Performance optimization to sqlite3_blob_read().

FossilOrigin-Name: 7459f4b7ed4007d9ec44c3bf0fcba04f5f8540a9

diff --git a/manifest b/manifest
index 90d70de805b4c2382b77b53c5d83b24dcc0d6a66..54fc47c9d1aba7ee41b4fa69cc5b09b38438acf7 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Minor\ssimplification\sand\sperformance\soptimization\sfor\sDirect\sOverflow\sRead.
-D 2017-01-26T16:27:32.813
+C Performance\soptimization\sto\ssqlite3_blob_read().
+D 2017-01-26T16:54:47.281
 F Makefile.in 5f415e7867296d678fed2e6779aea10c1318b4bc
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc b8ca53350ae545e3562403d5da2a69cec79308da
@@ -333,7 +333,7 @@ F src/auth.c 930b376a9c56998557367e6f7f8aaeac82a2a792
 F src/backup.c faf17e60b43233c214aae6a8179d24503a61e83b
 F src/bitvec.c 17ea48eff8ba979f1f5b04cc484c7bb2be632f33
 F src/btmutex.c 0e9ce2d56159b89b9bc8e197e023ee11e39ff8ca
-F src/btree.c a168da7c4fff00dbd939c49ad4445d378eff1b11
+F src/btree.c 6fe6a5853148b623c4f5e288ae916180632ebbd3
 F src/btree.h e6d352808956ec163a17f832193a3e198b3fb0ac
 F src/btreeInt.h 10c4b77c2fb399580babbcc7cf652ac10dba796e
 F src/build.c 9e799f1edd910dfa8a0bc29bd390d35d310596af
@@ -1547,7 +1547,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 9879be1899adf5634f551a2077b15ccb1133e4e3
-R d7cd9a6ab86d59aef41165d7cf109b11
+P 3e96d6efa867b765c8acf1454014b1e71b2e4f21
+R 252dcd60be80c6c5c6ba84d2de14b6df
 U drh
-Z 50b1b915cab08ae10917e730aa3424e6
+Z 39fbcc21c34e29a424df0af03b3f8d43

diff --git a/manifest.uuid b/manifest.uuid
index d3b805d95ad02b709bfde40f0355169ea2799c42..051cfd0da25747c305194cd0853d4f62860909b2 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-3e96d6efa867b765c8acf1454014b1e71b2e4f21
\ No newline at end of file
+7459f4b7ed4007d9ec44c3bf0fcba04f5f8540a9
\ No newline at end of file

diff --git a/src/btree.c b/src/btree.c
index 3150026a587b7bd08f2576b59d47b4897095e3ff..0a2106e04bde948912c1d38ab80b51846e2e9ae3 100644 (file)
--- a/src/btree.c
+++ b/src/btree.c
@@ -4665,21 +4665,34 @@ int sqlite3BtreePayload(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){
   assert( pCur->aiIdx[pCur->iPage]<pCur->apPage[pCur->iPage]->nCell );
   return accessPayload(pCur, offset, amt, (unsigned char*)pBuf, 0);
 }
+
+/*
+** This variant of sqlite3BtreePayload() works even if the cursor has not
+** in the CURSOR_VALID state.  It is only used by the sqlite3_blob_read()
+** interface.
+*/
 #ifndef SQLITE_OMIT_INCRBLOB
-int sqlite3BtreePayloadChecked(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){
+static SQLITE_NOINLINE int accessPayloadChecked(
+  BtCursor *pCur,
+  u32 offset,
+  u32 amt,
+  void *pBuf
+){
   int rc;
   if ( pCur->eState==CURSOR_INVALID ){
     return SQLITE_ABORT;
   }
   assert( cursorOwnsBtShared(pCur) );
   rc = restoreCursorPosition(pCur);
-  if( rc==SQLITE_OK ){
-    assert( pCur->eState==CURSOR_VALID );
-    assert( pCur->iPage>=0 && pCur->apPage[pCur->iPage] );
-    assert( pCur->aiIdx[pCur->iPage]<pCur->apPage[pCur->iPage]->nCell );
-    rc = accessPayload(pCur, offset, amt, pBuf, 0);
+  return rc ? rc : accessPayload(pCur, offset, amt, pBuf, 0);
+}
+int sqlite3BtreePayloadChecked(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){
+  if( pCur->eState==CURSOR_VALID ){
+    assert( cursorOwnsBtShared(pCur) );
+    return accessPayload(pCur, offset, amt, pBuf, 0);
+  }else{
+    return accessPayloadChecked(pCur, offset, amt, pBuf);
   }
-  return rc;
 }
 #endif /* SQLITE_OMIT_INCRBLOB */