From: drh <drh@noemail.net>
Date: Fri, 22 Aug 2014 20:35:29 +0000 (+0000)
Subject: Combine the pcacheAddToDirtyList() and pcacheRemoveFromDirtyList() routines
X-Git-Tag: version-3.8.7~169
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a8dcba9199cef12aa979e6be7c98c50d5a777c9e;p=thirdparty%2Fsqlite.git

Combine the pcacheAddToDirtyList() and pcacheRemoveFromDirtyList() routines
into a single pcacheManageDirtyList() routine.  The resulting binary code is
slightly faster and a few bytes smaller.

FossilOrigin-Name: 6bcf1af6a48dbda5ac6f6b3b02810bdfc4730000
---

diff --git a/manifest b/manifest
index 4718b15953..63a01156f0 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Performance\senhancement\sin\ssqlite3PutVarint().
-D 2014-08-22T18:48:25.634
+C Combine\sthe\spcacheAddToDirtyList()\sand\spcacheRemoveFromDirtyList()\sroutines\ninto\sa\ssingle\spcacheManageDirtyList()\sroutine.\s\sThe\sresulting\sbinary\scode\sis\nslightly\sfaster\sand\sa\sfew\sbytes\ssmaller.
+D 2014-08-22T20:35:29.948
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 5eb79e334a5de69c87740edd56af6527dd219308
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -214,7 +214,7 @@ F src/os_win.h 09e751b20bbc107ffbd46e13555dc73576d88e21
 F src/pager.c f6bb1fa6cdf2062f2d8aec3e64db302bca519ab8
 F src/pager.h ffd5607f7b3e4590b415b007a4382f693334d428
 F src/parse.y 22d6a074e5f5a7258947a1dc55a9bf946b765dd0
-F src/pcache.c d8eafac28290d4bb80332005435db44991d07fc2
+F src/pcache.c da602c5447051705cab41604bf3276815eb569d0
 F src/pcache.h a5e4f5d9f5d592051d91212c5949517971ae6222
 F src/pcache1.c 102e6f5a2fbc646154463eb856d1fd716867b64c
 F src/pragma.c d10ef67c4de79f78188b965b4b7988aff1d66f2e
@@ -1188,7 +1188,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P cf561d1f0bb60b3d638632d20bd686dda4fa4a04
-R 892fbe852e37f91de1b9f5afa35c0502
+P a929be551924144c9bc7aab608404d59e479abb5
+R 2ac5f67b7ba10391163889b9ff4c4145
 U drh
-Z c70614e9322ab39ef4e9fbe07eb13b05
+Z 6bffc4c72a94895b60e52defb6944efd
diff --git a/manifest.uuid b/manifest.uuid
index 12c08a2c09..da73897dba 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-a929be551924144c9bc7aab608404d59e479abb5
\ No newline at end of file
+6bcf1af6a48dbda5ac6f6b3b02810bdfc4730000
\ No newline at end of file
diff --git a/src/pcache.c b/src/pcache.c
index e18bf93be0..2e4b5d78b2 100644
--- a/src/pcache.c
+++ b/src/pcache.c
@@ -62,71 +62,73 @@ static int pcacheCheckSynced(PCache *pCache){
 }
 #endif /* !NDEBUG && SQLITE_ENABLE_EXPENSIVE_ASSERT */
 
+/* Allowed values for second argument to pcacheManageDirtyList() */
+#define PCACHE_DIRTYLIST_REMOVE   1    /* Remove pPage from dirty list */
+#define PCACHE_DIRTYLIST_ADD      2    /* Add pPage to the dirty list */
+#define PCACHE_DIRTYLIST_FRONT    3    /* Move pPage to the front of the list */
+
 /*
-** Remove page pPage from the list of dirty pages.
+** Manage pPage's participation on the dirty list.  Bits of the addRemove
+** argument determines what operation to do.  The 0x01 bit means first
+** remove pPage from the dirty list.  The 0x02 means add pPage back to
+** the dirty list.  Doing both moves pPage to the front of the dirty list.
 */
-static void pcacheRemoveFromDirtyList(PgHdr *pPage){
+static void pcacheManageDirtyList(PgHdr *pPage, u8 addRemove){
   PCache *p = pPage->pCache;
 
-  assert( pPage->pDirtyNext || pPage==p->pDirtyTail );
-  assert( pPage->pDirtyPrev || pPage==p->pDirty );
-
-  /* Update the PCache1.pSynced variable if necessary. */
-  if( p->pSynced==pPage ){
-    PgHdr *pSynced = pPage->pDirtyPrev;
-    while( pSynced && (pSynced->flags&PGHDR_NEED_SYNC) ){
-      pSynced = pSynced->pDirtyPrev;
+  if( addRemove & PCACHE_DIRTYLIST_REMOVE ){
+    assert( pPage->pDirtyNext || pPage==p->pDirtyTail );
+    assert( pPage->pDirtyPrev || pPage==p->pDirty );
+  
+    /* Update the PCache1.pSynced variable if necessary. */
+    if( p->pSynced==pPage ){
+      PgHdr *pSynced = pPage->pDirtyPrev;
+      while( pSynced && (pSynced->flags&PGHDR_NEED_SYNC) ){
+        pSynced = pSynced->pDirtyPrev;
+      }
+      p->pSynced = pSynced;
     }
-    p->pSynced = pSynced;
-  }
-
-  if( pPage->pDirtyNext ){
-    pPage->pDirtyNext->pDirtyPrev = pPage->pDirtyPrev;
-  }else{
-    assert( pPage==p->pDirtyTail );
-    p->pDirtyTail = pPage->pDirtyPrev;
-  }
-  if( pPage->pDirtyPrev ){
-    pPage->pDirtyPrev->pDirtyNext = pPage->pDirtyNext;
-  }else{
-    assert( pPage==p->pDirty );
-    p->pDirty = pPage->pDirtyNext;
-    if( p->pDirty==0 && p->bPurgeable ){
-      assert( p->eCreate==1 );
-      p->eCreate = 2;
+  
+    if( pPage->pDirtyNext ){
+      pPage->pDirtyNext->pDirtyPrev = pPage->pDirtyPrev;
+    }else{
+      assert( pPage==p->pDirtyTail );
+      p->pDirtyTail = pPage->pDirtyPrev;
     }
+    if( pPage->pDirtyPrev ){
+      pPage->pDirtyPrev->pDirtyNext = pPage->pDirtyNext;
+    }else{
+      assert( pPage==p->pDirty );
+      p->pDirty = pPage->pDirtyNext;
+      if( p->pDirty==0 && p->bPurgeable ){
+        assert( p->eCreate==1 );
+        p->eCreate = 2;
+      }
+    }
+    pPage->pDirtyNext = 0;
+    pPage->pDirtyPrev = 0;
+    expensive_assert( pcacheCheckSynced(p) );
+  }
+  if( addRemove & PCACHE_DIRTYLIST_ADD ){
+    assert( pPage->pDirtyNext==0 && pPage->pDirtyPrev==0 && p->pDirty!=pPage );
+  
+    pPage->pDirtyNext = p->pDirty;
+    if( pPage->pDirtyNext ){
+      assert( pPage->pDirtyNext->pDirtyPrev==0 );
+      pPage->pDirtyNext->pDirtyPrev = pPage;
+    }else if( p->bPurgeable ){
+      assert( p->eCreate==2 );
+      p->eCreate = 1;
+    }
+    p->pDirty = pPage;
+    if( !p->pDirtyTail ){
+      p->pDirtyTail = pPage;
+    }
+    if( !p->pSynced && 0==(pPage->flags&PGHDR_NEED_SYNC) ){
+      p->pSynced = pPage;
+    }
+    expensive_assert( pcacheCheckSynced(p) );
   }
-  pPage->pDirtyNext = 0;
-  pPage->pDirtyPrev = 0;
-
-  expensive_assert( pcacheCheckSynced(p) );
-}
-
-/*
-** Add page pPage to the head of the dirty list (PCache1.pDirty is set to
-** pPage).
-*/
-static void pcacheAddToDirtyList(PgHdr *pPage){
-  PCache *p = pPage->pCache;
-
-  assert( pPage->pDirtyNext==0 && pPage->pDirtyPrev==0 && p->pDirty!=pPage );
-
-  pPage->pDirtyNext = p->pDirty;
-  if( pPage->pDirtyNext ){
-    assert( pPage->pDirtyNext->pDirtyPrev==0 );
-    pPage->pDirtyNext->pDirtyPrev = pPage;
-  }else if( p->bPurgeable ){
-    assert( p->eCreate==2 );
-    p->eCreate = 1;
-  }
-  p->pDirty = pPage;
-  if( !p->pDirtyTail ){
-    p->pDirtyTail = pPage;
-  }
-  if( !p->pSynced && 0==(pPage->flags&PGHDR_NEED_SYNC) ){
-    p->pSynced = pPage;
-  }
-  expensive_assert( pcacheCheckSynced(p) );
 }
 
 /*
@@ -134,12 +136,11 @@ static void pcacheAddToDirtyList(PgHdr *pPage){
 ** being used for an in-memory database, this function is a no-op.
 */
 static void pcacheUnpin(PgHdr *p){
-  PCache *pCache = p->pCache;
-  if( pCache->bPurgeable ){
+  if( p->pCache->bPurgeable ){
     if( p->pgno==1 ){
-      pCache->pPage1 = 0;
+      p->pCache->pPage1 = 0;
     }
-    sqlite3GlobalConfig.pcache2.xUnpin(pCache->pCache, p->pPage, 0);
+    sqlite3GlobalConfig.pcache2.xUnpin(p->pCache->pCache, p->pPage, 0);
   }
 }
 
@@ -332,18 +333,16 @@ int sqlite3PcacheFetch(
 ** Decrement the reference count on a page. If the page is clean and the
 ** reference count drops to 0, then it is made elible for recycling.
 */
-void sqlite3PcacheRelease(PgHdr *p){
+void SQLITE_NOINLINE sqlite3PcacheRelease(PgHdr *p){
   assert( p->nRef>0 );
   p->nRef--;
   if( p->nRef==0 ){
-    PCache *pCache = p->pCache;
-    pCache->nRef--;
+    p->pCache->nRef--;
     if( (p->flags&PGHDR_DIRTY)==0 ){
       pcacheUnpin(p);
     }else{
       /* Move the page to the head of the dirty list. */
-      pcacheRemoveFromDirtyList(p);
-      pcacheAddToDirtyList(p);
+      pcacheManageDirtyList(p, PCACHE_DIRTYLIST_FRONT);
     }
   }
 }
@@ -362,17 +361,15 @@ void sqlite3PcacheRef(PgHdr *p){
 ** page pointed to by p is invalid.
 */
 void sqlite3PcacheDrop(PgHdr *p){
-  PCache *pCache;
   assert( p->nRef==1 );
   if( p->flags&PGHDR_DIRTY ){
-    pcacheRemoveFromDirtyList(p);
+    pcacheManageDirtyList(p, PCACHE_DIRTYLIST_REMOVE);
   }
-  pCache = p->pCache;
-  pCache->nRef--;
+  p->pCache->nRef--;
   if( p->pgno==1 ){
-    pCache->pPage1 = 0;
+    p->pCache->pPage1 = 0;
   }
-  sqlite3GlobalConfig.pcache2.xUnpin(pCache->pCache, p->pPage, 1);
+  sqlite3GlobalConfig.pcache2.xUnpin(p->pCache->pCache, p->pPage, 1);
 }
 
 /*
@@ -384,7 +381,7 @@ void sqlite3PcacheMakeDirty(PgHdr *p){
   assert( p->nRef>0 );
   if( 0==(p->flags & PGHDR_DIRTY) ){
     p->flags |= PGHDR_DIRTY;
-    pcacheAddToDirtyList( p);
+    pcacheManageDirtyList(p, PCACHE_DIRTYLIST_ADD);
   }
 }
 
@@ -394,7 +391,7 @@ void sqlite3PcacheMakeDirty(PgHdr *p){
 */
 void sqlite3PcacheMakeClean(PgHdr *p){
   if( (p->flags & PGHDR_DIRTY) ){
-    pcacheRemoveFromDirtyList(p);
+    pcacheManageDirtyList(p, PCACHE_DIRTYLIST_REMOVE);
     p->flags &= ~(PGHDR_DIRTY|PGHDR_NEED_SYNC);
     if( p->nRef==0 ){
       pcacheUnpin(p);
@@ -433,8 +430,7 @@ void sqlite3PcacheMove(PgHdr *p, Pgno newPgno){
   sqlite3GlobalConfig.pcache2.xRekey(pCache->pCache, p->pPage, p->pgno,newPgno);
   p->pgno = newPgno;
   if( (p->flags&PGHDR_DIRTY) && (p->flags&PGHDR_NEED_SYNC) ){
-    pcacheRemoveFromDirtyList(p);
-    pcacheAddToDirtyList(p);
+    pcacheManageDirtyList(p, PCACHE_DIRTYLIST_FRONT);
   }
 }