openGauss-server/contrib/test_decoding/test_decoding.cpp

364 lines
12 KiB
C++

/*-------------------------------------------------------------------------
*
* test_decoding.c
* example logical decoding output plugin
*
* Copyright (c) 2012-2014, PostgreSQL Global Development Group
*
* IDENTIFICATION
* contrib/test_decoding/test_decoding.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "knl/knl_variable.h"
#include "access/sysattr.h"
#include "catalog/pg_class.h"
#include "catalog/pg_type.h"
#include "nodes/parsenodes.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/rel.h"
#include "utils/relcache.h"
#include "utils/syscache.h"
#include "utils/typcache.h"
#include "replication/output_plugin.h"
#include "replication/logical.h"
PG_MODULE_MAGIC;
/* These must be available to pg_dlsym() */
extern "C" void _PG_init(void);
extern "C" void _PG_output_plugin_init(OutputPluginCallbacks* cb);
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_output_begin(
LogicalDecodingContext* ctx, PluginTestDecodingData* data, ReorderBufferTXN* txn, bool last_write);
static void pg_decode_commit_txn(LogicalDecodingContext* ctx, ReorderBufferTXN* txn, XLogRecPtr commit_lsn);
static void pg_decode_abort_txn(LogicalDecodingContext* ctx, ReorderBufferTXN* txn);
static void pg_decode_prepare_txn(LogicalDecodingContext* ctx, ReorderBufferTXN* txn);
static void pg_decode_change(
LogicalDecodingContext* ctx, ReorderBufferTXN* txn, Relation rel, ReorderBufferChange* change);
static bool pg_decode_filter(LogicalDecodingContext* ctx, RepOriginId origin_id);
void _PG_init(void)
{
/* other plugins can perform things here */
}
/* 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->abort_cb = pg_decode_abort_txn;
cb->prepare_cb = pg_decode_prepare_txn;
cb->filter_by_origin_cb = pg_decode_filter;
cb->shutdown_cb = pg_decode_shutdown;
}
/* initialize this plugin */
static void pg_decode_startup(LogicalDecodingContext* ctx, OutputPluginOptions* opt, bool is_init)
{
ListCell* option = NULL;
PluginTestDecodingData* data = NULL;
data = (PluginTestDecodingData*)palloc0(sizeof(PluginTestDecodingData));
data->context = AllocSetContextCreate(ctx->context,
"text conversion context",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
data->include_xids = true;
data->include_timestamp = true;
data->skip_empty_xacts = false;
data->only_local = true;
data->tableWhiteList = NIL;
ctx->output_plugin_private = data;
opt->output_type = OUTPUT_PLUGIN_TEXTUAL_OUTPUT;
foreach (option, ctx->output_plugin_options) {
ParseDecodingOptionPlugin(option, data, opt);
}
}
/* cleanup this plugin's resources */
static void pg_decode_shutdown(LogicalDecodingContext* ctx)
{
PluginTestDecodingData* data = (PluginTestDecodingData*)ctx->output_plugin_private;
/* cleanup our own resources via memory context reset */
MemoryContextDelete(data->context);
}
/* BEGIN callback */
static void pg_decode_begin_txn(LogicalDecodingContext* ctx, ReorderBufferTXN* txn)
{
PluginTestDecodingData* data = (PluginTestDecodingData*)ctx->output_plugin_private;
data->xact_wrote_changes = false;
if (data->skip_empty_xacts) {
return;
}
pg_output_begin(ctx, data, txn, true);
}
static void pg_output_begin(LogicalDecodingContext* ctx, PluginTestDecodingData* data, ReorderBufferTXN* txn,
bool last_write)
{
OutputPluginPrepareWrite(ctx, last_write);
if (data->include_xids)
appendStringInfo(ctx->out, "BEGIN %lu", txn->xid);
else
appendStringInfoString(ctx->out, "BEGIN");
OutputPluginWrite(ctx, last_write);
}
/* COMMIT callback */
static void pg_decode_commit_txn(LogicalDecodingContext* ctx, ReorderBufferTXN* txn, XLogRecPtr commit_lsn)
{
PluginTestDecodingData* data = (PluginTestDecodingData*)ctx->output_plugin_private;
if (data->skip_empty_xacts && !data->xact_wrote_changes)
return;
OutputPluginPrepareWrite(ctx, true);
if (data->include_xids)
appendStringInfo(ctx->out, "COMMIT %lu", txn->xid);
else
appendStringInfoString(ctx->out, "COMMIT");
if (data->include_timestamp)
appendStringInfo(ctx->out, " (at %s)", timestamptz_to_str(txn->commit_time));
appendStringInfo(ctx->out, " CSN %lu", txn->csn);
OutputPluginWrite(ctx, true);
}
/* ABORT callback */
static void pg_decode_abort_txn(LogicalDecodingContext* ctx, ReorderBufferTXN* txn)
{
PluginTestDecodingData* data = (PluginTestDecodingData*)ctx->output_plugin_private;
if (data->skip_empty_xacts && !data->xact_wrote_changes)
return;
OutputPluginPrepareWrite(ctx, true);
if (data->include_xids)
appendStringInfo(ctx->out, "ABORT %lu", txn->xid);
else
appendStringInfoString(ctx->out, "ABORT");
if (data->include_timestamp)
appendStringInfo(ctx->out, " (at %s)", timestamptz_to_str(txn->commit_time));
OutputPluginWrite(ctx, true);
}
/* PREPARE callback */
static void pg_decode_prepare_txn(LogicalDecodingContext* ctx, ReorderBufferTXN* txn)
{
PluginTestDecodingData* data = (PluginTestDecodingData*)ctx->output_plugin_private;
if (data->skip_empty_xacts && !data->xact_wrote_changes)
return;
OutputPluginPrepareWrite(ctx, true);
if (data->include_xids)
appendStringInfo(ctx->out, "PREPARE %lu", txn->xid);
else
appendStringInfoString(ctx->out, "PREPARE");
if (data->include_timestamp)
appendStringInfo(ctx->out, " (at %s)", timestamptz_to_str(txn->commit_time));
OutputPluginWrite(ctx, true);
}
static bool pg_decode_filter(LogicalDecodingContext* ctx, RepOriginId origin_id)
{
PluginTestDecodingData* data = (PluginTestDecodingData*)ctx->output_plugin_private;
if (data->only_local && origin_id != InvalidRepOriginId)
return true;
return false;
}
static void tuple_to_stringinfo(StringInfo s, TupleDesc tupdesc, HeapTuple tuple, bool skip_nulls)
{
if (HEAP_TUPLE_IS_COMPRESSED(tuple->t_data))
return;
if ((int)HeapTupleHeaderGetNatts(tuple->t_data, tupdesc) != tupdesc->natts)
return;
int natt;
Oid oid;
/* print oid of tuple, it's not included in the TupleDesc */
if ((oid = HeapTupleHeaderGetOid(tuple->t_data)) != InvalidOid) {
appendStringInfo(s, " oid[oid]:%u", oid);
}
/* print all columns individually */
for (natt = 0; natt < tupdesc->natts; natt++) {
Form_pg_attribute attr; /* the attribute itself */
Oid typid; /* type of current attribute */
Oid typoutput; /* output function */
bool typisvarlena = false;
Datum origval; /* possibly toasted Datum */
bool isnull = true; /* column is null? */
attr = tupdesc->attrs[natt];
/*
* don't print dropped columns, we can't be sure everything is
* available for them
*/
if (attr->attisdropped)
continue;
/*
* Don't print system columns, oid will already have been printed if
* present.
*/
if (attr->attnum < 0)
continue;
typid = attr->atttypid;
/* get Datum from tuple */
origval = heap_getattr(tuple, natt + 1, tupdesc, &isnull);
if (isnull && skip_nulls)
continue;
/* print attribute name */
appendStringInfoChar(s, ' ');
appendStringInfoString(s, quote_identifier(NameStr(attr->attname)));
/* print attribute type */
appendStringInfoChar(s, '[');
char* type_name = format_type_be(typid);
if (strlen(type_name) == strlen("clob") && strncmp(type_name, "clob", strlen("clob")) == 0) {
errno_t rc = strcpy_s(type_name, sizeof("clob"), "text");
securec_check_c(rc, "\0", "\0");
}
appendStringInfoString(s, type_name);
appendStringInfoChar(s, ']');
/* query output function */
getTypeOutputInfo(typid, &typoutput, &typisvarlena);
/* print separator */
appendStringInfoChar(s, ':');
/* print data */
if (isnull)
appendStringInfoString(s, "null");
else if (typisvarlena && VARATT_IS_EXTERNAL_ONDISK_B(origval))
appendStringInfoString(s, "unchanged-toast-datum");
else if (!typisvarlena)
PrintLiteral(s, typid, OidOutputFunctionCall(typoutput, origval));
else {
Datum val; /* definitely detoasted Datum */
val = PointerGetDatum(PG_DETOAST_DATUM(origval));
PrintLiteral(s, typid, OidOutputFunctionCall(typoutput, val));
}
}
}
/*
* callback for individual changed tuples
*/
static void pg_decode_change(
LogicalDecodingContext* ctx, ReorderBufferTXN* txn, Relation relation, ReorderBufferChange* change)
{
PluginTestDecodingData* data = NULL;
Form_pg_class class_form;
TupleDesc tupdesc;
MemoryContext old;
data = (PluginTestDecodingData*)ctx->output_plugin_private;
/* output BEGIN if we haven't yet */
if (data->skip_empty_xacts && !data->xact_wrote_changes) {
pg_output_begin(ctx, data, txn, false);
}
data->xact_wrote_changes = true;
class_form = RelationGetForm(relation);
tupdesc = RelationGetDescr(relation);
/* Avoid leaking memory by using and resetting our own context */
old = MemoryContextSwitchTo(data->context);
char *schema = get_namespace_name(class_form->relnamespace);
char *table = NameStr(class_form->relname);
if (data->tableWhiteList != NIL && !CheckWhiteList(data->tableWhiteList, schema, table)) {
(void)MemoryContextSwitchTo(old);
MemoryContextReset(data->context);
return;
}
OutputPluginPrepareWrite(ctx, true);
appendStringInfoString(ctx->out, "table ");
appendStringInfoString(ctx->out, quote_qualified_identifier(schema, table));
appendStringInfoString(ctx->out, ":");
switch (change->action) {
case REORDER_BUFFER_CHANGE_INSERT:
appendStringInfoString(ctx->out, " INSERT:");
if (change->data.tp.newtuple == NULL)
appendStringInfoString(ctx->out, " (no-tuple-data)");
else
tuple_to_stringinfo(ctx->out, tupdesc, &change->data.tp.newtuple->tuple, false);
break;
case REORDER_BUFFER_CHANGE_UPDATE:
appendStringInfoString(ctx->out, " UPDATE:");
if (change->data.tp.oldtuple != NULL) {
appendStringInfoString(ctx->out, " old-key:");
tuple_to_stringinfo(ctx->out, tupdesc, &change->data.tp.oldtuple->tuple, true);
appendStringInfoString(ctx->out, " new-tuple:");
}
if (change->data.tp.newtuple == NULL)
appendStringInfoString(ctx->out, " (no-tuple-data)");
else
tuple_to_stringinfo(ctx->out, tupdesc, &change->data.tp.newtuple->tuple, false);
break;
case REORDER_BUFFER_CHANGE_DELETE:
appendStringInfoString(ctx->out, " DELETE:");
/* if there was no PK, we only know that a delete happened */
if (change->data.tp.oldtuple == NULL)
appendStringInfoString(ctx->out, " (no-tuple-data)");
/* In DELETE, only the replica identity is present; display that */
else
tuple_to_stringinfo(ctx->out, tupdesc, &change->data.tp.oldtuple->tuple, true);
break;
default:
Assert(false);
}
MemoryContextSwitchTo(old);
MemoryContextReset(data->context);
OutputPluginWrite(ctx, true);
}