PostgreSQL Source Code  git master
fsmfuncs.c
Go to the documentation of this file.
1 /*-------------------------------------------------------------------------
2  *
3  * fsmfuncs.c
4  * Functions to investigate FSM pages
5  *
6  * These functions are restricted to superusers for the fear of introducing
7  * security holes if the input checking isn't as water-tight as it should.
8  * You'd need to be superuser to obtain a raw page image anyway, so
9  * there's hardly any use case for using these without superuser-rights
10  * anyway.
11  *
12  * Copyright (c) 2007-2022, PostgreSQL Global Development Group
13  *
14  * IDENTIFICATION
15  * contrib/pageinspect/fsmfuncs.c
16  *
17  *-------------------------------------------------------------------------
18  */
19 
20 #include "postgres.h"
21 
22 #include "funcapi.h"
23 #include "lib/stringinfo.h"
24 #include "miscadmin.h"
25 #include "pageinspect.h"
26 #include "storage/fsm_internals.h"
27 #include "utils/builtins.h"
28 
29 /*
30  * Dumps the contents of a FSM page.
31  */
33 
34 Datum
36 {
37  bytea *raw_page = PG_GETARG_BYTEA_P(0);
38  StringInfoData sinfo;
39  Page page;
40  FSMPage fsmpage;
41  int i;
42 
43  if (!superuser())
44  ereport(ERROR,
45  (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
46  errmsg("must be superuser to use raw page functions")));
47 
48  page = get_page_from_raw(raw_page);
49 
50  if (PageIsNew(page))
52 
53  fsmpage = (FSMPage) PageGetContents(page);
54 
55  initStringInfo(&sinfo);
56 
57  for (i = 0; i < NodesPerPage; i++)
58  {
59  if (fsmpage->fp_nodes[i] != 0)
60  appendStringInfo(&sinfo, "%d: %d\n", i, fsmpage->fp_nodes[i]);
61  }
62  appendStringInfo(&sinfo, "fp_next_slot: %d\n", fsmpage->fp_next_slot);
63 
65 }
Pointer Page
Definition: bufpage.h:78
#define PageIsNew(page)
Definition: bufpage.h:228
#define PageGetContents(page)
Definition: bufpage.h:245
int errcode(int sqlerrcode)
Definition: elog.c:693
int errmsg(const char *fmt,...)
Definition: elog.c:904
#define ERROR
Definition: elog.h:33
#define ereport(elevel,...)
Definition: elog.h:143
#define PG_RETURN_NULL()
Definition: fmgr.h:345
#define PG_RETURN_TEXT_P(x)
Definition: fmgr.h:372
#define PG_GETARG_BYTEA_P(n)
Definition: fmgr.h:335
#define PG_FUNCTION_ARGS
Definition: fmgr.h:193
#define NodesPerPage
Definition: fsm_internals.h:51
FSMPageData * FSMPage
Definition: fsm_internals.h:45
Datum fsm_page_contents(PG_FUNCTION_ARGS)
Definition: fsmfuncs.c:35
PG_FUNCTION_INFO_V1(fsm_page_contents)
int i
Definition: isn.c:73
Page get_page_from_raw(bytea *raw_page)
Definition: rawpage.c:215
uintptr_t Datum
Definition: postgres.h:411
void appendStringInfo(StringInfo str, const char *fmt,...)
Definition: stringinfo.c:91
void initStringInfo(StringInfo str)
Definition: stringinfo.c:59
uint8 fp_nodes[FLEXIBLE_ARRAY_MEMBER]
Definition: fsm_internals.h:42
Definition: c.h:633
bool superuser(void)
Definition: superuser.c:46
text * cstring_to_text_with_len(const char *s, int len)
Definition: varlena.c:200