Pager performance enhancements. (CVS 3125)

FossilOrigin-Name: 9c26570743d878dee963e37728969fb30a2fb436

2 files changed, 31 insertions, 43 deletions

diff --git a/src/pager.c b/src/pager.c
index d6a651806..66bd44869 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -18,7 +18,7 @@
 ** file simultaneously, or one process from reading the database while
 ** another is writing.
 **
-** @(#) $Id: pager.c,v 1.260 2006/02/24 03:09:37 drh Exp $
+** @(#) $Id: pager.c,v 1.261 2006/03/06 18:23:17 drh Exp $
 */
 #ifndef SQLITE_OMIT_DISKIO
 #include "sqliteInt.h"
@@ -52,8 +52,8 @@
 ** associated file-descriptor is returned. FILEHANDLEID() takes an OsFile
 ** struct as it's argument.
 */
-#define PAGERID(p) FILEHANDLEID(&(p)->fd)
-#define FILEHANDLEID(fd) (sqlite3OsFileHandle(&fd))
+#define PAGERID(p) ((int)(p->fd))
+#define FILEHANDLEID(fd) ((int)fd)
 
 /*
 ** The page cache as a whole is always in one of the following
@@ -190,9 +190,11 @@ struct PgHistory {
 ** A macro used for invoking the codec if there is one
 */
 #ifdef SQLITE_HAS_CODEC
-# define CODEC(P,D,N,X) if( P->xCodec ){ P->xCodec(P->pCodecArg,D,N,X); }
+# define CODEC1(P,D,N,X) if( P->xCodec!=0 ){ P->xCodec(P->pCodecArg,D,N,X); }
+# define CODEC2(P,D,N,X) ((char*)(P->xCodec!=0?P->xCodec(P->pCodecArg,D,N,X):D))
 #else
-# define CODEC(P,D,N,X)
+# define CODEC1(P,D,N,X) /* NO-OP */
+# define CODEC2(P,D,N,X) ((char*)D)
 #endif
 
 /*
@@ -290,7 +292,7 @@ struct Pager {
 #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 */
+  void *(*xCodec)(void*,void*,Pgno,int); /* Routine for en/decoding data */
   void *pCodecArg;            /* First argument to xCodec() */
   PgHdr *aHash[N_PG_HASH];    /* Hash table to map page number to PgHdr */
 #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
@@ -436,16 +438,6 @@ static int write32bits(OsFile *fd, u32 val){
 }
 
 /*
-** Write the 32-bit integer 'val' into the page identified by page header
-** 'p' at offset 'offset'.
-*/
-static void store32bits(u32 val, PgHdr *p, int offset){
-  char *ac;
-  ac = &((char*)PGHDR_TO_DATA(p))[offset];
-  put32bits(ac, val);
-}
-
-/*
 ** Read a 32-bit integer at offset 'offset' from the page identified by
 ** page header 'p'.
 */
@@ -1041,7 +1033,7 @@ static int pager_playback_one_page(Pager *pPager, OsFile *jfd, int useCksum){
 #ifdef SQLITE_CHECK_PAGES
     pPg->pageHash = pager_pagehash(pPg);
 #endif
-    CODEC(pPager, pData, pPg->pgno, 3);
+    CODEC1(pPager, pData, pPg->pgno, 3);
   }
   return rc;
 }
@@ -1154,7 +1146,7 @@ static int pager_reload_cache(Pager *pPager){
       }
       TRACE3("REFETCH %d page %d\n", PAGERID(pPager), pPg->pgno);
       if( rc ) break;
-      CODEC(pPager, zBuf, pPg->pgno, 2);
+      CODEC1(pPager, zBuf, pPg->pgno, 2);
     }else{
       memset(zBuf, 0, pPager->pageSize);
     }
@@ -2274,11 +2266,9 @@ static int pager_write_pagelist(PgHdr *pList){
     ** any such pages to the file.
     */
     if( pList->pgno<=pPager->dbSize ){
-      CODEC(pPager, PGHDR_TO_DATA(pList), pList->pgno, 6);
+      char *pData = CODEC2(pPager, PGHDR_TO_DATA(pList), pList->pgno, 6);
       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);
+      rc = sqlite3OsWrite(pPager->fd, pData, pPager->pageSize);
       TEST_INCR(pPager->nWrite);
     }
 #ifndef NDEBUG
@@ -2683,7 +2673,7 @@ int sqlite3pager_get(Pager *pPager, Pgno pgno, void **ppPage){
                               pPager->pageSize);
       }
       TRACE3("FETCH %d page %d\n", PAGERID(pPager), pPg->pgno);
-      CODEC(pPager, PGHDR_TO_DATA(pPg), pPg->pgno, 3);
+      CODEC1(pPager, PGHDR_TO_DATA(pPg), pPg->pgno, 3);
       if( rc!=SQLITE_OK ){
         i64 fileSize;
         int rc2 = sqlite3OsFileSize(pPager->fd, &fileSize);
@@ -3002,7 +2992,6 @@ int sqlite3pager_write(void *pData){
     if( !pPg->inJournal && (pPager->useJournal || MEMDB) ){
       if( (int)pPg->pgno <= pPager->origDbSize ){
         int szPg;
-        u32 saved;
         if( MEMDB ){
           PgHistory *pHist = PGHDR_TO_HIST(pPg, pPager);
           TRACE3("JOURNAL %d page %d\n", PAGERID(pPager), pPg->pgno);
@@ -3012,24 +3001,25 @@ int sqlite3pager_write(void *pData){
             memcpy(pHist->pOrig, PGHDR_TO_DATA(pPg), pPager->pageSize);
           }
         }else{
-          u32 cksum;
+          u32 cksum, saved;
+          char *pData2, *pEnd;
           /* We should never write to the journal file the page that
           ** contains the database locks.  The following assert verifies
           ** that we do not. */
           assert( pPg->pgno!=PAGER_MJ_PGNO(pPager) );
-          CODEC(pPager, pData, pPg->pgno, 7);
-          cksum = pager_cksum(pPager, pData);
-          saved = *(u32*)PGHDR_TO_EXTRA(pPg, pPager);
-          store32bits(cksum, pPg, pPager->pageSize);
+          pData2 = CODEC2(pPager, pData, pPg->pgno, 7);
+          cksum = pager_cksum(pPager, pData2);
+          pEnd = pData2 + pPager->pageSize;
+          pData2 -= 4;
+          saved = *(u32*)pEnd;
+          put32bits(pEnd, cksum);
           szPg = pPager->pageSize+8;
-          store32bits(pPg->pgno, pPg, -4);
-
-          rc = sqlite3OsWrite(pPager->jfd, &((char*)pData)[-4], szPg);
+          put32bits(pData2, pPg->pgno);
+          rc = sqlite3OsWrite(pPager->jfd, pData2, szPg);
           pPager->journalOff += szPg;
           TRACE4("JOURNAL %d page %d needSync=%d\n",
                   PAGERID(pPager), pPg->pgno, pPg->needSync);
-          CODEC(pPager, pData, pPg->pgno, 0);
-          *(u32*)PGHDR_TO_EXTRA(pPg, pPager) = saved;
+          *(u32*)pEnd = saved;
 
 	  /* An error has occured writing to the journal file. The 
           ** transaction will be rolled back by the layer above.
@@ -3074,12 +3064,10 @@ int sqlite3pager_write(void *pData){
         }
         TRACE3("STMT-JOURNAL %d page %d\n", PAGERID(pPager), pPg->pgno);
       }else{
-        store32bits(pPg->pgno, pPg, -4);
-        CODEC(pPager, pData, pPg->pgno, 7);
-        rc = sqlite3OsWrite(pPager->stfd,((char*)pData)-4,
-                               pPager->pageSize+4);
+        char *pData2 = CODEC2(pPager, pData, pPg->pgno, 7)-4;
+        put32bits(pData2, pPg->pgno);
+        rc = sqlite3OsWrite(pPager->stfd, pData2, pPager->pageSize+4);
         TRACE3("STMT-JOURNAL %d page %d\n", PAGERID(pPager), pPg->pgno);
-        CODEC(pPager, pData, pPg->pgno, 0);
         if( rc!=SQLITE_OK ){
           return rc;
         }
@@ -3551,7 +3539,7 @@ int sqlite3pager_nosync(Pager *pPager){
 */
 void sqlite3pager_set_codec(
   Pager *pPager,
-  void (*xCodec)(void*,void*,Pgno,int),
+  void *(*xCodec)(void*,void*,Pgno,int),
   void *pCodecArg
 ){
   pPager->xCodec = xCodec;
@@ -3580,7 +3568,7 @@ static int pager_incr_changecounter(Pager *pPager){
 
   /* Increment the value just read and write it back to byte 24. */
   change_counter++;
-  store32bits(change_counter, pPgHdr, 24);
+  put32bits(((char*)PGHDR_TO_DATA(pPgHdr))+24, change_counter);
 
   /* Release the page reference. */
   sqlite3pager_unref(pPage);
diff --git a/src/pager.h b/src/pager.h
index 253d3e94d..23d7a2d21 100644
--- a/src/pager.h
+++ b/src/pager.h
@@ -13,7 +13,7 @@
 ** subsystem.  The page cache subsystem reads and writes a file a page
 ** at a time and provides a journal for rollback.
 **
-** @(#) $Id: pager.h,v 1.49 2006/02/11 01:25:51 drh Exp $
+** @(#) $Id: pager.h,v 1.50 2006/03/06 18:23:17 drh Exp $
 */
 
 #ifndef _PAGER_H_
@@ -105,7 +105,7 @@ const char *sqlite3pager_dirname(Pager*);
 const char *sqlite3pager_journalname(Pager*);
 int sqlite3pager_nosync(Pager*);
 int sqlite3pager_rename(Pager*, const char *zNewName);
-void sqlite3pager_set_codec(Pager*,void(*)(void*,void*,Pgno,int),void*);
+void sqlite3pager_set_codec(Pager*,void*(*)(void*,void*,Pgno,int),void*);
 int sqlite3pager_movepage(Pager*,void*,Pgno);
 int sqlite3pager_reset(Pager*);
 int sqlite3pager_release_memory(int);