open-dsi
/
postgres
mirror of https://github.com/postgres/postgres
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

pageinspect: Add bt_page_items function with bytea argument

Browse Source 
Author: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Reviewed-by: Ashutosh Sharma <ashu.coek88@gmail.com>
pull/3/merge
Peter Eisentraut 8 years ago
parent 5ebeb579b9
commit 193f5f9e91
6 changed files with 211 additions and 51 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Show Stats Download Patch File Download Diff File
  1. 184
      contrib/pageinspect/btreefuncs.c
  2. 13
      contrib/pageinspect/expected/btree.out
  3. 14
      contrib/pageinspect/pageinspect--1.5--1.6.sql
  4. 4
      contrib/pageinspect/sql/btree.sql
  5. 32
      doc/src/sgml/pageinspect.sgml
  6. 1
      src/include/access/nbtree.h

184
contrib/pageinspect/btreefuncs.c
Unescape View File

@ -41,6 +41,7 @@
PG_FUNCTION_INFO_V1(bt_metap);
PG_FUNCTION_INFO_V1(bt_page_items);
PG_FUNCTION_INFO_V1(bt_page_items_bytea);
PG_FUNCTION_INFO_V1(bt_page_stats);
#define IS_INDEX(r) ((r)->rd_rel->relkind == RELKIND_INDEX)
@ -235,14 +236,6 @@ bt_page_stats(PG_FUNCTION_ARGS)
PG_RETURN_DATUM(result);
}
/*-------------------------------------------------------
* bt_page_items()
*
* Get IndexTupleData set in a btree page
*
* Usage: SELECT * FROM bt_page_items('t1_pkey', 1);
*-------------------------------------------------------
*/
/*
* cross-call data structure for SRF
@ -253,14 +246,72 @@ struct user_args
OffsetNumber offset;
};
/*-------------------------------------------------------
* bt_page_print_tuples()
*
* Form a tuple describing index tuple at a given offset
* ------------------------------------------------------
*/
static Datum
bt_page_print_tuples(FuncCallContext *fctx, Page page, OffsetNumber offset)
{
char *values[6];
HeapTuple tuple;
ItemId id;
IndexTuple itup;
int j;
int off;
int dlen;
char *dump;
char *ptr;
id = PageGetItemId(page, offset);
if (!ItemIdIsValid(id))
elog(ERROR, "invalid ItemId");
itup = (IndexTuple) PageGetItem(page, id);
j = 0;
values[j++] = psprintf("%d", offset);
values[j++] = psprintf("(%u,%u)",
ItemPointerGetBlockNumberNoCheck(&itup->t_tid),
ItemPointerGetOffsetNumberNoCheck(&itup->t_tid));
values[j++] = psprintf("%d", (int) IndexTupleSize(itup));
values[j++] = psprintf("%c", IndexTupleHasNulls(itup) ? 't' : 'f');
values[j++] = psprintf("%c", IndexTupleHasVarwidths(itup) ? 't' : 'f');
ptr = (char *) itup + IndexInfoFindDataOffset(itup->t_info);
dlen = IndexTupleSize(itup) - IndexInfoFindDataOffset(itup->t_info);
dump = palloc0(dlen * 3 + 1);
values[j] = dump;
for (off = 0; off < dlen; off++)
{
if (off > 0)
*dump++ = ' ';
sprintf(dump, "%02x", *(ptr + off) & 0xff);
dump += 2;
}
tuple = BuildTupleFromCStrings(fctx->attinmeta, values);
return HeapTupleGetDatum(tuple);
}
/*-------------------------------------------------------
* bt_page_items()
*
* Get IndexTupleData set in a btree page
*
* Usage: SELECT * FROM bt_page_items('t1_pkey', 1);
*-------------------------------------------------------
*/
Datum
bt_page_items(PG_FUNCTION_ARGS)
{
text *relname = PG_GETARG_TEXT_PP(0);
uint32 blkno = PG_GETARG_UINT32(1);
Datum result;
char *values[6];
HeapTuple tuple;
FuncCallContext *fctx;
MemoryContext mctx;
struct user_args *uargs;
@ -345,52 +396,97 @@ bt_page_items(PG_FUNCTION_ARGS)
if (fctx->call_cntr < fctx->max_calls)
{
ItemId id;
IndexTuple itup;
int j;
int off;
int dlen;
char *dump;
char *ptr;
id = PageGetItemId(uargs->page, uargs->offset);
result = bt_page_print_tuples(fctx, uargs->page, uargs->offset);
uargs->offset++;
SRF_RETURN_NEXT(fctx, result);
}
else
{
pfree(uargs->page);
pfree(uargs);
SRF_RETURN_DONE(fctx);
}
}
if (!ItemIdIsValid(id))
elog(ERROR, "invalid ItemId");
/*-------------------------------------------------------
* bt_page_items_bytea()
*
* Get IndexTupleData set in a btree page
*
* Usage: SELECT * FROM bt_page_items(get_raw_page('t1_pkey', 1));
*-------------------------------------------------------
*/
itup = (IndexTuple) PageGetItem(uargs->page, id);
Datum
bt_page_items_bytea(PG_FUNCTION_ARGS)
{
bytea *raw_page = PG_GETARG_BYTEA_P(0);
Datum result;
FuncCallContext *fctx;
struct user_args *uargs;
int raw_page_size;
j = 0;
values[j++] = psprintf("%d", uargs->offset);
values[j++] = psprintf("(%u,%u)",
ItemPointerGetBlockNumberNoCheck(&itup->t_tid),
ItemPointerGetOffsetNumberNoCheck(&itup->t_tid));
values[j++] = psprintf("%d", (int) IndexTupleSize(itup));
values[j++] = psprintf("%c", IndexTupleHasNulls(itup) ? 't' : 'f');
values[j++] = psprintf("%c", IndexTupleHasVarwidths(itup) ? 't' : 'f');
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
(errmsg("must be superuser to use pageinspect functions"))));
ptr = (char *) itup + IndexInfoFindDataOffset(itup->t_info);
dlen = IndexTupleSize(itup) - IndexInfoFindDataOffset(itup->t_info);
dump = palloc0(dlen * 3 + 1);
values[j] = dump;
for (off = 0; off < dlen; off++)
if (SRF_IS_FIRSTCALL())
{
if (off > 0)
*dump++ = ' ';
sprintf(dump, "%02x", *(ptr + off) & 0xff);
dump += 2;
}
BTPageOpaque opaque;
MemoryContext mctx;
TupleDesc tupleDesc;
tuple = BuildTupleFromCStrings(fctx->attinmeta, values);
result = HeapTupleGetDatum(tuple);
raw_page_size = VARSIZE(raw_page) - VARHDRSZ;
if (raw_page_size < SizeOfPageHeaderData)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("input page too small (%d bytes)", raw_page_size)));
fctx = SRF_FIRSTCALL_INIT();
mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);
uargs = palloc(sizeof(struct user_args));
uargs->page = VARDATA(raw_page);
uargs->offset = FirstOffsetNumber;
opaque = (BTPageOpaque) PageGetSpecialPointer(uargs->page);
if (P_ISMETA(opaque))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("block is a meta page")));
if (P_ISDELETED(opaque))
elog(NOTICE, "page is deleted");
fctx->max_calls = PageGetMaxOffsetNumber(uargs->page);
/* Build a tuple descriptor for our result type */
if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "return type must be a row type");
uargs->offset = uargs->offset + 1;
fctx->attinmeta = TupleDescGetAttInMetadata(tupleDesc);
fctx->user_fctx = uargs;
MemoryContextSwitchTo(mctx);
}
fctx = SRF_PERCALL_SETUP();
uargs = fctx->user_fctx;
if (fctx->call_cntr < fctx->max_calls)
{
result = bt_page_print_tuples(fctx, uargs->page, uargs->offset);
uargs->offset++;
SRF_RETURN_NEXT(fctx, result);
}
else
{
pfree(uargs->page);
pfree(uargs);
SRF_RETURN_DONE(fctx);
}

13
contrib/pageinspect/expected/btree.out
Unescape View File

@ -42,4 +42,17 @@ data | 01 00 00 00 00 00 00 01
SELECT * FROM bt_page_items('test1_a_idx', 2);
ERROR: block number out of range
SELECT * FROM bt_page_items(get_raw_page('test1_a_idx', 0));
ERROR: block is a meta page
SELECT * FROM bt_page_items(get_raw_page('test1_a_idx', 1));
-[ RECORD 1 ]-----------------------
itemoffset | 1
ctid | (0,1)
itemlen | 16
nulls | f
vars | f
data | 01 00 00 00 00 00 00 01
SELECT * FROM bt_page_items(get_raw_page('test1_a_idx', 2));
ERROR: block number 2 is out of range for relation "test1_a_idx"
DROP TABLE test1;

14
contrib/pageinspect/pageinspect--1.5--1.6.sql
Unescape View File

@ -83,3 +83,17 @@ CREATE FUNCTION page_checksum(IN page bytea, IN blkno int4)
RETURNS smallint
AS 'MODULE_PATHNAME', 'page_checksum'
LANGUAGE C STRICT PARALLEL SAFE;
--
-- bt_page_items_bytea()
--
CREATE FUNCTION bt_page_items(IN page bytea,
OUT itemoffset smallint,
OUT ctid tid,
OUT itemlen smallint,
OUT nulls bool,
OUT vars bool,
OUT data text)
RETURNS SETOF record
AS 'MODULE_PATHNAME', 'bt_page_items_bytea'
LANGUAGE C STRICT PARALLEL SAFE;

4
contrib/pageinspect/sql/btree.sql
Unescape View File

@ -14,4 +14,8 @@ SELECT * FROM bt_page_items('test1_a_idx', 0);
SELECT * FROM bt_page_items('test1_a_idx', 1);
SELECT * FROM bt_page_items('test1_a_idx', 2);
SELECT * FROM bt_page_items(get_raw_page('test1_a_idx', 0));
SELECT * FROM bt_page_items(get_raw_page('test1_a_idx', 1));
SELECT * FROM bt_page_items(get_raw_page('test1_a_idx', 2));
DROP TABLE test1;

32
doc/src/sgml/pageinspect.sgml
Unescape View File

@ -333,6 +333,38 @@ test=# SELECT * FROM bt_page_items('pg_cast_oid_index', 1);
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<function>bt_page_items(page bytea) returns setof record</function>
<indexterm>
<primary>bt_page_items</primary>
</indexterm>
</term>
<listitem>
<para>
It is also possible to pass a page to <function>bt_page_items</function>
as a <type>bytea</> value. A page image obtained
with <function>get_raw_page</function> should be passed as argument. So
the last example could also be rewritten like this:
<screen>
test=# SELECT * FROM bt_page_items(get_raw_page('pg_cast_oid_index', 1));
itemoffset | ctid | itemlen | nulls | vars | data
------------+---------+---------+-------+------+-------------
1 | (0,1) | 12 | f | f | 23 27 00 00
2 | (0,2) | 12 | f | f | 24 27 00 00
3 | (0,3) | 12 | f | f | 25 27 00 00
4 | (0,4) | 12 | f | f | 26 27 00 00
5 | (0,5) | 12 | f | f | 27 27 00 00
6 | (0,6) | 12 | f | f | 28 27 00 00
7 | (0,7) | 12 | f | f | 29 27 00 00
8 | (0,8) | 12 | f | f | 2a 27 00 00
</screen>
All the other details are the same as explained in the previous item.
</para>
</listitem>
</varlistentry>
</variablelist>
</sect2>

1
src/include/access/nbtree.h
Unescape View File

@ -176,6 +176,7 @@ typedef struct BTMetaPageData
#define P_ISLEAF(opaque) ((opaque)->btpo_flags & BTP_LEAF)
#define P_ISROOT(opaque) ((opaque)->btpo_flags & BTP_ROOT)
#define P_ISDELETED(opaque) ((opaque)->btpo_flags & BTP_DELETED)
#define P_ISMETA(opaque) ((opaque)->btpo_flags & BTP_META)
#define P_ISHALFDEAD(opaque) ((opaque)->btpo_flags & BTP_HALF_DEAD)
#define P_IGNORE(opaque) ((opaque)->btpo_flags & (BTP_DELETED|BTP_HALF_DEAD))
#define P_HAS_GARBAGE(opaque) ((opaque)->btpo_flags & BTP_HAS_GARBAGE)

Write Preview
Loading…
Cancel
Save