granicus.if.org Git - postgresql/blob - src/backend/commands/proclang.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * proclang.c
   4  *        PostgreSQL PROCEDURAL LANGUAGE support code.
   5  *
   6  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  * IDENTIFICATION
  10  *        $Header: /cvsroot/pgsql/src/backend/commands/proclang.c,v 1.28 2001/06/13 21:44:40 tgl Exp $
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14 #include "postgres.h"
  15
  16 #include <ctype.h>
  17
  18 #include "access/heapam.h"
  19 #include "catalog/catname.h"
  20 #include "catalog/indexing.h"
  21 #include "catalog/pg_language.h"
  22 #include "catalog/pg_proc.h"
  23 #include "commands/proclang.h"
  24 #include "fmgr.h"
  25 #include "miscadmin.h"
  26 #include "utils/builtins.h"
  27 #include "utils/syscache.h"
  28
  29
  30 static void
  31 case_translate_language_name(const char *input, char *output)
  32 {
  33 /*-------------------------------------------------------------------------
  34   Translate the input language name to lower case, except if it's C,
  35   translate to upper case.
  36 --------------------------------------------------------------------------*/
  37         int                     i;
  38
  39         for (i = 0; i < NAMEDATALEN && input[i]; ++i)
  40                 output[i] = tolower((unsigned char) input[i]);
  41
  42         output[i] = '\0';
  43
  44         if (strcmp(output, "c") == 0)
  45                 output[0] = 'C';
  46 }
  47
  48
  49 /* ---------------------------------------------------------------------
  50  * CREATE PROCEDURAL LANGUAGE
  51  * ---------------------------------------------------------------------
  52  */
  53 void
  54 CreateProceduralLanguage(CreatePLangStmt *stmt)
  55 {
  56         char            languageName[NAMEDATALEN];
  57         HeapTuple       procTup;
  58
  59         Oid                     typev[FUNC_MAX_ARGS];
  60         char            nulls[Natts_pg_language];
  61         Datum           values[Natts_pg_language];
  62         Relation        rel;
  63         HeapTuple       tup;
  64         TupleDesc       tupDesc;
  65
  66         int                     i;
  67
  68         /*
  69          * Check permission
  70          */
  71         if (!superuser())
  72                 elog(ERROR, "Only users with Postgres superuser privilege are "
  73                          "permitted to create procedural languages");
  74
  75         /*
  76          * Translate the language name and check that this language doesn't
  77          * already exist
  78          */
  79         case_translate_language_name(stmt->plname, languageName);
  80
  81         if (SearchSysCacheExists(LANGNAME,
  82                                                          PointerGetDatum(languageName),
  83                                                          0, 0, 0))
  84                 elog(ERROR, "Language %s already exists", languageName);
  85
  86         /*
  87          * Lookup the PL handler function and check that it is of return type
  88          * Opaque
  89          */
  90         memset(typev, 0, sizeof(typev));
  91         procTup = SearchSysCache(PROCNAME,
  92                                                          PointerGetDatum(stmt->plhandler),
  93                                                          Int32GetDatum(0),
  94                                                          PointerGetDatum(typev),
  95                                                          0);
  96         if (!HeapTupleIsValid(procTup))
  97                 elog(ERROR, "PL handler function %s() doesn't exist",
  98                          stmt->plhandler);
  99         if (((Form_pg_proc) GETSTRUCT(procTup))->prorettype != InvalidOid)
 100                 elog(ERROR, "PL handler function %s() isn't of return type Opaque",
 101                          stmt->plhandler);
 102
 103         /*
 104          * Insert the new language into pg_language
 105          */
 106         for (i = 0; i < Natts_pg_language; i++)
 107         {
 108                 nulls[i] = ' ';
 109                 values[i] = (Datum) NULL;
 110         }
 111
 112         i = 0;
 113         values[i++] = PointerGetDatum(languageName);
 114         values[i++] = BoolGetDatum(true);       /* lanispl */
 115         values[i++] = BoolGetDatum(stmt->pltrusted);
 116         values[i++] = ObjectIdGetDatum(procTup->t_data->t_oid);
 117         values[i++] = DirectFunctionCall1(textin,
 118                                                                           CStringGetDatum(stmt->plcompiler));
 119
 120         ReleaseSysCache(procTup);
 121
 122         rel = heap_openr(LanguageRelationName, RowExclusiveLock);
 123
 124         tupDesc = rel->rd_att;
 125         tup = heap_formtuple(tupDesc, values, nulls);
 126
 127         heap_insert(rel, tup);
 128
 129         if (RelationGetForm(rel)->relhasindex)
 130         {
 131                 Relation        idescs[Num_pg_language_indices];
 132
 133                 CatalogOpenIndices(Num_pg_language_indices, Name_pg_language_indices, idescs);
 134                 CatalogIndexInsert(idescs, Num_pg_language_indices, rel, tup);
 135                 CatalogCloseIndices(Num_pg_language_indices, idescs);
 136         }
 137
 138         heap_close(rel, RowExclusiveLock);
 139 }
 140
 141
 142 /* ---------------------------------------------------------------------
 143  * DROP PROCEDURAL LANGUAGE
 144  * ---------------------------------------------------------------------
 145  */
 146 void
 147 DropProceduralLanguage(DropPLangStmt *stmt)
 148 {
 149         char            languageName[NAMEDATALEN];
 150         HeapTuple       langTup;
 151         Relation        rel;
 152
 153         /*
 154          * Check permission
 155          */
 156         if (!superuser())
 157                 elog(ERROR, "Only users with Postgres superuser privilege are "
 158                          "permitted to drop procedural languages");
 159
 160         /*
 161          * Translate the language name, check that this language exist and is
 162          * a PL
 163          */
 164         case_translate_language_name(stmt->plname, languageName);
 165
 166         rel = heap_openr(LanguageRelationName, RowExclusiveLock);
 167
 168         langTup = SearchSysCacheCopy(LANGNAME,
 169                                                                  PointerGetDatum(languageName),
 170                                                                  0, 0, 0);
 171         if (!HeapTupleIsValid(langTup))
 172                 elog(ERROR, "Language %s doesn't exist", languageName);
 173
 174         if (!((Form_pg_language) GETSTRUCT(langTup))->lanispl)
 175                 elog(ERROR, "Language %s isn't a created procedural language",
 176                          languageName);
 177
 178         simple_heap_delete(rel, &langTup->t_self);
 179
 180         heap_freetuple(langTup);
 181         heap_close(rel, RowExclusiveLock);
 182 }