Streamline the decodeFlags() routine in btree.c for a small performance

increase.

FossilOrigin-Name: 4cb285210b4a2b14c80962bf2ecb35be310d3444c329c15d86b3073096455704

3 files changed, 53 insertions, 48 deletions

diff --git a/manifest b/manifest
index 3df90b2d8..4507d9d17 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Add\sbuild\sof\ssqlite3.mjs\s(ES6\smodule),\sadd\sa\stest\sapp\sfor\sit,\sand\sinclude\sit\sin\sthe\sdist\sbuild.
-D 2022-11-19T05:26:45.763
+C Streamline\sthe\sdecodeFlags()\sroutine\sin\sbtree.c\sfor\sa\ssmall\sperformance\nincrease.
+D 2022-11-19T13:09:03.004
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -578,7 +578,7 @@ F src/auth.c f4fa91b6a90bbc8e0d0f738aa284551739c9543a367071f55574681e0f24f8cf
 F src/backup.c a2891172438e385fdbe97c11c9745676bec54f518d4447090af97189fd8e52d7
 F src/bitvec.c 7c849aac407230278445cb069bebc5f89bf2ddd87c5ed9459b070a9175707b3d
 F src/btmutex.c 6ffb0a22c19e2f9110be0964d0731d2ef1c67b5f7fabfbaeb7b9dabc4b7740ca
-F src/btree.c e8fae9a95ea9561aebc41e467a9ee9ba9150ca373031e65773d62ff02d8250d2
+F src/btree.c 405994e58bdf8f58adb5b238cda4b428de2bfe67e8dac5577082f2fd70faeade
 F src/btree.h 4fcbb0b041013071dd5e9f53c538d49916c092e6ad8842185985e5270a0792de
 F src/btreeInt.h 8ce1332edd89dfd2461d561ac10a0ab5601c8e06200cb5230596c3caaf54482e
 F src/build.c d3e43e950e4e377c1d451a4862556792acdef1faba14a03f899d30d09731c48b
@@ -2057,8 +2057,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 10c723d96d61d2e552ec1102563d58f1eb11bc3d30e03606fd8e0279c5a9043a
-R 222130501cabad70ae0d5e4c47519919
-U stephan
-Z bbe51f75fec2c52a531f67e9a6ac36f6
+P 2e783670e10b59e67c14b0db7f4803b41790cc7730de221d54fa2d4483cfba33
+R b0bb099cec1bed805505fb24b4006305
+U drh
+Z 40c7b0608af0db932c6182b2b48b07d6
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 78bd7a46a..e95384805 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-2e783670e10b59e67c14b0db7f4803b41790cc7730de221d54fa2d4483cfba33
\ No newline at end of file
+4cb285210b4a2b14c80962bf2ecb35be310d3444c329c15d86b3073096455704
\ No newline at end of file
diff --git a/src/btree.c b/src/btree.c
index 1c6c14d4b..569b596c5 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -1900,62 +1900,67 @@ static int freeSpace(MemPage *pPage, u16 iStart, u16 iSize){
 ** Only the following combinations are supported.  Anything different
 ** indicates a corrupt database files:
 **
-**         PTF_ZERODATA
-**         PTF_ZERODATA | PTF_LEAF
-**         PTF_LEAFDATA | PTF_INTKEY
-**         PTF_LEAFDATA | PTF_INTKEY | PTF_LEAF
+**         PTF_ZERODATA                             (0x02,  2)
+**         PTF_LEAFDATA | PTF_INTKEY                (0x05,  5)
+**         PTF_ZERODATA | PTF_LEAF                  (0x0a, 10)
+**         PTF_LEAFDATA | PTF_INTKEY | PTF_LEAF     (0x0d, 13)
 */
 static int decodeFlags(MemPage *pPage, int flagByte){
   BtShared *pBt;     /* A copy of pPage->pBt */
 
   assert( pPage->hdrOffset==(pPage->pgno==1 ? 100 : 0) );
   assert( sqlite3_mutex_held(pPage->pBt->mutex) );
-  pPage->leaf = (u8)(flagByte>>3);  assert( PTF_LEAF == 1<<3 );
-  flagByte &= ~PTF_LEAF;
-  pPage->childPtrSize = 4-4*pPage->leaf;
   pBt = pPage->pBt;
-  if( flagByte==(PTF_LEAFDATA | PTF_INTKEY) ){
-    /* EVIDENCE-OF: R-07291-35328 A value of 5 (0x05) means the page is an
-    ** interior table b-tree page. */
-    assert( (PTF_LEAFDATA|PTF_INTKEY)==5 );
-    /* EVIDENCE-OF: R-26900-09176 A value of 13 (0x0d) means the page is a
-    ** leaf table b-tree page. */
-    assert( (PTF_LEAFDATA|PTF_INTKEY|PTF_LEAF)==13 );
-    pPage->intKey = 1;
-    if( pPage->leaf ){
+  pPage->max1bytePayload = pBt->max1bytePayload;
+  if( flagByte>=(PTF_ZERODATA | PTF_LEAF) ){
+    pPage->childPtrSize = 0;
+    pPage->leaf = 1;
+    if( flagByte==(PTF_LEAFDATA | PTF_INTKEY | PTF_LEAF) ){
       pPage->intKeyLeaf = 1;
       pPage->xCellSize = cellSizePtrTableLeaf;
       pPage->xParseCell = btreeParseCellPtr;
+      pPage->intKey = 1;
+      pPage->maxLocal = pBt->maxLeaf;
+      pPage->minLocal = pBt->minLeaf;
+    }else if( flagByte==(PTF_ZERODATA | PTF_LEAF) ){
+      pPage->intKey = 0;
+      pPage->intKeyLeaf = 0;
+      pPage->xCellSize = cellSizePtr;
+      pPage->xParseCell = btreeParseCellPtrIndex;
+      pPage->maxLocal = pBt->maxLocal;
+      pPage->minLocal = pBt->minLocal;
     }else{
+      pPage->intKey = 0;
+      pPage->intKeyLeaf = 0;
+      pPage->xCellSize = cellSizePtr;
+      pPage->xParseCell = btreeParseCellPtrIndex;
+      return SQLITE_CORRUPT_PAGE(pPage);
+    }
+  }else{
+    pPage->childPtrSize = 4;
+    pPage->leaf = 0;
+    if( flagByte==(PTF_ZERODATA) ){
+      pPage->intKey = 0;
+      pPage->intKeyLeaf = 0;
+      pPage->xCellSize = cellSizePtr;
+      pPage->xParseCell = btreeParseCellPtrIndex;
+      pPage->maxLocal = pBt->maxLocal;
+      pPage->minLocal = pBt->minLocal;
+    }else if( flagByte==(PTF_LEAFDATA | PTF_INTKEY) ){
       pPage->intKeyLeaf = 0;
       pPage->xCellSize = cellSizePtrNoPayload;
       pPage->xParseCell = btreeParseCellPtrNoPayload;
+      pPage->intKey = 1;
+      pPage->maxLocal = pBt->maxLeaf;
+      pPage->minLocal = pBt->minLeaf;
+    }else{
+      pPage->intKey = 0;
+      pPage->intKeyLeaf = 0;
+      pPage->xCellSize = cellSizePtr;
+      pPage->xParseCell = btreeParseCellPtrIndex;
+      return SQLITE_CORRUPT_PAGE(pPage);
     }
-    pPage->maxLocal = pBt->maxLeaf;
-    pPage->minLocal = pBt->minLeaf;
-  }else if( flagByte==PTF_ZERODATA ){
-    /* EVIDENCE-OF: R-43316-37308 A value of 2 (0x02) means the page is an
-    ** interior index b-tree page. */
-    assert( (PTF_ZERODATA)==2 );
-    /* EVIDENCE-OF: R-59615-42828 A value of 10 (0x0a) means the page is a
-    ** leaf index b-tree page. */
-    assert( (PTF_ZERODATA|PTF_LEAF)==10 );
-    pPage->intKey = 0;
-    pPage->intKeyLeaf = 0;
-    pPage->xCellSize = cellSizePtr;
-    pPage->xParseCell = btreeParseCellPtrIndex;
-    pPage->maxLocal = pBt->maxLocal;
-    pPage->minLocal = pBt->minLocal;
-  }else{
-    /* EVIDENCE-OF: R-47608-56469 Any other value for the b-tree page type is
-    ** an error. */
-    pPage->intKey = 0;
-    pPage->intKeyLeaf = 0;
-    pPage->xCellSize = cellSizePtr;
-    pPage->xParseCell = btreeParseCellPtrIndex;
-    return SQLITE_CORRUPT_PAGE(pPage);
   }
-  pPage->max1bytePayload = pBt->max1bytePayload;
   return SQLITE_OK;
 }