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-rw-r--r--contrib/test_decoding/test_decoding.c542
1 files changed, 542 insertions, 0 deletions
diff --git a/contrib/test_decoding/test_decoding.c b/contrib/test_decoding/test_decoding.c
new file mode 100644
index 0000000..93c9488
--- /dev/null
+++ b/contrib/test_decoding/test_decoding.c
@@ -0,0 +1,542 @@
+/*-------------------------------------------------------------------------
+ *
+ * test_decoding.c
+ * example logical decoding output plugin
+ *
+ * Copyright (c) 2012-2020, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ * contrib/test_decoding/test_decoding.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "catalog/pg_type.h"
+
+#include "replication/logical.h"
+#include "replication/origin.h"
+
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/memutils.h"
+#include "utils/rel.h"
+
+PG_MODULE_MAGIC;
+
+/* These must be available to dlsym() */
+extern void _PG_init(void);
+extern void _PG_output_plugin_init(OutputPluginCallbacks *cb);
+
+typedef struct
+{
+ MemoryContext context;
+ bool include_xids;
+ bool include_timestamp;
+ bool skip_empty_xacts;
+ bool xact_wrote_changes;
+ bool only_local;
+} TestDecodingData;
+
+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,
+ TestDecodingData *data,
+ ReorderBufferTXN *txn,
+ bool last_write);
+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_truncate(LogicalDecodingContext *ctx,
+ ReorderBufferTXN *txn,
+ int nrelations, Relation relations[],
+ ReorderBufferChange *change);
+static bool pg_decode_filter(LogicalDecodingContext *ctx,
+ RepOriginId origin_id);
+static void pg_decode_message(LogicalDecodingContext *ctx,
+ ReorderBufferTXN *txn, XLogRecPtr message_lsn,
+ bool transactional, const char *prefix,
+ Size sz, const char *message);
+
+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->truncate_cb = pg_decode_truncate;
+ cb->commit_cb = pg_decode_commit_txn;
+ cb->filter_by_origin_cb = pg_decode_filter;
+ cb->shutdown_cb = pg_decode_shutdown;
+ cb->message_cb = pg_decode_message;
+}
+
+
+/* initialize this plugin */
+static void
+pg_decode_startup(LogicalDecodingContext *ctx, OutputPluginOptions *opt,
+ bool is_init)
+{
+ ListCell *option;
+ TestDecodingData *data;
+
+ data = palloc0(sizeof(TestDecodingData));
+ data->context = AllocSetContextCreate(ctx->context,
+ "text conversion context",
+ ALLOCSET_DEFAULT_SIZES);
+ data->include_xids = true;
+ data->include_timestamp = false;
+ data->skip_empty_xacts = false;
+ data->only_local = false;
+
+ ctx->output_plugin_private = data;
+
+ opt->output_type = OUTPUT_PLUGIN_TEXTUAL_OUTPUT;
+ opt->receive_rewrites = false;
+
+ foreach(option, ctx->output_plugin_options)
+ {
+ DefElem *elem = lfirst(option);
+
+ Assert(elem->arg == NULL || IsA(elem->arg, String));
+
+ if (strcmp(elem->defname, "include-xids") == 0)
+ {
+ /* if option does not provide a value, it means its value is true */
+ if (elem->arg == NULL)
+ data->include_xids = true;
+ else if (!parse_bool(strVal(elem->arg), &data->include_xids))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("could not parse value \"%s\" for parameter \"%s\"",
+ strVal(elem->arg), elem->defname)));
+ }
+ else if (strcmp(elem->defname, "include-timestamp") == 0)
+ {
+ if (elem->arg == NULL)
+ data->include_timestamp = true;
+ else if (!parse_bool(strVal(elem->arg), &data->include_timestamp))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("could not parse value \"%s\" for parameter \"%s\"",
+ strVal(elem->arg), elem->defname)));
+ }
+ else if (strcmp(elem->defname, "force-binary") == 0)
+ {
+ bool force_binary;
+
+ if (elem->arg == NULL)
+ continue;
+ else if (!parse_bool(strVal(elem->arg), &force_binary))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("could not parse value \"%s\" for parameter \"%s\"",
+ strVal(elem->arg), elem->defname)));
+
+ if (force_binary)
+ opt->output_type = OUTPUT_PLUGIN_BINARY_OUTPUT;
+ }
+ else if (strcmp(elem->defname, "skip-empty-xacts") == 0)
+ {
+
+ if (elem->arg == NULL)
+ data->skip_empty_xacts = true;
+ else if (!parse_bool(strVal(elem->arg), &data->skip_empty_xacts))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("could not parse value \"%s\" for parameter \"%s\"",
+ strVal(elem->arg), elem->defname)));
+ }
+ else if (strcmp(elem->defname, "only-local") == 0)
+ {
+
+ if (elem->arg == NULL)
+ data->only_local = true;
+ else if (!parse_bool(strVal(elem->arg), &data->only_local))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("could not parse value \"%s\" for parameter \"%s\"",
+ strVal(elem->arg), elem->defname)));
+ }
+ else if (strcmp(elem->defname, "include-rewrites") == 0)
+ {
+
+ if (elem->arg == NULL)
+ continue;
+ else if (!parse_bool(strVal(elem->arg), &opt->receive_rewrites))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("could not parse value \"%s\" for parameter \"%s\"",
+ strVal(elem->arg), elem->defname)));
+ }
+ else
+ {
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("option \"%s\" = \"%s\" is unknown",
+ elem->defname,
+ elem->arg ? strVal(elem->arg) : "(null)")));
+ }
+ }
+}
+
+/* cleanup this plugin's resources */
+static void
+pg_decode_shutdown(LogicalDecodingContext *ctx)
+{
+ TestDecodingData *data = 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)
+{
+ TestDecodingData *data = 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, TestDecodingData *data, ReorderBufferTXN *txn, bool last_write)
+{
+ OutputPluginPrepareWrite(ctx, last_write);
+ if (data->include_xids)
+ appendStringInfo(ctx->out, "BEGIN %u", 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)
+{
+ TestDecodingData *data = 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 %u", txn->xid);
+ else
+ appendStringInfoString(ctx->out, "COMMIT");
+
+ 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)
+{
+ TestDecodingData *data = ctx->output_plugin_private;
+
+ if (data->only_local && origin_id != InvalidRepOriginId)
+ return true;
+ return false;
+}
+
+/*
+ * Print literal `outputstr' already represented as string of type `typid'
+ * into stringbuf `s'.
+ *
+ * Some builtin types aren't quoted, the rest is quoted. Escaping is done as
+ * if standard_conforming_strings were enabled.
+ */
+static void
+print_literal(StringInfo s, Oid typid, char *outputstr)
+{
+ const char *valptr;
+
+ switch (typid)
+ {
+ case INT2OID:
+ case INT4OID:
+ case INT8OID:
+ case OIDOID:
+ case FLOAT4OID:
+ case FLOAT8OID:
+ case NUMERICOID:
+ /* NB: We don't care about Inf, NaN et al. */
+ appendStringInfoString(s, outputstr);
+ break;
+
+ case BITOID:
+ case VARBITOID:
+ appendStringInfo(s, "B'%s'", outputstr);
+ break;
+
+ case BOOLOID:
+ if (strcmp(outputstr, "t") == 0)
+ appendStringInfoString(s, "true");
+ else
+ appendStringInfoString(s, "false");
+ break;
+
+ default:
+ appendStringInfoChar(s, '\'');
+ for (valptr = outputstr; *valptr; valptr++)
+ {
+ char ch = *valptr;
+
+ if (SQL_STR_DOUBLE(ch, false))
+ appendStringInfoChar(s, ch);
+ appendStringInfoChar(s, ch);
+ }
+ appendStringInfoChar(s, '\'');
+ break;
+ }
+}
+
+/* print the tuple 'tuple' into the StringInfo s */
+static void
+tuple_to_stringinfo(StringInfo s, TupleDesc tupdesc, HeapTuple tuple, bool skip_nulls)
+{
+ int natt;
+
+ /* 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;
+ Datum origval; /* possibly toasted Datum */
+ bool isnull; /* column is null? */
+
+ attr = TupleDescAttr(tupdesc, 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, '[');
+ appendStringInfoString(s, format_type_be(typid));
+ 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(origval))
+ appendStringInfoString(s, "unchanged-toast-datum");
+ else if (!typisvarlena)
+ print_literal(s, typid,
+ OidOutputFunctionCall(typoutput, origval));
+ else
+ {
+ Datum val; /* definitely detoasted Datum */
+
+ val = PointerGetDatum(PG_DETOAST_DATUM(origval));
+ print_literal(s, typid, OidOutputFunctionCall(typoutput, val));
+ }
+ }
+}
+
+/*
+ * callback for individual changed tuples
+ */
+static void
+pg_decode_change(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
+ Relation relation, ReorderBufferChange *change)
+{
+ TestDecodingData *data;
+ Form_pg_class class_form;
+ TupleDesc tupdesc;
+ MemoryContext old;
+
+ data = 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);
+
+ OutputPluginPrepareWrite(ctx, true);
+
+ appendStringInfoString(ctx->out, "table ");
+ appendStringInfoString(ctx->out,
+ quote_qualified_identifier(get_namespace_name(get_rel_namespace(RelationGetRelid(relation))),
+ class_form->relrewrite ?
+ get_rel_name(class_form->relrewrite) :
+ NameStr(class_form->relname)));
+ appendStringInfoChar(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);
+}
+
+static void
+pg_decode_truncate(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
+ int nrelations, Relation relations[], ReorderBufferChange *change)
+{
+ TestDecodingData *data;
+ MemoryContext old;
+ int i;
+
+ data = 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;
+
+ /* Avoid leaking memory by using and resetting our own context */
+ old = MemoryContextSwitchTo(data->context);
+
+ OutputPluginPrepareWrite(ctx, true);
+
+ appendStringInfoString(ctx->out, "table ");
+
+ for (i = 0; i < nrelations; i++)
+ {
+ if (i > 0)
+ appendStringInfoString(ctx->out, ", ");
+
+ appendStringInfoString(ctx->out,
+ quote_qualified_identifier(get_namespace_name(relations[i]->rd_rel->relnamespace),
+ NameStr(relations[i]->rd_rel->relname)));
+ }
+
+ appendStringInfoString(ctx->out, ": TRUNCATE:");
+
+ if (change->data.truncate.restart_seqs
+ || change->data.truncate.cascade)
+ {
+ if (change->data.truncate.restart_seqs)
+ appendStringInfoString(ctx->out, " restart_seqs");
+ if (change->data.truncate.cascade)
+ appendStringInfoString(ctx->out, " cascade");
+ }
+ else
+ appendStringInfoString(ctx->out, " (no-flags)");
+
+ MemoryContextSwitchTo(old);
+ MemoryContextReset(data->context);
+
+ OutputPluginWrite(ctx, true);
+}
+
+static void
+pg_decode_message(LogicalDecodingContext *ctx,
+ ReorderBufferTXN *txn, XLogRecPtr lsn, bool transactional,
+ const char *prefix, Size sz, const char *message)
+{
+ OutputPluginPrepareWrite(ctx, true);
+ appendStringInfo(ctx->out, "message: transactional: %d prefix: %s, sz: %zu content:",
+ transactional, prefix, sz);
+ appendBinaryStringInfo(ctx->out, message, sz);
+ OutputPluginWrite(ctx, true);
+}