diff options
Diffstat (limited to 'src/include/storage/bufpage.h')
| -rw-r--r-- | src/include/storage/bufpage.h | 196 |
1 files changed, 100 insertions, 96 deletions
diff --git a/src/include/storage/bufpage.h b/src/include/storage/bufpage.h index 3607e4e25e2..a252ccc3e44 100644 --- a/src/include/storage/bufpage.h +++ b/src/include/storage/bufpage.h @@ -1,16 +1,16 @@ /*------------------------------------------------------------------------- * * bufpage.h-- - * Standard POSTGRES buffer page definitions. + * Standard POSTGRES buffer page definitions. * * * Copyright (c) 1994, Regents of the University of California * - * $Id: bufpage.h,v 1.10 1997/08/26 23:31:58 momjian Exp $ + * $Id: bufpage.h,v 1.11 1997/09/07 05:01:10 momjian Exp $ * *------------------------------------------------------------------------- */ -#ifndef BUFPAGE_H +#ifndef BUFPAGE_H #define BUFPAGE_H #include <storage/off.h> @@ -27,19 +27,19 @@ * disk page is always a slotted page of the form: * * +----------------+---------------------------------+ - * | PageHeaderData | linp0 linp1 linp2 ... | + * | PageHeaderData | linp0 linp1 linp2 ... | * +-----------+----+---------------------------------+ - * | ... linpN | | + * | ... linpN | | * +-----------+--------------------------------------+ - * | ^ pd_lower | - * | | - * | v pd_upper | + * | ^ pd_lower | + * | | + * | v pd_upper | * +-------------+------------------------------------+ - * | | tupleN ... | + * | | tupleN ... | * +-------------+------------------+-----------------+ - * | ... tuple2 tuple1 tuple0 | "special space" | + * | ... tuple2 tuple1 tuple0 | "special space" | * +--------------------------------+-----------------+ - * ^ pd_special + * ^ pd_special * * a page is full when nothing can be added between pd_lower and * pd_upper. @@ -66,19 +66,19 @@ * 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.) + * 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 + * stored as the page trailer. an access method should always * initialize its pages with PageInit and then set its own opaque * fields. */ /* * PageIsValid -- - * True iff page is valid. + * True iff page is valid. */ -#define PageIsValid(page) PointerIsValid(page) +#define PageIsValid(page) PointerIsValid(page) /* @@ -93,39 +93,42 @@ 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. + * 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; +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; +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 + * misc support macros * ---------------- */ @@ -134,10 +137,10 @@ typedef enum { * 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)) +#define MAXTUPLEN (BLCKSZ - sizeof (PageHeaderData)) /* ---------------------------------------------------------------- - * page support macros + * page support macros * ---------------------------------------------------------------- */ /* @@ -146,146 +149,147 @@ typedef enum { /* * PageIsUsed -- - * True iff the page size is used. + * True iff the page size is used. * * Note: - * Assumes page is valid. + * Assumes page is valid. */ #define PageIsUsed(page) \ - (AssertMacro(PageIsValid(page)) ? \ - ((bool) (((PageHeader) (page))->pd_lower != 0)) : false) + (AssertMacro(PageIsValid(page)) ? \ + ((bool) (((PageHeader) (page))->pd_lower != 0)) : false) /* * PageIsEmpty -- - * returns true iff no itemid has been allocated on the page + * returns true iff no itemid has been allocated on the page */ #define PageIsEmpty(page) \ - (((PageHeader) (page))->pd_lower == \ - (sizeof(PageHeaderData) - sizeof(ItemIdData)) ? true : false) + (((PageHeader) (page))->pd_lower == \ + (sizeof(PageHeaderData) - sizeof(ItemIdData)) ? true : false) /* - * PageIsNew -- - * returns true iff page is not initialized (by PageInit) + * PageIsNew -- + * returns true iff page is not initialized (by PageInit) */ -#define PageIsNew(page) (((PageHeader) (page))->pd_upper == 0) +#define PageIsNew(page) (((PageHeader) (page))->pd_upper == 0) /* * PageGetItemId -- - * Returns an item identifier of a page. + * Returns an item identifier of a page. */ #define PageGetItemId(page, offsetNumber) \ - ((ItemId) (&((PageHeader) (page))->pd_linp[(-1) + (offsetNumber)])) + ((ItemId) (&((PageHeader) (page))->pd_linp[(-1) + (offsetNumber)])) /* ---------------- - * macros to access opaque space + * macros to access opaque space * ---------------- */ /* * PageSizeIsValid -- - * True iff the page size is valid. + * True iff the page size is valid. * * XXX currently all page sizes are "valid" but we only actually - * use BLCKSZ. + * use BLCKSZ. */ #define PageSizeIsValid(pageSize) 1 /* * PageGetPageSize -- - * Returns the page size of a page. + * 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) + ((Size) ((PageHeader) (page))->pd_opaque.od_pagesize) /* * PageSetPageSize -- - * Sets the page size of a page. + * Sets the page size of a page. */ #define PageSetPageSize(page, size) \ - ((PageHeader) (page))->pd_opaque.od_pagesize = (size) + ((PageHeader) (page))->pd_opaque.od_pagesize = (size) /* ---------------- - * page special data macros + * page special data macros * ---------------- */ /* * PageGetSpecialSize -- - * Returns size of special space on a page. + * Returns size of special space on a page. * * Note: - * Assumes page is locked. + * Assumes page is locked. */ #define PageGetSpecialSize(page) \ - ((uint16) (PageGetPageSize(page) - ((PageHeader)(page))->pd_special)) + ((uint16) (PageGetPageSize(page) - ((PageHeader)(page))->pd_special)) /* * PageGetSpecialPointer -- - * Returns pointer to special space on a page. + * Returns pointer to special space on a page. * * Note: - * Assumes page is locked. + * Assumes page is locked. */ #define PageGetSpecialPointer(page) \ - (AssertMacro(PageIsValid(page)) ? \ - (char *) ((char *) (page) + ((PageHeader) (page))->pd_special) \ - : (char *)0 ) + (AssertMacro(PageIsValid(page)) ? \ + (char *) ((char *) (page) + ((PageHeader) (page))->pd_special) \ + : (char *)0 ) /* * PageGetItem -- - * Retrieves an item on the given page. + * Retrieves an item on the given page. * * Note: - * This does change the status of any of the resources passed. - * The semantics may change in the future. + * This does change the status of any of the resources passed. + * The semantics may change in the future. */ #define PageGetItem(page, itemId) \ - (AssertMacro(PageIsValid(page)) ? \ - AssertMacro((itemId)->lp_flags & LP_USED) ? \ - (Item)(((char *)(page)) + (itemId)->lp_off) : false : false) + (AssertMacro(PageIsValid(page)) ? \ + AssertMacro((itemId)->lp_flags & LP_USED) ? \ + (Item)(((char *)(page)) + (itemId)->lp_off) : false : false) /* * BufferGetPageSize -- - * Returns the page size within a buffer. + * Returns the page size within a buffer. * * Notes: - * Assumes buffer is valid. + * Assumes buffer is valid. * - * The buffer can be a raw disk block and need not contain a valid - * (formatted) disk page. + * The buffer can be a raw disk block and need not contain a valid + * (formatted) disk page. */ /* XXX dig out of buffer descriptor */ #define BufferGetPageSize(buffer) \ - (AssertMacro(BufferIsValid(buffer)) ? \ - AssertMacro(PageSizeIsValid(pageSize)) ? \ - ((Size)BLCKSZ) : false : false) + (AssertMacro(BufferIsValid(buffer)) ? \ + AssertMacro(PageSizeIsValid(pageSize)) ? \ + ((Size)BLCKSZ) : false : false) /* * BufferGetPage -- - * Returns the page associated with a buffer. + * Returns the page associated with a buffer. */ #define BufferGetPage(buffer) ((Page)BufferGetBlock(buffer)) - + /* ---------------------------------------------------------------- - * extern declarations + * extern declarations * ---------------------------------------------------------------- */ -extern void PageInit(Page page, Size pageSize, Size specialSize); -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 void PageInit(Page page, Size pageSize, Size specialSize); +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 PageRepairFragmentation(Page page); +extern Size PageGetFreeSpace(Page page); +extern void PageManagerModeSet(PageManagerMode mode); +extern void PageIndexTupleDelete(Page page, OffsetNumber offset); -#endif /* BUFPAGE_H */ +#endif /* BUFPAGE_H */ |