nbtdesc.c

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/*-------------------------------------------------------------------------
 *
 * nbtdesc.c
 *    rmgr descriptor routines for access/nbtree/nbtxlog.c
 *
 * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *    src/backend/access/rmgrdesc/nbtdesc.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"
 
#include "access/nbtxlog.h"
#include "access/rmgrdesc_utils.h"
 
static void delvacuum_desc(StringInfo buf, char *block_data,
                           uint16 ndeleted, uint16 nupdated);
 
void
btree_desc(StringInfo buf, XLogReaderState *record)
{
    char       *rec = XLogRecGetData(record);
    uint8       info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
 
    switch (info)
    {
        case XLOG_BTREE_INSERT_LEAF:
        case XLOG_BTREE_INSERT_UPPER:
        case XLOG_BTREE_INSERT_META:
        case XLOG_BTREE_INSERT_POST:
            {
                xl_btree_insert *xlrec = (xl_btree_insert *) rec;
 
                appendStringInfo(buf, "off: %u", xlrec->offnum);
                break;
            }
        case XLOG_BTREE_SPLIT_L:
        case XLOG_BTREE_SPLIT_R:
            {
                xl_btree_split *xlrec = (xl_btree_split *) rec;
 
                appendStringInfo(buf, "level: %u, firstrightoff: %d, newitemoff: %d, postingoff: %d",
                                 xlrec->level, xlrec->firstrightoff,
                                 xlrec->newitemoff, xlrec->postingoff);
                break;
            }
        case XLOG_BTREE_DEDUP:
            {
                xl_btree_dedup *xlrec = (xl_btree_dedup *) rec;
 
                appendStringInfo(buf, "nintervals: %u", xlrec->nintervals);
                break;
            }
        case XLOG_BTREE_VACUUM:
            {
                xl_btree_vacuum *xlrec = (xl_btree_vacuum *) rec;
 
                appendStringInfo(buf, "ndeleted: %u, nupdated: %u",
                                 xlrec->ndeleted, xlrec->nupdated);
 
                if (XLogRecHasBlockData(record, 0))
                    delvacuum_desc(buf, XLogRecGetBlockData(record, 0, NULL),
                                   xlrec->ndeleted, xlrec->nupdated);
                break;
            }
        case XLOG_BTREE_DELETE:
            {
                xl_btree_delete *xlrec = (xl_btree_delete *) rec;
 
                appendStringInfo(buf, "snapshotConflictHorizon: %u, ndeleted: %u, nupdated: %u, isCatalogRel: %c",
                                 xlrec->snapshotConflictHorizon,
                                 xlrec->ndeleted, xlrec->nupdated,
                                 xlrec->isCatalogRel ? 'T' : 'F');
 
                if (XLogRecHasBlockData(record, 0))
                    delvacuum_desc(buf, XLogRecGetBlockData(record, 0, NULL),
                                   xlrec->ndeleted, xlrec->nupdated);
                break;
            }
        case XLOG_BTREE_MARK_PAGE_HALFDEAD:
            {
                xl_btree_mark_page_halfdead *xlrec = (xl_btree_mark_page_halfdead *) rec;
 
                appendStringInfo(buf, "topparent: %u, leaf: %u, left: %u, right: %u",
                                 xlrec->topparent, xlrec->leafblk, xlrec->leftblk, xlrec->rightblk);
                break;
            }
        case XLOG_BTREE_UNLINK_PAGE_META:
        case XLOG_BTREE_UNLINK_PAGE:
            {
                xl_btree_unlink_page *xlrec = (xl_btree_unlink_page *) rec;
 
                appendStringInfo(buf, "left: %u, right: %u, level: %u, safexid: %u:%u, ",
                                 xlrec->leftsib, xlrec->rightsib, xlrec->level,
                                 EpochFromFullTransactionId(xlrec->safexid),
                                 XidFromFullTransactionId(xlrec->safexid));
                appendStringInfo(buf, "leafleft: %u, leafright: %u, leaftopparent: %u",
                                 xlrec->leafleftsib, xlrec->leafrightsib,
                                 xlrec->leaftopparent);
                break;
            }
        case XLOG_BTREE_NEWROOT:
            {
                xl_btree_newroot *xlrec = (xl_btree_newroot *) rec;
 
                appendStringInfo(buf, "level: %u", xlrec->level);
                break;
            }
        case XLOG_BTREE_REUSE_PAGE:
            {
                xl_btree_reuse_page *xlrec = (xl_btree_reuse_page *) rec;
 
                appendStringInfo(buf, "rel: %u/%u/%u, snapshotConflictHorizon: %u:%u, isCatalogRel: %c",
                                 xlrec->locator.spcOid, xlrec->locator.dbOid,
                                 xlrec->locator.relNumber,
                                 EpochFromFullTransactionId(xlrec->snapshotConflictHorizon),
                                 XidFromFullTransactionId(xlrec->snapshotConflictHorizon),
                                 xlrec->isCatalogRel ? 'T' : 'F');
                break;
            }
        case XLOG_BTREE_META_CLEANUP:
            {
                xl_btree_metadata *xlrec;
 
                xlrec = (xl_btree_metadata *) XLogRecGetBlockData(record, 0,
                                                                  NULL);
                appendStringInfo(buf, "last_cleanup_num_delpages: %u",
                                 xlrec->last_cleanup_num_delpages);
                break;
            }
    }
}
 
const char *
btree_identify(uint8 info)
{
    const char *id = NULL;
 
    switch (info & ~XLR_INFO_MASK)
    {
        case XLOG_BTREE_INSERT_LEAF:
            id = "INSERT_LEAF";
            break;
        case XLOG_BTREE_INSERT_UPPER:
            id = "INSERT_UPPER";
            break;
        case XLOG_BTREE_INSERT_META:
            id = "INSERT_META";
            break;
        case XLOG_BTREE_SPLIT_L:
            id = "SPLIT_L";
            break;
        case XLOG_BTREE_SPLIT_R:
            id = "SPLIT_R";
            break;
        case XLOG_BTREE_INSERT_POST:
            id = "INSERT_POST";
            break;
        case XLOG_BTREE_DEDUP:
            id = "DEDUP";
            break;
        case XLOG_BTREE_VACUUM:
            id = "VACUUM";
            break;
        case XLOG_BTREE_DELETE:
            id = "DELETE";
            break;
        case XLOG_BTREE_MARK_PAGE_HALFDEAD:
            id = "MARK_PAGE_HALFDEAD";
            break;
        case XLOG_BTREE_UNLINK_PAGE:
            id = "UNLINK_PAGE";
            break;
        case XLOG_BTREE_UNLINK_PAGE_META:
            id = "UNLINK_PAGE_META";
            break;
        case XLOG_BTREE_NEWROOT:
            id = "NEWROOT";
            break;
        case XLOG_BTREE_REUSE_PAGE:
            id = "REUSE_PAGE";
            break;
        case XLOG_BTREE_META_CLEANUP:
            id = "META_CLEANUP";
            break;
    }
 
    return id;
}
 
static void
delvacuum_desc(StringInfo buf, char *block_data,
               uint16 ndeleted, uint16 nupdated)
{
    OffsetNumber *deletedoffsets;
    OffsetNumber *updatedoffsets;
    xl_btree_update *updates;
 
    /* Output deleted page offset number array */
    appendStringInfoString(buf, ", deleted:");
    deletedoffsets = (OffsetNumber *) block_data;
    array_desc(buf, deletedoffsets, sizeof(OffsetNumber), ndeleted,
               &offset_elem_desc, NULL);
 
    /*
     * Output updates as an array of "update objects", where each element
     * contains a page offset number from updated array.  (This is not the
     * most literal representation of the underlying physical data structure
     * that we could use.  Readability seems more important here.)
     */
    appendStringInfoString(buf, ", updated: [");
    updatedoffsets = (OffsetNumber *) (block_data + ndeleted *
                                       sizeof(OffsetNumber));
    updates = (xl_btree_update *) ((char *) updatedoffsets +
                                   nupdated *
                                   sizeof(OffsetNumber));
    for (int i = 0; i < nupdated; i++)
    {
        OffsetNumber off = updatedoffsets[i];
 
        Assert(OffsetNumberIsValid(off));
        Assert(updates->ndeletedtids > 0);
 
        /*
         * "ptid" is the symbol name used when building each xl_btree_update's
         * array of offsets into a posting list tuple's ItemPointerData array.
         * xl_btree_update describes a subset of the existing TIDs to delete.
         */
        appendStringInfo(buf, "{ off: %u, nptids: %u, ptids: [",
                         off, updates->ndeletedtids);
        for (int p = 0; p < updates->ndeletedtids; p++)
        {
            uint16     *ptid;
 
            ptid = (uint16 *) ((char *) updates + SizeOfBtreeUpdate) + p;
            appendStringInfo(buf, "%u", *ptid);
 
            if (p < updates->ndeletedtids - 1)
                appendStringInfoString(buf, ", ");
        }
        appendStringInfoString(buf, "] }");
        if (i < nupdated - 1)
            appendStringInfoString(buf, ", ");
 
        updates = (xl_btree_update *)
            ((char *) updates + SizeOfBtreeUpdate +
             updates->ndeletedtids * sizeof(uint16));
    }
    appendStringInfoChar(buf, ']');
}