From f54a80fe5c4afa61f17ec3380a4201b1fda630d7 Mon Sep 17 00:00:00 2001
From: drh <>
Date: Fri, 29 Jan 2021 13:47:36 +0000
Subject: [PATCH] Performance optimization (and size reduction) in
 sqlite3TriggerList() for the common case where there are no TEMP triggers.

FossilOrigin-Name: 0defaf730bdc82212a5d3feeb2e16f16423b1691b0aaa7da1787eb82ea39ae9e
---
 manifest      | 13 ++++++-------
 manifest.uuid |  2 +-
 src/trigger.c | 22 +++++++++++++---------
 3 files changed, 20 insertions(+), 17 deletions(-)

diff --git a/manifest b/manifest
index df58f37956..7045fd7798 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\san\sissue\swith\sIN\soperator\soptimization\sintroduced\sby\ncheck-in\s[4a43430fd23f8835]\sand\sdescribed\sby\sticket\s[ee51301f316c09e9].
-D 2021-01-27T19:15:06.983
+C Performance\soptimization\s(and\ssize\sreduction)\sin\ssqlite3TriggerList()\sfor\sthe\ncommon\scase\swhere\sthere\sare\sno\sTEMP\striggers.
+D 2021-01-29T13:47:36.426
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -607,7 +607,7 @@ F src/test_wsd.c 41cadfd9d97fe8e3e4e44f61a4a8ccd6f7ca8fe9
 F src/threads.c 4ae07fa022a3dc7c5beb373cf744a85d3c5c6c3c
 F src/tokenize.c c64c49d7c2ec4490c2fef1f24350167ba16b03b0c6cee58ad1a1d70a4325d4e9
 F src/treeview.c 4b92992176fb2caefbe06ba5bd06e0e0ebcde3d5564758da672631f17aa51cda
-F src/trigger.c 29680c54c1aa088fa1b4d50137d75669a40d5ef814394e321fab1e547868e3d3
+F src/trigger.c 731ea5ed6b308574b7dc2a5d2a9187ef5510a3692cc1ea06a34608a084b8f376
 F src/update.c 9f126204a6acb96bbe47391ae48e0fc579105d8e76a6d9c4fab3271367476580
 F src/upsert.c df8f1727d62b5987c4fd302cd4d7c0c84ae57cd65683c5a34a740dfe24039235
 F src/utf.c ee39565f0843775cc2c81135751ddd93eceb91a673ea2c57f61c76f288b041a0
@@ -1898,8 +1898,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 0571c24177d77ac966bcf42cb8ab00fdf541ce84af1468c8ef0b60c48c45a22f 390cf60a286b13f454429f4652a133f95a7891a75c1ec6d16cd39990590fd3fb
-R 4574041b82ab28e377188abbe28af4d5
-T +closed 390cf60a286b13f454429f4652a133f95a7891a75c1ec6d16cd39990590fd3fb
+P 9dc7fc9f04d5c14fc436e5ff5b4c06c1969ddde5857ebeb5dccd59b7c748c339
+R 0b7a0544b0d15fb4a458f0ab87fbb410
 U drh
-Z 071fbdee3969843efb30cf74f43578ee
+Z 6a477571c6e856bdd183f551e55df63b
diff --git a/manifest.uuid b/manifest.uuid
index 29b10f4d3b..6f87f82bcf 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-9dc7fc9f04d5c14fc436e5ff5b4c06c1969ddde5857ebeb5dccd59b7c748c339
\ No newline at end of file
+0defaf730bdc82212a5d3feeb2e16f16423b1691b0aaa7da1787eb82ea39ae9e
\ No newline at end of file
diff --git a/src/trigger.c b/src/trigger.c
index 0c8cf5334f..a9378fd3a3 100644
--- a/src/trigger.c
+++ b/src/trigger.c
@@ -48,28 +48,32 @@ void sqlite3DeleteTriggerStep(sqlite3 *db, TriggerStep *pTriggerStep){
 ** pTab as well as the triggers lised in pTab->pTrigger.
 */
 Trigger *sqlite3TriggerList(Parse *pParse, Table *pTab){
-  Schema * const pTmpSchema = pParse->db->aDb[1].pSchema;
-  Trigger *pList = 0;                  /* List of triggers to return */
+  Schema *pTmpSchema;       /* Schema of the pTab table */
+  Trigger *pList;           /* List of triggers to return */
+  HashElem *p;              /* Loop variable for TEMP triggers */
 
   if( pParse->disableTriggers ){
     return 0;
   }
-
+  pTmpSchema = pParse->db->aDb[1].pSchema;
+  p = sqliteHashFirst(&pTmpSchema->trigHash);
+  if( p==0 ){
+    return pTab->pTrigger;
+  }
+  pList = pTab->pTrigger;
   if( pTmpSchema!=pTab->pSchema ){
-    HashElem *p;
-    assert( sqlite3SchemaMutexHeld(pParse->db, 0, pTmpSchema) );
-    for(p=sqliteHashFirst(&pTmpSchema->trigHash); p; p=sqliteHashNext(p)){
+    while( p ){
       Trigger *pTrig = (Trigger *)sqliteHashData(p);
       if( pTrig->pTabSchema==pTab->pSchema
        && 0==sqlite3StrICmp(pTrig->table, pTab->zName) 
       ){
-        pTrig->pNext = (pList ? pList : pTab->pTrigger);
+        pTrig->pNext = pList;
         pList = pTrig;
       }
+      p = sqliteHashNext(p);    
     }
   }
-
-  return (pList ? pList : pTab->pTrigger);
+  return pList;  
 }
 
 /*