LCOV - differential code coverage report
Current view: top level - contrib/spi - refint.c (source / functions) Coverage Total Hit UBC CBC
Current: Differential Code Coverage HEAD vs 15 Lines: 74.0 % 208 154 54 154
Current Date: 2023-04-08 15:15:32 Functions: 100.0 % 6 6 6
Baseline: 15
Baseline Date: 2023-04-08 15:09:40
Legend: Lines: hit not hit

           TLA  Line data    Source code
       1                 : /*
       2                 :  * contrib/spi/refint.c
       3                 :  *
       4                 :  *
       5                 :  * refint.c --  set of functions to define referential integrity
       6                 :  *      constraints using general triggers.
       7                 :  */
       8                 : #include "postgres.h"
       9                 : 
      10                 : #include <ctype.h>
      11                 : 
      12                 : #include "commands/trigger.h"
      13                 : #include "executor/spi.h"
      14                 : #include "utils/builtins.h"
      15                 : #include "utils/memutils.h"
      16                 : #include "utils/rel.h"
      17                 : 
      18 CBC           6 : PG_MODULE_MAGIC;
      19                 : 
      20                 : typedef struct
      21                 : {
      22                 :     char       *ident;
      23                 :     int         nplans;
      24                 :     SPIPlanPtr *splan;
      25                 : } EPlan;
      26                 : 
      27                 : static EPlan *FPlans = NULL;
      28                 : static int  nFPlans = 0;
      29                 : static EPlan *PPlans = NULL;
      30                 : static int  nPPlans = 0;
      31                 : 
      32                 : static EPlan *find_plan(char *ident, EPlan **eplan, int *nplans);
      33                 : 
      34                 : /*
      35                 :  * check_primary_key () -- check that key in tuple being inserted/updated
      36                 :  *           references existing tuple in "primary" table.
      37                 :  * Though it's called without args You have to specify referenced
      38                 :  * table/keys while creating trigger:  key field names in triggered table,
      39                 :  * referenced table name, referenced key field names:
      40                 :  * EXECUTE PROCEDURE
      41                 :  * check_primary_key ('Fkey1', 'Fkey2', 'Ptable', 'Pkey1', 'Pkey2').
      42                 :  */
      43                 : 
      44               7 : PG_FUNCTION_INFO_V1(check_primary_key);
      45                 : 
      46                 : Datum
      47              48 : check_primary_key(PG_FUNCTION_ARGS)
      48                 : {
      49              48 :     TriggerData *trigdata = (TriggerData *) fcinfo->context;
      50                 :     Trigger    *trigger;        /* to get trigger name */
      51                 :     int         nargs;          /* # of args specified in CREATE TRIGGER */
      52                 :     char      **args;           /* arguments: column names and table name */
      53                 :     int         nkeys;          /* # of key columns (= nargs / 2) */
      54                 :     Datum      *kvals;          /* key values */
      55                 :     char       *relname;        /* referenced relation name */
      56                 :     Relation    rel;            /* triggered relation */
      57              48 :     HeapTuple   tuple = NULL;   /* tuple to return */
      58                 :     TupleDesc   tupdesc;        /* tuple description */
      59                 :     EPlan      *plan;           /* prepared plan */
      60              48 :     Oid        *argtypes = NULL;    /* key types to prepare execution plan */
      61                 :     bool        isnull;         /* to know is some column NULL or not */
      62                 :     char        ident[2 * NAMEDATALEN]; /* to identify myself */
      63                 :     int         ret;
      64                 :     int         i;
      65                 : 
      66                 : #ifdef  DEBUG_QUERY
      67                 :     elog(DEBUG4, "check_primary_key: Enter Function");
      68                 : #endif
      69                 : 
      70                 :     /*
      71                 :      * Some checks first...
      72                 :      */
      73                 : 
      74                 :     /* Called by trigger manager ? */
      75              48 :     if (!CALLED_AS_TRIGGER(fcinfo))
      76                 :         /* internal error */
      77 UBC           0 :         elog(ERROR, "check_primary_key: not fired by trigger manager");
      78                 : 
      79                 :     /* Should be called for ROW trigger */
      80 CBC          48 :     if (!TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
      81                 :         /* internal error */
      82 UBC           0 :         elog(ERROR, "check_primary_key: must be fired for row");
      83                 : 
      84                 :     /* If INSERTion then must check Tuple to being inserted */
      85 CBC          48 :     if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
      86              48 :         tuple = trigdata->tg_trigtuple;
      87                 : 
      88                 :     /* Not should be called for DELETE */
      89 UBC           0 :     else if (TRIGGER_FIRED_BY_DELETE(trigdata->tg_event))
      90                 :         /* internal error */
      91               0 :         elog(ERROR, "check_primary_key: cannot process DELETE events");
      92                 : 
      93                 :     /* If UPDATE, then must check new Tuple, not old one */
      94                 :     else
      95               0 :         tuple = trigdata->tg_newtuple;
      96                 : 
      97 CBC          48 :     trigger = trigdata->tg_trigger;
      98              48 :     nargs = trigger->tgnargs;
      99              48 :     args = trigger->tgargs;
     100                 : 
     101              48 :     if (nargs % 2 != 1)         /* odd number of arguments! */
     102                 :         /* internal error */
     103 UBC           0 :         elog(ERROR, "check_primary_key: odd number of arguments should be specified");
     104                 : 
     105 CBC          48 :     nkeys = nargs / 2;
     106              48 :     relname = args[nkeys];
     107              48 :     rel = trigdata->tg_relation;
     108              48 :     tupdesc = rel->rd_att;
     109                 : 
     110                 :     /* Connect to SPI manager */
     111              48 :     if ((ret = SPI_connect()) < 0)
     112                 :         /* internal error */
     113 UBC           0 :         elog(ERROR, "check_primary_key: SPI_connect returned %d", ret);
     114                 : 
     115                 :     /*
     116                 :      * We use SPI plan preparation feature, so allocate space to place key
     117                 :      * values.
     118                 :      */
     119 CBC          48 :     kvals = (Datum *) palloc(nkeys * sizeof(Datum));
     120                 : 
     121                 :     /*
     122                 :      * Construct ident string as TriggerName $ TriggeredRelationId and try to
     123                 :      * find prepared execution plan.
     124                 :      */
     125              48 :     snprintf(ident, sizeof(ident), "%s$%u", trigger->tgname, rel->rd_id);
     126              48 :     plan = find_plan(ident, &PPlans, &nPPlans);
     127                 : 
     128                 :     /* if there is no plan then allocate argtypes for preparation */
     129              48 :     if (plan->nplans <= 0)
     130               9 :         argtypes = (Oid *) palloc(nkeys * sizeof(Oid));
     131                 : 
     132                 :     /* For each column in key ... */
     133             126 :     for (i = 0; i < nkeys; i++)
     134                 :     {
     135                 :         /* get index of column in tuple */
     136              78 :         int         fnumber = SPI_fnumber(tupdesc, args[i]);
     137                 : 
     138                 :         /* Bad guys may give us un-existing column in CREATE TRIGGER */
     139              78 :         if (fnumber <= 0)
     140 UBC           0 :             ereport(ERROR,
     141                 :                     (errcode(ERRCODE_UNDEFINED_COLUMN),
     142                 :                      errmsg("there is no attribute \"%s\" in relation \"%s\"",
     143                 :                             args[i], SPI_getrelname(rel))));
     144                 : 
     145                 :         /* Well, get binary (in internal format) value of column */
     146 CBC          78 :         kvals[i] = SPI_getbinval(tuple, tupdesc, fnumber, &isnull);
     147                 : 
     148                 :         /*
     149                 :          * If it's NULL then nothing to do! DON'T FORGET call SPI_finish ()!
     150                 :          * DON'T FORGET return tuple! Executor inserts tuple you're returning!
     151                 :          * If you return NULL then nothing will be inserted!
     152                 :          */
     153              78 :         if (isnull)
     154                 :         {
     155 UBC           0 :             SPI_finish();
     156               0 :             return PointerGetDatum(tuple);
     157                 :         }
     158                 : 
     159 CBC          78 :         if (plan->nplans <= 0)    /* Get typeId of column */
     160              15 :             argtypes[i] = SPI_gettypeid(tupdesc, fnumber);
     161                 :     }
     162                 : 
     163                 :     /*
     164                 :      * If we have to prepare plan ...
     165                 :      */
     166              48 :     if (plan->nplans <= 0)
     167                 :     {
     168                 :         SPIPlanPtr  pplan;
     169                 :         char        sql[8192];
     170                 : 
     171                 :         /*
     172                 :          * Construct query: SELECT 1 FROM _referenced_relation_ WHERE Pkey1 =
     173                 :          * $1 [AND Pkey2 = $2 [...]]
     174                 :          */
     175               9 :         snprintf(sql, sizeof(sql), "select 1 from %s where ", relname);
     176              24 :         for (i = 0; i < nkeys; i++)
     177                 :         {
     178              15 :             snprintf(sql + strlen(sql), sizeof(sql) - strlen(sql), "%s = $%d %s",
     179              30 :                      args[i + nkeys + 1], i + 1, (i < nkeys - 1) ? "and " : "");
     180                 :         }
     181                 : 
     182                 :         /* Prepare plan for query */
     183               9 :         pplan = SPI_prepare(sql, nkeys, argtypes);
     184               9 :         if (pplan == NULL)
     185                 :             /* internal error */
     186 UBC           0 :             elog(ERROR, "check_primary_key: SPI_prepare returned %s", SPI_result_code_string(SPI_result));
     187                 : 
     188                 :         /*
     189                 :          * Remember that SPI_prepare places plan in current memory context -
     190                 :          * so, we have to save plan in TopMemoryContext for later use.
     191                 :          */
     192 CBC           9 :         if (SPI_keepplan(pplan))
     193                 :             /* internal error */
     194 UBC           0 :             elog(ERROR, "check_primary_key: SPI_keepplan failed");
     195 CBC           9 :         plan->splan = (SPIPlanPtr *) MemoryContextAlloc(TopMemoryContext,
     196                 :                                                         sizeof(SPIPlanPtr));
     197               9 :         *(plan->splan) = pplan;
     198               9 :         plan->nplans = 1;
     199                 :     }
     200                 : 
     201                 :     /*
     202                 :      * Ok, execute prepared plan.
     203                 :      */
     204              48 :     ret = SPI_execp(*(plan->splan), kvals, NULL, 1);
     205                 :     /* we have no NULLs - so we pass   ^^^^   here */
     206                 : 
     207              48 :     if (ret < 0)
     208                 :         /* internal error */
     209 UBC           0 :         elog(ERROR, "check_primary_key: SPI_execp returned %d", ret);
     210                 : 
     211                 :     /*
     212                 :      * If there are no tuples returned by SELECT then ...
     213                 :      */
     214 CBC          48 :     if (SPI_processed == 0)
     215               9 :         ereport(ERROR,
     216                 :                 (errcode(ERRCODE_TRIGGERED_ACTION_EXCEPTION),
     217                 :                  errmsg("tuple references non-existent key"),
     218                 :                  errdetail("Trigger \"%s\" found tuple referencing non-existent key in \"%s\".", trigger->tgname, relname)));
     219                 : 
     220              39 :     SPI_finish();
     221                 : 
     222              39 :     return PointerGetDatum(tuple);
     223                 : }
     224                 : 
     225                 : /*
     226                 :  * check_foreign_key () -- check that key in tuple being deleted/updated
     227                 :  *           is not referenced by tuples in "foreign" table(s).
     228                 :  * Though it's called without args You have to specify (while creating trigger):
     229                 :  * number of references, action to do if key referenced
     230                 :  * ('restrict' | 'setnull' | 'cascade'), key field names in triggered
     231                 :  * ("primary") table and referencing table(s)/keys:
     232                 :  * EXECUTE PROCEDURE
     233                 :  * check_foreign_key (2, 'restrict', 'Pkey1', 'Pkey2',
     234                 :  * 'Ftable1', 'Fkey11', 'Fkey12', 'Ftable2', 'Fkey21', 'Fkey22').
     235                 :  */
     236                 : 
     237               7 : PG_FUNCTION_INFO_V1(check_foreign_key);
     238                 : 
     239                 : Datum
     240              24 : check_foreign_key(PG_FUNCTION_ARGS)
     241                 : {
     242              24 :     TriggerData *trigdata = (TriggerData *) fcinfo->context;
     243                 :     Trigger    *trigger;        /* to get trigger name */
     244                 :     int         nargs;          /* # of args specified in CREATE TRIGGER */
     245                 :     char      **args;           /* arguments: as described above */
     246                 :     char      **args_temp;
     247                 :     int         nrefs;          /* number of references (== # of plans) */
     248                 :     char        action;         /* 'R'estrict | 'S'etnull | 'C'ascade */
     249                 :     int         nkeys;          /* # of key columns */
     250                 :     Datum      *kvals;          /* key values */
     251                 :     char       *relname;        /* referencing relation name */
     252                 :     Relation    rel;            /* triggered relation */
     253              24 :     HeapTuple   trigtuple = NULL;   /* tuple to being changed */
     254              24 :     HeapTuple   newtuple = NULL;    /* tuple to return */
     255                 :     TupleDesc   tupdesc;        /* tuple description */
     256                 :     EPlan      *plan;           /* prepared plan(s) */
     257              24 :     Oid        *argtypes = NULL;    /* key types to prepare execution plan */
     258                 :     bool        isnull;         /* to know is some column NULL or not */
     259              24 :     bool        isequal = true; /* are keys in both tuples equal (in UPDATE) */
     260                 :     char        ident[2 * NAMEDATALEN]; /* to identify myself */
     261              24 :     int         is_update = 0;
     262                 :     int         ret;
     263                 :     int         i,
     264                 :                 r;
     265                 : 
     266                 : #ifdef DEBUG_QUERY
     267                 :     elog(DEBUG4, "check_foreign_key: Enter Function");
     268                 : #endif
     269                 : 
     270                 :     /*
     271                 :      * Some checks first...
     272                 :      */
     273                 : 
     274                 :     /* Called by trigger manager ? */
     275              24 :     if (!CALLED_AS_TRIGGER(fcinfo))
     276                 :         /* internal error */
     277 UBC           0 :         elog(ERROR, "check_foreign_key: not fired by trigger manager");
     278                 : 
     279                 :     /* Should be called for ROW trigger */
     280 CBC          24 :     if (!TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
     281                 :         /* internal error */
     282 UBC           0 :         elog(ERROR, "check_foreign_key: must be fired for row");
     283                 : 
     284                 :     /* Not should be called for INSERT */
     285 CBC          24 :     if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
     286                 :         /* internal error */
     287 UBC           0 :         elog(ERROR, "check_foreign_key: cannot process INSERT events");
     288                 : 
     289                 :     /* Have to check tg_trigtuple - tuple being deleted */
     290 CBC          24 :     trigtuple = trigdata->tg_trigtuple;
     291                 : 
     292                 :     /*
     293                 :      * But if this is UPDATE then we have to return tg_newtuple. Also, if key
     294                 :      * in tg_newtuple is the same as in tg_trigtuple then nothing to do.
     295                 :      */
     296              24 :     is_update = 0;
     297              24 :     if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
     298                 :     {
     299               6 :         newtuple = trigdata->tg_newtuple;
     300               6 :         is_update = 1;
     301                 :     }
     302              24 :     trigger = trigdata->tg_trigger;
     303              24 :     nargs = trigger->tgnargs;
     304              24 :     args = trigger->tgargs;
     305                 : 
     306              24 :     if (nargs < 5)               /* nrefs, action, key, Relation, key - at
     307                 :                                  * least */
     308                 :         /* internal error */
     309 UBC           0 :         elog(ERROR, "check_foreign_key: too short %d (< 5) list of arguments", nargs);
     310                 : 
     311 CBC          24 :     nrefs = pg_strtoint32(args[0]);
     312              24 :     if (nrefs < 1)
     313                 :         /* internal error */
     314 UBC           0 :         elog(ERROR, "check_foreign_key: %d (< 1) number of references specified", nrefs);
     315 CBC          24 :     action = tolower((unsigned char) *(args[1]));
     316              24 :     if (action != 'r' && action != 'c' && action != 's')
     317                 :         /* internal error */
     318 UBC           0 :         elog(ERROR, "check_foreign_key: invalid action %s", args[1]);
     319 CBC          24 :     nargs -= 2;
     320              24 :     args += 2;
     321              24 :     nkeys = (nargs - nrefs) / (nrefs + 1);
     322              24 :     if (nkeys <= 0 || nargs != (nrefs + nkeys * (nrefs + 1)))
     323                 :         /* internal error */
     324 UBC           0 :         elog(ERROR, "check_foreign_key: invalid number of arguments %d for %d references",
     325                 :              nargs + 2, nrefs);
     326                 : 
     327 CBC          24 :     rel = trigdata->tg_relation;
     328              24 :     tupdesc = rel->rd_att;
     329                 : 
     330                 :     /* Connect to SPI manager */
     331              24 :     if ((ret = SPI_connect()) < 0)
     332                 :         /* internal error */
     333 UBC           0 :         elog(ERROR, "check_foreign_key: SPI_connect returned %d", ret);
     334                 : 
     335                 :     /*
     336                 :      * We use SPI plan preparation feature, so allocate space to place key
     337                 :      * values.
     338                 :      */
     339 CBC          24 :     kvals = (Datum *) palloc(nkeys * sizeof(Datum));
     340                 : 
     341                 :     /*
     342                 :      * Construct ident string as TriggerName $ TriggeredRelationId and try to
     343                 :      * find prepared execution plan(s).
     344                 :      */
     345              24 :     snprintf(ident, sizeof(ident), "%s$%u", trigger->tgname, rel->rd_id);
     346              24 :     plan = find_plan(ident, &FPlans, &nFPlans);
     347                 : 
     348                 :     /* if there is no plan(s) then allocate argtypes for preparation */
     349              24 :     if (plan->nplans <= 0)
     350               6 :         argtypes = (Oid *) palloc(nkeys * sizeof(Oid));
     351                 : 
     352                 :     /*
     353                 :      * else - check that we have exactly nrefs plan(s) ready
     354                 :      */
     355              18 :     else if (plan->nplans != nrefs)
     356                 :         /* internal error */
     357 UBC           0 :         elog(ERROR, "%s: check_foreign_key: # of plans changed in meantime",
     358                 :              trigger->tgname);
     359                 : 
     360                 :     /* For each column in key ... */
     361 CBC          60 :     for (i = 0; i < nkeys; i++)
     362                 :     {
     363                 :         /* get index of column in tuple */
     364              36 :         int         fnumber = SPI_fnumber(tupdesc, args[i]);
     365                 : 
     366                 :         /* Bad guys may give us un-existing column in CREATE TRIGGER */
     367              36 :         if (fnumber <= 0)
     368 UBC           0 :             ereport(ERROR,
     369                 :                     (errcode(ERRCODE_UNDEFINED_COLUMN),
     370                 :                      errmsg("there is no attribute \"%s\" in relation \"%s\"",
     371                 :                             args[i], SPI_getrelname(rel))));
     372                 : 
     373                 :         /* Well, get binary (in internal format) value of column */
     374 CBC          36 :         kvals[i] = SPI_getbinval(trigtuple, tupdesc, fnumber, &isnull);
     375                 : 
     376                 :         /*
     377                 :          * If it's NULL then nothing to do! DON'T FORGET call SPI_finish ()!
     378                 :          * DON'T FORGET return tuple! Executor inserts tuple you're returning!
     379                 :          * If you return NULL then nothing will be inserted!
     380                 :          */
     381              36 :         if (isnull)
     382                 :         {
     383 UBC           0 :             SPI_finish();
     384               0 :             return PointerGetDatum((newtuple == NULL) ? trigtuple : newtuple);
     385                 :         }
     386                 : 
     387                 :         /*
     388                 :          * If UPDATE then get column value from new tuple being inserted and
     389                 :          * compare is this the same as old one. For the moment we use string
     390                 :          * presentation of values...
     391                 :          */
     392 CBC          36 :         if (newtuple != NULL)
     393                 :         {
     394              12 :             char       *oldval = SPI_getvalue(trigtuple, tupdesc, fnumber);
     395                 :             char       *newval;
     396                 : 
     397                 :             /* this shouldn't happen! SPI_ERROR_NOOUTFUNC ? */
     398              12 :             if (oldval == NULL)
     399                 :                 /* internal error */
     400 UBC           0 :                 elog(ERROR, "check_foreign_key: SPI_getvalue returned %s", SPI_result_code_string(SPI_result));
     401 CBC          12 :             newval = SPI_getvalue(newtuple, tupdesc, fnumber);
     402              12 :             if (newval == NULL || strcmp(oldval, newval) != 0)
     403              12 :                 isequal = false;
     404                 :         }
     405                 : 
     406              36 :         if (plan->nplans <= 0)    /* Get typeId of column */
     407               9 :             argtypes[i] = SPI_gettypeid(tupdesc, fnumber);
     408                 :     }
     409              24 :     args_temp = args;
     410              24 :     nargs -= nkeys;
     411              24 :     args += nkeys;
     412                 : 
     413                 :     /*
     414                 :      * If we have to prepare plans ...
     415                 :      */
     416              24 :     if (plan->nplans <= 0)
     417                 :     {
     418                 :         SPIPlanPtr  pplan;
     419                 :         char        sql[8192];
     420               6 :         char      **args2 = args;
     421                 : 
     422               6 :         plan->splan = (SPIPlanPtr *) MemoryContextAlloc(TopMemoryContext,
     423                 :                                                         nrefs * sizeof(SPIPlanPtr));
     424                 : 
     425              15 :         for (r = 0; r < nrefs; r++)
     426                 :         {
     427               9 :             relname = args2[0];
     428                 : 
     429                 :             /*---------
     430                 :              * For 'R'estrict action we construct SELECT query:
     431                 :              *
     432                 :              *  SELECT 1
     433                 :              *  FROM _referencing_relation_
     434                 :              *  WHERE Fkey1 = $1 [AND Fkey2 = $2 [...]]
     435                 :              *
     436                 :              *  to check is tuple referenced or not.
     437                 :              *---------
     438                 :              */
     439               9 :             if (action == 'r')
     440                 : 
     441               3 :                 snprintf(sql, sizeof(sql), "select 1 from %s where ", relname);
     442                 : 
     443                 :             /*---------
     444                 :              * For 'C'ascade action we construct DELETE query
     445                 :              *
     446                 :              *  DELETE
     447                 :              *  FROM _referencing_relation_
     448                 :              *  WHERE Fkey1 = $1 [AND Fkey2 = $2 [...]]
     449                 :              *
     450                 :              * to delete all referencing tuples.
     451                 :              *---------
     452                 :              */
     453                 : 
     454                 :             /*
     455                 :              * Max : Cascade with UPDATE query i create update query that
     456                 :              * updates new key values in referenced tables
     457                 :              */
     458                 : 
     459                 : 
     460               6 :             else if (action == 'c')
     461                 :             {
     462               6 :                 if (is_update == 1)
     463                 :                 {
     464                 :                     int         fn;
     465                 :                     char       *nv;
     466                 :                     int         k;
     467                 : 
     468 UBC           0 :                     snprintf(sql, sizeof(sql), "update %s set ", relname);
     469               0 :                     for (k = 1; k <= nkeys; k++)
     470                 :                     {
     471               0 :                         int         is_char_type = 0;
     472                 :                         char       *type;
     473                 : 
     474               0 :                         fn = SPI_fnumber(tupdesc, args_temp[k - 1]);
     475               0 :                         Assert(fn > 0); /* already checked above */
     476               0 :                         nv = SPI_getvalue(newtuple, tupdesc, fn);
     477               0 :                         type = SPI_gettype(tupdesc, fn);
     478                 : 
     479               0 :                         if (strcmp(type, "text") == 0 ||
     480               0 :                             strcmp(type, "varchar") == 0 ||
     481               0 :                             strcmp(type, "char") == 0 ||
     482               0 :                             strcmp(type, "bpchar") == 0 ||
     483               0 :                             strcmp(type, "date") == 0 ||
     484               0 :                             strcmp(type, "timestamp") == 0)
     485               0 :                             is_char_type = 1;
     486                 : #ifdef  DEBUG_QUERY
     487                 :                         elog(DEBUG4, "check_foreign_key Debug value %s type %s %d",
     488                 :                              nv, type, is_char_type);
     489                 : #endif
     490                 : 
     491                 :                         /*
     492                 :                          * is_char_type =1 i set ' ' for define a new value
     493                 :                          */
     494               0 :                         snprintf(sql + strlen(sql), sizeof(sql) - strlen(sql),
     495                 :                                  " %s = %s%s%s %s ",
     496               0 :                                  args2[k], (is_char_type > 0) ? "'" : "",
     497                 :                                  nv, (is_char_type > 0) ? "'" : "", (k < nkeys) ? ", " : "");
     498                 :                     }
     499               0 :                     strcat(sql, " where ");
     500                 :                 }
     501                 :                 else
     502                 :                     /* DELETE */
     503 CBC           6 :                     snprintf(sql, sizeof(sql), "delete from %s where ", relname);
     504                 :             }
     505                 : 
     506                 :             /*
     507                 :              * For 'S'etnull action we construct UPDATE query - UPDATE
     508                 :              * _referencing_relation_ SET Fkey1 null [, Fkey2 null [...]]
     509                 :              * WHERE Fkey1 = $1 [AND Fkey2 = $2 [...]] - to set key columns in
     510                 :              * all referencing tuples to NULL.
     511                 :              */
     512 UBC           0 :             else if (action == 's')
     513                 :             {
     514               0 :                 snprintf(sql, sizeof(sql), "update %s set ", relname);
     515               0 :                 for (i = 1; i <= nkeys; i++)
     516                 :                 {
     517               0 :                     snprintf(sql + strlen(sql), sizeof(sql) - strlen(sql),
     518                 :                              "%s = null%s",
     519               0 :                              args2[i], (i < nkeys) ? ", " : "");
     520                 :                 }
     521               0 :                 strcat(sql, " where ");
     522                 :             }
     523                 : 
     524                 :             /* Construct WHERE qual */
     525 CBC          24 :             for (i = 1; i <= nkeys; i++)
     526                 :             {
     527              15 :                 snprintf(sql + strlen(sql), sizeof(sql) - strlen(sql), "%s = $%d %s",
     528              15 :                          args2[i], i, (i < nkeys) ? "and " : "");
     529                 :             }
     530                 : 
     531                 :             /* Prepare plan for query */
     532               9 :             pplan = SPI_prepare(sql, nkeys, argtypes);
     533               9 :             if (pplan == NULL)
     534                 :                 /* internal error */
     535 UBC           0 :                 elog(ERROR, "check_foreign_key: SPI_prepare returned %s", SPI_result_code_string(SPI_result));
     536                 : 
     537                 :             /*
     538                 :              * Remember that SPI_prepare places plan in current memory context
     539                 :              * - so, we have to save plan in Top memory context for later use.
     540                 :              */
     541 CBC           9 :             if (SPI_keepplan(pplan))
     542                 :                 /* internal error */
     543 UBC           0 :                 elog(ERROR, "check_foreign_key: SPI_keepplan failed");
     544                 : 
     545 CBC           9 :             plan->splan[r] = pplan;
     546                 : 
     547               9 :             args2 += nkeys + 1; /* to the next relation */
     548                 :         }
     549               6 :         plan->nplans = nrefs;
     550                 : #ifdef  DEBUG_QUERY
     551                 :         elog(DEBUG4, "check_foreign_key Debug Query is :  %s ", sql);
     552                 : #endif
     553                 :     }
     554                 : 
     555                 :     /*
     556                 :      * If UPDATE and key is not changed ...
     557                 :      */
     558              24 :     if (newtuple != NULL && isequal)
     559                 :     {
     560 UBC           0 :         SPI_finish();
     561               0 :         return PointerGetDatum(newtuple);
     562                 :     }
     563                 : 
     564                 :     /*
     565                 :      * Ok, execute prepared plan(s).
     566                 :      */
     567 CBC          48 :     for (r = 0; r < nrefs; r++)
     568                 :     {
     569                 :         /*
     570                 :          * For 'R'estrict we may to execute plan for one tuple only, for other
     571                 :          * actions - for all tuples.
     572                 :          */
     573              36 :         int         tcount = (action == 'r') ? 1 : 0;
     574                 : 
     575              36 :         relname = args[0];
     576                 : 
     577              36 :         snprintf(ident, sizeof(ident), "%s$%u", trigger->tgname, rel->rd_id);
     578              36 :         plan = find_plan(ident, &FPlans, &nFPlans);
     579              36 :         ret = SPI_execp(plan->splan[r], kvals, NULL, tcount);
     580                 :         /* we have no NULLs - so we pass   ^^^^  here */
     581                 : 
     582              30 :         if (ret < 0)
     583 UBC           0 :             ereport(ERROR,
     584                 :                     (errcode(ERRCODE_TRIGGERED_ACTION_EXCEPTION),
     585                 :                      errmsg("SPI_execp returned %d", ret)));
     586                 : 
     587                 :         /* If action is 'R'estrict ... */
     588 CBC          30 :         if (action == 'r')
     589                 :         {
     590                 :             /* If there is tuple returned by SELECT then ... */
     591              12 :             if (SPI_processed > 0)
     592               6 :                 ereport(ERROR,
     593                 :                         (errcode(ERRCODE_TRIGGERED_ACTION_EXCEPTION),
     594                 :                          errmsg("\"%s\": tuple is referenced in \"%s\"",
     595                 :                                 trigger->tgname, relname)));
     596                 :         }
     597                 :         else
     598                 :         {
     599                 : #ifdef REFINT_VERBOSE
     600              18 :             elog(NOTICE, "%s: " UINT64_FORMAT " tuple(s) of %s are %s",
     601                 :                  trigger->tgname, SPI_processed, relname,
     602                 :                  (action == 'c') ? "deleted" : "set to null");
     603                 : #endif
     604                 :         }
     605              24 :         args += nkeys + 1;      /* to the next relation */
     606                 :     }
     607                 : 
     608              12 :     SPI_finish();
     609                 : 
     610              12 :     return PointerGetDatum((newtuple == NULL) ? trigtuple : newtuple);
     611                 : }
     612                 : 
     613                 : static EPlan *
     614             108 : find_plan(char *ident, EPlan **eplan, int *nplans)
     615                 : {
     616                 :     EPlan      *newp;
     617                 :     int         i;
     618                 :     MemoryContext oldcontext;
     619                 : 
     620                 :     /*
     621                 :      * All allocations done for the plans need to happen in a session-safe
     622                 :      * context.
     623                 :      */
     624             108 :     oldcontext = MemoryContextSwitchTo(TopMemoryContext);
     625                 : 
     626             108 :     if (*nplans > 0)
     627                 :     {
     628             174 :         for (i = 0; i < *nplans; i++)
     629                 :         {
     630             165 :             if (strcmp((*eplan)[i].ident, ident) == 0)
     631              93 :                 break;
     632                 :         }
     633             102 :         if (i != *nplans)
     634                 :         {
     635              93 :             MemoryContextSwitchTo(oldcontext);
     636              93 :             return (*eplan + i);
     637                 :         }
     638               9 :         *eplan = (EPlan *) repalloc(*eplan, (i + 1) * sizeof(EPlan));
     639               9 :         newp = *eplan + i;
     640                 :     }
     641                 :     else
     642                 :     {
     643               6 :         newp = *eplan = (EPlan *) palloc(sizeof(EPlan));
     644               6 :         (*nplans) = i = 0;
     645                 :     }
     646                 : 
     647              15 :     newp->ident = pstrdup(ident);
     648              15 :     newp->nplans = 0;
     649              15 :     newp->splan = NULL;
     650              15 :     (*nplans)++;
     651                 : 
     652              15 :     MemoryContextSwitchTo(oldcontext);
     653              15 :     return newp;
     654                 : }
        

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