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
|
/**********************************************************************
* pl_handler.c - Handler for the PL/pgSQL
* procedural language
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_handler.c,v 1.10 2001/10/25 05:50:20 momjian Exp $
*
* This software is copyrighted by Jan Wieck - Hamburg.
*
* The author hereby grants permission to use, copy, modify,
* distribute, and license this software and its documentation
* for any purpose, provided that existing copyright notices are
* retained in all copies and that this notice is included
* verbatim in any distributions. No written agreement, license,
* or royalty fee is required for any of the authorized uses.
* Modifications to this software may be copyrighted by their
* author and need not follow the licensing terms described
* here, provided that the new terms are clearly indicated on
* the first page of each file where they apply.
*
* IN NO EVENT SHALL THE AUTHOR OR DISTRIBUTORS BE LIABLE TO ANY
* PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR
* CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF THIS
* SOFTWARE, ITS DOCUMENTATION, OR ANY DERIVATIVES THEREOF, EVEN
* IF THE AUTHOR HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE AUTHOR AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
* PURPOSE, AND NON-INFRINGEMENT. THIS SOFTWARE IS PROVIDED ON
* AN "AS IS" BASIS, AND THE AUTHOR AND DISTRIBUTORS HAVE NO
* OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
* ENHANCEMENTS, OR MODIFICATIONS.
*
**********************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include "plpgsql.h"
#include "pl.tab.h"
#include "access/heapam.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
#include "utils/builtins.h"
#include "utils/syscache.h"
/*
* Head of list of already-compiled functions
*/
static PLpgSQL_function *compiled_functions = NULL;
static bool func_up_to_date(PLpgSQL_function * func);
/* ----------
* plpgsql_call_handler
*
* This is the only visible function of the PL interpreter.
* The PostgreSQL function manager and trigger manager
* call this function for execution of PL/pgSQL procedures.
* ----------
*/
PG_FUNCTION_INFO_V1(plpgsql_call_handler);
Datum
plpgsql_call_handler(PG_FUNCTION_ARGS)
{
bool isTrigger = CALLED_AS_TRIGGER(fcinfo);
Oid funcOid = fcinfo->flinfo->fn_oid;
PLpgSQL_function *func;
Datum retval;
/*
* Connect to SPI manager
*/
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "plpgsql: cannot connect to SPI manager");
/*
* Check if we already compiled this function and saved the pointer
* (ie, current FmgrInfo has been used before)
*/
func = (PLpgSQL_function *) fcinfo->flinfo->fn_extra;
if (func != NULL)
{
Assert(func->fn_oid == funcOid);
/*
* But is the function still up to date?
*/
if (!func_up_to_date(func))
func = NULL;
}
if (func == NULL)
{
/*
* Check if we already compiled this function for another caller
*/
for (func = compiled_functions; func != NULL; func = func->next)
{
if (funcOid == func->fn_oid && func_up_to_date(func))
break;
}
/*
* If not, do so and add it to the compiled ones
*/
if (func == NULL)
{
func = plpgsql_compile(funcOid,
isTrigger ? T_TRIGGER : T_FUNCTION);
func->next = compiled_functions;
compiled_functions = func;
}
/*
* Save pointer in FmgrInfo to avoid search on subsequent calls
*/
fcinfo->flinfo->fn_extra = (void *) func;
}
/*
* Determine if called as function or trigger and call appropriate
* subhandler
*/
if (isTrigger)
retval = PointerGetDatum(plpgsql_exec_trigger(func,
(TriggerData *) fcinfo->context));
else
retval = plpgsql_exec_function(func, fcinfo);
/*
* Disconnect from SPI manager
*/
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "plpgsql: SPI_finish() failed");
return retval;
}
/*
* Check to see if a compiled function is still up-to-date. This
* is needed because CREATE OR REPLACE FUNCTION can modify the
* function's pg_proc entry without changing its OID.
*/
static bool
func_up_to_date(PLpgSQL_function * func)
{
HeapTuple procTup;
bool result;
procTup = SearchSysCache(PROCOID,
ObjectIdGetDatum(func->fn_oid),
0, 0, 0);
if (!HeapTupleIsValid(procTup))
elog(ERROR, "plpgsql: cache lookup for proc %u failed",
func->fn_oid);
result = (func->fn_xmin == procTup->t_data->t_xmin &&
func->fn_cmin == procTup->t_data->t_cmin);
ReleaseSysCache(procTup);
return result;
}
|
