From: drh <drh@noemail.net>
Date: Sat, 27 Jun 2015 14:59:26 +0000 (+0000)
Subject: Add releasePageNotNull() as an alternative to releasePage() when the argument
X-Git-Tag: version-3.8.11~111
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=bbf0f867d2142b02cfb9a1a654ccbf74daaf7e6f;p=thirdparty%2Fsqlite.git

Add releasePageNotNull() as an alternative to releasePage() when the argument
is guaranteed to be non-NULL, and use it for a small performance gain.

FossilOrigin-Name: 9383a688701ac2c366a308efc287c9c0f8977d4e
---

diff --git a/manifest b/manifest
index 0c5f8a6318..7a00537b8d 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Add\sthe\sMempage.aDataOfst\sfield\sand\suse\sit\sin\ssqlite3BtreeMovetoUnpacked()\nfor\sabout\sa\s2\smillion\scycle\sgain.
-D 2015-06-27T03:58:15.601
+C Add\sreleasePageNotNull()\sas\san\salternative\sto\sreleasePage()\swhen\sthe\sargument\nis\sguaranteed\sto\sbe\snon-NULL,\sand\suse\sit\sfor\sa\ssmall\sperformance\sgain.
+D 2015-06-27T14:59:26.791
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 285a0a234ed7610d431d91671c136098c2bd86a9
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -269,7 +269,7 @@ F src/auth.c b56c78ebe40a2110fd361379f7e8162d23f92240
 F src/backup.c ff743689c4d6c5cb55ad42ed9d174b2b3e71f1e3
 F src/bitvec.c 5eb7958c3bf65210211cbcfc44eff86d0ded7c9d
 F src/btmutex.c 45a968cc85afed9b5e6cf55bf1f42f8d18107f79
-F src/btree.c 2a7554d5607f8ded06bf282c8e9e609a32d9ce55
+F src/btree.c bcd36697aeef08a27603e1c3b49cba947dc989ff
 F src/btree.h 969adc948e89e449220ff0ff724c94bb2a52e9f1
 F src/btreeInt.h 426d1e0d1a15d06b3ad2304f4bedc5bb71e5b4a2
 F src/build.c b3f15255d5b16e42dafeaa638fd4f8a47c94ed70
@@ -1364,7 +1364,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 48bd54594752d5be3337f12c72f28d2080cb630b
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 7c610276bb41dbc80fe169d35fe9a3a3f6525635
-R 762529df533e804d7973bafd804366fc
+P bee94dc3510745ba2efa044e8f3299793cfc7e34
+R 94fda06abca767c903bae476355c8d33
 U drh
-Z 0b74e27756355a1dbfb2275608b79e03
+Z 5cbb493cc80b630214e6dea5f8f50f0d
diff --git a/manifest.uuid b/manifest.uuid
index 34069c5388..f45d7f1d33 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-bee94dc3510745ba2efa044e8f3299793cfc7e34
\ No newline at end of file
+9383a688701ac2c366a308efc287c9c0f8977d4e
\ No newline at end of file
diff --git a/src/btree.c b/src/btree.c
index bbec2dd0a2..cd96ba0f67 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -1947,16 +1947,17 @@ static int getAndInitPage(
 ** Release a MemPage.  This should be called once for each prior
 ** call to btreeGetPage.
 */
+static void releasePageNotNull(MemPage *pPage){
+  assert( pPage->aData );
+  assert( pPage->pBt );
+  assert( pPage->pDbPage!=0 );
+  assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage );
+  assert( sqlite3PagerGetData(pPage->pDbPage)==pPage->aData );
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  sqlite3PagerUnrefNotNull(pPage->pDbPage);
+}
 static void releasePage(MemPage *pPage){
-  if( pPage ){
-    assert( pPage->aData );
-    assert( pPage->pBt );
-    assert( pPage->pDbPage!=0 );
-    assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage );
-    assert( sqlite3PagerGetData(pPage->pDbPage)==pPage->aData );
-    assert( sqlite3_mutex_held(pPage->pBt->mutex) );
-    sqlite3PagerUnrefNotNull(pPage->pDbPage);
-  }
+  if( pPage ) releasePageNotNull(pPage);
 }
 
 /*
@@ -2931,7 +2932,7 @@ static void unlockBtreeIfUnused(BtShared *pBt){
     assert( pPage1->aData );
     assert( sqlite3PagerRefcount(pBt->pPager)==1 );
     pBt->pPage1 = 0;
-    releasePage(pPage1);
+    releasePageNotNull(pPage1);
   }
 }
 
@@ -4705,11 +4706,9 @@ static void moveToParent(BtCursor *pCur){
     pCur->apPage[pCur->iPage]->pgno
   );
   testcase( pCur->aiIdx[pCur->iPage-1] > pCur->apPage[pCur->iPage-1]->nCell );
-
-  releasePage(pCur->apPage[pCur->iPage]);
-  pCur->iPage--;
   pCur->info.nSize = 0;
   pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);
+  releasePageNotNull(pCur->apPage[pCur->iPage--]);
 }
 
 /*
@@ -4750,7 +4749,10 @@ static int moveToRoot(BtCursor *pCur){
   }
 
   if( pCur->iPage>=0 ){
-    while( pCur->iPage ) releasePage(pCur->apPage[pCur->iPage--]);
+    while( pCur->iPage ){
+      assert( pCur->apPage[pCur->iPage]!=0 );
+      releasePageNotNull(pCur->apPage[pCur->iPage--]);
+    }
   }else if( pCur->pgnoRoot==0 ){
     pCur->eState = CURSOR_INVALID;
     return SQLITE_OK;