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More structure rearrangements for additional size reductions. Ticket #1253. (CVS 2468)

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FossilOrigin-Name: 6b6e525b294a5bbf8a5e56a2f60aa096865aedbd
This commit is contained in:
drh
2005-05-21 02:48:08 +00:00
parent 6d156e464d
commit fcd35c7b8c
4 changed files with 66 additions and 52 deletions
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60
src/pager.c
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@@ -18,7 +18,7 @@
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.204 2005/05/20 20:11:21 drh Exp $
** @(#) $Id: pager.c,v 1.205 2005/05/21 02:48:09 drh Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
@@ -234,23 +234,6 @@ struct PgHistory {
** A open page cache is an instance of the following structure.
*/
struct Pager {
char *zFilename; /* Name of the database file */
char *zJournal; /* Name of the journal file */
char *zDirectory; /* Directory hold database and journal files */
OsFile fd, jfd; /* File descriptors for database and journal */
OsFile stfd; /* File descriptor for the statement subjournal*/
int dbSize; /* Number of pages in the file */
int origDbSize; /* dbSize before the current change */
int stmtSize; /* Size of database (in pages) at stmt_begin() */
int nRec; /* Number of pages written to the journal */
u32 cksumInit; /* Quasi-random value added to every checksum */
int stmtNRec; /* Number of records in stmt subjournal */
int nExtra; /* Add this many bytes to each in-memory page */
int pageSize; /* Number of bytes in a page */
int nPage; /* Total number of in-memory pages */
int nMaxPage; /* High water mark of nPage */
int nRef; /* Number of in-memory pages with PgHdr.nRef>0 */
int mxPage; /* Maximum number of pages to hold in cache */
u8 journalOpen; /* True if journal file descriptors is valid */
u8 journalStarted; /* True if header of journal is synced */
u8 useJournal; /* Use a rollback journal on this file */
@@ -269,8 +252,25 @@ struct Pager {
u8 alwaysRollback; /* Disable dont_rollback() for all pages */
u8 memDb; /* True to inhibit all file I/O */
u8 setMaster; /* True if a m-j name has been written to jrnl */
int dbSize; /* Number of pages in the file */
int origDbSize; /* dbSize before the current change */
int stmtSize; /* Size of database (in pages) at stmt_begin() */
int nRec; /* Number of pages written to the journal */
u32 cksumInit; /* Quasi-random value added to every checksum */
int stmtNRec; /* Number of records in stmt subjournal */
int nExtra; /* Add this many bytes to each in-memory page */
int pageSize; /* Number of bytes in a page */
int nPage; /* Total number of in-memory pages */
int nMaxPage; /* High water mark of nPage */
int nRef; /* Number of in-memory pages with PgHdr.nRef>0 */
int mxPage; /* Maximum number of pages to hold in cache */
u8 *aInJournal; /* One bit for each page in the database file */
u8 *aInStmt; /* One bit for each page in the database */
char *zFilename; /* Name of the database file */
char *zJournal; /* Name of the journal file */
char *zDirectory; /* Directory hold database and journal files */
OsFile fd, jfd; /* File descriptors for database and journal */
OsFile stfd; /* File descriptor for the statement subjournal*/
BusyHandler *pBusyHandler; /* Pointer to sqlite.busyHandler */
PgHdr *pFirst, *pLast; /* List of free pages */
PgHdr *pFirstSynced; /* First free page with PgHdr.needSync==0 */
@@ -282,8 +282,10 @@ struct Pager {
i64 stmtCksum; /* cksumInit when statement was started */
i64 stmtJSize; /* Size of journal at stmt_begin() */
int sectorSize; /* Assumed sector size during rollback */
#ifdef SQLITE_TEST
int nHit, nMiss, nOvfl; /* Cache hits, missing, and LRU overflows */
int nRead,nWrite; /* Database pages read/written */
#endif
void (*xDestructor)(void*,int); /* Call this routine when freeing pages */
void (*xReiniter)(void*,int); /* Call this routine when reloading pages */
void (*xCodec)(void*,void*,Pgno,int); /* Routine for en/decoding data */
@@ -291,6 +293,16 @@ struct Pager {
PgHdr *aHash[N_PG_HASH]; /* Hash table to map page number to PgHdr */
};
/*
** If SQLITE_TEST is defined then increment the variable given in
** the argument
*/
#ifdef SQLITE_TEST
# define TEST_INCR(x) x++
#else
# define TEST_INCR(x)
#endif
/*
** These are bits that can be set in Pager.errMask.
*/
@@ -2202,7 +2214,7 @@ static int pager_write_pagelist(PgHdr *pList){
TRACE3("STORE %d page %d\n", PAGERID(pPager), pList->pgno);
rc = sqlite3OsWrite(&pPager->fd, PGHDR_TO_DATA(pList), pPager->pageSize);
CODEC(pPager, PGHDR_TO_DATA(pList), pList->pgno, 0);
pPager->nWrite++;
TEST_INCR(pPager->nWrite);
}
#ifndef NDEBUG
else{
@@ -2373,7 +2385,7 @@ int sqlite3pager_get(Pager *pPager, Pgno pgno, void **ppPage){
if( pPg==0 ){
/* The requested page is not in the page cache. */
int h;
pPager->nMiss++;
TEST_INCR(pPager->nMiss);
if( pPager->nPage<pPager->mxPage || pPager->pFirst==0 || MEMDB ){
/* Create a new page */
pPg = sqliteMallocRaw( sizeof(*pPg) + pPager->pageSize
@@ -2459,7 +2471,7 @@ int sqlite3pager_get(Pager *pPager, Pgno pgno, void **ppPage){
/* Unlink the old page from the free list and the hash table
*/
unlinkPage(pPg);
pPager->nOvfl++;
TEST_INCR(pPager->nOvfl);
}
pPg->pgno = pgno;
if( pPager->aInJournal && (int)pgno<=pPager->origDbSize ){
@@ -2515,7 +2527,7 @@ int sqlite3pager_get(Pager *pPager, Pgno pgno, void **ppPage){
memset(PGHDR_TO_DATA(pPg), 0, pPager->pageSize);
}
}else{
pPager->nRead++;
TEST_INCR(pPager->nRead);
}
}
#ifdef SQLITE_CHECK_PAGES
@@ -2523,7 +2535,7 @@ int sqlite3pager_get(Pager *pPager, Pgno pgno, void **ppPage){
#endif
}else{
/* The requested page is in the page cache. */
pPager->nHit++;
TEST_INCR(pPager->nHit);
page_ref(pPg);
}
*ppPage = PGHDR_TO_DATA(pPg);
@@ -3192,11 +3204,13 @@ int *sqlite3pager_stats(Pager *pPager){
a[3] = pPager->dbSize;
a[4] = pPager->state;
a[5] = pPager->errMask;
#ifdef SQLITE_TEST
a[6] = pPager->nHit;
a[7] = pPager->nMiss;
a[8] = pPager->nOvfl;
a[9] = pPager->nRead;
a[10] = pPager->nWrite;
#endif
return a;
}