From: drh <drh@noemail.net>
Date: Mon, 29 Jun 2015 00:21:00 +0000 (+0000)
Subject: Use tail recursion in pcache1Unpin() to get a small size reduction and
X-Git-Tag: version-3.8.11~103
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=95c91e145adac9a16280d575b2b806266803c437;p=thirdparty%2Fsqlite.git

Use tail recursion in pcache1Unpin() to get a small size reduction and
speed improvement.

FossilOrigin-Name: fde70472aebc09b34a517131f676e6847d02b747
---

diff --git a/manifest b/manifest
index 2505603254..d8f09afc9d 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Comment\stypo\sfix\sand\sminor\scleanup\sin\sthe\spager.\s\sNo\slogic\schanges.
-D 2015-06-28T17:33:11.230
+C Use\stail\srecursion\sin\spcache1Unpin()\sto\sget\sa\ssmall\ssize\sreduction\sand\nspeed\simprovement.
+D 2015-06-29T00:21:00.874
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 285a0a234ed7610d431d91671c136098c2bd86a9
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -319,7 +319,7 @@ F src/pager.h c3476e7c89cdf1c6914e50a11f3714e30b4e0a77
 F src/parse.y 6d60dda8f8d418b6dc034f1fbccd816c459983a8
 F src/pcache.c d8b19632706dd6b81b03d0c5fd1e6bab8c13d0b9
 F src/pcache.h b44658c9c932d203510279439d891a2a83e12ba8
-F src/pcache1.c 8e3799b33c41d517d86444d4abefc80d4f02adca
+F src/pcache1.c 9ec20f98f50ed7415019303ae9bd3745d4b7bd9b
 F src/pragma.c c1f4d012ea9f6b1ce52d341b2cd0ad72d560afd7
 F src/pragma.h b8632d7cdda7b25323fa580e3e558a4f0d4502cc
 F src/prepare.c 82e5db1013846a819f198336fed72c44c974e7b1
@@ -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 9cd30d33b1d02dc8c55c1d74bdbcefab63ebf2a7
-R b8484b94b4d1a85c0081f4649a289df8
+P 94ef17012855b7be725594c34bcea75f34c40190
+R 33d15daee3cafade223d75c1a4d78a0b
 U drh
-Z b085b905d03794e34ce8f566e5412526
+Z 83eec004ab67e81db298053e8cf0783c
diff --git a/manifest.uuid b/manifest.uuid
index b03653669c..8003997611 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-94ef17012855b7be725594c34bcea75f34c40190
\ No newline at end of file
+fde70472aebc09b34a517131f676e6847d02b747
\ No newline at end of file
diff --git a/src/pcache1.c b/src/pcache1.c
index c394ff1787..7185ab441b 100644
--- a/src/pcache1.c
+++ b/src/pcache1.c
@@ -462,10 +462,11 @@ static PgHdr1 *pcache1PinPage(PgHdr1 *pPage){
 /*
 ** Remove the page supplied as an argument from the hash table 
 ** (PCache1.apHash structure) that it is currently stored in.
+** Also free the page if freePage is true.
 **
 ** The PGroup mutex must be held when this function is called.
 */
-static void pcache1RemoveFromHash(PgHdr1 *pPage){
+static void pcache1RemoveFromHash(PgHdr1 *pPage, int freeFlag){
   unsigned int h;
   PCache1 *pCache = pPage->pCache;
   PgHdr1 **pp;
@@ -476,6 +477,7 @@ static void pcache1RemoveFromHash(PgHdr1 *pPage){
   *pp = (*pp)->pNext;
 
   pCache->nPage--;
+  if( freeFlag ) pcache1FreePage(pPage);
 }
 
 /*
@@ -489,8 +491,7 @@ static void pcache1EnforceMaxPage(PGroup *pGroup){
     assert( p->pCache->pGroup==pGroup );
     assert( p->isPinned==0 );
     pcache1PinPage(p);
-    pcache1RemoveFromHash(p);
-    pcache1FreePage(p);
+    pcache1RemoveFromHash(p, 1);
   }
 }
 
@@ -714,7 +715,7 @@ static SQLITE_NOINLINE PgHdr1 *pcache1FetchStage2(
     PCache1 *pOther;
     pPage = pGroup->pLruTail;
     assert( pPage->isPinned==0 );
-    pcache1RemoveFromHash(pPage);
+    pcache1RemoveFromHash(pPage, 0);
     pcache1PinPage(pPage);
     pOther = pPage->pCache;
 
@@ -912,8 +913,7 @@ static void pcache1Unpin(
   assert( pPage->isPinned==1 );
 
   if( reuseUnlikely || pGroup->nCurrentPage>pGroup->nMaxPage ){
-    pcache1RemoveFromHash(pPage);
-    pcache1FreePage(pPage);
+    pcache1RemoveFromHash(pPage, 1);
   }else{
     /* Add the page to the PGroup LRU list. */
     if( pGroup->pLruHead ){
@@ -1067,8 +1067,7 @@ int sqlite3PcacheReleaseMemory(int nReq){
 #endif
       assert( p->isPinned==0 );
       pcache1PinPage(p);
-      pcache1RemoveFromHash(p);
-      pcache1FreePage(p);
+      pcache1RemoveFromHash(p, 1);
     }
     pcache1LeaveMutex(&pcache1.grp);
   }