From: drh <drh@noemail.net>
Date: Tue, 15 Aug 2017 14:14:36 +0000 (+0000)
Subject: Small size and performance in the OP_Column opcode.
X-Git-Tag: version-3.21.0~157
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6cd8c8c57a249feac637ea97f21a8d3de7670de3;p=thirdparty%2Fsqlite.git

Small size and performance in the OP_Column opcode.

FossilOrigin-Name: 2cf3f3de8a48465bd6b0af7763bfe905f3bb0151488f63c9ecc3147bcb345094
---

diff --git a/manifest b/manifest
index 3ee6a346e3..43be9dbc63 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Btree\soptimization:\s\sNew\sfield\sBtCursor.pPage\sthat\spoints\sto\sthe\scurrent\spage,\nsaving\sa\ssingle\spointer\sdereference\son\seach\saccess.
-D 2017-08-15T03:46:47.011
+C Small\ssize\sand\sperformance\sin\sthe\sOP_Column\sopcode.
+D 2017-08-15T14:14:36.511
 F Makefile.in d9873c9925917cca9990ee24be17eb9613a668012c85a343aef7e5536ae266e8
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 02b469e9dcd5b7ee63fc1fb05babc174260ee4cfa4e0ef2e48c3c6801567a016
@@ -522,7 +522,7 @@ F src/update.c 5404be9e840717323a69209190cdbc9d0d34adaedaaf1d1a1069babf2c4171c0
 F src/utf.c 810fbfebe12359f10bc2a011520a6e10879ab2a163bcb26c74768eab82ea62a5
 F src/util.c fc081ec6f63448dcd80d3dfad35baecfa104823254a815b081a4d9fe76e1db23
 F src/vacuum.c 90839322fd5f00df9617eb21b68beda9b6e2a2937576b0d65985e4aeb1c53739
-F src/vdbe.c 821b3edde2d17ec60da0617db1018a88f38634c359d22f3c8f7be10336c82636
+F src/vdbe.c ebfc41ca25465888b2dc2969a0059d0d563c2a36e31696352573198cdec51fad
 F src/vdbe.h d50cadf12bcf9fb99117ef392ce1ea283aa429270481426b6e8b0280c101fd97
 F src/vdbeInt.h ff2b7db0968d20e6184aee256d2e535d565f5a172e3588a78adb166a41fc4911
 F src/vdbeapi.c 05d6b14ab73952db0d73f6452d6960216997bd966a710266b2fe051f25326abc
@@ -1647,7 +1647,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 16969338841734d00ab906a94b82480c7e1e426eb0ddf7b9e6aed722aee5d91f
-R 3d6cdbe8a873abb5b839027115a07163
+P 373b71d19cad785922d5a80828f2fee0cbe7dff6594743e625bbdfa31b1ca131
+R 36da37536a24b366658dfab60814a38c
 U drh
-Z 53459ac0c08285b40b84acbd692920bc
+Z 16cc8098bdc3d63f9bef627e24ebd270
diff --git a/manifest.uuid b/manifest.uuid
index d331463c6a..f58cbd3506 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-373b71d19cad785922d5a80828f2fee0cbe7dff6594743e625bbdfa31b1ca131
\ No newline at end of file
+2cf3f3de8a48465bd6b0af7763bfe905f3bb0151488f63c9ecc3147bcb345094
\ No newline at end of file
diff --git a/src/vdbe.c b/src/vdbe.c
index d04a4f2c91..e44f06f3c9 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -2388,7 +2388,6 @@ case OP_Column: {
   const u8 *zEndHdr; /* Pointer to first byte after the header */
   u32 offset;        /* Offset into the data */
   u64 offset64;      /* 64-bit offset */
-  u32 avail;         /* Number of bytes of available data */
   u32 t;             /* A type code from the record header */
   Mem *pReg;         /* PseudoTable input register */
 
@@ -2419,7 +2418,7 @@ case OP_Column: {
         pReg = &aMem[pC->uc.pseudoTableReg];
         assert( pReg->flags & MEM_Blob );
         assert( memIsValid(pReg) );
-        pC->payloadSize = pC->szRow = avail = pReg->n;
+        pC->payloadSize = pC->szRow = pReg->n;
         pC->aRow = (u8*)pReg->z;
       }else{
         sqlite3VdbeMemSetNull(pDest);
@@ -2431,14 +2430,11 @@ case OP_Column: {
       assert( pCrsr );
       assert( sqlite3BtreeCursorIsValid(pCrsr) );
       pC->payloadSize = sqlite3BtreePayloadSize(pCrsr);
-      pC->aRow = sqlite3BtreePayloadFetch(pCrsr, &avail);
-      assert( avail<=65536 );  /* Maximum page size is 64KiB */
-      if( pC->payloadSize <= (u32)avail ){
-        pC->szRow = pC->payloadSize;
-      }else if( pC->payloadSize > (u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){
+      pC->aRow = sqlite3BtreePayloadFetch(pCrsr, &pC->szRow);
+      assert( pC->szRow<=pC->payloadSize );
+      assert( pC->szRow<=65536 );  /* Maximum page size is 64KiB */
+      if( pC->payloadSize > (u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){
         goto too_big;
-      }else{
-        pC->szRow = avail;
       }
     }
     pC->cacheStatus = p->cacheCtr;
@@ -2447,7 +2443,7 @@ case OP_Column: {
     aOffset[0] = offset;
 
 
-    if( avail<offset ){      /*OPTIMIZATION-IF-FALSE*/
+    if( pC->szRow<offset ){      /*OPTIMIZATION-IF-FALSE*/
       /* pC->aRow does not have to hold the entire row, but it does at least
       ** need to cover the header of the record.  If pC->aRow does not contain
       ** the complete header, then set it to zero, forcing the header to be