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mirror of https://github.com/sqlite/sqlite.git synced 2025-11-06 15:49:35 +03:00

Rework the column-cache mechanism to be more robust (and more correct).

The column-alias cache is currently disabled, (CVS 6538)

FossilOrigin-Name: dd4d67a67454a3ff13c286a2a8360c5f0432c91d
This commit is contained in:
drh
2009-04-23 13:22:42 +00:00
parent 044925be0b
commit ceea33217b
10 changed files with 242 additions and 130 deletions

View File

@@ -11,7 +11,7 @@
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.859 2009/04/22 15:32:59 drh Exp $
** @(#) $Id: sqliteInt.h,v 1.860 2009/04/23 13:22:44 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_
@@ -1893,6 +1893,13 @@ struct SelectDest {
int nMem; /* Number of registers allocated */
};
/*
** Size of the column cache
*/
#ifndef SQLITE_N_COLCACHE
# define SQLITE_N_COLCACHE 10
#endif
/*
** An SQL parser context. A copy of this structure is passed through
** the parser and down into all the parser action routine in order to
@@ -1929,15 +1936,19 @@ struct Parse {
int nMem; /* Number of memory cells used so far */
int nSet; /* Number of sets used so far */
int ckBase; /* Base register of data during check constraints */
int disableColCache; /* True to disable adding to column cache */
int nColCache; /* Number of entries in the column cache */
int iColCache; /* Next entry of the cache to replace */
int iCacheLevel; /* ColCache valid when aColCache[].iLevel<=iCacheLevel */
int iCacheCnt; /* Counter used to generate aColCache[].lru values */
u8 nColCache; /* Number of entries in the column cache */
u8 iColCache; /* Next entry of the cache to replace */
struct yColCache {
int iTable; /* Table cursor number */
int iColumn; /* Table column number */
char affChange; /* True if this register has had an affinity change */
int iReg; /* Register holding value of this column */
} aColCache[10]; /* One for each valid column cache entry */
u8 affChange; /* True if this register has had an affinity change */
u8 tempReg; /* iReg is a temp register that needs to be freed */
int iLevel; /* Nesting level */
int iReg; /* Reg with value of this column. 0 means none. */
int lru; /* Least recently used entry has the smallest value */
} aColCache[SQLITE_N_COLCACHE]; /* One for each column cache entry */
u32 writeMask; /* Start a write transaction on these databases */
u32 cookieMask; /* Bitmask of schema verified databases */
int cookieGoto; /* Address of OP_Goto to cookie verifier subroutine */
@@ -2446,9 +2457,12 @@ void sqlite3WhereEnd(WhereInfo*);
int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, int);
void sqlite3ExprCodeMove(Parse*, int, int, int);
void sqlite3ExprCodeCopy(Parse*, int, int, int);
void sqlite3ExprClearColumnCache(Parse*, int);
void sqlite3ExprCacheStore(Parse*, int, int, int);
void sqlite3ExprCachePush(Parse*);
void sqlite3ExprCachePop(Parse*, int);
void sqlite3ExprCacheRemove(Parse*, int);
void sqlite3ExprCacheClear(Parse*);
void sqlite3ExprCacheAffinityChange(Parse*, int, int);
void sqlite3ExprWritableRegister(Parse*,int);
void sqlite3ExprHardCopy(Parse*,int,int);
int sqlite3ExprCode(Parse*, Expr*, int);
int sqlite3ExprCodeTemp(Parse*, Expr*, int*);