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/*-------------------------------------------------------------------------
*
* buf_internals.h
* Internal definitions.
*
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: buf_internals.h,v 1.33 1999/09/24 00:25:27 tgl Exp $
*
* NOTE
* If BUFFERPAGE0 is defined, then 0 will be used as a
* valid buffer page number.
*
*-------------------------------------------------------------------------
*/
#ifndef BUFMGR_INTERNALS_H
#define BUFMGR_INTERNALS_H
#include "storage/buf.h"
#include "storage/lmgr.h"
/* Buf Mgr constants */
/* in bufmgr.c */
extern int NBuffers;
extern int Data_Descriptors;
extern int Free_List_Descriptor;
extern int Lookup_List_Descriptor;
extern int Num_Descriptors;
/*
* Flags for buffer descriptors
*/
#define BM_DIRTY (1 << 0)
#define BM_PRIVATE (1 << 1)
#define BM_VALID (1 << 2)
#define BM_DELETED (1 << 3)
#define BM_FREE (1 << 4)
#define BM_IO_IN_PROGRESS (1 << 5)
#define BM_IO_ERROR (1 << 6)
#define BM_JUST_DIRTIED (1 << 7)
typedef bits16 BufFlags;
typedef struct sbufdesc BufferDesc;
typedef struct sbufdesc BufferHdr;
typedef struct buftag BufferTag;
/* long * so alignment will be correct */
typedef long **BufferBlock;
struct buftag
{
LockRelId relId;
BlockNumber blockNum; /* blknum relative to begin of reln */
};
#define CLEAR_BUFFERTAG(a) \
( \
(a)->relId.dbId = InvalidOid, \
(a)->relId.relId = InvalidOid, \
(a)->blockNum = InvalidBlockNumber \
)
#define INIT_BUFFERTAG(a,xx_reln,xx_blockNum) \
( \
(a)->blockNum = (xx_blockNum), \
(a)->relId = (xx_reln)->rd_lockInfo.lockRelId \
)
#define BAD_BUFFER_ID(bid) ((bid) < 1 || (bid) > NBuffers)
#define INVALID_DESCRIPTOR (-3)
/*
* struct sbufdesc -- shared buffer cache metadata for a single
* shared buffer descriptor.
*
* We keep the name of the database and relation in which this
* buffer appears in order to avoid a catalog lookup on cache
* flush if we don't have the reldesc in the cache. It is also
* possible that the relation to which this buffer belongs is
* not visible to all backends at the time that it gets flushed.
* Dbname, relname, dbid, and relid are enough to determine where
* to put the buffer, for all storage managers.
*/
struct sbufdesc
{
Buffer freeNext; /* link for freelist chain */
Buffer freePrev;
SHMEM_OFFSET data; /* pointer to data in buf pool */
/* tag and id must be together for table lookup to work */
BufferTag tag; /* file/block identifier */
int buf_id; /* maps global desc to local desc */
BufFlags flags; /* described below */
unsigned refcount; /* # of times buffer is pinned */
#ifdef HAS_TEST_AND_SET
/* can afford a dedicated lock if test-and-set locks are available */
slock_t io_in_progress_lock;
slock_t cntx_lock; /* to lock access to page context */
#endif /* HAS_TEST_AND_SET */
unsigned r_locks; /* # of shared locks */
bool ri_lock; /* read-intent lock */
bool w_lock; /* context exclusively locked */
char sb_dbname[NAMEDATALEN]; /* name of db in which buf belongs */
char sb_relname[NAMEDATALEN]; /* name of reln */
};
/*
* Buffer lock infos in BufferLocks below.
* We have to free these locks in elog(ERROR)...
*/
#define BL_IO_IN_PROGRESS (1 << 0) /* unimplemented */
#define BL_R_LOCK (1 << 1)
#define BL_RI_LOCK (1 << 2)
#define BL_W_LOCK (1 << 3)
/*
* mao tracing buffer allocation
*/
/*#define BMTRACE*/
#ifdef BMTRACE
typedef struct _bmtrace
{
int bmt_pid;
long bmt_buf;
long bmt_dbid;
long bmt_relid;
int bmt_blkno;
int bmt_op;
#define BMT_NOTUSED 0
#define BMT_ALLOCFND 1
#define BMT_ALLOCNOTFND 2
#define BMT_DEALLOC 3
} bmtrace;
#endif /* BMTRACE */
/*
* Bufmgr Interface:
*/
/* Internal routines: only called by buf.c */
/*freelist.c*/
extern void AddBufferToFreelist(BufferDesc *bf);
extern void PinBuffer(BufferDesc *buf);
extern void PinBuffer_Debug(char *file, int line, BufferDesc *buf);
extern void UnpinBuffer(BufferDesc *buf);
extern BufferDesc *GetFreeBuffer(void);
extern void InitFreeList(bool init);
/* buf_table.c */
extern void InitBufTable(void);
extern BufferDesc *BufTableLookup(BufferTag *tagPtr);
extern bool BufTableDelete(BufferDesc *buf);
extern bool BufTableInsert(BufferDesc *buf);
/* bufmgr.c */
extern BufferDesc *BufferDescriptors;
extern BufferBlock BufferBlocks;
extern long *PrivateRefCount;
extern bits8 *BufferLocks;
extern long *CommitInfoNeedsSave;
extern SPINLOCK BufMgrLock;
/* localbuf.c */
extern long *LocalRefCount;
extern BufferDesc *LocalBufferDescriptors;
extern int NLocBuffer;
extern BufferDesc *LocalBufferAlloc(Relation reln, BlockNumber blockNum,
bool *foundPtr);
extern int WriteLocalBuffer(Buffer buffer, bool release);
extern int FlushLocalBuffer(Buffer buffer, bool release);
extern void InitLocalBuffer(void);
extern void LocalBufferSync(void);
extern void ResetLocalBufferPool(void);
#endif /* BUFMGR_INTERNALS_H */