speedups for large histories. from camino branch. (r=bryner/sr=sfraser, bug

180109)

xpfe/components/history/src/nsGlobalHistory.cpp

@@ -118,7 +118,7 @@ nsIPrefBranch* nsGlobalHistory::gPrefBranch = nsnull;
 // the value of mLastNow expires every 3 seconds
 #define HISTORY_EXPIRE_NOW_TIMEOUT (3 * PR_MSEC_PER_SEC)
 
-#define MSECS_PER_DAY (PR_MSEC_PER_SEC * 60 * 60 * 24)
+static const PRInt64 MSECS_PER_DAY = LL_INIT(20, 500654080);  // (1000000LL * 60 * 60 * 24)
 
 //----------------------------------------------------------------------
 //
@@ -145,8 +145,8 @@ struct matchSearchTerm_t {
   
   searchTerm *term;
   PRBool haveClosure;           // are the rest of the fields valid?
-  PRInt64 now;
   PRInt32 intValue;
+  nsGlobalHistory* globalHist;
 };
 
 struct matchQuery_t {
@@ -259,53 +259,43 @@ CharsToPRInt64(const char* aBuf, PRUint32 aCount, PRInt64* aResult)
   return NS_OK;
 }
 
-static PRTime
-NormalizeTime(PRInt64 aTime)
+
+PRTime
+nsGlobalHistory::NormalizeTime(PRInt64 aTime)
 {
-  // normalize both now and date to midnight of the day they occur on
-  PRExplodedTime explodedTime;
-  PR_ExplodeTime(aTime, PR_LocalTimeParameters, &explodedTime);
+  // we can optimize this by converting the time to local time, rounding
+  // down to the previous day boundary, and then converting back to UTC.
+  // This avoids two costly calls to localtime()
 
-  // set to midnight (0:00)
-  explodedTime.tm_min =
-    explodedTime.tm_hour =
-    explodedTime.tm_sec =
-    explodedTime.tm_usec = 0;
-
-  return PR_ImplodeTime(&explodedTime);
+  // we calculate (gmtTime - (gmtTime % MSECS_PER_DAY)) - mCachedGMTOffset
+  PRInt64 gmtTime;
+  LL_ADD(gmtTime, aTime, mCachedGMTOffset);
+  PRInt64 curDayUSec;
+  LL_MOD(curDayUSec, gmtTime, MSECS_PER_DAY);
+  PRInt64 gmtMidnight;
+  LL_SUB(gmtMidnight, gmtTime, curDayUSec);
+  PRInt64 localMidnight;
+  LL_SUB(localMidnight, gmtMidnight, mCachedGMTOffset);
+  
+  return localMidnight;
 }
 
-// pass in a pre-normalized now and a date, and we'll find
-// the difference since midnight on each of the days..
-static PRInt32
-GetAgeInDays(PRInt64 aNormalizedNow, PRInt64 aDate)
+PRInt32
+nsGlobalHistory::GetAgeInDays(PRInt64 aDate)
 {
+  PRInt64 timeNow      = GetNow();
   PRInt64 dateMidnight = NormalizeTime(aDate);
 
   PRInt64 diff;
-  LL_SUB(diff, aNormalizedNow, dateMidnight);
-
-  // two-step process since I can't seem to load
-  // MSECS_PER_DAY * PR_MSEC_PER_SEC into a PRInt64 at compile time
-  PRInt64 msecPerSec;
-  LL_I2L(msecPerSec, PR_MSEC_PER_SEC);
-  PRInt64 ageInSeconds;
-  LL_DIV(ageInSeconds, diff, msecPerSec);
-
-  PRInt32 ageSec; LL_L2I(ageSec, ageInSeconds);
-  
-  PRInt64 msecPerDay;
-  LL_I2L(msecPerDay, MSECS_PER_DAY);
-  
+  LL_SUB(diff, timeNow, dateMidnight);
   PRInt64 ageInDays;
-  LL_DIV(ageInDays, ageInSeconds, msecPerDay);
-
+  LL_DIV(ageInDays, diff, MSECS_PER_DAY);
   PRInt32 retval;
   LL_L2I(retval, ageInDays);
+
   return retval;
 }
 
-
 PRBool
 nsGlobalHistory::MatchExpiration(nsIMdbRow *row, PRInt64* expirationDate)
 {
@@ -340,7 +330,6 @@ matchAgeInDaysCallback(nsIMdbRow *row, void *aClosure)
     PRInt32 err;
     // Need to create an nsAutoString to use ToInteger
     matchSearchTerm->intValue =  nsAutoString(term->text).ToInteger(&err);
-    matchSearchTerm->now = NormalizeTime(PR_Now());
     if (err != 0) return PR_FALSE;
     matchSearchTerm->haveClosure = PR_TRUE;
   }
@@ -358,7 +347,7 @@ matchAgeInDaysCallback(nsIMdbRow *row, void *aClosure)
   
   CharsToPRInt64((const char*)yarn.mYarn_Buf, yarn.mYarn_Fill, &rowDate);
 
-  PRInt32 days = GetAgeInDays(matchSearchTerm->now, rowDate);
+  PRInt32 days = matchSearchTerm->globalHist->GetAgeInDays(rowDate);
   
   if (term->method.Equals("is"))
     return (days == matchSearchTerm->intValue);
@@ -1686,7 +1675,7 @@ nsGlobalHistory::GetTarget(nsIRDFResource* aSource,
       rv = GetRowValue(row, kToken_LastVisitDateColumn, &lastVisitDate);
       if (NS_FAILED(rv)) return rv;
       
-      PRInt32 days = GetAgeInDays(NormalizeTime(GetNow()), lastVisitDate);
+      PRInt32 days = GetAgeInDays(lastVisitDate);
 
       nsCOMPtr<nsIRDFInt> ageLiteral;
       rv = gRDFService->GetIntLiteral(days, getter_AddRefs(ageLiteral));
@@ -1810,6 +1799,15 @@ nsGlobalHistory::GetNow()
 {
   if (!mNowValid) {             // not dirty, mLastNow is crufty
     mLastNow = PR_Now();
+
+    // we also cache our offset from GMT, to optimize NormalizeTime()
+    // note that this cache is only valid if GetNow() is called before
+    // NormalizeTime(), but that is always the case here.
+    PRExplodedTime explodedNow;
+    PR_ExplodeTime(mLastNow, PR_LocalTimeParameters, &explodedNow);
+    mCachedGMTOffset = nsInt64(explodedNow.tm_params.tp_gmt_offset) * nsInt64((PRUint32)PR_USEC_PER_SEC) +
+                       nsInt64(explodedNow.tm_params.tp_dst_offset) * nsInt64((PRUint32)PR_USEC_PER_SEC);
+
     mNowValid = PR_TRUE;
     if (!mExpireNowTimer)
       mExpireNowTimer = do_CreateInstance("@mozilla.org/timer;1");
@@ -3338,7 +3336,7 @@ nsGlobalHistory::NotifyFindAssertions(nsIRDFResource *aSource,
   PRInt64 lastVisited;
   GetRowValue(aRow, kToken_LastVisitDateColumn, &lastVisited);
 
-  PRInt32 ageInDays = GetAgeInDays(NormalizeTime(GetNow()), lastVisited);
+  PRInt32 ageInDays = GetAgeInDays(lastVisited);
   nsCAutoString ageString; ageString.AppendInt(ageInDays);
 
   nsCAutoString hostname;
@@ -3430,7 +3428,7 @@ nsGlobalHistory::NotifyFindUnassertions(nsIRDFResource *aSource,
   //    first get age in days
   PRInt64 lastVisited;
   GetRowValue(aRow, kToken_LastVisitDateColumn, &lastVisited);
-  PRInt32 ageInDays = GetAgeInDays(NormalizeTime(GetNow()), lastVisited);
+  PRInt32 ageInDays = GetAgeInDays(lastVisited);
   nsCAutoString ageString; ageString.AppendInt(ageInDays);
 
   //    now get hostname
@@ -3814,7 +3812,7 @@ nsGlobalHistory::RowMatches(nsIMdbRow *aRow,
     if (term->match) {
       // queue up some values just in case callback needs it
       // (how would we do this dynamically?)
-      matchSearchTerm_t matchSearchTerm = { mEnv, mStore, term , PR_FALSE};
+      matchSearchTerm_t matchSearchTerm = { mEnv, mStore, term, PR_FALSE, 0, this };
       
       if (!term->match(aRow, (void *)&matchSearchTerm))
         return PR_FALSE;
@@ -3837,7 +3835,7 @@ nsGlobalHistory::RowMatches(nsIMdbRow *aRow,
       if (err != 0 || !yarn.mYarn_Buf) return PR_FALSE;
 
       const char* startPtr;
-      PRInt32 yarnLength = yarn.mYarn_Fill;;
+      PRInt32 yarnLength = yarn.mYarn_Fill;
       nsCAutoString titleStr;
       if (property_column == kToken_NameColumn) {
         titleStr =  NS_ConvertUCS2toUTF8((const PRUnichar*)yarn.mYarn_Buf, yarnLength);

xpfe/components/history/src/nsGlobalHistory.h

@@ -153,6 +153,10 @@ public:
   PRBool MatchHost(nsIMdbRow *row, matchHost_t *hostInfo);
   PRBool RowMatches(nsIMdbRow* aRow, searchQuery *aQuery);
 
+  PRInt64 GetNow();
+  PRTime  NormalizeTime(PRInt64 aTime);
+  PRInt32 GetAgeInDays(PRInt64 aDate);
+
 protected:
 
   //
@@ -236,11 +240,12 @@ protected:
   // caching of PR_Now() so we don't call it every time we do
   // a history query
   PRInt64   mLastNow;           // cache the last PR_Now()
+  PRInt64   mCachedGMTOffset;   // cached offset from GMT
+
   PRInt32   mBatchesInProgress;
   PRBool    mNowValid;          // is mLastNow valid?
   nsCOMPtr<nsITimer> mExpireNowTimer;
   
-  PRInt64 GetNow();
   void ExpireNow();
   
   static void expireNowTimer(nsITimer *aTimer, void *aClosure)