Another size and performance optimization to readDbPage(). This time we

eliminate some unnecessary local variables.

FossilOrigin-Name: 745bc8decd18d4dc00589474fd3928a3a9f4156d09e05e6f5b8623de6491795a

diff --git a/manifest b/manifest
index 1e5d32d66bf3ed4d9a7ac80e819ed26dbfa21b9a..558153cf2fc5b299ba31540fde6826bcc5aa00fc 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Size\sand\sperformance\soptimization\sthe\sreadDbPage()\sroutine\sin\sthe\spager.
-D 2017-08-18T21:14:50.622
+C Another\ssize\sand\sperformance\soptimization\sto\sreadDbPage().\s\sThis\stime\swe\neliminate\ssome\sunnecessary\slocal\svariables.
+D 2017-08-18T22:30:20.164
 F Makefile.in d9873c9925917cca9990ee24be17eb9613a668012c85a343aef7e5536ae266e8
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 02b469e9dcd5b7ee63fc1fb05babc174260ee4cfa4e0ef2e48c3c6801567a016
@@ -443,7 +443,7 @@ F src/os_setup.h 0dbaea40a7d36bf311613d31342e0b99e2536586
 F src/os_unix.c 0a7730f6cb797ba1fd12825e4ea751e1325041410c063c258e30089ca71f9a88
 F src/os_win.c 964165b66cde03abc72fe948198b01be608436894732eadb94c8720d2467f223
 F src/os_win.h 7b073010f1451abe501be30d12f6bc599824944a
-F src/pager.c fb9a8f40417d6dfbd6b8be91237f2f64d51cc867ab28687420acbc5cab786a3c
+F src/pager.c c1dc0609f04a0659519bb2b8ca1440a64b0ad82b6c2afd675f1a50f6c918321a
 F src/pager.h f2a99646c5533ffe11afa43e9e0bea74054e4efa
 F src/parse.y 52ef3cecd0934e9da4a45b585883a03243ad615d338ad94f44501a05891dcdfa
 F src/pcache.c 62835bed959e2914edd26afadfecce29ece0e870
@@ -1649,7 +1649,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 3075cfa07489eaf13cb9a2760e2391e79dd73181fe1730fae7bdcd6ad66d2a1f
-R 73e91e0689b3737aa34e053426722c6a
+P ca9e1875c3a893321d70a131fc4ffc76d169ad05e0b48b7006f53b6b467db4be
+R 2ae3b6889f1fe566e9272b8874e17865
 U drh
-Z 58f532a67b173dfa15cad7f44c1bc81c
+Z 970c0b65cb119d003a12faf3a1e4e18e

diff --git a/manifest.uuid b/manifest.uuid
index 59813005d8efd68ba894842ab5155428ca04610c..6c04ddf6a785df36956d207d7a3dfb6884ab5b7e 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-ca9e1875c3a893321d70a131fc4ffc76d169ad05e0b48b7006f53b6b467db4be
\ No newline at end of file
+745bc8decd18d4dc00589474fd3928a3a9f4156d09e05e6f5b8623de6491795a
\ No newline at end of file

diff --git a/src/pager.c b/src/pager.c
index 9a430476a1c77482eac0dfa93b56ea6f78b6b326..5986afdae10e78d25bb03d316a3faf034d4db5d5 100644 (file)
--- a/src/pager.c
+++ b/src/pager.c
@@ -2995,29 +2995,27 @@ end_playback:
 */
 static int readDbPage(PgHdr *pPg){
   Pager *pPager = pPg->pPager; /* Pager object associated with page pPg */
-  Pgno pgno = pPg->pgno;       /* Page number to read */
   int rc = SQLITE_OK;          /* Return code */
-  int pgsz = pPager->pageSize; /* Number of bytes to read */
   u32 iFrame = 0;              /* Frame of WAL containing pgno */
 
   assert( pPager->eState>=PAGER_READER && !MEMDB );
   assert( isOpen(pPager->fd) );
 
   if( pagerUseWal(pPager) ){
-    rc = sqlite3WalFindFrame(pPager->pWal, pgno, &iFrame);
+    rc = sqlite3WalFindFrame(pPager->pWal, pPg->pgno, &iFrame);
     if( rc ) return rc;
   }
   if( iFrame ){
-    rc = sqlite3WalReadFrame(pPager->pWal, iFrame, pgsz, pPg->pData);
+    rc = sqlite3WalReadFrame(pPager->pWal, iFrame,pPager->pageSize,pPg->pData);
   }else{
-    i64 iOffset = (pgno-1)*(i64)pPager->pageSize;
-    rc = sqlite3OsRead(pPager->fd, pPg->pData, pgsz, iOffset);
+    i64 iOffset = (pPg->pgno-1)*(i64)pPager->pageSize;
+    rc = sqlite3OsRead(pPager->fd, pPg->pData, pPager->pageSize, iOffset);
     if( rc==SQLITE_IOERR_SHORT_READ ){
       rc = SQLITE_OK;
     }
   }
 
-  if( pgno==1 ){
+  if( pPg->pgno==1 ){
     if( rc ){
       /* If the read is unsuccessful, set the dbFileVers[] to something
       ** that will never be a valid file version.  dbFileVers[] is a copy
@@ -3037,13 +3035,13 @@ static int readDbPage(PgHdr *pPg){
       memcpy(&pPager->dbFileVers, dbFileVers, sizeof(pPager->dbFileVers));
     }
   }
-  CODEC1(pPager, pPg->pData, pgno, 3, rc = SQLITE_NOMEM_BKPT);
+  CODEC1(pPager, pPg->pData, pPg->pgno, 3, rc = SQLITE_NOMEM_BKPT);
 
   PAGER_INCR(sqlite3_pager_readdb_count);
   PAGER_INCR(pPager->nRead);
-  IOTRACE(("PGIN %p %d\n", pPager, pgno));
+  IOTRACE(("PGIN %p %d\n", pPager, pPg->pgno));
   PAGERTRACE(("FETCH %d page %d hash(%08x)\n",
-               PAGERID(pPager), pgno, pager_pagehash(pPg)));
+               PAGERID(pPager), pPg->pgno, pager_pagehash(pPg)));
 
   return rc;
 }