From: drh <>
Date: Wed, 13 Sep 2023 13:12:08 +0000 (+0000)
Subject: In the ChooseLeaf algorithm of RTREE, do an initial pass through the cells
X-Git-Tag: version-3.44.0~193^2~3
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=cdae00b3e8e4b1513276e746cad21cacaf056eff;p=thirdparty%2Fsqlite.git

In the ChooseLeaf algorithm of RTREE, do an initial pass through the cells
of a node looking for solutions that involve no cell enlargement.  Only look
for the minimum cell enlargement if the enlargement is non-zero for all cells.
This results in a performance improvement by reducing the number of calls
to cellUnion().

FossilOrigin-Name: 59f0e239d19393190911ea3bd89b5a24be0d85d64ccf51906efc9537ad5d7298
---

diff --git a/ext/rtree/rtree.c b/ext/rtree/rtree.c
index b2e8b3b65b..5a1450801f 100644
--- a/ext/rtree/rtree.c
+++ b/ext/rtree/rtree.c
@@ -2221,32 +2221,49 @@ static int ChooseLeaf(
   for(ii=0; rc==SQLITE_OK && ii<(pRtree->iDepth-iHeight); ii++){
     int iCell;
     sqlite3_int64 iBest = 0;
-
+    int bFound = 0;
     RtreeDValue fMinGrowth = RTREE_ZERO;
     RtreeDValue fMinArea = RTREE_ZERO;
-
     int nCell = NCELL(pNode);
     RtreeNode *pChild = 0;
 
-    /* Select the child node which will be enlarged the least if pCell
-    ** is inserted into it. Resolve ties by choosing the entry with
-    ** the smallest area.
+    /* First check to see if there is are any cells in pNode that completely
+    ** contains pCell.  If two or more cells in pNode completely contain pCell
+    ** then pick the smallest.
     */
     for(iCell=0; iCell<nCell; iCell++){
       RtreeCell cell;
-      RtreeDValue growth;
-      RtreeDValue area;
       nodeGetCell(pRtree, pNode, iCell, &cell);
-      area = cellArea(pRtree, &cell);
-      cellUnion(pRtree, &cell, pCell);
-      growth = cellArea(pRtree, &cell)-area;
-      if( iCell==0
-       || growth<fMinGrowth
-       || (growth==fMinGrowth && area<fMinArea)
-      ){
-        fMinGrowth = growth;
-        fMinArea = area;
-        iBest = cell.iRowid;
+      if( cellContains(pRtree, &cell, pCell) ){
+        RtreeDValue area = cellArea(pRtree, &cell);
+        if( bFound==0 || area<fMinArea ){
+          iBest = cell.iRowid;
+          fMinArea = area;
+          bFound = 1;
+        }
+      }
+    }
+    if( !bFound ){
+      /* No cells of pNode will completely contain pCell.  So pick the
+      ** cell of pNode that grows by the least amount when pCell is added.
+      ** Break ties by selecting the smaller cell.
+      */
+      for(iCell=0; iCell<nCell; iCell++){
+        RtreeCell cell;
+        RtreeDValue growth;
+        RtreeDValue area;
+        nodeGetCell(pRtree, pNode, iCell, &cell);
+        area = cellArea(pRtree, &cell);
+        cellUnion(pRtree, &cell, pCell);
+        growth = cellArea(pRtree, &cell)-area;
+        if( iCell==0
+         || growth<fMinGrowth
+         || (growth==fMinGrowth && area<fMinArea)
+        ){
+          fMinGrowth = growth;
+          fMinArea = area;
+          iBest = cell.iRowid;
+        }
       }
     }
 
diff --git a/manifest b/manifest
index e485376945..d5c9bfae1c 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Reduce\sthe\snumber\sof\scalls\sto\scellArea()\sin\sthe\sChooseLeaf()\salgorithm\sof\nrtree.
-D 2023-09-13T12:06:02.688
+C In\sthe\sChooseLeaf\salgorithm\sof\sRTREE,\sdo\san\sinitial\spass\sthrough\sthe\scells\nof\sa\snode\slooking\sfor\ssolutions\sthat\sinvolve\sno\scell\senlargement.\s\sOnly\slook\nfor\sthe\sminimum\scell\senlargement\sif\sthe\senlargement\sis\snon-zero\sfor\sall\scells.\nThis\sresults\sin\sa\sperformance\simprovement\sby\sreducing\sthe\snumber\sof\scalls\nto\scellUnion().
+D 2023-09-13T13:12:08.325
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -471,7 +471,7 @@ F ext/repair/test/checkindex01.test b530f141413b587c9eb78ff734de6bb79bc3515c3350
 F ext/repair/test/test.tcl 686d76d888dffd021f64260abf29a55c57b2cedfa7fc69150b42b1d6119aac3c
 F ext/rtree/README 6315c0d73ebf0ec40dedb5aa0e942bc8b54e3761
 F ext/rtree/geopoly.c 971e0b5bd9adaf0811feb8c0842a310811159da10319eb0e74fdb42bf26b99ca
-F ext/rtree/rtree.c 2cf6c6a643bf7bd0eca116b37d81c65ad2407136ee523729050cb56da0e1651a
+F ext/rtree/rtree.c 14e745969e69f128b27c3106318fd9bb5f87eb00c5bfdd5ccbb60a1872deb5b7
 F ext/rtree/rtree.h 4a690463901cb5e6127cf05eb8e642f127012fd5003830dbc974eca5802d9412
 F ext/rtree/rtree1.test 877d40b8b61b1f88cec9d4dc0ff8334f5b05299fac12a35141532e2881860e9d
 F ext/rtree/rtree2.test 9d9deddbb16fd0c30c36e6b4fdc3ee3132d765567f0f9432ee71e1303d32603d
@@ -2119,8 +2119,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P fb2e4a8067edc29ba64973820f265b21dfee0d32f4d675d32100d5eef93c2830
-R 50c424399f759c0884768065cbc409ef
+P c633fe6be0edc07a0aa1ac819d58b6c629b7c95b47b63516ae1b0a937f6a2b89
+R c022f3599d3f41d22b9b1469e98905ec
 U drh
-Z ac2eaf32235b1d74f19a79e1691a60ae
+Z 4cc63f132e0276d1f1f57289f0e4433b
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 7099b27f68..8422100f5d 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-c633fe6be0edc07a0aa1ac819d58b6c629b7c95b47b63516ae1b0a937f6a2b89
\ No newline at end of file
+59f0e239d19393190911ea3bd89b5a24be0d85d64ccf51906efc9537ad5d7298
\ No newline at end of file