1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
/*-------------------------------------------------------------------------
*
* proclang.c
* PostgreSQL PROCEDURAL LANGUAGE support code.
*
*-------------------------------------------------------------------------
*/
#include <ctype.h>
#include <string.h>
#include "postgres.h"
#include "access/heapam.h"
#include "catalog/catname.h"
#include "catalog/pg_language.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_shadow.h"
#include "commands/proclang.h"
#include "fmgr.h"
#include "utils/syscache.h"
static void
case_translate_language_name(const char *input, char *output)
{
/*-------------------------------------------------------------------------
Translate the input language name to lower case, except if it's C,
translate to upper case.
--------------------------------------------------------------------------*/
int i;
for (i = 0; i < NAMEDATALEN && input[i]; ++i)
output[i] = tolower(input[i]);
output[i] = '\0';
if (strcmp(output, "c") == 0)
output[0] = 'C';
}
/* ---------------------------------------------------------------------
* CREATE PROCEDURAL LANGUAGE
* ---------------------------------------------------------------------
*/
void
CreateProceduralLanguage(CreatePLangStmt *stmt)
{
char languageName[NAMEDATALEN];
HeapTuple langTup;
HeapTuple procTup;
Oid typev[8];
char nulls[Natts_pg_language];
Datum values[Natts_pg_language];
Relation rel;
HeapTuple tup;
TupleDesc tupDesc;
int i;
/* ----------------
* Check permission
* ----------------
*/
if (!superuser())
{
elog(ERROR, "Only users with Postgres superuser privilege are "
"permitted to create procedural languages");
}
/* ----------------
* Translate the language name and check that
* this language doesn't already exist
* ----------------
*/
case_translate_language_name(stmt->plname, languageName);
langTup = SearchSysCacheTuple(LANNAME,
PointerGetDatum(languageName),
0, 0, 0);
if (HeapTupleIsValid(langTup))
elog(ERROR, "Language %s already exists", languageName);
/* ----------------
* Lookup the PL handler function and check that it is
* of return type Opaque
* ----------------
*/
memset(typev, 0, sizeof(typev));
procTup = SearchSysCacheTuple(PRONAME,
PointerGetDatum(stmt->plhandler),
Int32GetDatum(0),
PointerGetDatum(typev),
0);
if (!HeapTupleIsValid(procTup))
{
elog(ERROR, "PL handler function %s() doesn't exist",
stmt->plhandler);
}
if (((Form_pg_proc) GETSTRUCT(procTup))->prorettype != InvalidOid)
{
elog(ERROR, "PL handler function %s() isn't of return type Opaque",
stmt->plhandler);
}
/* ----------------
* Insert the new language into pg_language
* ----------------
*/
for (i = 0; i < Natts_pg_language; i++)
{
nulls[i] = ' ';
values[i] = (Datum) NULL;
}
i = 0;
values[i++] = PointerGetDatum(languageName);
values[i++] = Int8GetDatum((bool) 1);
values[i++] = Int8GetDatum(stmt->pltrusted);
values[i++] = ObjectIdGetDatum(procTup->t_data->t_oid);
values[i++] = (Datum) fmgr(F_TEXTIN, stmt->plcompiler);
rel = heap_openr(LanguageRelationName);
tupDesc = rel->rd_att;
tup = heap_formtuple(tupDesc, values, nulls);
heap_insert(rel, tup);
heap_close(rel);
return;
}
/* ---------------------------------------------------------------------
* DROP PROCEDURAL LANGUAGE
* ---------------------------------------------------------------------
*/
void
DropProceduralLanguage(DropPLangStmt *stmt)
{
char languageName[NAMEDATALEN];
HeapTuple langTup;
Relation rel;
/* ----------------
* Check permission
* ----------------
*/
if (!superuser())
{
elog(ERROR, "Only users with Postgres superuser privilege are "
"permitted to drop procedural languages");
}
/* ----------------
* Translate the language name, check that
* this language exist and is a PL
* ----------------
*/
case_translate_language_name(stmt->plname, languageName);
langTup = SearchSysCacheTupleCopy(LANNAME,
PointerGetDatum(languageName),
0, 0, 0);
if (!HeapTupleIsValid(langTup))
elog(ERROR, "Language %s doesn't exist", languageName);
if (!((Form_pg_language) GETSTRUCT(langTup))->lanispl)
{
elog(ERROR, "Language %s isn't a created procedural language",
languageName);
}
rel = heap_openr(LanguageRelationName);
heap_delete(rel, &langTup->t_self, NULL);
pfree(langTup);
heap_close(rel);
}
|
