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Turn on quick-balance by default. (CVS 2221)

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FossilOrigin-Name: d0356dee55bd43f361ede1344e90d1ba6b5cde1e
This commit is contained in:
drh
2005-01-16 23:21:00 +00:00
parent 0d477437ac
commit 615ae553fc
4 changed files with 50 additions and 38 deletions
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58
src/btree.c
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@@ -9,7 +9,7 @@
** May you share freely, never taking more than you give.
**
*************************************************************************
** $Id: btree.c,v 1.237 2005/01/16 11:07:07 danielk1977 Exp $
** $Id: btree.c,v 1.238 2005/01/16 23:21:00 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
@@ -358,12 +358,24 @@ struct BtCursor {
u8 isValid; /* TRUE if points to a valid entry */
};
/*
** The TRACE macro will print high-level status information about the
** btree operation when the global variable sqlite3_btree_trace is
** enabled.
*/
#if SQLITE_TEST
# define TRACE(X) if( sqlite3_btree_trace )\
{ sqlite3DebugPrintf X; fflush(stdout); }
#else
# define TRACE(X)
#endif
int sqlite3_btree_trace=0; /* True to enable tracing */
/*
** Forward declaration
*/
static int checkReadLocks(Btree*,Pgno,BtCursor*);
/*
** Read or write a two- and four-byte big-endian integer values.
*/
@@ -420,12 +432,18 @@ static void put4byte(unsigned char *p, u32 v){
#define PTRMAP_ISPAGE(pgsz, pgno) (PTRMAP_PAGENO(pgsz,pgno)==pgno)
/*
** The pointer map is a lookup table that contains an entry for each database
** page in the file except for page 1. In this context 'database page' refers
** to any page that is not part of the pointer map itself. Each pointer map
** entry consists of a single byte 'type' and a 4 byte page number. The
** PTRMAP_XXX identifiers below are the valid types. The interpretation
** of the page-number depends on the type, as follows:
** The pointer map is a lookup table that identifies the parent page for
** each child page in the database file. The parent page is the page that
** contains a pointer to the child. Every page in the database contains
** 0 or 1 parent pages. (In this context 'database page' refers
** to any page that is not part of the pointer map itself.) Each pointer map
** entry consists of a single byte 'type' and a 4 byte parent page number.
** The PTRMAP_XXX identifiers below are the valid types.
**
** The purpose of the pointer map is to facility moving pages from one
** position in the file to another as part of autovacuum. When a page
** is moved, the pointer in its parent must be updated to point to the
** new location. The pointer map is used to locate the parent page quickly.
**
** PTRMAP_ROOTPAGE: The database page is a root-page. The page-number is not
** used in this case.
@@ -457,7 +475,7 @@ static void put4byte(unsigned char *p, u32 v){
** so that it maps to type 'eType' and parent page number 'pgno'.
** An error code is returned if something goes wrong, otherwise SQLITE_OK.
*/
static int ptrmapPut(Btree *pBt, Pgno key, u8 eType, Pgno pgno){
static int ptrmapPut(Btree *pBt, Pgno key, u8 eType, Pgno parent){
u8 *pPtrmap; /* The pointer map page */
Pgno iPtrmap; /* The pointer map page number */
int offset; /* Offset in pointer map page */
@@ -472,13 +490,14 @@ static int ptrmapPut(Btree *pBt, Pgno key, u8 eType, Pgno pgno){
}
offset = PTRMAP_PTROFFSET(pBt->usableSize, key);
if( eType!=pPtrmap[offset] || get4byte(&pPtrmap[offset+1])!=pgno ){
if( eType!=pPtrmap[offset] || get4byte(&pPtrmap[offset+1])!=parent ){
TRACE(("PTRMAP_UPDATE: %d->(%d,%d)\n", key, eType, parent));
rc = sqlite3pager_write(pPtrmap);
if( rc!=0 ){
return rc;
}
pPtrmap[offset] = eType;
put4byte(&pPtrmap[offset+1], pgno);
put4byte(&pPtrmap[offset+1], parent);
}
sqlite3pager_unref(pPtrmap);
@@ -1563,19 +1582,6 @@ int sqlite3BtreeBeginTrans(Btree *pBt, int wrflag){
return rc;
}
/*
** The TRACE macro will print high-level status information about the
** btree operation when the global variable sqlite3_btree_trace is
** enabled.
*/
#if SQLITE_TEST
# define TRACE(X) if( sqlite3_btree_trace )\
{ sqlite3DebugPrintf X; fflush(stdout); }
#else
# define TRACE(X)
#endif
int sqlite3_btree_trace=0; /* True to enable tracing */
#ifndef SQLITE_OMIT_AUTOVACUUM
/*
@@ -3571,6 +3577,7 @@ static void assemblePage(
/* Forward reference */
static int balance(MemPage*, int);
#ifndef SQLITE_OMIT_QUICKBALANCE
/*
** This version of balance() handles the common special case where
** a new entry is being inserted on the extreme right-end of the
@@ -3658,6 +3665,7 @@ static int balance_quick(MemPage *pPage, MemPage *pParent){
releasePage(pNew);
return balance(pParent, 0);
}
#endif /* SQLITE_OMIT_QUICKBALANCE */
/*
** The ISAUTOVACUUM macro is used within balance_nonroot() to determine
@@ -3747,7 +3755,7 @@ static int balance_nonroot(MemPage *pPage){
assert( pParent );
TRACE(("BALANCE: begin page %d child of %d\n", pPage->pgno, pParent->pgno));
#ifdef SQLITE_BALANCE_QUICK
#ifndef SQLITE_OMIT_QUICKBALANCE
/*
** A special case: If a new entry has just been inserted into a
** table (that is, a btree with integer keys and all data at the leaves)