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220db7ccd8
strings. This patch introduces four support functions cstring_to_text, cstring_to_text_with_len, text_to_cstring, and text_to_cstring_buffer, and two macros CStringGetTextDatum and TextDatumGetCString. A number of existing macros that provided variants on these themes were removed. Most of the places that need to make such conversions now require just one function or macro call, in place of the multiple notational layers that used to be needed. There are no longer any direct calls of textout or textin, and we got most of the places that were using handmade conversions via memcpy (there may be a few still lurking, though). This commit doesn't make any serious effort to eliminate transient memory leaks caused by detoasting toasted text objects before they reach text_to_cstring. We changed PG_GETARG_TEXT_P to PG_GETARG_TEXT_PP in a few places where it was easy, but much more could be done. Brendan Jurd and Tom Lane
93 lines
2.7 KiB
C
93 lines
2.7 KiB
C
/*
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* insert_username.c
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* $Modified: Thu Oct 16 08:13:42 1997 by brook $
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* $PostgreSQL: pgsql/contrib/spi/insert_username.c,v 1.16 2008/03/25 22:42:42 tgl Exp $
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*
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* insert user name in response to a trigger
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* usage: insert_username (column_name)
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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 "miscadmin.h" /* for GetUserName() */
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PG_MODULE_MAGIC;
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extern Datum insert_username(PG_FUNCTION_ARGS);
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PG_FUNCTION_INFO_V1(insert_username);
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Datum
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insert_username(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 arguments */
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Datum newval; /* new value of column */
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char **args; /* arguments */
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char *relname; /* triggered relation name */
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Relation rel; /* triggered relation */
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HeapTuple rettuple = NULL;
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TupleDesc tupdesc; /* tuple description */
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int attnum;
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/* sanity checks from autoinc.c */
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if (!CALLED_AS_TRIGGER(fcinfo))
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/* internal error */
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elog(ERROR, "insert_username: not fired by trigger manager");
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if (TRIGGER_FIRED_FOR_STATEMENT(trigdata->tg_event))
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/* internal error */
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elog(ERROR, "insert_username: cannot process STATEMENT events");
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if (TRIGGER_FIRED_AFTER(trigdata->tg_event))
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/* internal error */
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elog(ERROR, "insert_username: must be fired before event");
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if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
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rettuple = trigdata->tg_trigtuple;
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else if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
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rettuple = trigdata->tg_newtuple;
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else
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/* internal error */
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elog(ERROR, "insert_username: cannot process DELETE events");
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rel = trigdata->tg_relation;
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relname = SPI_getrelname(rel);
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trigger = trigdata->tg_trigger;
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nargs = trigger->tgnargs;
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if (nargs != 1)
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/* internal error */
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elog(ERROR, "insert_username (%s): one argument was expected", relname);
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args = trigger->tgargs;
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tupdesc = rel->rd_att;
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attnum = SPI_fnumber(tupdesc, args[0]);
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if (attnum < 0)
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ereport(ERROR,
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(errcode(ERRCODE_TRIGGERED_ACTION_EXCEPTION),
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errmsg("\"%s\" has no attribute \"%s\"", relname, args[0])));
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if (SPI_gettypeid(tupdesc, attnum) != TEXTOID)
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ereport(ERROR,
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(errcode(ERRCODE_TRIGGERED_ACTION_EXCEPTION),
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errmsg("attribute \"%s\" of \"%s\" must be type TEXT",
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args[0], relname)));
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/* create fields containing name */
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newval = CStringGetTextDatum(GetUserNameFromId(GetUserId()));
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/* construct new tuple */
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rettuple = SPI_modifytuple(rel, rettuple, 1, &attnum, &newval, NULL);
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if (rettuple == NULL)
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/* internal error */
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elog(ERROR, "insert_username (\"%s\"): %d returned by SPI_modifytuple",
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relname, SPI_result);
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pfree(relname);
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return PointerGetDatum(rettuple);
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}
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