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92288a1cf9
o Change all current CVS messages of NOTICE to WARNING. We were going to do this just before 7.3 beta but it has to be done now, as you will see below. o Change current INFO messages that should be controlled by client_min_messages to NOTICE. o Force remaining INFO messages, like from EXPLAIN, VACUUM VERBOSE, etc. to always go to the client. o Remove INFO from the client_min_messages options and add NOTICE. Seems we do need three non-ERROR elog levels to handle the various behaviors we need for these messages. Regression passed.
108 lines
2.8 KiB
C
108 lines
2.8 KiB
C
/*
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* noup.c -- functions to remove update permission from a column
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*/
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#include "executor/spi.h" /* this is what you need to work with SPI */
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#include "commands/trigger.h" /* -"- and triggers */
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#include <ctype.h> /* tolower () */
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extern Datum noup(PG_FUNCTION_ARGS);
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/*
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* noup () -- revoke permission on column
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*
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* Though it's called without args You have to specify referenced
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* table/column while creating trigger:
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* EXECUTE PROCEDURE noup ('col').
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*/
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PG_FUNCTION_INFO_V1(noup);
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Datum
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noup(PG_FUNCTION_ARGS)
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{
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TriggerData *trigdata = (TriggerData *) fcinfo->context;
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Trigger *trigger; /* to get trigger name */
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int nargs; /* # of args specified in CREATE TRIGGER */
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char **args; /* arguments: column names and table name */
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int nkeys; /* # of key columns (= nargs / 2) */
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Datum *kvals; /* key values */
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Relation rel; /* triggered relation */
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HeapTuple tuple = NULL; /* tuple to return */
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TupleDesc tupdesc; /* tuple description */
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bool isnull; /* to know is some column NULL or not */
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int ret;
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int i;
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/*
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* Some checks first...
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*/
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/* Called by trigger manager ? */
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if (!CALLED_AS_TRIGGER(fcinfo))
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elog(ERROR, "noup: not fired by trigger manager");
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/* Should be called for ROW trigger */
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if (TRIGGER_FIRED_FOR_STATEMENT(trigdata->tg_event))
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elog(ERROR, "noup: can't process STATEMENT events");
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/* Not should be called for INSERT */
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if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
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elog(ERROR, "noup: can't process INSERT events");
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/* Not should be called for DELETE */
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else if (TRIGGER_FIRED_BY_DELETE(trigdata->tg_event))
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elog(ERROR, "noup: can't process DELETE events");
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/* check new Tuple */
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tuple = trigdata->tg_newtuple;
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trigger = trigdata->tg_trigger;
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nargs = trigger->tgnargs;
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args = trigger->tgargs;
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nkeys = nargs;
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rel = trigdata->tg_relation;
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tupdesc = rel->rd_att;
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/* Connect to SPI manager */
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if ((ret = SPI_connect()) < 0)
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elog(ERROR, "noup: SPI_connect returned %d", ret);
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/*
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* We use SPI plan preparation feature, so allocate space to place key
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* values.
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*/
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kvals = (Datum *) palloc(nkeys * sizeof(Datum));
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/* For each column in key ... */
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for (i = 0; i < nkeys; i++)
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{
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/* get index of column in tuple */
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int fnumber = SPI_fnumber(tupdesc, args[i]);
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/* Bad guys may give us un-existing column in CREATE TRIGGER */
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if (fnumber < 0)
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elog(ERROR, "noup: there is no attribute %s in relation %s",
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args[i], SPI_getrelname(rel));
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/* Well, get binary (in internal format) value of column */
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kvals[i] = SPI_getbinval(tuple, tupdesc, fnumber, &isnull);
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/*
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* If it's NOT NULL then cancel update
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*/
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if (!isnull)
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{
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elog(WARNING, "%s: update not allowed", args[i]);
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SPI_finish();
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return PointerGetDatum(NULL);
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}
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}
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SPI_finish();
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return PointerGetDatum(tuple);
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}
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