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autoinc.c File Reference
#include "postgres.h"
#include "access/htup_details.h"
#include "catalog/pg_type.h"
#include "commands/sequence.h"
#include "commands/trigger.h"
#include "executor/spi.h"
#include "utils/builtins.h"
#include "utils/rel.h"
Include dependency graph for autoinc.c:

Go to the source code of this file.

Functions

 PG_FUNCTION_INFO_V1 (autoinc)
 
Datum autoinc (PG_FUNCTION_ARGS)
 

Variables

 PG_MODULE_MAGIC
 

Function Documentation

Datum autoinc ( PG_FUNCTION_ARGS  )

Definition at line 19 of file autoinc.c.

References generate_unaccent_rules::args, CALLED_AS_TRIGGER, CStringGetTextDatum, DatumGetInt32, DatumGetInt64, DatumGetTextPP, DirectFunctionCall1, elog, ereport, errcode(), errmsg(), ERROR, heap_modify_tuple_by_cols(), i, Int32GetDatum, INT4OID, nextval(), NULL, palloc(), pfree(), PointerGetDatum, SPI_fnumber(), SPI_getbinval(), SPI_getrelname(), SPI_gettypeid(), TriggerData::tg_event, TriggerData::tg_newtuple, TriggerData::tg_relation, TriggerData::tg_trigger, TriggerData::tg_trigtuple, Trigger::tgnargs, TRIGGER_FIRED_BEFORE, TRIGGER_FIRED_BY_INSERT, TRIGGER_FIRED_BY_UPDATE, TRIGGER_FIRED_FOR_ROW, and val.

20 {
21  TriggerData *trigdata = (TriggerData *) fcinfo->context;
22  Trigger *trigger; /* to get trigger name */
23  int nargs; /* # of arguments */
24  int *chattrs; /* attnums of attributes to change */
25  int chnattrs = 0; /* # of above */
26  Datum *newvals; /* vals of above */
27  bool *newnulls; /* null flags for above */
28  char **args; /* arguments */
29  char *relname; /* triggered relation name */
30  Relation rel; /* triggered relation */
31  HeapTuple rettuple = NULL;
32  TupleDesc tupdesc; /* tuple description */
33  bool isnull;
34  int i;
35 
36  if (!CALLED_AS_TRIGGER(fcinfo))
37  /* internal error */
38  elog(ERROR, "not fired by trigger manager");
39  if (!TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
40  /* internal error */
41  elog(ERROR, "must be fired for row");
42  if (!TRIGGER_FIRED_BEFORE(trigdata->tg_event))
43  /* internal error */
44  elog(ERROR, "must be fired before event");
45 
46  if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
47  rettuple = trigdata->tg_trigtuple;
48  else if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
49  rettuple = trigdata->tg_newtuple;
50  else
51  /* internal error */
52  elog(ERROR, "cannot process DELETE events");
53 
54  rel = trigdata->tg_relation;
55  relname = SPI_getrelname(rel);
56 
57  trigger = trigdata->tg_trigger;
58 
59  nargs = trigger->tgnargs;
60  if (nargs <= 0 || nargs % 2 != 0)
61  /* internal error */
62  elog(ERROR, "autoinc (%s): even number gt 0 of arguments was expected", relname);
63 
64  args = trigger->tgargs;
65  tupdesc = rel->rd_att;
66 
67  chattrs = (int *) palloc(nargs / 2 * sizeof(int));
68  newvals = (Datum *) palloc(nargs / 2 * sizeof(Datum));
69  newnulls = (bool *) palloc(nargs / 2 * sizeof(bool));
70 
71  for (i = 0; i < nargs;)
72  {
73  int attnum = SPI_fnumber(tupdesc, args[i]);
74  int32 val;
75  Datum seqname;
76 
77  if (attnum <= 0)
78  ereport(ERROR,
79  (errcode(ERRCODE_TRIGGERED_ACTION_EXCEPTION),
80  errmsg("\"%s\" has no attribute \"%s\"",
81  relname, args[i])));
82 
83  if (SPI_gettypeid(tupdesc, attnum) != INT4OID)
84  ereport(ERROR,
85  (errcode(ERRCODE_TRIGGERED_ACTION_EXCEPTION),
86  errmsg("attribute \"%s\" of \"%s\" must be type INT4",
87  args[i], relname)));
88 
89  val = DatumGetInt32(SPI_getbinval(rettuple, tupdesc, attnum, &isnull));
90 
91  if (!isnull && val != 0)
92  {
93  i += 2;
94  continue;
95  }
96 
97  i++;
98  chattrs[chnattrs] = attnum;
99  seqname = CStringGetTextDatum(args[i]);
100  newvals[chnattrs] = DirectFunctionCall1(nextval, seqname);
101  /* nextval now returns int64; coerce down to int32 */
102  newvals[chnattrs] = Int32GetDatum((int32) DatumGetInt64(newvals[chnattrs]));
103  if (DatumGetInt32(newvals[chnattrs]) == 0)
104  {
105  newvals[chnattrs] = DirectFunctionCall1(nextval, seqname);
106  newvals[chnattrs] = Int32GetDatum((int32) DatumGetInt64(newvals[chnattrs]));
107  }
108  newnulls[chnattrs] = false;
109  pfree(DatumGetTextPP(seqname));
110  chnattrs++;
111  i++;
112  }
113 
114  if (chnattrs > 0)
115  {
116  rettuple = heap_modify_tuple_by_cols(rettuple, tupdesc,
117  chnattrs, chattrs,
118  newvals, newnulls);
119  }
120 
121  pfree(relname);
122  pfree(chattrs);
123  pfree(newvals);
124  pfree(newnulls);
125 
126  return PointerGetDatum(rettuple);
127 }
int SPI_fnumber(TupleDesc tupdesc, const char *fname)
Definition: spi.c:761
Oid SPI_gettypeid(TupleDesc tupdesc, int fnumber)
Definition: spi.c:892
#define DatumGetInt32(X)
Definition: postgres.h:478
#define PointerGetDatum(X)
Definition: postgres.h:562
#define DatumGetTextPP(X)
Definition: fmgr.h:256
Datum nextval(PG_FUNCTION_ARGS)
Definition: sequence.c:547
#define INT4OID
Definition: pg_type.h:316
int errcode(int sqlerrcode)
Definition: elog.c:575
#define DirectFunctionCall1(func, arg1)
Definition: fmgr.h:584
HeapTuple tg_trigtuple
Definition: trigger.h:35
signed int int32
Definition: c.h:256
void pfree(void *pointer)
Definition: mcxt.c:950
#define ERROR
Definition: elog.h:43
Datum SPI_getbinval(HeapTuple tuple, TupleDesc tupdesc, int fnumber, bool *isnull)
Definition: spi.c:836
#define DatumGetInt64(X)
Definition: postgres.h:613
#define ereport(elevel, rest)
Definition: elog.h:122
uintptr_t Datum
Definition: postgres.h:372
Trigger * tg_trigger
Definition: trigger.h:37
HeapTuple tg_newtuple
Definition: trigger.h:36
char * SPI_getrelname(Relation rel)
Definition: spi.c:910
#define NULL
Definition: c.h:229
#define CALLED_AS_TRIGGER(fcinfo)
Definition: trigger.h:25
TriggerEvent tg_event
Definition: trigger.h:33
HeapTuple heap_modify_tuple_by_cols(HeapTuple tuple, TupleDesc tupleDesc, int nCols, int *replCols, Datum *replValues, bool *replIsnull)
Definition: heaptuple.c:862
#define TRIGGER_FIRED_BEFORE(event)
Definition: trigger.h:88
#define Int32GetDatum(X)
Definition: postgres.h:485
#define TRIGGER_FIRED_BY_INSERT(event)
Definition: trigger.h:70
void * palloc(Size size)
Definition: mcxt.c:849
int errmsg(const char *fmt,...)
Definition: elog.c:797
int i
int16 tgnargs
Definition: reltrigger.h:37
#define CStringGetTextDatum(s)
Definition: builtins.h:91
#define elog
Definition: elog.h:219
#define TRIGGER_FIRED_FOR_ROW(event)
Definition: trigger.h:82
#define TRIGGER_FIRED_BY_UPDATE(event)
Definition: trigger.h:76
long val
Definition: informix.c:689
Relation tg_relation
Definition: trigger.h:34
PG_FUNCTION_INFO_V1 ( autoinc  )

Variable Documentation

PG_MODULE_MAGIC

Definition at line 14 of file autoinc.c.