mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-07-14 05:39:18 +02:00
0bd61548ab
conversion of basic ASCII letters. Remove all uses of strcasecmp and strncasecmp in favor of new functions pg_strcasecmp and pg_strncasecmp; remove most but not all direct uses of toupper and tolower in favor of pg_toupper and pg_tolower. These functions use the same notions of case folding already developed for identifier case conversion. I left the straight locale-based folding in place for situations where we are just manipulating user data and not trying to match it to built-in strings --- for example, the SQL upper() function is still locale dependent. Perhaps this will prove not to be what's wanted, but at the moment we can initdb and pass regression tests in Turkish locale.
545 lines
14 KiB
C
545 lines
14 KiB
C
/*
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* timetravel.c -- function to get time travel feature
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* using general triggers.
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*/
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/* Modified by BÖJTHE Zoltán, Hungary, mailto:urdesobt@axelero.hu */
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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 GetPgUserName() */
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#include <ctype.h> /* tolower () */
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#define ABSTIMEOID 702 /* it should be in pg_type.h */
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/* AbsoluteTime currabstime(void); */
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Datum timetravel(PG_FUNCTION_ARGS);
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Datum set_timetravel(PG_FUNCTION_ARGS);
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Datum get_timetravel(PG_FUNCTION_ARGS);
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typedef struct
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{
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char *ident;
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void *splan;
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} EPlan;
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static EPlan *Plans = NULL; /* for UPDATE/DELETE */
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static int nPlans = 0;
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typedef struct _TTOffList
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{
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struct _TTOffList *next;
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char name[1];
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} TTOffList;
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static TTOffList TTOff = {NULL, {0}};
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static int findTTStatus(char *name);
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static EPlan *find_plan(char *ident, EPlan ** eplan, int *nplans);
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/*
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* timetravel () --
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* 1. IF an update affects tuple with stop_date eq INFINITY
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* then form (and return) new tuple with start_date eq current date
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* and stop_date eq INFINITY [ and update_user eq current user ]
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* and all other column values as in new tuple, and insert tuple
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* with old data and stop_date eq current date
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* ELSE - skip updation of tuple.
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* 2. IF an delete affects tuple with stop_date eq INFINITY
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* then insert the same tuple with stop_date eq current date
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* [ and delete_user eq current user ]
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* ELSE - skip deletion of tuple.
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* 3. On INSERT, if start_date is NULL then current date will be
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* inserted, if stop_date is NULL then INFINITY will be inserted.
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* [ and insert_user eq current user, update_user and delete_user
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* eq NULL ]
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*
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* In CREATE TRIGGER you are to specify start_date and stop_date column
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* names:
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* EXECUTE PROCEDURE
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* timetravel ('date_on', 'date_off' [,'insert_user', 'update_user', 'delete_user' ] ).
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*/
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#define MaxAttrNum 5
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#define MinAttrNum 2
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#define a_time_on 0
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#define a_time_off 1
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#define a_ins_user 2
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#define a_upd_user 3
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#define a_del_user 4
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PG_FUNCTION_INFO_V1(timetravel);
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Datum /* have to return HeapTuple to Executor */
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timetravel(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 argc;
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char **args; /* arguments */
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int attnum[MaxAttrNum]; /* fnumbers of start/stop columns */
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Datum oldtimeon,
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oldtimeoff;
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Datum newtimeon,
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newtimeoff,
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newuser,
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nulltext;
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Datum *cvals; /* column values */
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char *cnulls; /* column nulls */
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char *relname; /* triggered relation name */
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Relation rel; /* triggered relation */
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HeapTuple trigtuple;
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HeapTuple newtuple = NULL;
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HeapTuple rettuple;
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TupleDesc tupdesc; /* tuple description */
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int natts; /* # of attributes */
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EPlan *plan; /* prepared plan */
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char ident[2 * NAMEDATALEN];
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bool isnull; /* to know is some column NULL or not */
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bool isinsert = false;
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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, "timetravel: 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, "timetravel: can't process STATEMENT events");
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/* Should be called BEFORE */
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if (TRIGGER_FIRED_AFTER(trigdata->tg_event))
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elog(ERROR, "timetravel: must be fired before event");
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/* INSERT ? */
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if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
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isinsert = true;
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if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
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newtuple = trigdata->tg_newtuple;
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trigtuple = trigdata->tg_trigtuple;
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rel = trigdata->tg_relation;
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relname = SPI_getrelname(rel);
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/* check if TT is OFF for this relation */
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if (0 == findTTStatus(relname))
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{
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/* OFF - nothing to do */
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pfree(relname);
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return PointerGetDatum((newtuple != NULL) ? newtuple : trigtuple);
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}
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trigger = trigdata->tg_trigger;
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argc = trigger->tgnargs;
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if (argc != MinAttrNum && argc != MaxAttrNum)
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elog(ERROR, "timetravel (%s): invalid (!= %d or %d) number of arguments %d",
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relname, MinAttrNum, MaxAttrNum, trigger->tgnargs);
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args = trigger->tgargs;
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tupdesc = rel->rd_att;
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natts = tupdesc->natts;
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for (i = 0; i < MinAttrNum; i++)
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{
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attnum[i] = SPI_fnumber(tupdesc, args[i]);
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if (attnum[i] < 0)
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elog(ERROR, "timetravel (%s): there is no attribute %s", relname, args[i]);
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if (SPI_gettypeid(tupdesc, attnum[i]) != ABSTIMEOID)
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elog(ERROR, "timetravel (%s): attribute %s must be of abstime type",
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relname, args[i]);
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}
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for (; i < argc; i++)
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{
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attnum[i] = SPI_fnumber(tupdesc, args[i]);
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if (attnum[i] < 0)
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elog(ERROR, "timetravel (%s): there is no attribute %s", relname, args[i]);
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if (SPI_gettypeid(tupdesc, attnum[i]) != TEXTOID)
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elog(ERROR, "timetravel (%s): attribute %s must be of text type",
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relname, args[i]);
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}
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/* create fields containing name */
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newuser = DirectFunctionCall1(textin, CStringGetDatum(GetUserNameFromId(GetUserId())));
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nulltext = (Datum) NULL;
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if (isinsert)
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{ /* INSERT */
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int chnattrs = 0;
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int chattrs[MaxAttrNum];
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Datum newvals[MaxAttrNum];
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char newnulls[MaxAttrNum];
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oldtimeon = SPI_getbinval(trigtuple, tupdesc, attnum[a_time_on], &isnull);
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if (isnull)
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{
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newvals[chnattrs] = GetCurrentAbsoluteTime();
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newnulls[chnattrs] = ' ';
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chattrs[chnattrs] = attnum[a_time_on];
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chnattrs++;
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}
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oldtimeoff = SPI_getbinval(trigtuple, tupdesc, attnum[a_time_off], &isnull);
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if (isnull)
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{
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if ((chnattrs == 0 && DatumGetInt32(oldtimeon) >= NOEND_ABSTIME) ||
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(chnattrs > 0 && DatumGetInt32(newvals[a_time_on]) >= NOEND_ABSTIME))
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elog(ERROR, "timetravel (%s): %s is infinity", relname, args[a_time_on]);
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newvals[chnattrs] = NOEND_ABSTIME;
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newnulls[chnattrs] = ' ';
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chattrs[chnattrs] = attnum[a_time_off];
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chnattrs++;
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}
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else
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{
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if ((chnattrs == 0 && DatumGetInt32(oldtimeon) > DatumGetInt32(oldtimeoff)) ||
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(chnattrs > 0 && DatumGetInt32(newvals[a_time_on]) > DatumGetInt32(oldtimeoff)))
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elog(ERROR, "timetravel (%s): %s gt %s", relname, args[a_time_on], args[a_time_off]);
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}
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pfree(relname);
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if (chnattrs <= 0)
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return PointerGetDatum(trigtuple);
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if (argc == MaxAttrNum)
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{
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/* clear update_user value */
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newvals[chnattrs] = nulltext;
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newnulls[chnattrs] = 'n';
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chattrs[chnattrs] = attnum[a_upd_user];
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chnattrs++;
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/* clear delete_user value */
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newvals[chnattrs] = nulltext;
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newnulls[chnattrs] = 'n';
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chattrs[chnattrs] = attnum[a_del_user];
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chnattrs++;
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/* set insert_user value */
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newvals[chnattrs] = newuser;
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newnulls[chnattrs] = ' ';
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chattrs[chnattrs] = attnum[a_ins_user];
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chnattrs++;
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}
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rettuple = SPI_modifytuple(rel, trigtuple, chnattrs, chattrs, newvals, newnulls);
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return PointerGetDatum(rettuple);
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/* end of INSERT */
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}
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/* UPDATE/DELETE: */
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oldtimeon = SPI_getbinval(trigtuple, tupdesc, attnum[a_time_on], &isnull);
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if (isnull)
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elog(ERROR, "timetravel (%s): %s must be NOT NULL", relname, args[a_time_on]);
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oldtimeoff = SPI_getbinval(trigtuple, tupdesc, attnum[a_time_off], &isnull);
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if (isnull)
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elog(ERROR, "timetravel (%s): %s must be NOT NULL", relname, args[a_time_off]);
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/*
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* If DELETE/UPDATE of tuple with stop_date neq INFINITY then say
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* upper Executor to skip operation for this tuple
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*/
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if (newtuple != NULL)
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{ /* UPDATE */
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newtimeon = SPI_getbinval(newtuple, tupdesc, attnum[a_time_on], &isnull);
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if (isnull)
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elog(ERROR, "timetravel (%s): %s must be NOT NULL", relname, args[a_time_on]);
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newtimeoff = SPI_getbinval(newtuple, tupdesc, attnum[a_time_off], &isnull);
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if (isnull)
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elog(ERROR, "timetravel (%s): %s must be NOT NULL", relname, args[a_time_off]);
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if (oldtimeon != newtimeon || oldtimeoff != newtimeoff)
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elog(ERROR, "timetravel (%s): you can't change %s and/or %s columns (use set_timetravel)",
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relname, args[a_time_on], args[a_time_off]);
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}
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if (oldtimeoff != NOEND_ABSTIME)
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{ /* current record is a deleted/updated
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* record */
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pfree(relname);
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return PointerGetDatum(NULL);
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}
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newtimeoff = GetCurrentAbsoluteTime();
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/* Connect to SPI manager */
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if ((ret = SPI_connect()) < 0)
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elog(ERROR, "timetravel (%s): SPI_connect returned %d", relname, ret);
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/* Fetch tuple values and nulls */
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cvals = (Datum *) palloc(natts * sizeof(Datum));
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cnulls = (char *) palloc(natts * sizeof(char));
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for (i = 0; i < natts; i++)
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{
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cvals[i] = SPI_getbinval(trigtuple, tupdesc, i + 1, &isnull);
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cnulls[i] = (isnull) ? 'n' : ' ';
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}
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/* change date column(s) */
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cvals[attnum[a_time_off] - 1] = newtimeoff; /* stop_date eq current
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* date */
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cnulls[attnum[a_time_off] - 1] = ' ';
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if (!newtuple)
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{ /* DELETE */
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if (argc == MaxAttrNum)
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{
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cvals[attnum[a_del_user] - 1] = newuser; /* set delete user */
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cnulls[attnum[a_del_user] - 1] = ' ';
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}
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}
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/*
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* Construct ident string as TriggerName $ TriggeredRelationId and try
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* to find prepared execution plan.
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*/
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snprintf(ident, sizeof(ident), "%s$%u", trigger->tgname, rel->rd_id);
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plan = find_plan(ident, &Plans, &nPlans);
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/* if there is no plan ... */
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if (plan->splan == NULL)
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{
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void *pplan;
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Oid *ctypes;
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char sql[8192];
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char separ=' ';
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/* allocate ctypes for preparation */
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ctypes = (Oid *) palloc(natts * sizeof(Oid));
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/*
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* Construct query: INSERT INTO _relation_ VALUES ($1, ...)
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*/
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snprintf(sql, sizeof(sql), "INSERT INTO %s VALUES (", relname);
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for (i = 1; i <= natts; i++)
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{
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ctypes[i - 1] = SPI_gettypeid(tupdesc, i);
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if (!(tupdesc->attrs[i - 1]->attisdropped)) /* skip dropped columns */
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{
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snprintf(sql + strlen(sql), sizeof(sql) - strlen(sql), "%c$%d", separ,i);
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separ = ',';
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}
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}
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snprintf(sql + strlen(sql), sizeof(sql) - strlen(sql), ")");
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elog(DEBUG4, "timetravel (%s) update: sql: %s", relname, sql);
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/* Prepare plan for query */
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pplan = SPI_prepare(sql, natts, ctypes);
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if (pplan == NULL)
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elog(ERROR, "timetravel (%s): SPI_prepare returned %d", relname, SPI_result);
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/*
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* Remember that SPI_prepare places plan in current memory context
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* - so, we have to save plan in Top memory context for latter
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* use.
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*/
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pplan = SPI_saveplan(pplan);
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if (pplan == NULL)
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elog(ERROR, "timetravel (%s): SPI_saveplan returned %d", relname, SPI_result);
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plan->splan = pplan;
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}
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/*
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* Ok, execute prepared plan.
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*/
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ret = SPI_execp(plan->splan, cvals, cnulls, 0);
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if (ret < 0)
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elog(ERROR, "timetravel (%s): SPI_execp returned %d", relname, ret);
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/* Tuple to return to upper Executor ... */
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if (newtuple)
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{ /* UPDATE */
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int chnattrs = 0;
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int chattrs[MaxAttrNum];
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Datum newvals[MaxAttrNum];
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char newnulls[MaxAttrNum];
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newvals[chnattrs] = newtimeoff;
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newnulls[chnattrs] = ' ';
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chattrs[chnattrs] = attnum[a_time_on];
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chnattrs++;
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newvals[chnattrs] = NOEND_ABSTIME;
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newnulls[chnattrs] = ' ';
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chattrs[chnattrs] = attnum[a_time_off];
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chnattrs++;
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if (argc == MaxAttrNum)
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{
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/* set update_user value */
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newvals[chnattrs] = newuser;
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newnulls[chnattrs] = ' ';
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chattrs[chnattrs] = attnum[a_upd_user];
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chnattrs++;
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/* clear delete_user value */
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newvals[chnattrs] = nulltext;
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newnulls[chnattrs] = 'n';
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chattrs[chnattrs] = attnum[a_del_user];
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chnattrs++;
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/* set insert_user value */
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newvals[chnattrs] = nulltext;
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newnulls[chnattrs] = 'n';
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chattrs[chnattrs] = attnum[a_ins_user];
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chnattrs++;
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}
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rettuple = SPI_modifytuple(rel, newtuple, chnattrs, chattrs, newvals, newnulls);
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/*
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* SPI_copytuple allocates tmptuple in upper executor context -
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* have to free allocation using SPI_pfree
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*/
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/* SPI_pfree(tmptuple); */
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}
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else
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/* DELETE case */
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rettuple = trigtuple;
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SPI_finish(); /* don't forget say Bye to SPI mgr */
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pfree(relname);
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return PointerGetDatum(rettuple);
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}
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/*
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* set_timetravel (relname, on) --
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* turn timetravel for specified relation ON/OFF
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*/
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PG_FUNCTION_INFO_V1(set_timetravel);
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Datum
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set_timetravel(PG_FUNCTION_ARGS)
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{
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Name relname = PG_GETARG_NAME(0);
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int32 on = PG_GETARG_INT32(1);
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char *rname;
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char *d;
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char *s;
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int32 ret;
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TTOffList *p,
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*pp;
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for (pp = (p = &TTOff)->next; pp; pp = (p = pp)->next)
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{
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if (namestrcmp(relname, pp->name) == 0)
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break;
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}
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if (pp)
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{
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/* OFF currently */
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if (on != 0)
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{
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/* turn ON */
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p->next = pp->next;
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free(pp);
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}
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ret = 0;
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}
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else
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{
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/* ON currently */
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if (on == 0)
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{
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/* turn OFF */
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s = rname = DatumGetCString(DirectFunctionCall1(nameout, NameGetDatum(relname)));
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if (s)
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{
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pp = malloc(sizeof(TTOffList) + strlen(rname));
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if (pp)
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{
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pp->next = NULL;
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p->next = pp;
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d = pp->name;
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while (*s)
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*d++ = tolower((unsigned char) *s++);
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*d = '\0';
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}
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pfree(rname);
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}
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}
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ret = 1;
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}
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PG_RETURN_INT32(ret);
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}
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/*
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* get_timetravel (relname) --
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* get timetravel status for specified relation (ON/OFF)
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*/
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PG_FUNCTION_INFO_V1(get_timetravel);
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Datum
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get_timetravel(PG_FUNCTION_ARGS)
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{
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Name relname = PG_GETARG_NAME(0);
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TTOffList *pp;
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for (pp = TTOff.next; pp; pp = pp->next)
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{
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if (namestrcmp(relname, pp->name) == 0)
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PG_RETURN_INT32(0);
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|
}
|
|
PG_RETURN_INT32(1);
|
|
}
|
|
|
|
static int
|
|
findTTStatus(char *name)
|
|
{
|
|
TTOffList *pp;
|
|
|
|
for (pp = TTOff.next; pp; pp = pp->next)
|
|
if (pg_strcasecmp(name, pp->name) == 0)
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
AbsoluteTime
|
|
currabstime()
|
|
{
|
|
return (GetCurrentAbsoluteTime());
|
|
}
|
|
*/
|
|
|
|
static EPlan *
|
|
find_plan(char *ident, EPlan ** eplan, int *nplans)
|
|
{
|
|
EPlan *newp;
|
|
int i;
|
|
|
|
if (*nplans > 0)
|
|
{
|
|
for (i = 0; i < *nplans; i++)
|
|
{
|
|
if (strcmp((*eplan)[i].ident, ident) == 0)
|
|
break;
|
|
}
|
|
if (i != *nplans)
|
|
return (*eplan + i);
|
|
*eplan = (EPlan *) realloc(*eplan, (i + 1) * sizeof(EPlan));
|
|
newp = *eplan + i;
|
|
}
|
|
else
|
|
{
|
|
newp = *eplan = (EPlan *) malloc(sizeof(EPlan));
|
|
(*nplans) = i = 0;
|
|
}
|
|
|
|
newp->ident = (char *) malloc(strlen(ident) + 1);
|
|
strcpy(newp->ident, ident);
|
|
newp->splan = NULL;
|
|
(*nplans)++;
|
|
|
|
return (newp);
|
|
}
|