Performance improve to the 'localtime' and 'utc' modifiers for date/time

functions.

FossilOrigin-Name: 85cb6014751a0572d28ebd839331d5d7a78de45c9e522adcd834a8a85746f32e

diff --git a/manifest b/manifest
index a69fef3bd2d772bb9fcc241dd231526dea15a8c0..36eecc3606db23b0beff15d46db0c86a80e86fae 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Faster\simplementation\sof\sthe\sdate(),\stime(),\sand\sdatetime()\sfunctions.
-D 2022-02-10T12:57:53.736
+C Performance\simprove\sto\sthe\s'localtime'\sand\s'utc'\smodifiers\sfor\sdate/time\nfunctions.
+D 2022-02-10T15:40:40.522
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -499,7 +499,7 @@ F src/build.c b59ff41525c10b429adc277d3bca6e433b09d055b0df8c1529385763cea8bb04
 F src/callback.c 4c19af69835787bfe790ac560f3071a824eb629f34e41f97b52ce5235c77de1c
 F src/complete.c a3634ab1e687055cd002e11b8f43eb75c17da23e
 F src/ctime.c 2cce39df1a13e05b7633e6d21b651f21492471f991dd7b323a4ee4e7b7f0b7f1
-F src/date.c c9275705b097fe875ad4d194ed20e0af115f6d50058038e03ac8f8e417ee06eb
+F src/date.c 9d865dac4a796035a8cfb027c7c8450bc7ec54f8b51ebedbc5b8369e032e1cb9
 F src/dbpage.c 8a01e865bf8bc6d7b1844b4314443a6436c07c3efe1d488ed89e81719047833a
 F src/dbstat.c 861e08690fcb0f2ee1165eff0060ea8d4f3e2ea10f80dab7d32ad70443a6ff2d
 F src/delete.c b5f1716b4d723db48254ee0f896e362cd029e865e05414139ea7f539f3884e1d
@@ -837,7 +837,7 @@ F test/ctime.test 340f362f41f92972bbd71f44e10569a5cc694062b692231bd08aa6fe6c1c47
 F test/cursorhint.test 0175e4404181ace3ceca8b114eb0a98eae600d565aa4e2705abbe6614c7fe201
 F test/cursorhint2.test 6f3aa9cb19e7418967a10ec6905209bcbb5968054da855fc36c8beee9ae9c42f
 F test/dataversion1.test 6e5e86ac681f0782e766ebcb56c019ae001522d114e0e111e5ebf68ccf2a7bb8
-F test/date.test 9b73bbeb1b82d9c1f44dec5cf563bf7da58d2373
+F test/date.test 7e1da08fca5492081605a2bf445370b06be6a95db1150f3133b70eb672b33cb3
 F test/date2.test 7e12ec14aaf4d5e6294b4ba140445b0eca06ea50062a9c3a69c4ee13d0b6f8b1
 F test/date3.test a1b77abf05c6772fe5ca2337cac1398892f2a41e62bce7e6be0f4a08a0e64ae5
 F test/dbdata.test 042f49acff3438f940eeba5868d3af080ae64ddf26ae78f80c92bec3ca7d8603
@@ -1944,8 +1944,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 4565f711291bae5daaff6dd2b7b2991b17e139a576b1b73bb1f81f08a4c1a13f
-R 83b35984d6e76589cbc31defad98bf4a
+P fa1b393bdb66b985f6552190a8242ed878f91d653a03352f65aa8d750de3cec4
+R 67dc667c505ca83a0a8211aab2594ab6
 U drh
-Z f2060761086c3825d641957e607d18e2
+Z f3fee6ce5a9f7a29390c33b813554b1e
 # Remove this line to create a well-formed Fossil manifest.

diff --git a/manifest.uuid b/manifest.uuid
index f9285f75aca96f67cf4dee10da2f1c9d41a20ee5..6a69ddd7b759ca067347f48346571c97d94f1057 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-fa1b393bdb66b985f6552190a8242ed878f91d653a03352f65aa8d750de3cec4
\ No newline at end of file
+85cb6014751a0572d28ebd839331d5d7a78de45c9e522adcd834a8a85746f32e
\ No newline at end of file

diff --git a/src/date.c b/src/date.c
index 2001d50ab4686e28d1338e3d07c94036a110097e..3225a5528d4be199e30605be8a200a3b00727bca 100644 (file)
--- a/src/date.c
+++ b/src/date.c
@@ -544,67 +544,56 @@ static int osLocaltime(time_t *t, struct tm *pTm){
 
 #ifndef SQLITE_OMIT_LOCALTIME
 /*
-** Compute the difference (in milliseconds) between localtime and UTC
-** (a.k.a. GMT) for the time value p where p is in UTC. If no error occurs,
-** return this value and set *pRc to SQLITE_OK. 
-**
-** Or, if an error does occur, set *pRc to SQLITE_ERROR. The returned value
-** is undefined in this case.
+** Assuming the input DateTime is UTC, move it to its localtime equivalent.
 */
-static sqlite3_int64 localtimeOffset(
-  DateTime *p,                    /* Date at which to calculate offset */
-  sqlite3_context *pCtx,          /* Write error here if one occurs */
-  int *pRc                        /* OUT: Error code. SQLITE_OK or ERROR */
+static int toLocaltime(
+  DateTime *p,                   /* Date at which to calculate offset */
+  sqlite3_context *pCtx          /* Write error here if one occurs */
 ){
-  DateTime x, y;
   time_t t;
   struct tm sLocal;
+  int iYearDiff;
 
   /* Initialize the contents of sLocal to avoid a compiler warning. */
   memset(&sLocal, 0, sizeof(sLocal));
 
-  x = *p;
-  computeYMD_HMS(&x);
-  if( x.Y<1971 || x.Y>=2038 ){
+  computeJD(p);
+  if( p->iJD<21086676000*(i64)10000 /* 1970-01-01 */
+   || p->iJD>21301414560*(i64)10000 /* 2038-01-18 */
+  ){
     /* EVIDENCE-OF: R-55269-29598 The localtime_r() C function normally only
     ** works for years between 1970 and 2037. For dates outside this range,
     ** SQLite attempts to map the year into an equivalent year within this
     ** range, do the calculation, then map the year back.
     */
-    x.Y = 2000;
-    x.M = 1;
-    x.D = 1;
-    x.h = 0;
-    x.m = 0;
-    x.s = 0.0;
-  } else {
-    int s = (int)(x.s + 0.5);
-    x.s = s;
+    DateTime x = *p;
+    computeYMD_HMS(&x);
+    iYearDiff = (2000 + x.Y%4) - x.Y;
+    x.Y += iYearDiff;
+    x.validJD = 0;
+    computeJD(&x);
+    t = (time_t)(x.iJD/1000 -  21086676*(i64)10000);
+  }else{
+    iYearDiff = 0;
+    t = (time_t)(p->iJD/1000 -  21086676*(i64)10000);
   }
-  x.tz = 0;
-  x.validJD = 0;
-  computeJD(&x);
-  t = (time_t)(x.iJD/1000 - 21086676*(i64)10000);
   if( osLocaltime(&t, &sLocal) ){
     sqlite3_result_error(pCtx, "local time unavailable", -1);
-    *pRc = SQLITE_ERROR;
-    return 0;
+    return SQLITE_ERROR;
   }
-  y.Y = sLocal.tm_year + 1900;
-  y.M = sLocal.tm_mon + 1;
-  y.D = sLocal.tm_mday;
-  y.h = sLocal.tm_hour;
-  y.m = sLocal.tm_min;
-  y.s = sLocal.tm_sec;
-  y.validYMD = 1;
-  y.validHMS = 1;
-  y.validJD = 0;
-  y.rawS = 0;
-  y.validTZ = 0;
-  y.isError = 0;
-  computeJD(&y);
-  *pRc = SQLITE_OK;
-  return y.iJD - x.iJD;
+  p->Y = sLocal.tm_year + 1900 - iYearDiff;
+  p->M = sLocal.tm_mon + 1;
+  p->D = sLocal.tm_mday;
+  p->h = sLocal.tm_hour;
+  p->m = sLocal.tm_min;
+  p->s = sLocal.tm_sec;
+  p->validYMD = 1;
+  p->validHMS = 1;
+  p->validJD = 0;
+  p->rawS = 0;
+  p->validTZ = 0;
+  p->isError = 0;
+  return SQLITE_OK;
 }
 #endif /* SQLITE_OMIT_LOCALTIME */
 
@@ -713,9 +702,7 @@ static int parseModifier(
       ** show local time.
       */
       if( sqlite3_stricmp(z, "localtime")==0 && sqlite3NotPureFunc(pCtx) ){
-        computeJD(p);
-        p->iJD += localtimeOffset(p, pCtx, &rc);
-        clearYMD_HMS_TZ(p);
+        rc = toLocaltime(p, pCtx);
       }
       break;
     }
@@ -741,18 +728,31 @@ static int parseModifier(
 #ifndef SQLITE_OMIT_LOCALTIME
       else if( sqlite3_stricmp(z, "utc")==0 && sqlite3NotPureFunc(pCtx) ){
         if( p->tzSet==0 ){
-          sqlite3_int64 c1;
+          i64 iOrigJD;              /* Original localtime */
+          i64 iGuess;               /* Guess at the corresponding utc time */
+          int cnt = 0;              /* Safety to prevent infinite loop */
+          int iErr;                 /* Guess is off by this much */
+
           computeJD(p);
-          c1 = localtimeOffset(p, pCtx, &rc);
-          if( rc==SQLITE_OK ){
-            p->iJD -= c1;
-            clearYMD_HMS_TZ(p);
-            p->iJD += c1 - localtimeOffset(p, pCtx, &rc);
-          }
+          iGuess = iOrigJD = p->iJD;
+          iErr = 0;
+          do{
+            DateTime new;
+            memset(&new, 0, sizeof(new));
+            iGuess -= iErr;
+            new.iJD = iGuess;
+            new.validJD = 1;
+            rc = toLocaltime(&new, pCtx);
+            if( rc ) return rc;
+            computeJD(&new);
+            iErr = new.iJD - iOrigJD;
+          }while( iErr && cnt++<3 );
+          memset(p, 0, sizeof(*p));
+          p->iJD = iGuess;
+          p->validJD = 1;
           p->tzSet = 1;
-        }else{
-          rc = SQLITE_OK;
         }
+        rc = SQLITE_OK;
       }
 #endif
       break;

diff --git a/test/date.test b/test/date.test
index f002334d17d3b41108fa24c600152f4a0a70d00d..2e5859ad294528431743cb5c02d3286b314273f8 100644 (file)
--- a/test/date.test
+++ b/test/date.test
@@ -332,9 +332,9 @@ if {$tzoffset_new==4} {
   }
   datetest 6.7.2 {datetime('2007-03-11 01:59:00','utc')} {2007-03-11 06:59:00}
 
-  datetest 6.8 {datetime('2000-04-02 02:00:00','utc')} {2000-04-02 06:00:00}
-  datetest 6.8.1 {datetime('2006-04-02 02:00:00','utc')} {2006-04-02 06:00:00}
-  datetest 6.8.2 {datetime('2007-03-11 02:00:00','utc')} {2007-03-11 06:00:00}
+  datetest 6.8 {datetime('2000-04-02 02:00:00','utc')} {2000-04-02 07:00:00}
+  datetest 6.8.1 {datetime('2006-04-02 02:00:00','utc')} {2006-04-02 07:00:00}
+  datetest 6.8.2 {datetime('2007-03-11 02:00:00','utc')} {2007-03-11 07:00:00}
 
   # The 'utc' modifier is a no-op if the LHS is known to already be in UTC
   datetest 6.9.1 {datetime('2015-12-23 12:00:00','utc')} {2015-12-23 17:00:00}
@@ -353,10 +353,10 @@ if {$tzoffset_new==4} {
       {2039-01-01 07:00:00}
   datetest 6.13 {datetime('2000-07-01 12:00:00','localtime')} \
       {2000-07-01 08:00:00}
-  datetest 6.14 {datetime('1969-07-01 12:00:00','localtime')} \
-      {1969-07-01 07:00:00}
-  datetest 6.15 {datetime('2039-07-01 12:00:00','localtime')} \
-      {2039-07-01 07:00:00}
+  datetest 6.14 {datetime('1969-11-01 12:00:00','localtime')} \
+      {1969-11-01 07:00:00}
+  datetest 6.15 {datetime('2039-02-01 12:00:00','localtime')} \
+      {2039-02-01 07:00:00}
   set sqlite_current_time \
      [db eval {SELECT strftime('%s','2000-07-01 12:34:56')}]
   datetest 6.16 {datetime('now','localtime')} {2000-07-01 08:34:56}