hashfuncs.c File Reference

#include "postgres.h"
#include "access/hash.h"
#include "access/htup_details.h"
#include "access/relation.h"
#include "catalog/pg_am.h"
#include "catalog/pg_type.h"
#include "funcapi.h"
#include "miscadmin.h"
#include "pageinspect.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/rel.h"

Include dependency graph for hashfuncs.c:

Go to the source code of this file.

Data Structures
struct	HashPageStat
struct	user_args

Macros
#define	IS_INDEX(r)   ((r)->rd_rel->relkind == RELKIND_INDEX)
#define	IS_HASH(r)   ((r)->rd_rel->relam == HASH_AM_OID)

Typedefs
typedef struct HashPageStat	HashPageStat

Functions
	PG_FUNCTION_INFO_V1 (hash_page_type)
	PG_FUNCTION_INFO_V1 (hash_page_stats)
	PG_FUNCTION_INFO_V1 (hash_page_items)
	PG_FUNCTION_INFO_V1 (hash_bitmap_info)
	PG_FUNCTION_INFO_V1 (hash_metapage_info)
static Page	verify_hash_page (bytea *raw_page, int flags)
static void	GetHashPageStatistics (Page page, HashPageStat *stat)
Datum	hash_page_type (PG_FUNCTION_ARGS)
Datum	hash_page_stats (PG_FUNCTION_ARGS)
Datum	hash_page_items (PG_FUNCTION_ARGS)
Datum	hash_bitmap_info (PG_FUNCTION_ARGS)
Datum	hash_metapage_info (PG_FUNCTION_ARGS)

Macro Definition Documentation

IS_HASH

#define IS_HASH

(

r

)

((r)->rd_rel->relam == HASH_AM_OID)

Definition at line 32 of file hashfuncs.c.

IS_INDEX

#define IS_INDEX

(

r

)

((r)->rd_rel->relkind == RELKIND_INDEX)

Definition at line 31 of file hashfuncs.c.

Typedef Documentation

HashPageStat

typedef struct HashPageStat HashPageStat

Function Documentation

GetHashPageStatistics()

static void GetHashPageStatistics ( Page  page, HashPageStat *  stat  )

static

Definition at line 156 of file hashfuncs.c.

{
    OffsetNumber maxoff = PageGetMaxOffsetNumber(page);
    HashPageOpaque opaque = HashPageGetOpaque(page);
    int         off;
 
    stat->dead_items = stat->live_items = 0;
    stat->page_size = PageGetPageSize(page);
 
    /* hash page opaque data */
    stat->hasho_prevblkno = opaque->hasho_prevblkno;
    stat->hasho_nextblkno = opaque->hasho_nextblkno;
    stat->hasho_bucket = opaque->hasho_bucket;
    stat->hasho_flag = opaque->hasho_flag;
    stat->hasho_page_id = opaque->hasho_page_id;
 
    /* count live and dead tuples, and free space */
    for (off = FirstOffsetNumber; off <= maxoff; off++)
    {
        ItemId      id = PageGetItemId(page, off);
 
        if (!ItemIdIsDead(id))
            stat->live_items++;
        else
            stat->dead_items++;
    }
    stat->free_size = PageGetFreeSpace(page);
}

References FirstOffsetNumber, HashPageOpaqueData::hasho_bucket, HashPageOpaqueData::hasho_flag, HashPageOpaqueData::hasho_nextblkno, HashPageOpaqueData::hasho_page_id, HashPageOpaqueData::hasho_prevblkno, HashPageGetOpaque, ItemIdIsDead, PageGetFreeSpace(), PageGetItemId(), PageGetMaxOffsetNumber(), and PageGetPageSize().

Referenced by hash_page_stats().

hash_bitmap_info()

Datum hash_bitmap_info

(

PG_FUNCTION_ARGS

)

Definition at line 391 of file hashfuncs.c.

{
    Oid         indexRelid = PG_GETARG_OID(0);
    int64       ovflblkno = PG_GETARG_INT64(1);
    HashMetaPage metap;
    Buffer      metabuf,
                mapbuf;
    BlockNumber bitmapblkno;
    Page        mappage;
    bool        bit = false;
    TupleDesc   tupleDesc;
    Relation    indexRel;
    uint32      ovflbitno;
    int32       bitmappage,
                bitmapbit;
    HeapTuple   tuple;
    int         i,
                j;
    Datum       values[3];
    bool        nulls[3] = {0};
    uint32     *freep;
 
    if (!superuser())
        ereport(ERROR,
                (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                 errmsg("must be superuser to use raw page functions")));
 
    indexRel = relation_open(indexRelid, AccessShareLock);
 
    if (!IS_INDEX(indexRel) || !IS_HASH(indexRel))
        ereport(ERROR,
                (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                 errmsg("\"%s\" is not a %s index",
                        RelationGetRelationName(indexRel), "hash")));
 
    if (RELATION_IS_OTHER_TEMP(indexRel))
        ereport(ERROR,
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("cannot access temporary tables of other sessions")));
 
    if (ovflblkno < 0 || ovflblkno > MaxBlockNumber)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("invalid block number")));
 
    if (ovflblkno >= RelationGetNumberOfBlocks(indexRel))
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("block number %lld is out of range for relation \"%s\"",
                        (long long int) ovflblkno, RelationGetRelationName(indexRel))));
 
    /* Read the metapage so we can determine which bitmap page to use */
    metabuf = _hash_getbuf(indexRel, HASH_METAPAGE, HASH_READ, LH_META_PAGE);
    metap = HashPageGetMeta(BufferGetPage(metabuf));
 
    /*
     * Reject attempt to read the bit for a metapage or bitmap page; this is
     * only meaningful for overflow pages.
     */
    if (ovflblkno == 0)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("invalid overflow block number %u",
                        (BlockNumber) ovflblkno)));
    for (i = 0; i < metap->hashm_nmaps; i++)
        if (metap->hashm_mapp[i] == ovflblkno)
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                     errmsg("invalid overflow block number %u",
                            (BlockNumber) ovflblkno)));
 
    /*
     * Identify overflow bit number.  This will error out for primary bucket
     * pages, and we've already rejected the metapage and bitmap pages above.
     */
    ovflbitno = _hash_ovflblkno_to_bitno(metap, (BlockNumber) ovflblkno);
 
    bitmappage = ovflbitno >> BMPG_SHIFT(metap);
    bitmapbit = ovflbitno & BMPG_MASK(metap);
 
    if (bitmappage >= metap->hashm_nmaps)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("invalid overflow block number %u",
                        (BlockNumber) ovflblkno)));
 
    bitmapblkno = metap->hashm_mapp[bitmappage];
 
    _hash_relbuf(indexRel, metabuf);
 
    /* Check the status of bitmap bit for overflow page */
    mapbuf = _hash_getbuf(indexRel, bitmapblkno, HASH_READ, LH_BITMAP_PAGE);
    mappage = BufferGetPage(mapbuf);
    freep = HashPageGetBitmap(mappage);
 
    bit = ISSET(freep, bitmapbit) != 0;
 
    _hash_relbuf(indexRel, mapbuf);
    index_close(indexRel, AccessShareLock);
 
    /* 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");
    tupleDesc = BlessTupleDesc(tupleDesc);
 
    j = 0;
    values[j++] = Int64GetDatum((int64) bitmapblkno);
    values[j++] = Int32GetDatum(bitmapbit);
    values[j++] = BoolGetDatum(bit);
 
    tuple = heap_form_tuple(tupleDesc, values, nulls);
 
    PG_RETURN_DATUM(HeapTupleGetDatum(tuple));
}

References _hash_getbuf(), _hash_ovflblkno_to_bitno(), _hash_relbuf(), AccessShareLock, bit(), BlessTupleDesc(), BMPG_MASK, BMPG_SHIFT, BoolGetDatum(), BufferGetPage(), elog, ereport, errcode(), errmsg(), ERROR, get_call_result_type(), HASH_METAPAGE, HASH_READ, HashMetaPageData::hashm_mapp, HashMetaPageData::hashm_nmaps, HashPageGetBitmap, HashPageGetMeta, heap_form_tuple(), HeapTupleGetDatum(), i, index_close(), Int32GetDatum(), Int64GetDatum(), IS_HASH, IS_INDEX, ISSET, j, LH_BITMAP_PAGE, LH_META_PAGE, MaxBlockNumber, PG_GETARG_INT64, PG_GETARG_OID, PG_RETURN_DATUM, RELATION_IS_OTHER_TEMP, relation_open(), RelationGetNumberOfBlocks, RelationGetRelationName, superuser(), TYPEFUNC_COMPOSITE, and values.

hash_metapage_info()

Datum hash_metapage_info

(

PG_FUNCTION_ARGS

)

Definition at line 515 of file hashfuncs.c.

{
    bytea      *raw_page = PG_GETARG_BYTEA_P(0);
    Page        page;
    HashMetaPageData *metad;
    TupleDesc   tupleDesc;
    HeapTuple   tuple;
    int         i,
                j;
    Datum       values[16];
    bool        nulls[16] = {0};
    Datum       spares[HASH_MAX_SPLITPOINTS];
    Datum       mapp[HASH_MAX_BITMAPS];
 
    if (!superuser())
        ereport(ERROR,
                (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                 errmsg("must be superuser to use raw page functions")));
 
    page = verify_hash_page(raw_page, LH_META_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");
    tupleDesc = BlessTupleDesc(tupleDesc);
 
    metad = HashPageGetMeta(page);
 
    j = 0;
    values[j++] = Int64GetDatum((int64) metad->hashm_magic);
    values[j++] = Int64GetDatum((int64) metad->hashm_version);
    values[j++] = Float8GetDatum(metad->hashm_ntuples);
    values[j++] = Int32GetDatum((int32) metad->hashm_ffactor);
    values[j++] = Int32GetDatum((int32) metad->hashm_bsize);
    values[j++] = Int32GetDatum((int32) metad->hashm_bmsize);
    values[j++] = Int32GetDatum((int32) metad->hashm_bmshift);
    values[j++] = Int64GetDatum((int64) metad->hashm_maxbucket);
    values[j++] = Int64GetDatum((int64) metad->hashm_highmask);
    values[j++] = Int64GetDatum((int64) metad->hashm_lowmask);
    values[j++] = Int64GetDatum((int64) metad->hashm_ovflpoint);
    values[j++] = Int64GetDatum((int64) metad->hashm_firstfree);
    values[j++] = Int64GetDatum((int64) metad->hashm_nmaps);
    values[j++] = ObjectIdGetDatum((Oid) metad->hashm_procid);
 
    for (i = 0; i < HASH_MAX_SPLITPOINTS; i++)
        spares[i] = Int64GetDatum((int64) metad->hashm_spares[i]);
    values[j++] = PointerGetDatum(construct_array_builtin(spares, HASH_MAX_SPLITPOINTS, INT8OID));
 
    for (i = 0; i < HASH_MAX_BITMAPS; i++)
        mapp[i] = Int64GetDatum((int64) metad->hashm_mapp[i]);
    values[j++] = PointerGetDatum(construct_array_builtin(mapp, HASH_MAX_BITMAPS, INT8OID));
 
    tuple = heap_form_tuple(tupleDesc, values, nulls);
 
    PG_RETURN_DATUM(HeapTupleGetDatum(tuple));
}

References BlessTupleDesc(), construct_array_builtin(), elog, ereport, errcode(), errmsg(), ERROR, Float8GetDatum(), get_call_result_type(), HASH_MAX_BITMAPS, HASH_MAX_SPLITPOINTS, HashMetaPageData::hashm_bmshift, HashMetaPageData::hashm_bmsize, HashMetaPageData::hashm_bsize, HashMetaPageData::hashm_ffactor, HashMetaPageData::hashm_firstfree, HashMetaPageData::hashm_highmask, HashMetaPageData::hashm_lowmask, HashMetaPageData::hashm_magic, HashMetaPageData::hashm_mapp, HashMetaPageData::hashm_maxbucket, HashMetaPageData::hashm_nmaps, HashMetaPageData::hashm_ntuples, HashMetaPageData::hashm_ovflpoint, HashMetaPageData::hashm_procid, HashMetaPageData::hashm_spares, HashMetaPageData::hashm_version, HashPageGetMeta, heap_form_tuple(), HeapTupleGetDatum(), i, Int32GetDatum(), Int64GetDatum(), j, LH_META_PAGE, ObjectIdGetDatum(), user_args::page, PG_GETARG_BYTEA_P, PG_RETURN_DATUM, PointerGetDatum(), superuser(), TYPEFUNC_COMPOSITE, values, and verify_hash_page().

hash_page_items()

Datum hash_page_items

(

PG_FUNCTION_ARGS

)

Definition at line 300 of file hashfuncs.c.

{
    bytea      *raw_page = PG_GETARG_BYTEA_P(0);
    Page        page;
    Datum       result;
    Datum       values[3];
    bool        nulls[3] = {0};
    uint32      hashkey;
    HeapTuple   tuple;
    FuncCallContext *fctx;
    MemoryContext mctx;
    struct user_args *uargs;
 
    if (!superuser())
        ereport(ERROR,
                (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                 errmsg("must be superuser to use raw page functions")));
 
    if (SRF_IS_FIRSTCALL())
    {
        TupleDesc   tupleDesc;
 
        fctx = SRF_FIRSTCALL_INIT();
 
        mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);
 
        page = verify_hash_page(raw_page, LH_BUCKET_PAGE | LH_OVERFLOW_PAGE);
 
        uargs = palloc(sizeof(struct user_args));
 
        uargs->page = page;
 
        uargs->offset = FirstOffsetNumber;
 
        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");
        tupleDesc = BlessTupleDesc(tupleDesc);
 
        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)
    {
        ItemId      id;
        IndexTuple  itup;
        int         j;
 
        id = PageGetItemId(uargs->page, uargs->offset);
 
        if (!ItemIdIsValid(id))
            elog(ERROR, "invalid ItemId");
 
        itup = (IndexTuple) PageGetItem(uargs->page, id);
 
        j = 0;
        values[j++] = Int32GetDatum((int32) uargs->offset);
        values[j++] = PointerGetDatum(&itup->t_tid);
 
        hashkey = _hash_get_indextuple_hashkey(itup);
        values[j] = Int64GetDatum((int64) hashkey);
 
        tuple = heap_form_tuple(fctx->attinmeta->tupdesc, values, nulls);
        result = HeapTupleGetDatum(tuple);
 
        uargs->offset = uargs->offset + 1;
 
        SRF_RETURN_NEXT(fctx, result);
    }
 
    SRF_RETURN_DONE(fctx);
}

References _hash_get_indextuple_hashkey(), FuncCallContext::attinmeta, BlessTupleDesc(), FuncCallContext::call_cntr, elog, ereport, errcode(), errmsg(), ERROR, FirstOffsetNumber, get_call_result_type(), heap_form_tuple(), HeapTupleGetDatum(), Int32GetDatum(), Int64GetDatum(), ItemIdIsValid, j, LH_BUCKET_PAGE, LH_OVERFLOW_PAGE, FuncCallContext::max_calls, MemoryContextSwitchTo(), FuncCallContext::multi_call_memory_ctx, user_args::offset, user_args::page, PageGetItem(), PageGetItemId(), PageGetMaxOffsetNumber(), palloc(), PG_GETARG_BYTEA_P, PointerGetDatum(), SRF_FIRSTCALL_INIT, SRF_IS_FIRSTCALL, SRF_PERCALL_SETUP, SRF_RETURN_DONE, SRF_RETURN_NEXT, superuser(), IndexTupleData::t_tid, AttInMetadata::tupdesc, TupleDescGetAttInMetadata(), TYPEFUNC_COMPOSITE, FuncCallContext::user_fctx, values, and verify_hash_page().

hash_page_stats()

Datum hash_page_stats

(

PG_FUNCTION_ARGS

)

Definition at line 237 of file hashfuncs.c.

{
    bytea      *raw_page = PG_GETARG_BYTEA_P(0);
    Page        page;
    int         j;
    Datum       values[9];
    bool        nulls[9] = {0};
    HashPageStat stat;
    HeapTuple   tuple;
    TupleDesc   tupleDesc;
 
    if (!superuser())
        ereport(ERROR,
                (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                 errmsg("must be superuser to use raw page functions")));
 
    page = verify_hash_page(raw_page, LH_BUCKET_PAGE | LH_OVERFLOW_PAGE);
 
    /* keep compiler quiet */
    stat.hasho_prevblkno = stat.hasho_nextblkno = InvalidBlockNumber;
    stat.hasho_flag = stat.hasho_page_id = stat.free_size = 0;
 
    GetHashPageStatistics(page, &stat);
 
    /* 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");
    tupleDesc = BlessTupleDesc(tupleDesc);
 
    j = 0;
    values[j++] = Int32GetDatum(stat.live_items);
    values[j++] = Int32GetDatum(stat.dead_items);
    values[j++] = Int32GetDatum(stat.page_size);
    values[j++] = Int32GetDatum(stat.free_size);
    values[j++] = Int64GetDatum((int64) stat.hasho_prevblkno);
    values[j++] = Int64GetDatum((int64) stat.hasho_nextblkno);
    values[j++] = Int64GetDatum((int64) stat.hasho_bucket);
    values[j++] = Int32GetDatum((int32) stat.hasho_flag);
    values[j++] = Int32GetDatum((int32) stat.hasho_page_id);
 
    tuple = heap_form_tuple(tupleDesc, values, nulls);
 
    PG_RETURN_DATUM(HeapTupleGetDatum(tuple));
}

References BlessTupleDesc(), elog, ereport, errcode(), errmsg(), ERROR, get_call_result_type(), GetHashPageStatistics(), heap_form_tuple(), HeapTupleGetDatum(), Int32GetDatum(), Int64GetDatum(), InvalidBlockNumber, j, LH_BUCKET_PAGE, LH_OVERFLOW_PAGE, PG_GETARG_BYTEA_P, PG_RETURN_DATUM, stat, superuser(), TYPEFUNC_COMPOSITE, values, and verify_hash_page().

hash_page_type()

Datum hash_page_type

(

PG_FUNCTION_ARGS

)

Definition at line 192 of file hashfuncs.c.

{
    bytea      *raw_page = PG_GETARG_BYTEA_P(0);
    Page        page;
    HashPageOpaque opaque;
    int         pagetype;
    const char *type;
 
    if (!superuser())
        ereport(ERROR,
                (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                 errmsg("must be superuser to use raw page functions")));
 
    page = verify_hash_page(raw_page, 0);
 
    if (PageIsNew(page))
        type = "unused";
    else
    {
        opaque = HashPageGetOpaque(page);
 
        /* page type (flags) */
        pagetype = opaque->hasho_flag & LH_PAGE_TYPE;
        if (pagetype == LH_META_PAGE)
            type = "metapage";
        else if (pagetype == LH_OVERFLOW_PAGE)
            type = "overflow";
        else if (pagetype == LH_BUCKET_PAGE)
            type = "bucket";
        else if (pagetype == LH_BITMAP_PAGE)
            type = "bitmap";
        else
            type = "unused";
    }
 
    PG_RETURN_TEXT_P(cstring_to_text(type));
}

References cstring_to_text(), ereport, errcode(), errmsg(), ERROR, HashPageOpaqueData::hasho_flag, HashPageGetOpaque, LH_BITMAP_PAGE, LH_BUCKET_PAGE, LH_META_PAGE, LH_OVERFLOW_PAGE, LH_PAGE_TYPE, PageIsNew(), PG_GETARG_BYTEA_P, PG_RETURN_TEXT_P, superuser(), type, and verify_hash_page().

PG_FUNCTION_INFO_V1() [1/5]

PG_FUNCTION_INFO_V1

(

hash_bitmap_info

)

PG_FUNCTION_INFO_V1() [2/5]

PG_FUNCTION_INFO_V1

(

hash_metapage_info

)

PG_FUNCTION_INFO_V1() [3/5]

PG_FUNCTION_INFO_V1

(

hash_page_items

)

PG_FUNCTION_INFO_V1() [4/5]

PG_FUNCTION_INFO_V1

(

hash_page_stats

)

PG_FUNCTION_INFO_V1() [5/5]

PG_FUNCTION_INFO_V1

(

hash_page_type

)

verify_hash_page()

static Page verify_hash_page ( bytea *  raw_page, int  flags  )

static

Definition at line 59 of file hashfuncs.c.

{
    Page        page = get_page_from_raw(raw_page);
    int         pagetype = LH_UNUSED_PAGE;
 
    /* Treat new pages as unused. */
    if (!PageIsNew(page))
    {
        HashPageOpaque pageopaque;
 
        if (PageGetSpecialSize(page) != MAXALIGN(sizeof(HashPageOpaqueData)))
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                     errmsg("input page is not a valid %s page", "hash"),
                     errdetail("Expected special size %d, got %d.",
                               (int) MAXALIGN(sizeof(HashPageOpaqueData)),
                               (int) PageGetSpecialSize(page))));
 
        pageopaque = HashPageGetOpaque(page);
        if (pageopaque->hasho_page_id != HASHO_PAGE_ID)
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                     errmsg("input page is not a valid %s page", "hash"),
                     errdetail("Expected %08x, got %08x.",
                               HASHO_PAGE_ID, pageopaque->hasho_page_id)));
 
        pagetype = pageopaque->hasho_flag & LH_PAGE_TYPE;
    }
 
    /* Check that page type is sane. */
    if (pagetype != LH_OVERFLOW_PAGE && pagetype != LH_BUCKET_PAGE &&
        pagetype != LH_BITMAP_PAGE && pagetype != LH_META_PAGE &&
        pagetype != LH_UNUSED_PAGE)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("invalid hash page type %08x", pagetype)));
 
    /* If requested, verify page type. */
    if (flags != 0 && (pagetype & flags) == 0)
    {
        switch (flags)
        {
            case LH_META_PAGE:
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                         errmsg("page is not a hash meta page")));
                break;
            case LH_BUCKET_PAGE | LH_OVERFLOW_PAGE:
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                         errmsg("page is not a hash bucket or overflow page")));
                break;
            case LH_OVERFLOW_PAGE:
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                         errmsg("page is not a hash overflow page")));
                break;
            default:
                elog(ERROR,
                     "hash page of type %08x not in mask %08x",
                     pagetype, flags);
                break;
        }
    }
 
    /*
     * If it is the metapage, also verify magic number and version.
     */
    if (pagetype == LH_META_PAGE)
    {
        HashMetaPage metap = HashPageGetMeta(page);
 
        if (metap->hashm_magic != HASH_MAGIC)
            ereport(ERROR,
                    (errcode(ERRCODE_INDEX_CORRUPTED),
                     errmsg("invalid magic number for metadata"),
                     errdetail("Expected 0x%08x, got 0x%08x.",
                               HASH_MAGIC, metap->hashm_magic)));
 
        if (metap->hashm_version != HASH_VERSION)
            ereport(ERROR,
                    (errcode(ERRCODE_INDEX_CORRUPTED),
                     errmsg("invalid version for metadata"),
                     errdetail("Expected %d, got %d.",
                               HASH_VERSION, metap->hashm_version)));
    }
 
    return page;
}

References elog, ereport, errcode(), errdetail(), errmsg(), ERROR, get_page_from_raw(), HASH_MAGIC, HASH_VERSION, HashMetaPageData::hashm_magic, HashMetaPageData::hashm_version, HashPageOpaqueData::hasho_flag, HashPageOpaqueData::hasho_page_id, HASHO_PAGE_ID, HashPageGetMeta, HashPageGetOpaque, LH_BITMAP_PAGE, LH_BUCKET_PAGE, LH_META_PAGE, LH_OVERFLOW_PAGE, LH_PAGE_TYPE, LH_UNUSED_PAGE, MAXALIGN, PageGetSpecialSize(), and PageIsNew().

Referenced by hash_metapage_info(), hash_page_items(), hash_page_stats(), and hash_page_type().