Slightly smaller and faster implementation of the OP_MakeRecord opcode.

FossilOrigin-Name: 3bdce7ef1a6bb03affe978243fec603d5a55c071aa6d87c469a3c199d23f3b5e

manifest

@@ -1,5 +1,5 @@
-C Changes\sto\soserror.test\sso\sthat\sit\sworks\seven\son\ssystems\sthat\sallow\nan\sunusually\slarge\snumber\sof\sfile\sdescriptors.
-D 2019-04-29T16:44:11.554
+C Slightly\ssmaller\sand\sfaster\simplementation\sof\sthe\sOP_MakeRecord\sopcode.
+D 2019-04-30T01:08:42.471
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -591,7 +591,7 @@ F src/upsert.c 0dd81b40206841814d46942a7337786932475f085716042d0cb2fc7791bf8ca4
 F src/utf.c 2f0fac345c7660d5c5bd3df9e9d8d33d4c27f366bcfb09e07443064d751a0507
 F src/util.c 5061987401c2e8003177fa30d73196aa036727c8f04bf36a2df0c82b1904a236
 F src/vacuum.c 82dcec9e7b1afa980288718ad11bc499651c722d7b9f32933c4d694d91cb6ebf
-F src/vdbe.c 711ef421b3bb3db3b2476067b2dc3c71ef5844d9b1a723026578f89f6da621e8
+F src/vdbe.c 2782da511932d17e45e128f04f73314e5f5d765f7a499f5ac4bb1e0a82e082cc
 F src/vdbe.h 712bca562eaed1c25506b9faf9680bdc75fc42e2f4a1cd518d883fa79c7a4237
 F src/vdbeInt.h 2c12704db9740c8e899786ecfc7a5797a9d067563496eb1b6ed03c592d7b8d90
 F src/vdbeapi.c 2ddd60f4a351f15ee98d841e346af16111ad59dfa4d25d2dd4012e9875bf7d92
@@ -1821,7 +1821,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 1b1dd4d48cd79a585e1fa7ee79128e9f2a9ee9846339dc56bbd67b75112dcad5
-R 0bcdc9eac356966e584a16ee79a622df
+P a27b0b880d76c6838c0365f66bcd69b1b49b7594470993b608f4e490cbdc4882
+R b12c0740e7e730a41b03261e6f060f1c
 U drh
-Z e312b5e28707c934ce76aba346ace36f
+Z b866775507213d2cd189ff81277fbb67

manifest.uuid

@@ -1 +1 @@
-a27b0b880d76c6838c0365f66bcd69b1b49b7594470993b608f4e490cbdc4882
+3bdce7ef1a6bb03affe978243fec603d5a55c071aa6d87c469a3c199d23f3b5e

src/vdbe.c

@@ -2791,7 +2791,6 @@ case OP_Affinity: {
 ** If P4 is NULL then all index fields have the affinity BLOB.
 */
 case OP_MakeRecord: {
-  u8 *zNewRecord;        /* A buffer to hold the data for the new record */
   Mem *pRec;             /* The new record */
   u64 nData;             /* Number of bytes of data space */
   int nHdr;              /* Number of bytes of header space */
@@ -2804,9 +2803,9 @@ case OP_MakeRecord: {
   int nField;            /* Number of fields in the record */
   char *zAffinity;       /* The affinity string for the record */
   int file_format;       /* File format to use for encoding */
-  int i;                 /* Space used in zNewRecord[] header */
-  int j;                 /* Space used in zNewRecord[] content */
   u32 len;               /* Length of a field */
+  u8 *zHdr;              /* Where to write next byte of the header */
+  u8 *zPayload;          /* Where to write next byte of the payload */
 
   /* Assuming the record contains N fields, the record format looks
   ** like this:
@@ -2933,34 +2932,34 @@ case OP_MakeRecord: {
       goto no_mem;
     }
   }
-  zNewRecord = (u8 *)pOut->z;
-
-  /* Write the record */
-  i = putVarint32(zNewRecord, nHdr);
-  j = nHdr;
-  assert( pData0<=pLast );
-  pRec = pData0;
-  do{
-    serial_type = pRec->uTemp;
-    /* EVIDENCE-OF: R-06529-47362 Following the size varint are one or more
-    ** additional varints, one per column. */
-    i += putVarint32(&zNewRecord[i], serial_type);            /* serial type */
-    /* EVIDENCE-OF: R-64536-51728 The values for each column in the record
-    ** immediately follow the header. */
-    j += sqlite3VdbeSerialPut(&zNewRecord[j], pRec, serial_type); /* content */
-  }while( (++pRec)<=pLast );
-  assert( i==nHdr );
-  assert( j==nByte );
-
-  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
   pOut->n = (int)nByte;
   pOut->flags = MEM_Blob;
   if( nZero ){
     pOut->u.nZero = nZero;
     pOut->flags |= MEM_Zero;
   }
-  REGISTER_TRACE(pOp->p3, pOut);
   UPDATE_MAX_BLOBSIZE(pOut);
+  zHdr = (u8 *)pOut->z;
+  zPayload = zHdr + nHdr;
+
+  /* Write the record */
+  zHdr += putVarint32(zHdr, nHdr);
+  assert( pData0<=pLast );
+  pRec = pData0;
+  do{
+    serial_type = pRec->uTemp;
+    /* EVIDENCE-OF: R-06529-47362 Following the size varint are one or more
+    ** additional varints, one per column. */
+    zHdr += putVarint32(zHdr, serial_type);            /* serial type */
+    /* EVIDENCE-OF: R-64536-51728 The values for each column in the record
+    ** immediately follow the header. */
+    zPayload += sqlite3VdbeSerialPut(zPayload, pRec, serial_type); /* content */
+  }while( (++pRec)<=pLast );
+  assert( nHdr==(int)(zHdr - (u8*)pOut->z) );
+  assert( nByte==(int)(zPayload - (u8*)pOut->z) );
+
+  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
+  REGISTER_TRACE(pOp->p3, pOut);
   break;
 }