LCOV - differential code coverage report
Current view: top level - contrib/pageinspect - btreefuncs.c (source / functions) Coverage Total Hit UNC LBC UIC GBC GIC GNC CBC EUB ECB DUB DCB
Current: Differential Code Coverage HEAD vs 15 Lines: 85.6 % 334 286 4 16 28 12 131 74 69 35 179 1 22
Current Date: 2023-04-08 15:15:32 Functions: 100.0 % 20 20 9 5 6 12 2
Baseline: 15
Baseline Date: 2023-04-08 15:09:40
Legend: Lines: hit not hit

           TLA  Line data    Source code
       1                 : /*
       2                 :  * contrib/pageinspect/btreefuncs.c
       3                 :  *
       4                 :  *
       5                 :  * btreefuncs.c
       6                 :  *
       7                 :  * Copyright (c) 2006 Satoshi Nagayasu <nagayasus@nttdata.co.jp>
       8                 :  *
       9                 :  * Permission to use, copy, modify, and distribute this software and
      10                 :  * its documentation for any purpose, without fee, and without a
      11                 :  * written agreement is hereby granted, provided that the above
      12                 :  * copyright notice and this paragraph and the following two
      13                 :  * paragraphs appear in all copies.
      14                 :  *
      15                 :  * IN NO EVENT SHALL THE AUTHOR BE LIABLE TO ANY PARTY FOR DIRECT,
      16                 :  * INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
      17                 :  * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
      18                 :  * DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED
      19                 :  * OF THE POSSIBILITY OF SUCH DAMAGE.
      20                 :  *
      21                 :  * THE AUTHOR SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
      22                 :  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
      23                 :  * A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS
      24                 :  * IS" BASIS, AND THE AUTHOR HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE,
      25                 :  * SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
      26                 :  */
      27                 : 
      28                 : #include "postgres.h"
      29                 : 
      30                 : #include "access/nbtree.h"
      31                 : #include "access/relation.h"
      32                 : #include "catalog/namespace.h"
      33                 : #include "catalog/pg_am.h"
      34                 : #include "catalog/pg_type.h"
      35                 : #include "funcapi.h"
      36                 : #include "miscadmin.h"
      37                 : #include "pageinspect.h"
      38                 : #include "utils/array.h"
      39                 : #include "utils/builtins.h"
      40                 : #include "utils/rel.h"
      41                 : #include "utils/varlena.h"
      42                 : 
      43 CBC          25 : PG_FUNCTION_INFO_V1(bt_metap);
      44               7 : PG_FUNCTION_INFO_V1(bt_page_items_1_9);
      45              13 : PG_FUNCTION_INFO_V1(bt_page_items);
      46              13 : PG_FUNCTION_INFO_V1(bt_page_items_bytea);
      47               7 : PG_FUNCTION_INFO_V1(bt_page_stats_1_9);
      48               7 : PG_FUNCTION_INFO_V1(bt_page_stats);
      49 GNC           6 : PG_FUNCTION_INFO_V1(bt_multi_page_stats);
      50 ECB             : 
      51                 : #define IS_INDEX(r) ((r)->rd_rel->relkind == RELKIND_INDEX)
      52                 : #define IS_BTREE(r) ((r)->rd_rel->relam == BTREE_AM_OID)
      53                 : 
      54                 : /* ------------------------------------------------
      55                 :  * structure for single btree page statistics
      56                 :  * ------------------------------------------------
      57                 :  */
      58                 : typedef struct BTPageStat
      59                 : {
      60                 :     uint32      blkno;
      61                 :     uint32      live_items;
      62                 :     uint32      dead_items;
      63                 :     uint32      page_size;
      64                 :     uint32      max_avail;
      65                 :     uint32      free_size;
      66                 :     uint32      avg_item_size;
      67                 :     char        type;
      68                 : 
      69                 :     /* opaque data */
      70                 :     BlockNumber btpo_prev;
      71                 :     BlockNumber btpo_next;
      72                 :     uint32      btpo_level;
      73                 :     uint16      btpo_flags;
      74                 :     BTCycleId   btpo_cycleid;
      75                 : } BTPageStat;
      76                 : 
      77                 : /*
      78                 :  * cross-call data structure for SRF for page stats
      79                 :  */
      80                 : typedef struct ua_page_stats
      81                 : {
      82                 :     Oid         relid;
      83                 :     int64       blkno;
      84                 :     int64       blk_count;
      85                 :     bool        allpages;
      86                 : } ua_page_stats;
      87                 : 
      88                 : /*
      89                 :  * cross-call data structure for SRF for page items
      90                 :  */
      91                 : typedef struct ua_page_items
      92                 : {
      93                 :     Page        page;
      94                 :     OffsetNumber offset;
      95                 :     bool        leafpage;
      96                 :     bool        rightmost;
      97                 :     TupleDesc   tupd;
      98                 : } ua_page_items;
      99                 : 
     100                 : 
     101                 : /* -------------------------------------------------
     102                 :  * GetBTPageStatistics()
     103                 :  *
     104                 :  * Collect statistics of single b-tree page
     105                 :  * -------------------------------------------------
     106                 :  */
     107                 : static void
     108 GIC          10 : GetBTPageStatistics(BlockNumber blkno, Buffer buffer, BTPageStat *stat)
     109                 : {
     110              10 :     Page        page = BufferGetPage(buffer);
     111              10 :     PageHeader  phdr = (PageHeader) page;
     112              10 :     OffsetNumber maxoff = PageGetMaxOffsetNumber(page);
     113              10 :     BTPageOpaque opaque = BTPageGetOpaque(page);
     114              10 :     int         item_size = 0;
     115                 :     int         off;
     116                 : 
     117              10 :     stat->blkno = blkno;
     118                 : 
     119              10 :     stat->max_avail = BLCKSZ - (BLCKSZ - phdr->pd_special + SizeOfPageHeaderData);
     120                 : 
     121              10 :     stat->dead_items = stat->live_items = 0;
     122                 : 
     123              10 :     stat->page_size = PageGetPageSize(page);
     124                 : 
     125 ECB             :     /* page type (flags) */
     126 GIC          10 :     if (P_ISDELETED(opaque))
     127 ECB             :     {
     128                 :         /* We divide deleted pages into leaf ('d') or internal ('D') */
     129 LBC           0 :         if (P_ISLEAF(opaque) || !P_HAS_FULLXID(opaque))
     130               0 :             stat->type = 'd';
     131 ECB             :         else
     132 UIC           0 :             stat->type = 'D';
     133                 : 
     134 ECB             :         /*
     135                 :          * Report safexid in a deleted page.
     136                 :          *
     137                 :          * Handle pg_upgrade'd deleted pages that used the previous safexid
     138                 :          * representation in btpo_level field (this used to be a union type
     139                 :          * called "bpto").
     140                 :          */
     141 UIC           0 :         if (P_HAS_FULLXID(opaque))
     142                 :         {
     143 LBC           0 :             FullTransactionId safexid = BTPageGetDeleteXid(page);
     144                 : 
     145 UIC           0 :             elog(DEBUG2, "deleted page from block %u has safexid %u:%u",
     146 EUB             :                  blkno, EpochFromFullTransactionId(safexid),
     147                 :                  XidFromFullTransactionId(safexid));
     148                 :         }
     149                 :         else
     150 UIC           0 :             elog(DEBUG2, "deleted page from block %u has safexid %u",
     151                 :                  blkno, opaque->btpo_level);
     152                 : 
     153                 :         /* Don't interpret BTDeletedPageData as index tuples */
     154               0 :         maxoff = InvalidOffsetNumber;
     155                 :     }
     156 GIC          10 :     else if (P_IGNORE(opaque))
     157 UIC           0 :         stat->type = 'e';
     158 GBC          10 :     else if (P_ISLEAF(opaque))
     159 GIC           8 :         stat->type = 'l';
     160 GBC           2 :     else if (P_ISROOT(opaque))
     161 GIC           2 :         stat->type = 'r';
     162 EUB             :     else
     163 UIC           0 :         stat->type = 'i';
     164                 : 
     165                 :     /* btpage opaque data */
     166 GIC          10 :     stat->btpo_prev = opaque->btpo_prev;
     167 GBC          10 :     stat->btpo_next = opaque->btpo_next;
     168 GIC          10 :     stat->btpo_level = opaque->btpo_level;
     169              10 :     stat->btpo_flags = opaque->btpo_flags;
     170              10 :     stat->btpo_cycleid = opaque->btpo_cycleid;
     171 EUB             : 
     172                 :     /* count live and dead tuples, and free space */
     173 CBC        2022 :     for (off = FirstOffsetNumber; off <= maxoff; off++)
     174 EUB             :     {
     175 ECB             :         IndexTuple  itup;
     176                 : 
     177 CBC        2012 :         ItemId      id = PageGetItemId(page, off);
     178 ECB             : 
     179 GIC        2012 :         itup = (IndexTuple) PageGetItem(page, id);
     180 EUB             : 
     181 GIC        2012 :         item_size += IndexTupleSize(itup);
     182                 : 
     183 CBC        2012 :         if (!ItemIdIsDead(id))
     184            2012 :             stat->live_items++;
     185 ECB             :         else
     186 LBC           0 :             stat->dead_items++;
     187 ECB             :     }
     188 GIC          10 :     stat->free_size = PageGetFreeSpace(page);
     189                 : 
     190 CBC          10 :     if ((stat->live_items + stat->dead_items) > 0)
     191 GIC          10 :         stat->avg_item_size = item_size / (stat->live_items + stat->dead_items);
     192                 :     else
     193 UIC           0 :         stat->avg_item_size = 0;
     194 CBC          10 : }
     195                 : 
     196                 : /* -----------------------------------------------
     197                 :  * check_relation_block_range()
     198                 :  *
     199                 :  * Verify that a block number (given as int64) is valid for the relation.
     200                 :  * -----------------------------------------------
     201                 :  */
     202                 : static void
     203 GNC          15 : check_relation_block_range(Relation rel, int64 blkno)
     204                 : {
     205                 :     /* Ensure we can cast to BlockNumber */
     206              15 :     if (blkno < 0 || blkno > MaxBlockNumber)
     207               2 :         ereport(ERROR,
     208                 :                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
     209                 :                  errmsg("invalid block number %lld",
     210                 :                         (long long) blkno)));
     211                 : 
     212              13 :     if ((BlockNumber) (blkno) >= RelationGetNumberOfBlocks(rel))
     213               3 :         ereport(ERROR,
     214                 :                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
     215                 :                  errmsg("block number %lld is out of range",
     216                 :                         (long long) blkno)));
     217              10 : }
     218                 : 
     219                 : /* -----------------------------------------------
     220                 :  * bt_index_block_validate()
     221                 :  *
     222                 :  * Validate index type is btree and block number
     223                 :  * is valid (and not the metapage).
     224                 :  * -----------------------------------------------
     225                 :  */
     226                 : static void
     227              18 : bt_index_block_validate(Relation rel, int64 blkno)
     228                 : {
     229              18 :     if (!IS_INDEX(rel) || !IS_BTREE(rel))
     230               2 :         ereport(ERROR,
     231                 :                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
     232                 :                  errmsg("\"%s\" is not a %s index",
     233                 :                         RelationGetRelationName(rel), "btree")));
     234                 : 
     235                 :     /*
     236                 :      * Reject attempts to read non-local temporary relations; we would be
     237                 :      * likely to get wrong data since we have no visibility into the owning
     238                 :      * session's local buffers.
     239                 :      */
     240              16 :     if (RELATION_IS_OTHER_TEMP(rel))
     241 UNC           0 :         ereport(ERROR,
     242                 :                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
     243                 :                  errmsg("cannot access temporary tables of other sessions")));
     244                 : 
     245 GNC          16 :     if (blkno == 0)
     246               3 :         ereport(ERROR,
     247                 :                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
     248                 :                  errmsg("block 0 is a meta page")));
     249                 : 
     250              13 :     check_relation_block_range(rel, blkno);
     251               8 : }
     252                 : 
     253 ECB             : /* -----------------------------------------------
     254                 :  * bt_page_stats()
     255                 :  *
     256                 :  * Usage: SELECT * FROM bt_page_stats('t1_pkey', 1);
     257                 :  * Arguments are index relation name and block number
     258                 :  * -----------------------------------------------
     259                 :  */
     260                 : static Datum
     261 GBC           6 : bt_page_stats_internal(PG_FUNCTION_ARGS, enum pageinspect_version ext_version)
     262                 : {
     263 CBC           6 :     text       *relname = PG_GETARG_TEXT_PP(0);
     264 GIC           6 :     int64       blkno = (ext_version == PAGEINSPECT_V1_8 ? PG_GETARG_UINT32(1) : PG_GETARG_INT64(1));
     265 ECB             :     Buffer      buffer;
     266                 :     Relation    rel;
     267                 :     RangeVar   *relrv;
     268 EUB             :     Datum       result;
     269 ECB             :     HeapTuple   tuple;
     270                 :     TupleDesc   tupleDesc;
     271                 :     int         j;
     272                 :     char       *values[11];
     273                 :     BTPageStat  stat;
     274                 : 
     275 GIC           6 :     if (!superuser())
     276 UIC           0 :         ereport(ERROR,
     277                 :                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
     278 ECB             :                  errmsg("must be superuser to use pageinspect functions")));
     279                 : 
     280 GIC           6 :     relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
     281 CBC           6 :     rel = relation_openrv(relrv, AccessShareLock);
     282 ECB             : 
     283 GNC           6 :     bt_index_block_validate(rel, blkno);
     284                 : 
     285 GIC           2 :     buffer = ReadBuffer(rel, blkno);
     286               2 :     LockBuffer(buffer, BUFFER_LOCK_SHARE);
     287                 : 
     288                 :     /* keep compiler quiet */
     289 CBC           2 :     stat.btpo_prev = stat.btpo_next = InvalidBlockNumber;
     290 GBC           2 :     stat.btpo_flags = stat.free_size = stat.avg_item_size = 0;
     291                 : 
     292 GIC           2 :     GetBTPageStatistics(blkno, buffer, &stat);
     293                 : 
     294 CBC           2 :     UnlockReleaseBuffer(buffer);
     295               2 :     relation_close(rel, AccessShareLock);
     296                 : 
     297                 :     /* Build a tuple descriptor for our result type */
     298 GIC           2 :     if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
     299 LBC           0 :         elog(ERROR, "return type must be a row type");
     300 ECB             : 
     301 GIC           2 :     j = 0;
     302               2 :     values[j++] = psprintf("%u", stat.blkno);
     303               2 :     values[j++] = psprintf("%c", stat.type);
     304               2 :     values[j++] = psprintf("%u", stat.live_items);
     305               2 :     values[j++] = psprintf("%u", stat.dead_items);
     306               2 :     values[j++] = psprintf("%u", stat.avg_item_size);
     307               2 :     values[j++] = psprintf("%u", stat.page_size);
     308               2 :     values[j++] = psprintf("%u", stat.free_size);
     309               2 :     values[j++] = psprintf("%u", stat.btpo_prev);
     310 CBC           2 :     values[j++] = psprintf("%u", stat.btpo_next);
     311 GIC           2 :     values[j++] = psprintf("%u", stat.btpo_level);
     312 CBC           2 :     values[j++] = psprintf("%d", stat.btpo_flags);
     313 ECB             : 
     314 GIC           2 :     tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(tupleDesc),
     315                 :                                    values);
     316                 : 
     317               2 :     result = HeapTupleGetDatum(tuple);
     318                 : 
     319               2 :     PG_RETURN_DATUM(result);
     320                 : }
     321                 : 
     322                 : Datum
     323               5 : bt_page_stats_1_9(PG_FUNCTION_ARGS)
     324 ECB             : {
     325 GBC           5 :     return bt_page_stats_internal(fcinfo, PAGEINSPECT_V1_9);
     326                 : }
     327                 : 
     328                 : /* entry point for old extension version */
     329 ECB             : Datum
     330 CBC           1 : bt_page_stats(PG_FUNCTION_ARGS)
     331                 : {
     332               1 :     return bt_page_stats_internal(fcinfo, PAGEINSPECT_V1_8);
     333                 : }
     334 ECB             : 
     335                 : 
     336                 : /* -----------------------------------------------
     337                 :  * bt_multi_page_stats()
     338                 :  *
     339                 :  * Usage: SELECT * FROM bt_page_stats('t1_pkey', 1, 2);
     340                 :  * Arguments are index relation name, first block number, number of blocks
     341                 :  * (but number of blocks can be negative to mean "read all the rest")
     342                 :  * -----------------------------------------------
     343                 :  */
     344                 : Datum
     345 GNC          14 : bt_multi_page_stats(PG_FUNCTION_ARGS)
     346                 : {
     347                 :     Relation    rel;
     348                 :     ua_page_stats *uargs;
     349                 :     FuncCallContext *fctx;
     350                 :     MemoryContext mctx;
     351                 : 
     352              14 :     if (!superuser())
     353 UNC           0 :         ereport(ERROR,
     354                 :                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
     355                 :                  errmsg("must be superuser to use pageinspect functions")));
     356                 : 
     357 GNC          14 :     if (SRF_IS_FIRSTCALL())
     358                 :     {
     359               6 :         text       *relname = PG_GETARG_TEXT_PP(0);
     360               6 :         int64       blkno = PG_GETARG_INT64(1);
     361               6 :         int64       blk_count = PG_GETARG_INT64(2);
     362                 :         RangeVar   *relrv;
     363                 : 
     364               6 :         fctx = SRF_FIRSTCALL_INIT();
     365                 : 
     366               6 :         relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
     367               6 :         rel = relation_openrv(relrv, AccessShareLock);
     368                 : 
     369                 :         /* Check that rel is a valid btree index and 1st block number is OK */
     370               6 :         bt_index_block_validate(rel, blkno);
     371                 : 
     372                 :         /*
     373                 :          * Check if upper bound of the specified range is valid. If only one
     374                 :          * page is requested, skip as we've already validated the page. (Also,
     375                 :          * it's important to skip this if blk_count is negative.)
     376                 :          */
     377               4 :         if (blk_count > 1)
     378               2 :             check_relation_block_range(rel, blkno + blk_count - 1);
     379                 : 
     380                 :         /* Save arguments for reuse */
     381               4 :         mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);
     382                 : 
     383               4 :         uargs = palloc(sizeof(ua_page_stats));
     384                 : 
     385               4 :         uargs->relid = RelationGetRelid(rel);
     386               4 :         uargs->blkno = blkno;
     387               4 :         uargs->blk_count = blk_count;
     388               4 :         uargs->allpages = (blk_count < 0);
     389                 : 
     390               4 :         fctx->user_fctx = uargs;
     391                 : 
     392               4 :         MemoryContextSwitchTo(mctx);
     393                 : 
     394                 :         /*
     395                 :          * To avoid possibly leaking a relcache reference if the SRF isn't run
     396                 :          * to completion, we close and re-open the index rel each time
     397                 :          * through, using the index's OID for re-opens to ensure we get the
     398                 :          * same rel.  Keep the AccessShareLock though, to ensure it doesn't go
     399                 :          * away underneath us.
     400                 :          */
     401               4 :         relation_close(rel, NoLock);
     402                 :     }
     403                 : 
     404              12 :     fctx = SRF_PERCALL_SETUP();
     405              12 :     uargs = fctx->user_fctx;
     406                 : 
     407                 :     /* We should have lock already */
     408              12 :     rel = relation_open(uargs->relid, NoLock);
     409                 : 
     410                 :     /* In all-pages mode, recheck the index length each time */
     411              12 :     if (uargs->allpages)
     412               5 :         uargs->blk_count = RelationGetNumberOfBlocks(rel) - uargs->blkno;
     413                 : 
     414              12 :     if (uargs->blk_count > 0)
     415                 :     {
     416                 :         /* We need to fetch next block statistics */
     417                 :         Buffer      buffer;
     418                 :         Datum       result;
     419                 :         HeapTuple   tuple;
     420                 :         int         j;
     421                 :         char       *values[11];
     422                 :         BTPageStat  stat;
     423                 :         TupleDesc   tupleDesc;
     424                 : 
     425               8 :         buffer = ReadBuffer(rel, uargs->blkno);
     426               8 :         LockBuffer(buffer, BUFFER_LOCK_SHARE);
     427                 : 
     428                 :         /* keep compiler quiet */
     429               8 :         stat.btpo_prev = stat.btpo_next = InvalidBlockNumber;
     430               8 :         stat.btpo_flags = stat.free_size = stat.avg_item_size = 0;
     431                 : 
     432               8 :         GetBTPageStatistics(uargs->blkno, buffer, &stat);
     433                 : 
     434               8 :         UnlockReleaseBuffer(buffer);
     435               8 :         relation_close(rel, NoLock);
     436                 : 
     437                 :         /* Build a tuple descriptor for our result type */
     438               8 :         if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
     439 UNC           0 :             elog(ERROR, "return type must be a row type");
     440                 : 
     441 GNC           8 :         j = 0;
     442               8 :         values[j++] = psprintf("%u", stat.blkno);
     443               8 :         values[j++] = psprintf("%c", stat.type);
     444               8 :         values[j++] = psprintf("%u", stat.live_items);
     445               8 :         values[j++] = psprintf("%u", stat.dead_items);
     446               8 :         values[j++] = psprintf("%u", stat.avg_item_size);
     447               8 :         values[j++] = psprintf("%u", stat.page_size);
     448               8 :         values[j++] = psprintf("%u", stat.free_size);
     449               8 :         values[j++] = psprintf("%u", stat.btpo_prev);
     450               8 :         values[j++] = psprintf("%u", stat.btpo_next);
     451               8 :         values[j++] = psprintf("%u", stat.btpo_level);
     452               8 :         values[j++] = psprintf("%d", stat.btpo_flags);
     453                 : 
     454                 :         /* Construct tuple to be returned */
     455               8 :         tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(tupleDesc),
     456                 :                                        values);
     457                 : 
     458               8 :         result = HeapTupleGetDatum(tuple);
     459                 : 
     460                 :         /*
     461                 :          * Move to the next block number and decrement the number of blocks
     462                 :          * still to be fetched
     463                 :          */
     464               8 :         uargs->blkno++;
     465               8 :         uargs->blk_count--;
     466                 : 
     467               8 :         SRF_RETURN_NEXT(fctx, result);
     468                 :     }
     469                 : 
     470                 :     /* Done, so finally we can release the index lock */
     471               4 :     relation_close(rel, AccessShareLock);
     472               4 :     SRF_RETURN_DONE(fctx);
     473                 : }
     474 ECB             : 
     475 EUB             : /*-------------------------------------------------------
     476                 :  * bt_page_print_tuples()
     477 ECB             :  *
     478                 :  * Form a tuple describing index tuple at a given offset
     479                 :  * ------------------------------------------------------
     480                 :  */
     481                 : static Datum
     482 GNC           3 : bt_page_print_tuples(ua_page_items *uargs)
     483 ECB             : {
     484 CBC           3 :     Page        page = uargs->page;
     485               3 :     OffsetNumber offset = uargs->offset;
     486               3 :     bool        leafpage = uargs->leafpage;
     487               3 :     bool        rightmost = uargs->rightmost;
     488 ECB             :     bool        ispivottuple;
     489                 :     Datum       values[9];
     490                 :     bool        nulls[9];
     491                 :     HeapTuple   tuple;
     492                 :     ItemId      id;
     493                 :     IndexTuple  itup;
     494                 :     int         j;
     495                 :     int         off;
     496                 :     int         dlen;
     497                 :     char       *dump,
     498                 :                *datacstring;
     499                 :     char       *ptr;
     500                 :     ItemPointer htid;
     501                 : 
     502 GIC           3 :     id = PageGetItemId(page, offset);
     503                 : 
     504               3 :     if (!ItemIdIsValid(id))
     505 UIC           0 :         elog(ERROR, "invalid ItemId");
     506 ECB             : 
     507 GIC           3 :     itup = (IndexTuple) PageGetItem(page, id);
     508 ECB             : 
     509 GIC           3 :     j = 0;
     510               3 :     memset(nulls, 0, sizeof(nulls));
     511               3 :     values[j++] = DatumGetInt16(offset);
     512               3 :     values[j++] = ItemPointerGetDatum(&itup->t_tid);
     513               3 :     values[j++] = Int32GetDatum((int) IndexTupleSize(itup));
     514               3 :     values[j++] = BoolGetDatum(IndexTupleHasNulls(itup));
     515               3 :     values[j++] = BoolGetDatum(IndexTupleHasVarwidths(itup));
     516                 : 
     517               3 :     ptr = (char *) itup + IndexInfoFindDataOffset(itup->t_info);
     518               3 :     dlen = IndexTupleSize(itup) - IndexInfoFindDataOffset(itup->t_info);
     519                 : 
     520                 :     /*
     521 ECB             :      * Make sure that "data" column does not include posting list or pivot
     522                 :      * tuple representation of heap TID(s).
     523                 :      *
     524                 :      * Note: BTreeTupleIsPivot() won't work reliably on !heapkeyspace indexes
     525                 :      * (those built before BTREE_VERSION 4), but we have no way of determining
     526                 :      * if this page came from a !heapkeyspace index.  We may only have a bytea
     527                 :      * nbtree page image to go on, so in general there is no metapage that we
     528                 :      * can check.
     529 EUB             :      *
     530                 :      * That's okay here because BTreeTupleIsPivot() can only return false for
     531                 :      * a !heapkeyspace pivot, never true for a !heapkeyspace non-pivot.  Since
     532                 :      * heap TID isn't part of the keyspace in a !heapkeyspace index anyway,
     533 ECB             :      * there cannot possibly be a pivot tuple heap TID representation that we
     534                 :      * fail to make an adjustment for.  A !heapkeyspace index can have
     535                 :      * BTreeTupleIsPivot() return true (due to things like suffix truncation
     536                 :      * for INCLUDE indexes in Postgres v11), but when that happens
     537                 :      * BTreeTupleGetHeapTID() can be trusted to work reliably (i.e. return
     538                 :      * NULL).
     539                 :      *
     540                 :      * Note: BTreeTupleIsPosting() always works reliably, even with
     541                 :      * !heapkeyspace indexes.
     542                 :      */
     543 CBC           3 :     if (BTreeTupleIsPosting(itup))
     544 UIC           0 :         dlen -= IndexTupleSize(itup) - BTreeTupleGetPostingOffset(itup);
     545 GIC           3 :     else if (BTreeTupleIsPivot(itup) && BTreeTupleGetHeapTID(itup) != NULL)
     546 LBC           0 :         dlen -= MAXALIGN(sizeof(ItemPointerData));
     547                 : 
     548 GIC           3 :     if (dlen < 0 || dlen > INDEX_SIZE_MASK)
     549 UIC           0 :         elog(ERROR, "invalid tuple length %d for tuple at offset number %u",
     550                 :              dlen, offset);
     551 GIC           3 :     dump = palloc0(dlen * 3 + 1);
     552               3 :     datacstring = dump;
     553 CBC          27 :     for (off = 0; off < dlen; off++)
     554 ECB             :     {
     555 GIC          24 :         if (off > 0)
     556              21 :             *dump++ = ' ';
     557 CBC          24 :         sprintf(dump, "%02x", *(ptr + off) & 0xff);
     558 GIC          24 :         dump += 2;
     559 ECB             :     }
     560 GIC           3 :     values[j++] = CStringGetTextDatum(datacstring);
     561 CBC           3 :     pfree(datacstring);
     562 ECB             : 
     563                 :     /*
     564                 :      * We need to work around the BTreeTupleIsPivot() !heapkeyspace limitation
     565                 :      * again.  Deduce whether or not tuple must be a pivot tuple based on
     566                 :      * whether or not the page is a leaf page, as well as the page offset
     567                 :      * number of the tuple.
     568                 :      */
     569 GIC           3 :     ispivottuple = (!leafpage || (!rightmost && offset == P_HIKEY));
     570                 : 
     571                 :     /* LP_DEAD bit can never be set for pivot tuples, so show a NULL there */
     572               3 :     if (!ispivottuple)
     573               3 :         values[j++] = BoolGetDatum(ItemIdIsDead(id));
     574                 :     else
     575                 :     {
     576 UIC           0 :         Assert(!ItemIdIsDead(id));
     577 LBC           0 :         nulls[j++] = true;
     578                 :     }
     579                 : 
     580 CBC           3 :     htid = BTreeTupleGetHeapTID(itup);
     581               3 :     if (ispivottuple && !BTreeTupleIsPivot(itup))
     582                 :     {
     583                 :         /* Don't show bogus heap TID in !heapkeyspace pivot tuple */
     584 LBC           0 :         htid = NULL;
     585                 :     }
     586                 : 
     587 CBC           3 :     if (htid)
     588               3 :         values[j++] = ItemPointerGetDatum(htid);
     589                 :     else
     590 LBC           0 :         nulls[j++] = true;
     591                 : 
     592 GIC           3 :     if (BTreeTupleIsPosting(itup))
     593                 :     {
     594                 :         /* Build an array of item pointers */
     595                 :         ItemPointer tids;
     596                 :         Datum      *tids_datum;
     597                 :         int         nposting;
     598                 : 
     599 UIC           0 :         tids = BTreeTupleGetPosting(itup);
     600               0 :         nposting = BTreeTupleGetNPosting(itup);
     601 LBC           0 :         tids_datum = (Datum *) palloc(nposting * sizeof(Datum));
     602               0 :         for (int i = 0; i < nposting; i++)
     603 UIC           0 :             tids_datum[i] = ItemPointerGetDatum(&tids[i]);
     604 UNC           0 :         values[j++] = PointerGetDatum(construct_array_builtin(tids_datum, nposting, TIDOID));
     605 UIC           0 :         pfree(tids_datum);
     606 ECB             :     }
     607                 :     else
     608 GIC           3 :         nulls[j++] = true;
     609                 : 
     610 ECB             :     /* Build and return the result tuple */
     611 GBC           3 :     tuple = heap_form_tuple(uargs->tupd, values, nulls);
     612                 : 
     613 CBC           3 :     return HeapTupleGetDatum(tuple);
     614 ECB             : }
     615                 : 
     616                 : /*-------------------------------------------------------
     617                 :  * bt_page_items()
     618                 :  *
     619                 :  * Get IndexTupleData set in a btree page
     620                 :  *
     621                 :  * Usage: SELECT * FROM bt_page_items('t1_pkey', 1);
     622                 :  *-------------------------------------------------------
     623                 :  */
     624                 : static Datum
     625 GIC           8 : bt_page_items_internal(PG_FUNCTION_ARGS, enum pageinspect_version ext_version)
     626                 : {
     627 CBC           8 :     text       *relname = PG_GETARG_TEXT_PP(0);
     628 GIC           8 :     int64       blkno = (ext_version == PAGEINSPECT_V1_8 ? PG_GETARG_UINT32(1) : PG_GETARG_INT64(1));
     629                 :     Datum       result;
     630 ECB             :     FuncCallContext *fctx;
     631                 :     MemoryContext mctx;
     632                 :     ua_page_items *uargs;
     633                 : 
     634 GIC           8 :     if (!superuser())
     635 UIC           0 :         ereport(ERROR,
     636 ECB             :                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
     637                 :                  errmsg("must be superuser to use pageinspect functions")));
     638                 : 
     639 CBC           8 :     if (SRF_IS_FIRSTCALL())
     640                 :     {
     641                 :         RangeVar   *relrv;
     642                 :         Relation    rel;
     643 ECB             :         Buffer      buffer;
     644                 :         BTPageOpaque opaque;
     645                 :         TupleDesc   tupleDesc;
     646                 : 
     647 GIC           6 :         fctx = SRF_FIRSTCALL_INIT();
     648                 : 
     649               6 :         relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
     650               6 :         rel = relation_openrv(relrv, AccessShareLock);
     651                 : 
     652 GNC           6 :         bt_index_block_validate(rel, blkno);
     653 ECB             : 
     654 GIC           2 :         buffer = ReadBuffer(rel, blkno);
     655 CBC           2 :         LockBuffer(buffer, BUFFER_LOCK_SHARE);
     656 ECB             : 
     657                 :         /*
     658                 :          * We copy the page into local storage to avoid holding pin on the
     659                 :          * buffer longer than we must, and possibly failing to release it at
     660                 :          * all if the calling query doesn't fetch all rows.
     661                 :          */
     662 GIC           2 :         mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);
     663 ECB             : 
     664 GNC           2 :         uargs = palloc(sizeof(ua_page_items));
     665                 : 
     666 GIC           2 :         uargs->page = palloc(BLCKSZ);
     667               2 :         memcpy(uargs->page, BufferGetPage(buffer), BLCKSZ);
     668                 : 
     669               2 :         UnlockReleaseBuffer(buffer);
     670               2 :         relation_close(rel, AccessShareLock);
     671                 : 
     672               2 :         uargs->offset = FirstOffsetNumber;
     673                 : 
     674               2 :         opaque = BTPageGetOpaque(uargs->page);
     675                 : 
     676               2 :         if (!P_ISDELETED(opaque))
     677               2 :             fctx->max_calls = PageGetMaxOffsetNumber(uargs->page);
     678                 :         else
     679                 :         {
     680                 :             /* Don't interpret BTDeletedPageData as index tuples */
     681 UIC           0 :             elog(NOTICE, "page from block " INT64_FORMAT " is deleted", blkno);
     682               0 :             fctx->max_calls = 0;
     683                 :         }
     684 GIC           2 :         uargs->leafpage = P_ISLEAF(opaque);
     685               2 :         uargs->rightmost = P_RIGHTMOST(opaque);
     686                 : 
     687                 :         /* Build a tuple descriptor for our result type */
     688               2 :         if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
     689 LBC           0 :             elog(ERROR, "return type must be a row type");
     690 GBC           2 :         tupleDesc = BlessTupleDesc(tupleDesc);
     691 ECB             : 
     692 GBC           2 :         uargs->tupd = tupleDesc;
     693                 : 
     694 CBC           2 :         fctx->user_fctx = uargs;
     695 EUB             : 
     696 GIC           2 :         MemoryContextSwitchTo(mctx);
     697 ECB             :     }
     698                 : 
     699 CBC           4 :     fctx = SRF_PERCALL_SETUP();
     700 GIC           4 :     uargs = fctx->user_fctx;
     701 ECB             : 
     702 CBC           4 :     if (fctx->call_cntr < fctx->max_calls)
     703 ECB             :     {
     704 CBC           2 :         result = bt_page_print_tuples(uargs);
     705 GIC           2 :         uargs->offset++;
     706 CBC           2 :         SRF_RETURN_NEXT(fctx, result);
     707 ECB             :     }
     708                 : 
     709 GIC           2 :     SRF_RETURN_DONE(fctx);
     710                 : }
     711                 : 
     712                 : Datum
     713               6 : bt_page_items_1_9(PG_FUNCTION_ARGS)
     714                 : {
     715 CBC           6 :     return bt_page_items_internal(fcinfo, PAGEINSPECT_V1_9);
     716                 : }
     717                 : 
     718 ECB             : /* entry point for old extension version */
     719                 : Datum
     720 GIC           2 : bt_page_items(PG_FUNCTION_ARGS)
     721                 : {
     722 GBC           2 :     return bt_page_items_internal(fcinfo, PAGEINSPECT_V1_8);
     723 EUB             : }
     724                 : 
     725                 : /*-------------------------------------------------------
     726 ECB             :  * bt_page_items_bytea()
     727                 :  *
     728                 :  * Get IndexTupleData set in a btree page
     729                 :  *
     730 EUB             :  * Usage: SELECT * FROM bt_page_items(get_raw_page('t1_pkey', 1));
     731                 :  *-------------------------------------------------------
     732                 :  */
     733 ECB             : 
     734                 : Datum
     735 GIC           9 : bt_page_items_bytea(PG_FUNCTION_ARGS)
     736 EUB             : {
     737 GIC           9 :     bytea      *raw_page = PG_GETARG_BYTEA_P(0);
     738 ECB             :     Datum       result;
     739                 :     FuncCallContext *fctx;
     740                 :     ua_page_items *uargs;
     741                 : 
     742 GIC           9 :     if (!superuser())
     743 UIC           0 :         ereport(ERROR,
     744                 :                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
     745 EUB             :                  errmsg("must be superuser to use raw page functions")));
     746                 : 
     747 GBC           9 :     if (SRF_IS_FIRSTCALL())
     748 EUB             :     {
     749                 :         BTPageOpaque opaque;
     750                 :         MemoryContext mctx;
     751                 :         TupleDesc   tupleDesc;
     752                 : 
     753 GIC           8 :         fctx = SRF_FIRSTCALL_INIT();
     754 CBC           8 :         mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);
     755                 : 
     756 GNC           8 :         uargs = palloc(sizeof(ua_page_items));
     757 ECB             : 
     758 GIC           8 :         uargs->page = get_page_from_raw(raw_page);
     759 ECB             : 
     760 GIC           7 :         if (PageIsNew(uargs->page))
     761                 :         {
     762               1 :             MemoryContextSwitchTo(mctx);
     763               1 :             PG_RETURN_NULL();
     764                 :         }
     765                 : 
     766               6 :         uargs->offset = FirstOffsetNumber;
     767                 : 
     768                 :         /* verify the special space has the expected size */
     769               6 :         if (PageGetSpecialSize(uargs->page) != MAXALIGN(sizeof(BTPageOpaqueData)))
     770               2 :             ereport(ERROR,
     771 ECB             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
     772                 :                      errmsg("input page is not a valid %s page", "btree"),
     773                 :                      errdetail("Expected special size %d, got %d.",
     774                 :                                (int) MAXALIGN(sizeof(BTPageOpaqueData)),
     775                 :                                (int) PageGetSpecialSize(uargs->page))));
     776                 : 
     777 GIC           4 :         opaque = BTPageGetOpaque(uargs->page);
     778                 : 
     779               4 :         if (P_ISMETA(opaque))
     780 CBC           2 :             ereport(ERROR,
     781 EUB             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
     782                 :                      errmsg("block is a meta page")));
     783                 : 
     784 GIC           2 :         if (P_ISLEAF(opaque) && opaque->btpo_level != 0)
     785 CBC           1 :             ereport(ERROR,
     786                 :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
     787                 :                      errmsg("block is not a valid btree leaf page")));
     788                 : 
     789 GIC           1 :         if (P_ISDELETED(opaque))
     790 UIC           0 :             elog(NOTICE, "page is deleted");
     791                 : 
     792 GIC           1 :         if (!P_ISDELETED(opaque))
     793 CBC           1 :             fctx->max_calls = PageGetMaxOffsetNumber(uargs->page);
     794                 :         else
     795 ECB             :         {
     796                 :             /* Don't interpret BTDeletedPageData as index tuples */
     797 UIC           0 :             elog(NOTICE, "page from block is deleted");
     798 LBC           0 :             fctx->max_calls = 0;
     799                 :         }
     800 CBC           1 :         uargs->leafpage = P_ISLEAF(opaque);
     801               1 :         uargs->rightmost = P_RIGHTMOST(opaque);
     802                 : 
     803                 :         /* Build a tuple descriptor for our result type */
     804 GIC           1 :         if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
     805 UIC           0 :             elog(ERROR, "return type must be a row type");
     806 GIC           1 :         tupleDesc = BlessTupleDesc(tupleDesc);
     807                 : 
     808 CBC           1 :         uargs->tupd = tupleDesc;
     809                 : 
     810               1 :         fctx->user_fctx = uargs;
     811                 : 
     812               1 :         MemoryContextSwitchTo(mctx);
     813 ECB             :     }
     814                 : 
     815 CBC           2 :     fctx = SRF_PERCALL_SETUP();
     816               2 :     uargs = fctx->user_fctx;
     817                 : 
     818               2 :     if (fctx->call_cntr < fctx->max_calls)
     819                 :     {
     820               1 :         result = bt_page_print_tuples(uargs);
     821 GIC           1 :         uargs->offset++;
     822 CBC           1 :         SRF_RETURN_NEXT(fctx, result);
     823 ECB             :     }
     824                 : 
     825 GIC           1 :     SRF_RETURN_DONE(fctx);
     826                 : }
     827 EUB             : 
     828                 : /* Number of output arguments (columns) for bt_metap() */
     829                 : #define BT_METAP_COLS_V1_8      9
     830 ECB             : 
     831                 : /* ------------------------------------------------
     832                 :  * bt_metap()
     833                 :  *
     834                 :  * Get a btree's meta-page information
     835 EUB             :  *
     836 ECB             :  * Usage: SELECT * FROM bt_metap('t1_pkey')
     837                 :  * ------------------------------------------------
     838                 :  */
     839                 : Datum
     840 CBC           2 : bt_metap(PG_FUNCTION_ARGS)
     841                 : {
     842               2 :     text       *relname = PG_GETARG_TEXT_PP(0);
     843                 :     Datum       result;
     844                 :     Relation    rel;
     845 ECB             :     RangeVar   *relrv;
     846                 :     BTMetaPageData *metad;
     847                 :     TupleDesc   tupleDesc;
     848                 :     int         j;
     849                 :     char       *values[9];
     850                 :     Buffer      buffer;
     851                 :     Page        page;
     852                 :     HeapTuple   tuple;
     853                 : 
     854 GIC           2 :     if (!superuser())
     855 LBC           0 :         ereport(ERROR,
     856                 :                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
     857                 :                  errmsg("must be superuser to use pageinspect functions")));
     858                 : 
     859 CBC           2 :     relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
     860 GIC           2 :     rel = relation_openrv(relrv, AccessShareLock);
     861 ECB             : 
     862 GIC           2 :     if (!IS_INDEX(rel) || !IS_BTREE(rel))
     863               1 :         ereport(ERROR,
     864                 :                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
     865                 :                  errmsg("\"%s\" is not a %s index",
     866 ECB             :                         RelationGetRelationName(rel), "btree")));
     867                 : 
     868                 :     /*
     869                 :      * Reject attempts to read non-local temporary relations; we would be
     870                 :      * likely to get wrong data since we have no visibility into the owning
     871                 :      * session's local buffers.
     872                 :      */
     873 GIC           1 :     if (RELATION_IS_OTHER_TEMP(rel))
     874 UIC           0 :         ereport(ERROR,
     875                 :                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
     876                 :                  errmsg("cannot access temporary tables of other sessions")));
     877                 : 
     878 GIC           1 :     buffer = ReadBuffer(rel, 0);
     879               1 :     LockBuffer(buffer, BUFFER_LOCK_SHARE);
     880                 : 
     881 CBC           1 :     page = BufferGetPage(buffer);
     882 GIC           1 :     metad = BTPageGetMeta(page);
     883 ECB             : 
     884                 :     /* Build a tuple descriptor for our result type */
     885 GIC           1 :     if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
     886 UIC           0 :         elog(ERROR, "return type must be a row type");
     887                 : 
     888 ECB             :     /*
     889 EUB             :      * We need a kluge here to detect API versions prior to 1.8.  Earlier
     890                 :      * versions incorrectly used int4 for certain columns.
     891                 :      *
     892                 :      * There is no way to reliably avoid the problems created by the old
     893 ECB             :      * function definition at this point, so insist that the user update the
     894                 :      * extension.
     895                 :      */
     896 GIC           1 :     if (tupleDesc->natts < BT_METAP_COLS_V1_8)
     897 UIC           0 :         ereport(ERROR,
     898                 :                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
     899 ECB             :                  errmsg("function has wrong number of declared columns"),
     900                 :                  errhint("To resolve the problem, update the \"pageinspect\" extension to the latest version.")));
     901                 : 
     902 CBC           1 :     j = 0;
     903 GIC           1 :     values[j++] = psprintf("%d", metad->btm_magic);
     904 CBC           1 :     values[j++] = psprintf("%d", metad->btm_version);
     905 GIC           1 :     values[j++] = psprintf(INT64_FORMAT, (int64) metad->btm_root);
     906 CBC           1 :     values[j++] = psprintf(INT64_FORMAT, (int64) metad->btm_level);
     907 GIC           1 :     values[j++] = psprintf(INT64_FORMAT, (int64) metad->btm_fastroot);
     908 CBC           1 :     values[j++] = psprintf(INT64_FORMAT, (int64) metad->btm_fastlevel);
     909 ECB             : 
     910                 :     /*
     911                 :      * Get values of extended metadata if available, use default values
     912                 :      * otherwise.  Note that we rely on the assumption that btm_allequalimage
     913                 :      * is initialized to zero with indexes that were built on versions prior
     914                 :      * to Postgres 13 (just like _bt_metaversion()).
     915                 :      */
     916 CBC           1 :     if (metad->btm_version >= BTREE_NOVAC_VERSION)
     917                 :     {
     918 GIC           2 :         values[j++] = psprintf(INT64_FORMAT,
     919               1 :                                (int64) metad->btm_last_cleanup_num_delpages);
     920               1 :         values[j++] = psprintf("%f", metad->btm_last_cleanup_num_heap_tuples);
     921               1 :         values[j++] = metad->btm_allequalimage ? "t" : "f";
     922                 :     }
     923 ECB             :     else
     924                 :     {
     925 LBC           0 :         values[j++] = "0";
     926               0 :         values[j++] = "-1";
     927 UIC           0 :         values[j++] = "f";
     928                 :     }
     929                 : 
     930 CBC           1 :     tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(tupleDesc),
     931 ECB             :                                    values);
     932                 : 
     933 GIC           1 :     result = HeapTupleGetDatum(tuple);
     934                 : 
     935 CBC           1 :     UnlockReleaseBuffer(buffer);
     936 GBC           1 :     relation_close(rel, AccessShareLock);
     937                 : 
     938 CBC           1 :     PG_RETURN_DATUM(result);
     939 ECB             : }
        

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