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bdr_output.c
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bdr_output.c
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/*-------------------------------------------------------------------------
*
* bdr_output.c
* BDR output plugin
*
* Copyright (c) 2012-2015, PostgreSQL Global Development Group
*
* IDENTIFICATION
* bdr_output.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "bdr.h"
#include "bdr_internal.h"
#include "miscadmin.h"
#include "access/sysattr.h"
#include "access/tuptoaster.h"
#include "access/xact.h"
#include "catalog/catversion.h"
#include "catalog/index.h"
#include "catalog/namespace.h"
#include "catalog/pg_class.h"
#include "catalog/pg_database.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_type.h"
#include "commands/dbcommands.h"
#include "executor/spi.h"
#include "libpq/pqformat.h"
#include "mb/pg_wchar.h"
#include "nodes/parsenodes.h"
#include "replication/logical.h"
#include "replication/output_plugin.h"
#include "replication/replication_identifier.h"
#include "replication/slot.h"
#include "replication/walsender_private.h"
#include "storage/proc.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/rel.h"
#include "utils/syscache.h"
#include "utils/timestamp.h"
#include "utils/typcache.h"
extern void _PG_output_plugin_init(OutputPluginCallbacks *cb);
typedef struct
{
MemoryContext context;
uint64 remote_sysid;
TimeLineID remote_timeline;
Oid remote_dboid;
bool allow_binary_protocol;
bool allow_sendrecv_protocol;
bool int_datetime_mismatch;
bool forward_changesets;
uint32 client_pg_version;
uint32 client_pg_catversion;
uint32 client_bdr_version;
char *client_bdr_variant;
uint32 client_min_bdr_version;
size_t client_sizeof_int;
size_t client_sizeof_long;
size_t client_sizeof_datum;
size_t client_maxalign;
bool client_bigendian;
bool client_float4_byval;
bool client_float8_byval;
bool client_int_datetime;
char *client_db_encoding;
Oid bdr_schema_oid;
Oid bdr_conflict_handlers_reloid;
Oid bdr_locks_reloid;
Oid bdr_conflict_history_reloid;
int num_replication_sets;
char **replication_sets;
} BdrOutputData;
/* These must be available to pg_dlsym() */
static void pg_decode_startup(LogicalDecodingContext * ctx, OutputPluginOptions *opt,
bool is_init);
static void pg_decode_shutdown(LogicalDecodingContext * ctx);
static void pg_decode_begin_txn(LogicalDecodingContext *ctx,
ReorderBufferTXN *txn);
static void pg_decode_commit_txn(LogicalDecodingContext *ctx,
ReorderBufferTXN *txn, XLogRecPtr commit_lsn);
static void pg_decode_change(LogicalDecodingContext *ctx,
ReorderBufferTXN *txn, Relation rel,
ReorderBufferChange *change);
static void pg_decode_message(LogicalDecodingContext *ctx,
ReorderBufferTXN *txn, XLogRecPtr message_lsn,
bool transactional, Size sz,
const char *message);
/* private prototypes */
static void write_rel(StringInfo out, Relation rel);
static void write_tuple(BdrOutputData *data, StringInfo out, Relation rel,
HeapTuple tuple);
/* specify output plugin callbacks */
void
_PG_output_plugin_init(OutputPluginCallbacks *cb)
{
AssertVariableIsOfType(&_PG_output_plugin_init, LogicalOutputPluginInit);
cb->startup_cb = pg_decode_startup;
cb->begin_cb = pg_decode_begin_txn;
cb->change_cb = pg_decode_change;
cb->commit_cb = pg_decode_commit_txn;
cb->message_cb = pg_decode_message;
cb->shutdown_cb = pg_decode_shutdown;
}
/* Ensure a bdr_parse_... arg is non-null */
static void
bdr_parse_notnull(DefElem *elem, const char *paramtype)
{
if (elem->arg == NULL || strVal(elem->arg) == NULL)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("%s parameter \"%s\" had no value",
paramtype, elem->defname)));
}
static void
bdr_parse_uint32(DefElem *elem, uint32 *res)
{
bdr_parse_notnull(elem, "uint32");
errno = 0;
*res = strtoul(strVal(elem->arg), NULL, 0);
if (errno != 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not parse uint32 value \"%s\" for parameter \"%s\": %m",
strVal(elem->arg), elem->defname)));
}
static void
bdr_parse_size_t(DefElem *elem, size_t *res)
{
bdr_parse_notnull(elem, "size_t");
errno = 0;
*res = strtoull(strVal(elem->arg), NULL, 0);
if (errno != 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not parse size_t value \"%s\" for parameter \"%s\": %m",
strVal(elem->arg), elem->defname)));
}
static void
bdr_parse_bool(DefElem *elem, bool *res)
{
bdr_parse_notnull(elem, "bool");
if (!parse_bool(strVal(elem->arg), res))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not parse boolean value \"%s\" for parameter \"%s\": %m",
strVal(elem->arg), elem->defname)));
}
static void
bdr_parse_identifier_list_arr(DefElem *elem, char ***list, int *len)
{
List *namelist;
ListCell *c;
bdr_parse_notnull(elem, "list");
if (!SplitIdentifierString(pstrdup(strVal(elem->arg)),
',', &namelist))
{
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not identifier list value \"%s\" for parameter \"%s\": %m",
strVal(elem->arg), elem->defname)));
}
*len = 0;
*list = palloc(list_length(namelist) * sizeof(char *));
foreach(c, namelist)
{
(*list)[(*len)++] = pstrdup(lfirst(c));
}
list_free(namelist);
}
static void
bdr_parse_str(DefElem *elem, char **res)
{
bdr_parse_notnull(elem, "string");
*res = pstrdup(strVal(elem->arg));
}
static void
bdr_req_param(const char *param)
{
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("missing value for for parameter \"%s\"",
param)));
}
/*
* Check bdr.bdr_nodes entry in local DB and if status != r
* and we're trying to begin logical replay, raise an error.
*
* Also prevents slot creation if the BDR extension isn't installed in the
* local node.
*
* If this function returns it's safe to begin replay.
*/
static void
bdr_ensure_node_ready(BdrOutputData *data)
{
int spi_ret;
const uint64 sysid = GetSystemIdentifier();
char our_status;
char remote_status;
BDRNodeInfo *our_node;
BDRNodeInfo *remote_node;
NameData dbname;
char *tmp_dbname;
/* We need dbname valid outside this transaction, so copy it */
tmp_dbname = get_database_name(MyDatabaseId);
strncpy(NameStr(dbname), tmp_dbname, NAMEDATALEN);
NameStr(dbname)[NAMEDATALEN-1] = '\0';
pfree(tmp_dbname);
/*
* Refuse to begin replication if the local node isn't yet ready to
* send data. Check the status in bdr.bdr_nodes.
*/
spi_ret = SPI_connect();
if (spi_ret != SPI_OK_CONNECT)
elog(ERROR, "Local SPI connect failed; shouldn't happen");
our_node = bdr_nodes_get_local_info(sysid, ThisTimeLineID, MyDatabaseId);
remote_node = bdr_nodes_get_local_info(
data->remote_sysid, data->remote_timeline, data->remote_dboid);
our_status = our_node == NULL ? '\0' : our_node->status;
remote_status = remote_node == NULL ? '\0' : remote_node->status;
bdr_bdr_node_free(our_node);
bdr_bdr_node_free(remote_node);
SPI_finish();
if (remote_status == 'k')
{
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("bdr output plugin: slot usage rejected, node killed")));
}
/*
* Complain if node isn't ready,
* i.e. state is fully 'r'eady, or waiting for inbound sl'o't creation.
*/
/* TODO: Allow soft error so caller can sleep and recheck? */
if (our_status != 'r' && our_status != 'o')
{
const char * const base_msg =
"bdr output plugin: slot creation rejected, bdr.bdr_nodes entry for local node (sysid=" UINT64_FORMAT
", timelineid=%u, dboid=%u): %s";
switch (our_status)
{
case 'r':
case 'o':
break; /* unreachable */
case '\0':
case 'b':
/*
* Can't allow replay when BDR hasn't started yet, as
* replica init might still need to run, causing a dump to
* be applied, catchup from a remote node, etc.
*
* If there's no init_replica set, the bdr extension will
* create a bdr.bdr_nodes entry with 'r' state shortly
* after it starts, so we won't hit this.
*/
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg(base_msg, sysid, ThisTimeLineID, MyDatabaseId,
"does not exist"),
errdetail("BDR is not active on this database or is still initializing."),
errhint("Add bdr to shared_preload_libraries and check logs for bdr startup errors.")));
break;
case 'c':
/*
* Can't allow replay while still catching up. We get the
* real origin node ID and LSN over the protocol in catchup
* mode, but changes are written to WAL with the ID and LSN
* of the immediate origin node. So if we cascade them to
* another node now, they'll incorrectly see the immediate
* origin node ID and LSN, not the true original ones.
*
* It should be possible to lift this restriction later,
* if we write the original node id and lsn in WAL.
*/
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg(base_msg, sysid, ThisTimeLineID, MyDatabaseId,
"status='c', bdr still starting up: catching up from remote node"),
errhint("Monitor pg_stat_replication on the remote node, watch the logs and wait until the node has caught up")));
break;
case 'i':
/*
* Can't allow replay while still applying a dump because the
* origin_id and origin_lsn are not preserved on the dump, so
* we'd replay all the changes. If the connections are from
* nodes that already have that data (or the origin node),
* that'll create a right mess.
*/
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg(base_msg, sysid, ThisTimeLineID, MyDatabaseId,
"status='i', bdr still starting up: applying initial dump of remote node"),
errhint("Monitor pg_stat_activity and the logs, wait until the node has caught up")));
break;
case 'k':
elog(ERROR, "node is exiting");
break;
default:
elog(ERROR, "Unhandled case status=%c", our_status);
break;
}
}
}
/* initialize this plugin */
static void
pg_decode_startup(LogicalDecodingContext * ctx, OutputPluginOptions *opt, bool is_init)
{
ListCell *option;
BdrOutputData *data;
Oid schema_oid;
bool tx_started = false;
Oid local_dboid;
data = palloc0(sizeof(BdrOutputData));
data->context = AllocSetContextCreate(TopMemoryContext,
"bdr conversion context",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
ctx->output_plugin_private = data;
opt->output_type = OUTPUT_PLUGIN_BINARY_OUTPUT;
data->bdr_conflict_history_reloid = InvalidOid;
data->bdr_conflict_handlers_reloid = InvalidOid;
data->bdr_locks_reloid = InvalidOid;
data->bdr_schema_oid = InvalidOid;
data->num_replication_sets = -1;
/* parse where the connection has to be from */
bdr_parse_slot_name(NameStr(MyReplicationSlot->data.name),
&data->remote_sysid,
&data->remote_timeline,
&data->remote_dboid,
&local_dboid);
/* parse options passed in by the client */
foreach(option, ctx->output_plugin_options)
{
DefElem *elem = lfirst(option);
Assert(elem->arg == NULL || IsA(elem->arg, String));
if (strcmp(elem->defname, "pg_version") == 0)
bdr_parse_uint32(elem, &data->client_pg_version);
else if (strcmp(elem->defname, "pg_catversion") == 0)
bdr_parse_uint32(elem, &data->client_pg_catversion);
else if (strcmp(elem->defname, "bdr_version") == 0)
bdr_parse_uint32(elem, &data->client_bdr_version);
else if (strcmp(elem->defname, "bdr_variant") == 0)
bdr_parse_str(elem, &data->client_bdr_variant);
else if (strcmp(elem->defname, "min_bdr_version") == 0)
bdr_parse_uint32(elem, &data->client_min_bdr_version);
else if (strcmp(elem->defname, "sizeof_int") == 0)
bdr_parse_size_t(elem, &data->client_sizeof_int);
else if (strcmp(elem->defname, "sizeof_long") == 0)
bdr_parse_size_t(elem, &data->client_sizeof_long);
else if (strcmp(elem->defname, "sizeof_datum") == 0)
bdr_parse_size_t(elem, &data->client_sizeof_datum);
else if (strcmp(elem->defname, "maxalign") == 0)
bdr_parse_size_t(elem, &data->client_maxalign);
else if (strcmp(elem->defname, "bigendian") == 0)
bdr_parse_bool(elem, &data->client_bigendian);
else if (strcmp(elem->defname, "float4_byval") == 0)
bdr_parse_bool(elem, &data->client_float4_byval);
else if (strcmp(elem->defname, "float8_byval") == 0)
bdr_parse_bool(elem, &data->client_float8_byval);
else if (strcmp(elem->defname, "integer_datetimes") == 0)
bdr_parse_bool(elem, &data->client_int_datetime);
else if (strcmp(elem->defname, "db_encoding") == 0)
data->client_db_encoding = pstrdup(strVal(elem->arg));
else if (strcmp(elem->defname, "forward_changesets") == 0)
bdr_parse_bool(elem, &data->forward_changesets);
else if (strcmp(elem->defname, "unidirectional") == 0)
{
bool is_unidirectional;
bdr_parse_bool(elem, &is_unidirectional);
if (is_unidirectional)
elog(ERROR, "support for unidirectional connections has been removed");
}
else if (strcmp(elem->defname, "replication_sets") == 0)
{
int i;
/* parse list */
bdr_parse_identifier_list_arr(elem,
&data->replication_sets,
&data->num_replication_sets);
Assert(data->num_replication_sets >= 0);
/* validate elements */
for (i = 0; i < data->num_replication_sets; i++)
bdr_validate_replication_set_name(data->replication_sets[i],
true);
/* make it bsearch()able */
qsort(data->replication_sets, data->num_replication_sets,
sizeof(char *), pg_qsort_strcmp);
}
else if (strcmp(elem->defname, "interactive") == 0)
{
/*
* Set defaults for interactive mode
*
* This is used for examining the replication queue from SQL.
*/
data->client_pg_version = PG_VERSION_NUM;
data->client_pg_catversion = CATALOG_VERSION_NO;
data->client_bdr_version = BDR_VERSION_NUM;
data->client_bdr_variant = BDR_VARIANT;
data->client_min_bdr_version = BDR_VERSION_NUM;
data->client_sizeof_int = sizeof(int);
data->client_sizeof_long = sizeof(long);
data->client_sizeof_datum = sizeof(Datum);
data->client_maxalign = MAXIMUM_ALIGNOF;
data->client_bigendian = bdr_get_bigendian();
data->client_float4_byval = bdr_get_float4byval();
data->client_float8_byval = bdr_get_float8byval();
data->client_int_datetime = bdr_get_integer_timestamps();
data->client_db_encoding = pstrdup(GetDatabaseEncodingName());
}
else
{
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("option \"%s\" = \"%s\" is unknown",
elem->defname,
elem->arg ? strVal(elem->arg) : "(null)")));
}
}
/*
* Ensure that the BDR extension is installed on this database.
*
* We must prevent slot creation before the BDR extension is created,
* otherwise the event trigger for DDL replication will record the
* extension's creation in bdr.bdr_queued_commands and the slot position
* will be before then, causing CREATE EXTENSION to be replayed. Since
* the other end already has the BDR extension (obviously) this will
* cause replay to fail.
*
* TODO: Should really test for the extension its self, but this is faster
* and easier...
*/
if (!IsTransactionState())
{
tx_started = true;
StartTransactionCommand();
}
/* BDR extension must be installed. */
if (get_namespace_oid("bdr", true) == InvalidOid)
{
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("bdr extension does not exist on " BDR_LOCALID_FORMAT,
BDR_LOCALID_FORMAT_ARGS),
errdetail("Cannot create a BDR slot without the BDR extension installed")));
}
/* no options are passed in during initialization, so don't complain there */
if (!is_init)
{
if (data->client_pg_version == 0)
bdr_req_param("pg_version");
if (data->client_pg_catversion == 0)
bdr_req_param("pg_catversion");
if (data->client_bdr_version == 0)
bdr_req_param("bdr_version");
if (data->client_min_bdr_version == 0)
bdr_req_param("min_bdr_version");
if (data->client_sizeof_int == 0)
bdr_req_param("sizeof_int");
if (data->client_sizeof_long == 0)
bdr_req_param("sizeof_long");
if (data->client_sizeof_datum == 0)
bdr_req_param("sizeof_datum");
if (data->client_maxalign == 0)
bdr_req_param("maxalign");
/* XXX: can't check for boolean values this way */
if (data->client_db_encoding == NULL)
bdr_req_param("db_encoding");
/* check incompatibilities we cannot work around */
if (strcmp(data->client_db_encoding, GetDatabaseEncodingName()) != 0)
elog(ERROR, "mismatching encodings are not yet supported");
if (data->client_min_bdr_version > BDR_VERSION_NUM)
elog(ERROR, "incompatible bdr client and server versions, server too old");
if (data->client_bdr_version < BDR_MIN_REMOTE_VERSION_NUM)
elog(ERROR, "incompatible bdr client and server versions, client too old");
data->allow_binary_protocol = true;
data->allow_sendrecv_protocol = true;
/*
* Now use the passed in information to determine how to encode the
* data sent by the output plugin. We don't make datatype specific
* decisions here, just generic decisions about using binary and/or
* send/recv protocols.
*/
/*
* Don't use the binary protocol if there are fundamental arch
* differences.
*/
if (data->client_sizeof_int != sizeof(int) ||
data->client_sizeof_long != sizeof(long) ||
data->client_sizeof_datum != sizeof(Datum))
{
data->allow_binary_protocol = false;
elog(LOG, "disabling binary protocol because of sizeof differences");
}
else if (data->client_bigendian != bdr_get_bigendian())
{
data->allow_binary_protocol = false;
elog(LOG, "disabling binary protocol because of endianess difference");
}
/*
* We also can't use the binary protocol if there are critical
* differences in compile time settings.
*/
if (data->client_float4_byval != bdr_get_float4byval() ||
data->client_float8_byval != bdr_get_float8byval())
data->allow_binary_protocol = false;
if (data->client_int_datetime != bdr_get_integer_timestamps())
data->int_datetime_mismatch = true;
else
data->int_datetime_mismatch = false;
/*
* Don't use the send/recv protocol if there are version
* differences. There currently isn't any guarantee for cross version
* compatibility of the send/recv representations. But there actually
* *is* a compat. guarantee for architecture differences...
*
* XXX: We could easily do better by doing per datatype considerations
* if there are known incompatibilities.
*/
if (data->client_pg_version / 100 != PG_VERSION_NUM / 100)
data->allow_sendrecv_protocol = false;
bdr_maintain_schema(false);
data->bdr_schema_oid = get_namespace_oid("bdr", true);
schema_oid = data->bdr_schema_oid;
if (schema_oid != InvalidOid)
{
data->bdr_conflict_handlers_reloid =
get_relname_relid("bdr_conflict_handlers", schema_oid);
if (data->bdr_conflict_handlers_reloid == InvalidOid)
elog(ERROR, "cache lookup for relation bdr.bdr_conflict_handlers failed");
else
elog(DEBUG1, "bdr.bdr_conflict_handlers OID set to %u",
data->bdr_conflict_handlers_reloid);
data->bdr_conflict_history_reloid =
get_relname_relid("bdr_conflict_history", schema_oid);
if (data->bdr_conflict_history_reloid == InvalidOid)
elog(ERROR, "cache lookup for relation bdr.bdr_conflict_history failed");
data->bdr_locks_reloid =
get_relname_relid("bdr_global_locks", schema_oid);
if (data->bdr_locks_reloid == InvalidOid)
elog(ERROR, "cache lookup for relation bdr.bdr_locks failed");
}
else
elog(WARNING, "cache lookup for schema bdr failed");
/*
* Make sure it's safe to begin playing changes to the remote end.
* This'll ERROR out if we're not ready. Note that this does NOT
* prevent slot creation, only START_REPLICATION from the slot.
*/
bdr_ensure_node_ready(data);
}
if (tx_started)
CommitTransactionCommand();
/*
* Everything looks ok. Acquire a shmem slot to represent us running.
*/
{
uint32 worker_idx;
LWLockAcquire(BdrWorkerCtl->lock, LW_EXCLUSIVE);
if (BdrWorkerCtl->worker_management_paused)
{
elog(ERROR, "BDR worker management is currently paused, walsender exiting. Retry later.");
LWLockRelease(BdrWorkerCtl->lock);
}
bdr_worker_shmem_alloc(BDR_WORKER_WALSENDER, &worker_idx);
bdr_worker_shmem_acquire(BDR_WORKER_WALSENDER, worker_idx, true);
bdr_worker_slot->worker_pid = MyProcPid;
bdr_worker_slot->worker_proc = MyProc;
/* can be null if sql interface is used */
bdr_worker_slot->data.walsnd.walsender = MyWalSnd;
bdr_worker_slot->data.walsnd.slot = MyReplicationSlot;
bdr_worker_slot->data.walsnd.remote_sysid = data->remote_sysid;
bdr_worker_slot->data.walsnd.remote_timeline = data->remote_timeline;
bdr_worker_slot->data.walsnd.remote_dboid = data->remote_dboid;
LWLockRelease(BdrWorkerCtl->lock);
}
}
static void
pg_decode_shutdown(LogicalDecodingContext * ctx)
{
/* release and free slot */
bdr_worker_shmem_release();
}
/*
* Only changesets generated on the local node should be replicated
* to the client unless we're in changeset forwarding mode.
*/
static inline bool
should_forward_changeset(LogicalDecodingContext *ctx, BdrOutputData *data,
ReorderBufferTXN *txn)
{
return txn->origin_id == InvalidRepNodeId || data->forward_changesets;
}
static inline bool
should_forward_change(LogicalDecodingContext *ctx, BdrOutputData *data,
BDRRelation *r, enum ReorderBufferChangeType change)
{
/* internal bdr relations that may not be replicated */
if (RelationGetRelid(r->rel) == data->bdr_conflict_handlers_reloid ||
RelationGetRelid(r->rel) == data->bdr_locks_reloid ||
RelationGetRelid(r->rel) == data->bdr_conflict_history_reloid)
return false;
/*
* Quite ugly, but there's no neat way right now: Flush replication set
* configuration from bdr's relcache.
*/
if (RelationGetRelid(r->rel) == BdrReplicationSetConfigRelid)
BDRRelcacheHashInvalidateCallback(0, InvalidOid);
/* always replicate other stuff in the bdr schema */
if (r->rel->rd_rel->relnamespace == data->bdr_schema_oid)
return true;
if (!r->computed_repl_valid)
bdr_heap_compute_replication_settings(r,
data->num_replication_sets,
data->replication_sets);
/* Check whether the current action is configured to be replicated */
switch (change)
{
case REORDER_BUFFER_CHANGE_INSERT:
return r->computed_repl_insert;
case REORDER_BUFFER_CHANGE_UPDATE:
return r->computed_repl_update;
case REORDER_BUFFER_CHANGE_DELETE:
return r->computed_repl_delete;
default:
elog(ERROR, "should be unreachable");
}
}
/*
* BEGIN callback
*
* If you change this you must also change the corresponding code in
* bdr_apply.c . Make sure that any flags are in sync.
*/
void
pg_decode_begin_txn(LogicalDecodingContext *ctx, ReorderBufferTXN *txn)
{
BdrOutputData *data = ctx->output_plugin_private;
int flags = 0;
AssertVariableIsOfType(&pg_decode_begin_txn, LogicalDecodeBeginCB);
if (!should_forward_changeset(ctx, data, txn))
return;
OutputPluginPrepareWrite(ctx, true);
pq_sendbyte(ctx->out, 'B'); /* BEGIN */
/*
* Are we forwarding changesets from other nodes? If so, we must include
* the origin node ID and LSN in BEGIN records.
*/
if (data->forward_changesets)
flags |= BDR_OUTPUT_TRANSACTION_HAS_ORIGIN;
/* send the flags field its self */
pq_sendint(ctx->out, flags, 4);
/* fixed fields */
pq_sendint64(ctx->out, txn->final_lsn);
pq_sendint64(ctx->out, txn->commit_time);
pq_sendint(ctx->out, txn->xid, 4);
/* and optional data selected above */
if (flags & BDR_OUTPUT_TRANSACTION_HAS_ORIGIN)
{
/*
* The RepNodeId in txn->origin_id is our local identifier for the
* origin node, but it's not valid outside our node. It must be
* converted into the (sysid, tlid, dboid) that uniquely identifies the
* node globally so that can be sent.
*/
uint64 origin_sysid;
TimeLineID origin_tlid;
Oid origin_dboid = InvalidOid;
bdr_fetch_sysid_via_node_id(txn->origin_id, &origin_sysid,
&origin_tlid, &origin_dboid);
pq_sendint64(ctx->out, origin_sysid);
pq_sendint(ctx->out, origin_tlid, 4);
pq_sendint(ctx->out, origin_dboid, 4);
pq_sendint64(ctx->out, txn->origin_lsn);
}
OutputPluginWrite(ctx, true);
return;
}
/*
* COMMIT callback
*
* Send the LSN at the time of the commit, the commit time, and the end LSN.
*
* The presence of additional records is controlled by a flag field, with
* records that're present appearing strictly in the order they're listed
* here. There is no sub-record header or other structure beyond the flags
* field.
*
* If you change this, you'll need to change process_remote_commit(...)
* too. Make sure to keep any flags in sync.
*/
void
pg_decode_commit_txn(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
XLogRecPtr commit_lsn)
{
BdrOutputData *data = ctx->output_plugin_private;
int flags = 0;
if (!should_forward_changeset(ctx, data, txn))
return;
OutputPluginPrepareWrite(ctx, true);
pq_sendbyte(ctx->out, 'C'); /* sending COMMIT */
/* send the flags field its self */
pq_sendint(ctx->out, flags, 4);
/* Send fixed fields */
pq_sendint64(ctx->out, commit_lsn);
pq_sendint64(ctx->out, txn->end_lsn);
pq_sendint64(ctx->out, txn->commit_time);
OutputPluginWrite(ctx, true);
}
void
pg_decode_change(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
Relation relation, ReorderBufferChange *change)
{
BdrOutputData *data;
MemoryContext old;
BDRRelation *bdr_relation;
bdr_relation = bdr_heap_open(RelationGetRelid(relation), NoLock);
data = ctx->output_plugin_private;
/* Avoid leaking memory by using and resetting our own context */
old = MemoryContextSwitchTo(data->context);
if (!should_forward_changeset(ctx, data, txn))
return;
if (!should_forward_change(ctx, data, bdr_relation, change->action))
return;
OutputPluginPrepareWrite(ctx, true);
switch (change->action)
{
case REORDER_BUFFER_CHANGE_INSERT:
pq_sendbyte(ctx->out, 'I'); /* action INSERT */
write_rel(ctx->out, relation);
pq_sendbyte(ctx->out, 'N'); /* new tuple follows */
write_tuple(data, ctx->out, relation, &change->data.tp.newtuple->tuple);
break;
case REORDER_BUFFER_CHANGE_UPDATE:
pq_sendbyte(ctx->out, 'U'); /* action UPDATE */
write_rel(ctx->out, relation);
if (change->data.tp.oldtuple != NULL)
{
pq_sendbyte(ctx->out, 'K'); /* old key follows */
write_tuple(data, ctx->out, relation,
&change->data.tp.oldtuple->tuple);
}
pq_sendbyte(ctx->out, 'N'); /* new tuple follows */
write_tuple(data, ctx->out, relation,
&change->data.tp.newtuple->tuple);
break;
case REORDER_BUFFER_CHANGE_DELETE:
pq_sendbyte(ctx->out, 'D'); /* action DELETE */
write_rel(ctx->out, relation);
if (change->data.tp.oldtuple != NULL)
{
pq_sendbyte(ctx->out, 'K'); /* old key follows */
write_tuple(data, ctx->out, relation,
&change->data.tp.oldtuple->tuple);
}
else
pq_sendbyte(ctx->out, 'E'); /* empty */
break;
default:
Assert(false);
}
OutputPluginWrite(ctx, true);
MemoryContextSwitchTo(old);
MemoryContextReset(data->context);
bdr_heap_close(bdr_relation, NoLock);
}
/*
* Write schema.relation to the output stream.
*/
static void
write_rel(StringInfo out, Relation rel)
{
const char *nspname;
int64 nspnamelen;
const char *relname;
int64 relnamelen;
nspname = get_namespace_name(rel->rd_rel->relnamespace);
if (nspname == NULL)
elog(ERROR, "cache lookup failed for namespace %u",
rel->rd_rel->relnamespace);
nspnamelen = strlen(nspname) + 1;
relname = NameStr(rel->rd_rel->relname);
relnamelen = strlen(relname) + 1;
pq_sendint(out, nspnamelen, 2); /* schema name length */
appendBinaryStringInfo(out, nspname, nspnamelen);
pq_sendint(out, relnamelen, 2); /* table name length */
appendBinaryStringInfo(out, relname, relnamelen);
}
/*
* Make the executive decision about which protocol to use.
*/
static void
decide_datum_transfer(BdrOutputData *data,
Form_pg_attribute att, Form_pg_type typclass,
bool *use_binary, bool *use_sendrecv)
{
/* always disallow fancyness if there's type representation mismatches */
if (data->int_datetime_mismatch &&
(att->atttypid == TIMESTAMPOID || att->atttypid == TIMESTAMPTZOID ||
att->atttypid == TIMEOID))
{
*use_binary = false;
*use_sendrecv = false;
}
/*
* Use the binary protocol, if allowed, for builtin & plain datatypes.
*/
else if (data->allow_binary_protocol &&
typclass->typtype == 'b' &&
att->atttypid < FirstNormalObjectId &&
typclass->typelem == InvalidOid)
{
*use_binary = true;
}
/*
* Use send/recv, if allowed, if the type is plain or builtin.
*
* XXX: we can't use send/recv for array or composite types for now due to
* the embedded oids.
*/
else if (data->allow_sendrecv_protocol &&
OidIsValid(typclass->typreceive) &&
(att->atttypid < FirstNormalObjectId || typclass->typtype != 'c') &&
(att->atttypid < FirstNormalObjectId || typclass->typelem == InvalidOid))
{
*use_sendrecv = true;
}
}
/*
* Write a tuple to the outputstream, in the most efficient format possible.
*/
static void
write_tuple(BdrOutputData *data, StringInfo out, Relation rel,
HeapTuple tuple)
{
TupleDesc desc;
Datum values[MaxTupleAttributeNumber];
bool isnull[MaxTupleAttributeNumber];
int i;
desc = RelationGetDescr(rel);
pq_sendbyte(out, 'T'); /* tuple follows */
pq_sendint(out, desc->natts, 4); /* number of attributes */
/* try to allocate enough memory from the get go */
enlargeStringInfo(out, tuple->t_len +
desc->natts * ( 1 + 4));
/*
* XXX: should this prove to be a relevant bottleneck, it might be
* interesting to inline heap_deform_tuple() here, we don't actually need
* the information in the form we get from it.
*/
heap_deform_tuple(tuple, desc, values, isnull);
for (i = 0; i < desc->natts; i++)
{
HeapTuple typtup;
Form_pg_type typclass;
Form_pg_attribute att = desc->attrs[i];
bool use_binary = false;
bool use_sendrecv = false;