diff options
Diffstat (limited to 'src/include/storage/buf_internals.h')
| -rw-r--r-- | src/include/storage/buf_internals.h | 69 |
1 files changed, 30 insertions, 39 deletions
diff --git a/src/include/storage/buf_internals.h b/src/include/storage/buf_internals.h index f401791d93a..fc83396ff0d 100644 --- a/src/include/storage/buf_internals.h +++ b/src/include/storage/buf_internals.h @@ -8,7 +8,7 @@ * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/storage/buf_internals.h,v 1.68 2004/02/12 15:06:56 wieck Exp $ + * $PostgreSQL: pgsql/src/include/storage/buf_internals.h,v 1.69 2004/04/19 23:27:17 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -21,15 +21,6 @@ #include "storage/lwlock.h" -/* Buf Mgr constants */ -/* in bufmgr.c */ -extern int Data_Descriptors; -extern int Free_List_Descriptor; -extern int Lookup_List_Descriptor; -extern int Num_Descriptors; - -extern int ShowPinTrace; - /* * Flags for buffer descriptors */ @@ -51,10 +42,13 @@ typedef bits16 BufFlags; * that the backend flushing the buffer doesn't even believe the relation is * visible yet (its xact may have started before the xact that created the * rel). The storage manager must be able to cope anyway. + * + * Note: if there's any pad bytes in the struct, INIT_BUFFERTAG will have + * to be fixed to zero them, since this struct is used as a hash key. */ typedef struct buftag { - RelFileNode rnode; + RelFileNode rnode; /* physical relation identifier */ BlockNumber blockNum; /* blknum relative to begin of reln */ } BufferTag; @@ -71,12 +65,6 @@ typedef struct buftag (a)->rnode = (xx_reln)->rd_node \ ) -#define BUFFERTAG_EQUALS(a,xx_reln,xx_blockNum) \ -( \ - (a)->rnode.tblNode == (xx_reln)->rd_node.tblNode && \ - (a)->rnode.relNode == (xx_reln)->rd_node.relNode && \ - (a)->blockNum == (xx_blockNum) \ -) #define BUFFERTAGS_EQUAL(a,b) \ ( \ (a)->rnode.tblNode == (b)->rnode.tblNode && \ @@ -93,7 +81,7 @@ typedef struct sbufdesc Buffer bufNext; /* link in freelist chain */ SHMEM_OFFSET data; /* pointer to data in buf pool */ - /* tag and id must be together for table lookup */ + /* tag and id must be together for table lookup (still true?) */ BufferTag tag; /* file/block identifier */ int buf_id; /* buffer's index number (from 0) */ @@ -108,7 +96,7 @@ typedef struct sbufdesc /* * We can't physically remove items from a disk page if another * backend has the buffer pinned. Hence, a backend may need to wait - * for all other pins to go away. This is signaled by setting its own + * for all other pins to go away. This is signaled by storing its own * backend ID into wait_backend_id and setting flag bit * BM_PIN_COUNT_WAITER. At present, there can be only one such waiter * per buffer. @@ -128,17 +116,17 @@ typedef struct sbufdesc #define BL_IO_IN_PROGRESS (1 << 0) /* unimplemented */ #define BL_PIN_COUNT_LOCK (1 << 1) -/* entry for buffer hashtable */ +/* entry for buffer lookup hashtable */ typedef struct { - BufferTag key; - Buffer id; + BufferTag key; /* Tag of a disk page */ + int id; /* CDB id of associated CDB */ } BufferLookupEnt; /* * Definitions for the buffer replacement strategy */ -#define STRAT_LIST_UNUSED -1 +#define STRAT_LIST_UNUSED (-1) #define STRAT_LIST_B1 0 #define STRAT_LIST_T1 1 #define STRAT_LIST_T2 2 @@ -150,12 +138,13 @@ typedef struct */ typedef struct { - int prev; /* links in the queue */ + int prev; /* list links */ int next; - int list; /* current list */ - BufferTag buf_tag; /* buffer key */ - Buffer buf_id; /* currently assigned data buffer */ + short list; /* ID of list it is currently in */ + bool t1_vacuum; /* t => present only because of VACUUM */ TransactionId t1_xid; /* the xid this entry went onto T1 */ + BufferTag buf_tag; /* page identifier */ + int buf_id; /* currently assigned data buffer, or -1 */ } BufferStrategyCDB; /* @@ -163,7 +152,6 @@ typedef struct */ typedef struct { - int target_T1_size; /* What T1 size are we aiming for */ int listUnusedCDB; /* All unused StrategyCDB */ int listHead[STRAT_NUM_LISTS]; /* ARC lists B1, T1, T2 and B2 */ @@ -175,8 +163,10 @@ typedef struct long num_hit[STRAT_NUM_LISTS]; time_t stat_report; - BufferStrategyCDB cdb[1]; /* The cache directory */ + /* Array of CDB's starts here */ + BufferStrategyCDB cdb[1]; /* VARIABLE SIZE ARRAY */ } BufferStrategyControl; + /* counters in buf_init.c */ extern long int ReadBufferCount; @@ -191,24 +181,25 @@ extern long int LocalBufferFlushCount; * Bufmgr Interface: */ -/* Internal routines: only called by buf.c */ +/* Internal routines: only called by bufmgr */ -/*freelist.c*/ -extern void PinBuffer(BufferDesc *buf); -extern void UnpinBuffer(BufferDesc *buf); -extern BufferDesc *StrategyBufferLookup(BufferTag *tagPtr, bool recheck); -extern BufferDesc *StrategyGetBuffer(void); -extern void StrategyReplaceBuffer(BufferDesc *buf, Relation rnode, BlockNumber blockNum); +/* freelist.c */ +extern BufferDesc *StrategyBufferLookup(BufferTag *tagPtr, bool recheck, + int *cdb_found_index); +extern BufferDesc *StrategyGetBuffer(int *cdb_replace_index); +extern void StrategyReplaceBuffer(BufferDesc *buf, BufferTag *newTag, + int cdb_found_index, int cdb_replace_index); extern void StrategyInvalidateBuffer(BufferDesc *buf); extern void StrategyHintVacuum(bool vacuum_active); -extern int StrategyDirtyBufferList(int *buffer_dirty, int max_buffers); +extern int StrategyDirtyBufferList(BufferDesc **buffers, BufferTag *buftags, + int max_buffers); extern void StrategyInitialize(bool init); /* buf_table.c */ extern void InitBufTable(int size); extern int BufTableLookup(BufferTag *tagPtr); -extern bool BufTableInsert(BufferTag *tagPtr, Buffer buf_id); -extern bool BufTableDelete(BufferTag *tagPtr); +extern void BufTableInsert(BufferTag *tagPtr, int cdb_id); +extern void BufTableDelete(BufferTag *tagPtr); /* bufmgr.c */ extern BufferDesc *BufferDescriptors; |