get here if the plugin was used in SQL interface as the
+	 * RelSchemaSyncCache is destroyed when the decoding finishes, but there
+	 * is no way to unregister the relcache invalidation callback.
+	 */
+	if (RelationSyncCache == NULL)
+		return;
+
+	/*
+	 * There is no way to find which entry in our cache the hash belongs to so
+	 * mark the whole cache as invalid.
+	 */
+	hash_seq_init(&status, RelationSyncCache);
+	while ((entry = (RelationSyncEntry *) hash_seq_search(&status)) != NULL)
+	{
+		entry->replicate_valid = false;
+
+		/*
+		 * There might be some relations dropped from the publication so we
+		 * don't need to publish the changes for them.
+		 */
+		entry->pubactions.pubinsert = false;
+		entry->pubactions.pubupdate = false;
+		entry->pubactions.pubdelete = false;
+		entry->pubactions.pubtruncate = false;
+	}
+}
+
+/*
+ * Try to update progress and send a keepalive message if too many changes were
+ * processed.
+ *
+ * For a large transaction, if we don't send any change to the downstream for a
+ * long time (exceeds the wal_receiver_timeout of standby) then it can timeout.
+ * This can happen when all or most of the changes are not published.
+ */
+static void
+update_replication_progress(LogicalDecodingContext *ctx)
+{
+	static int	changes_count = 0;
+
+	/*
+	 * We don't want to try sending a keepalive message after processing each
+	 * change as that can have overhead. Tests revealed that there is no
+	 * noticeable overhead in doing it after continuously processing 100 or so
+	 * changes.
+	 */
+#define CHANGES_THRESHOLD 100
+
+	/*
+	 * If we are at the end of transaction LSN, update progress tracking.
+	 * Otherwise, after continuously processing CHANGES_THRESHOLD changes, we
+	 * try to send a keepalive message if required.
+	 */
+	if (ctx->end_xact || ++changes_count >= CHANGES_THRESHOLD)
+	{
+		OutputPluginUpdateProgress(ctx);
+		changes_count = 0;
+	}
+}