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diff --git a/src/backend/storage/bufpage.h b/src/backend/storage/bufpage.h
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-/*-------------------------------------------------------------------------
- *
- * bufpage.h--
- * Standard POSTGRES buffer page definitions.
- *
- *
- * Copyright (c) 1994, Regents of the University of California
- *
- * $Id: bufpage.h,v 1.1.1.1 1996/07/09 06:21:52 scrappy Exp $
- *
- *-------------------------------------------------------------------------
- */
-#ifndef BUFPAGE_H
-#define BUFPAGE_H
-
-#include "c.h"
-#include "machine.h" /* for BLCKSZ */
-
-#include "storage/buf.h"
-#include "storage/item.h"
-#include "storage/itemid.h"
-#include "storage/itemptr.h"
-
-/*
- * a postgres disk page is an abstraction layered on top of a postgres
- * disk block (which is simply a unit of i/o, see block.h).
- *
- * specifically, while a disk block can be unformatted, a postgres
- * disk page is always a slotted page of the form:
- *
- * +----------------+---------------------------------+
- * | PageHeaderData | linp0 linp1 linp2 ... |
- * +-----------+----+---------------------------------+
- * | ... linpN | |
- * +-----------+--------------------------------------+
- * | ^ pd_lower |
- * | |
- * | v pd_upper |
- * +-------------+------------------------------------+
- * | | tupleN ... |
- * +-------------+------------------+-----------------+
- * | ... tuple2 tuple1 tuple0 | "special space" |
- * +--------------------------------+-----------------+
- * ^ pd_special
- *
- * a page is full when nothing can be added between pd_lower and
- * pd_upper.
- *
- * all blocks written out by an access method must be disk pages.
- *
- * EXCEPTIONS:
- *
- * obviously, a page is not formatted before it is initialized with by
- * a call to PageInit.
- *
- * the contents of the special pg_variable/pg_time/pg_log tables are
- * raw disk blocks with special formats. these are the only "access
- * methods" that need not write disk pages.
- *
- * NOTES:
- *
- * linp0..N form an ItemId array. ItemPointers point into this array
- * rather than pointing directly to a tuple.
- *
- * tuple0..N are added "backwards" on the page. because a tuple's
- * ItemPointer points to its ItemId entry rather than its actual
- * byte-offset position, tuples can be physically shuffled on a page
- * whenever the need arises.
- *
- * AM-generic per-page information is kept in the pd_opaque field of
- * the PageHeaderData. (this is currently only the page size.)
- * AM-specific per-page data is kept in the area marked "special
- * space"; each AM has an "opaque" structure defined somewhere that is
- * stored as the page trailer. an access method should always
- * initialize its pages with PageInit and then set its own opaque
- * fields.
- */
-typedef Pointer Page;
-
-/*
- * PageIsValid --
- * True iff page is valid.
- */
-#define PageIsValid(page) PointerIsValid(page)
-
-
-/*
- * location (byte offset) within a page.
- *
- * note that this is actually limited to 2^13 because we have limited
- * ItemIdData.lp_off and ItemIdData.lp_len to 13 bits (see itemid.h).
- */
-typedef uint16 LocationIndex;
-
-
-/*
- * space management information generic to any page
- *
- * od_pagesize - size in bytes.
- * in reality, we need at least 64B to fit the
- * page header, opaque space and a minimal tuple;
- * on the high end, we can only support pages up
- * to 8KB because lp_off/lp_len are 13 bits.
- */
-typedef struct OpaqueData {
- uint16 od_pagesize;
-} OpaqueData;
-
-typedef OpaqueData *Opaque;
-
-
-/*
- * disk page organization
- */
-typedef struct PageHeaderData {
- LocationIndex pd_lower; /* offset to start of free space */
- LocationIndex pd_upper; /* offset to end of free space */
- LocationIndex pd_special; /* offset to start of special space */
- OpaqueData pd_opaque; /* AM-generic information */
- ItemIdData pd_linp[1]; /* line pointers */
-} PageHeaderData;
-
-typedef PageHeaderData *PageHeader;
-
-typedef enum {
- ShufflePageManagerMode,
- OverwritePageManagerMode
-} PageManagerMode;
-
-/* ----------------
- * misc support macros
- * ----------------
- */
-
-/*
- * XXX this is wrong -- ignores padding/alignment, variable page size,
- * AM-specific opaque space at the end of the page (as in btrees), ...
- * however, it at least serves as an upper bound for heap pages.
- */
-#define MAXTUPLEN (BLCKSZ - sizeof (PageHeaderData))
-
-/* ----------------------------------------------------------------
- * page support macros
- * ----------------------------------------------------------------
- */
-/*
- * PageIsValid -- This is defined in page.h.
- */
-
-/*
- * PageIsUsed --
- * True iff the page size is used.
- *
- * Note:
- * Assumes page is valid.
- */
-#define PageIsUsed(page) \
- (AssertMacro(PageIsValid(page)) ? \
- ((bool) (((PageHeader) (page))->pd_lower != 0)) : false)
-
-/*
- * PageIsEmpty --
- * returns true iff no itemid has been allocated on the page
- */
-#define PageIsEmpty(page) \
- (((PageHeader) (page))->pd_lower == \
- (sizeof(PageHeaderData) - sizeof(ItemIdData)) ? true : false)
-
-/*
- * PageGetItemId --
- * Returns an item identifier of a page.
- */
-#define PageGetItemId(page, offsetNumber) \
- ((ItemId) (&((PageHeader) (page))->pd_linp[(-1) + (offsetNumber)]))
-
-/* ----------------
- * macros to access opaque space
- * ----------------
- */
-
-/*
- * PageSizeIsValid --
- * True iff the page size is valid.
- *
- * XXX currently all page sizes are "valid" but we only actually
- * use BLCKSZ.
- */
-#define PageSizeIsValid(pageSize) 1
-
-/*
- * PageGetPageSize --
- * Returns the page size of a page.
- *
- * this can only be called on a formatted page (unlike
- * BufferGetPageSize, which can be called on an unformatted page).
- * however, it can be called on a page for which there is no buffer.
- */
-#define PageGetPageSize(page) \
- ((Size) ((PageHeader) (page))->pd_opaque.od_pagesize)
-
-/*
- * PageSetPageSize --
- * Sets the page size of a page.
- */
-#define PageSetPageSize(page, size) \
- ((PageHeader) (page))->pd_opaque.od_pagesize = (size)
-
-/* ----------------
- * page special data macros
- * ----------------
- */
-/*
- * PageGetSpecialSize --
- * Returns size of special space on a page.
- *
- * Note:
- * Assumes page is locked.
- */
-#define PageGetSpecialSize(page) \
- ((uint16) (PageGetPageSize(page) - ((PageHeader)page)->pd_special))
-
-/*
- * PageGetSpecialPointer --
- * Returns pointer to special space on a page.
- *
- * Note:
- * Assumes page is locked.
- */
-#define PageGetSpecialPointer(page) \
- (AssertMacro(PageIsValid(page)) ? \
- (char *) ((char *) (page) + ((PageHeader) (page))->pd_special) \
- : (char *) 0)
-
-/* ----------------------------------------------------------------
- * extern declarations
- * ----------------------------------------------------------------
- */
-
-extern Size BufferGetPageSize(Buffer buffer);
-extern Page BufferGetPage(Buffer buffer);
-extern void PageInit(Page page, Size pageSize, Size specialSize);
-extern Item PageGetItem(Page page, ItemId itemId);
-extern OffsetNumber PageAddItem(Page page, Item item, Size size,
- OffsetNumber offsetNumber, ItemIdFlags flags);
-extern Page PageGetTempPage(Page page, Size specialSize);
-extern void PageRestoreTempPage(Page tempPage, Page oldPage);
-extern OffsetNumber PageGetMaxOffsetNumber(Page page);
-extern void PageRepairFragmentation(Page page);
-extern Size PageGetFreeSpace(Page page);
-extern void PageManagerModeSet(PageManagerMode mode);
-extern void PageIndexTupleDelete(Page page, OffsetNumber offset);
-extern void PageIndexTupleDeleteAdjustLinePointers(PageHeader phdr,
- char *location, Size size);
-
-
-#endif /* BUFPAGE_H */
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