Adding upstream version 15.4.upstream/15.4upstream

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

1 files changed, 354 insertions, 0 deletions

diff --git a/src/test/modules/plsample/plsample.c b/src/test/modules/plsample/plsample.c
new file mode 100644
index 0000000..780db72
--- /dev/null
+++ b/src/test/modules/plsample/plsample.c
@@ -0,0 +1,354 @@
+/*-------------------------------------------------------------------------
+ *
+ * plsample.c
+ *	  Handler for the PL/Sample procedural language
+ *
+ * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *		src/test/modules/plsample/plsample.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "catalog/pg_proc.h"
+#include "catalog/pg_type.h"
+#include "commands/event_trigger.h"
+#include "commands/trigger.h"
+#include "executor/spi.h"
+#include "funcapi.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/syscache.h"
+
+PG_MODULE_MAGIC;
+
+PG_FUNCTION_INFO_V1(plsample_call_handler);
+
+static Datum plsample_func_handler(PG_FUNCTION_ARGS);
+static HeapTuple plsample_trigger_handler(PG_FUNCTION_ARGS);
+
+/*
+ * Handle function, procedure, and trigger calls.
+ */
+Datum
+plsample_call_handler(PG_FUNCTION_ARGS)
+{
+	Datum		retval = (Datum) 0;
+
+	/*
+	 * Many languages will require cleanup that happens even in the event of
+	 * an error.  That can happen in the PG_FINALLY block.  If none is needed,
+	 * this PG_TRY construct can be omitted.
+	 */
+	PG_TRY();
+	{
+		/*
+		 * Determine if called as function or trigger and call appropriate
+		 * subhandler.
+		 */
+		if (CALLED_AS_TRIGGER(fcinfo))
+		{
+			/*
+			 * This function has been called as a trigger function, where
+			 * (TriggerData *) fcinfo->context includes the information of the
+			 * context.
+			 */
+			retval = PointerGetDatum(plsample_trigger_handler(fcinfo));
+		}
+		else if (CALLED_AS_EVENT_TRIGGER(fcinfo))
+		{
+			/*
+			 * This function is called as an event trigger function, where
+			 * (EventTriggerData *) fcinfo->context includes the information
+			 * of the context.
+			 *
+			 * TODO: provide an example handler.
+			 */
+		}
+		else
+		{
+			/* Regular function handler */
+			retval = plsample_func_handler(fcinfo);
+		}
+	}
+	PG_FINALLY();
+	{
+	}
+	PG_END_TRY();
+
+	return retval;
+}
+
+/*
+ * plsample_func_handler
+ *
+ * Function called by the call handler for function execution.
+ */
+static Datum
+plsample_func_handler(PG_FUNCTION_ARGS)
+{
+	HeapTuple	pl_tuple;
+	Datum		ret;
+	char	   *source;
+	bool		isnull;
+	FmgrInfo   *arg_out_func;
+	Form_pg_type type_struct;
+	HeapTuple	type_tuple;
+	Form_pg_proc pl_struct;
+	volatile MemoryContext proc_cxt = NULL;
+	Oid		   *argtypes;
+	char	  **argnames;
+	char	   *argmodes;
+	char	   *proname;
+	Form_pg_type pg_type_entry;
+	Oid			result_typioparam;
+	Oid			prorettype;
+	FmgrInfo	result_in_func;
+	int			numargs;
+
+	/* Fetch the function's pg_proc entry. */
+	pl_tuple = SearchSysCache1(PROCOID,
+							   ObjectIdGetDatum(fcinfo->flinfo->fn_oid));
+	if (!HeapTupleIsValid(pl_tuple))
+		elog(ERROR, "cache lookup failed for function %u",
+			 fcinfo->flinfo->fn_oid);
+
+	/*
+	 * Extract and print the source text of the function.  This can be used as
+	 * a base for the function validation and execution.
+	 */
+	pl_struct = (Form_pg_proc) GETSTRUCT(pl_tuple);
+	proname = pstrdup(NameStr(pl_struct->proname));
+	ret = SysCacheGetAttr(PROCOID, pl_tuple, Anum_pg_proc_prosrc, &isnull);
+	if (isnull)
+		elog(ERROR, "could not find source text of function \"%s\"",
+			 proname);
+	source = DatumGetCString(DirectFunctionCall1(textout, ret));
+	ereport(NOTICE,
+			(errmsg("source text of function \"%s\": %s",
+					proname, source)));
+
+	/*
+	 * Allocate a context that will hold all the Postgres data for the
+	 * procedure.
+	 */
+	proc_cxt = AllocSetContextCreate(TopMemoryContext,
+									 "PL/Sample function",
+									 ALLOCSET_SMALL_SIZES);
+
+	arg_out_func = (FmgrInfo *) palloc0(fcinfo->nargs * sizeof(FmgrInfo));
+	numargs = get_func_arg_info(pl_tuple, &argtypes, &argnames, &argmodes);
+
+	/*
+	 * Iterate through all of the function arguments, printing each input
+	 * value.
+	 */
+	for (int i = 0; i < numargs; i++)
+	{
+		Oid			argtype = pl_struct->proargtypes.values[i];
+		char	   *value;
+
+		type_tuple = SearchSysCache1(TYPEOID, ObjectIdGetDatum(argtype));
+		if (!HeapTupleIsValid(type_tuple))
+			elog(ERROR, "cache lookup failed for type %u", argtype);
+
+		type_struct = (Form_pg_type) GETSTRUCT(type_tuple);
+		fmgr_info_cxt(type_struct->typoutput, &(arg_out_func[i]), proc_cxt);
+		ReleaseSysCache(type_tuple);
+
+		value = OutputFunctionCall(&arg_out_func[i], fcinfo->args[i].value);
+		ereport(NOTICE,
+				(errmsg("argument: %d; name: %s; value: %s",
+						i, argnames[i], value)));
+	}
+
+	/* Type of the result */
+	prorettype = pl_struct->prorettype;
+	ReleaseSysCache(pl_tuple);
+
+	/*
+	 * Get the required information for input conversion of the return value.
+	 *
+	 * If the function uses VOID as result, it is better to return NULL.
+	 * Anyway, let's be honest.  This is just a template, so there is not much
+	 * we can do here.  This returns NULL except if the result type is text,
+	 * where the result is the source text of the function.
+	 */
+	if (prorettype != TEXTOID)
+		PG_RETURN_NULL();
+
+	type_tuple = SearchSysCache1(TYPEOID,
+								 ObjectIdGetDatum(prorettype));
+	if (!HeapTupleIsValid(type_tuple))
+		elog(ERROR, "cache lookup failed for type %u", prorettype);
+	pg_type_entry = (Form_pg_type) GETSTRUCT(type_tuple);
+	result_typioparam = getTypeIOParam(type_tuple);
+
+	fmgr_info_cxt(pg_type_entry->typinput, &result_in_func, proc_cxt);
+	ReleaseSysCache(type_tuple);
+
+	ret = InputFunctionCall(&result_in_func, source, result_typioparam, -1);
+	PG_RETURN_DATUM(ret);
+}
+
+/*
+ * plsample_trigger_handler
+ *
+ * Function called by the call handler for trigger execution.
+ */
+static HeapTuple
+plsample_trigger_handler(PG_FUNCTION_ARGS)
+{
+	TriggerData *trigdata = (TriggerData *) fcinfo->context;
+	char	   *string;
+	volatile HeapTuple rettup;
+	HeapTuple	pl_tuple;
+	Datum		ret;
+	char	   *source;
+	bool		isnull;
+	Form_pg_proc pl_struct;
+	char	   *proname;
+	int			rc PG_USED_FOR_ASSERTS_ONLY;
+
+	/* Make sure this is being called from a trigger. */
+	if (!CALLED_AS_TRIGGER(fcinfo))
+		elog(ERROR, "not called by trigger manager");
+
+	/* Connect to the SPI manager */
+	if (SPI_connect() != SPI_OK_CONNECT)
+		elog(ERROR, "could not connect to SPI manager");
+
+	rc = SPI_register_trigger_data(trigdata);
+	Assert(rc >= 0);
+
+	/* Fetch the function's pg_proc entry. */
+	pl_tuple = SearchSysCache1(PROCOID,
+							   ObjectIdGetDatum(fcinfo->flinfo->fn_oid));
+	if (!HeapTupleIsValid(pl_tuple))
+		elog(ERROR, "cache lookup failed for function %u",
+			 fcinfo->flinfo->fn_oid);
+
+	/*
+	 * Code Retrieval
+	 *
+	 * Extract and print the source text of the function.  This can be used as
+	 * a base for the function validation and execution.
+	 */
+	pl_struct = (Form_pg_proc) GETSTRUCT(pl_tuple);
+	proname = pstrdup(NameStr(pl_struct->proname));
+	ret = SysCacheGetAttr(PROCOID, pl_tuple, Anum_pg_proc_prosrc, &isnull);
+	if (isnull)
+		elog(ERROR, "could not find source text of function \"%s\"",
+			 proname);
+	source = DatumGetCString(DirectFunctionCall1(textout, ret));
+	ereport(NOTICE,
+			(errmsg("source text of function \"%s\": %s",
+					proname, source)));
+
+	/*
+	 * We're done with the pg_proc tuple, so release it.  (Note that the
+	 * "proname" and "source" strings are now standalone copies.)
+	 */
+	ReleaseSysCache(pl_tuple);
+
+	/*
+	 * Code Augmentation
+	 *
+	 * The source text may be augmented here, such as by wrapping it as the
+	 * body of a function in the target language, prefixing a parameter list
+	 * with names like TD_name, TD_relid, TD_table_name, TD_table_schema,
+	 * TD_event, TD_when, TD_level, TD_NEW, TD_OLD, and args, using whatever
+	 * types in the target language are convenient. The augmented text can be
+	 * cached in a longer-lived memory context, or, if the target language
+	 * uses a compilation step, that can be done here, caching the result of
+	 * the compilation.
+	 */
+
+	/*
+	 * Code Execution
+	 *
+	 * Here the function (the possibly-augmented source text, or the result of
+	 * compilation if the target language uses such a step) should be
+	 * executed, after binding values from the TriggerData struct to the
+	 * appropriate parameters.
+	 *
+	 * In this example we just print a lot of info via ereport.
+	 */
+
+	PG_TRY();
+	{
+		ereport(NOTICE,
+				(errmsg("trigger name: %s", trigdata->tg_trigger->tgname)));
+		string = SPI_getrelname(trigdata->tg_relation);
+		ereport(NOTICE, (errmsg("trigger relation: %s", string)));
+
+		string = SPI_getnspname(trigdata->tg_relation);
+		ereport(NOTICE, (errmsg("trigger relation schema: %s", string)));
+
+		/* Example handling of different trigger aspects. */
+
+		if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
+		{
+			ereport(NOTICE, (errmsg("triggered by INSERT")));
+			rettup = trigdata->tg_trigtuple;
+		}
+		else if (TRIGGER_FIRED_BY_DELETE(trigdata->tg_event))
+		{
+			ereport(NOTICE, (errmsg("triggered by DELETE")));
+			rettup = trigdata->tg_trigtuple;
+		}
+		else if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
+		{
+			ereport(NOTICE, (errmsg("triggered by UPDATE")));
+			rettup = trigdata->tg_trigtuple;
+		}
+		else if (TRIGGER_FIRED_BY_TRUNCATE(trigdata->tg_event))
+		{
+			ereport(NOTICE, (errmsg("triggered by TRUNCATE")));
+			rettup = trigdata->tg_trigtuple;
+		}
+		else
+			elog(ERROR, "unrecognized event: %u", trigdata->tg_event);
+
+		if (TRIGGER_FIRED_BEFORE(trigdata->tg_event))
+			ereport(NOTICE, (errmsg("triggered BEFORE")));
+		else if (TRIGGER_FIRED_AFTER(trigdata->tg_event))
+			ereport(NOTICE, (errmsg("triggered AFTER")));
+		else if (TRIGGER_FIRED_INSTEAD(trigdata->tg_event))
+			ereport(NOTICE, (errmsg("triggered INSTEAD OF")));
+		else
+			elog(ERROR, "unrecognized when: %u", trigdata->tg_event);
+
+		if (TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
+			ereport(NOTICE, (errmsg("triggered per row")));
+		else if (TRIGGER_FIRED_FOR_STATEMENT(trigdata->tg_event))
+			ereport(NOTICE, (errmsg("triggered per statement")));
+		else
+			elog(ERROR, "unrecognized level: %u", trigdata->tg_event);
+
+		/*
+		 * Iterate through all of the trigger arguments, printing each input
+		 * value.
+		 */
+		for (int i = 0; i < trigdata->tg_trigger->tgnargs; i++)
+			ereport(NOTICE,
+					(errmsg("trigger arg[%i]: %s", i,
+							trigdata->tg_trigger->tgargs[i])));
+	}
+	PG_CATCH();
+	{
+		/* Error cleanup code would go here */
+		PG_RE_THROW();
+	}
+	PG_END_TRY();
+
+	if (SPI_finish() != SPI_OK_FINISH)
+		elog(ERROR, "SPI_finish() failed");
+
+	return rettup;
+}