Various speed enhancements. (CVS 1498)

FossilOrigin-Name: a0db15bba64af0c529d5be366659bca1165ff21b

7 files changed, 113 insertions, 87 deletions

diff --git a/src/btree.c b/src/btree.c
index dcf0eac10..8057be79b 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -9,7 +9,7 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** $Id: btree.c,v 1.151 2004/05/30 19:19:05 drh Exp $
+** $Id: btree.c,v 1.152 2004/05/30 20:46:09 drh Exp $
 **
 ** This file implements a external (disk-based) database using BTrees.
 ** For a detailed discussion of BTrees, refer to
@@ -1735,11 +1735,9 @@ int sqlite3BtreeData(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){
 ** Return a pointer to payload information from the entry that the 
 ** pCur cursor is pointing to.  The pointer is to the beginning of
 ** the key if skipKey==0 and it points to the beginning of data if
-** skipKey==1.
-**
-** At least amt bytes of information must be available on the local
-** page or else this routine returns NULL.  If amt<0 then the entire
-** key/data must be available.
+** skipKey==1.  The number of bytes of available key/data is written
+** into *pAmt.  If *pAmt==0, then the value returned will not be
+** a valid pointer.
 **
 ** This routine is an optimization.  It is common for the entire key
 ** and data to fit on the local page and for there to be no overflow
@@ -1754,7 +1752,7 @@ int sqlite3BtreeData(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){
 */
 static const unsigned char *fetchPayload(
   BtCursor *pCur,      /* Cursor pointing to entry to read from */
-  int amt,             /* Amount requested */
+  int *pAmt,           /* Write the number of available bytes here */
   int skipKey          /* read beginning at data if this is true */
 ){
   unsigned char *aPayload;
@@ -1780,43 +1778,33 @@ static const unsigned char *fetchPayload(
   if( skipKey ){
     aPayload += nKey;
     nLocal = pCur->info.nLocal - nKey;
-    if( amt<0 ) amt = pCur->info.nData;
-    assert( amt<=pCur->info.nData );
   }else{
     nLocal = pCur->info.nLocal;
-    if( amt<0 ) amt = nKey;
-    assert( amt<=nKey );
-  }
-  if( amt>nLocal ){
-    return 0;  /* If any of the data is not local, return nothing */
+    if( nLocal>nKey ){
+      nLocal = nKey;
+    }
   }
+  *pAmt = nLocal;
   return aPayload;
 }
 
 
 /*
-** Return a pointer to the first amt bytes of the key or data
-** for record that cursor pCur is point to if the entire request
-** exists in contiguous memory on the main tree page.  If any
-** any part of the request is on an overflow page, return 0.
-** If pCur is not pointing to a valid entry return 0.
-**
-** If amt<0 then return the entire key or data.
+** For the entry that cursor pCur is point to, return as
+** many bytes of the key or data as are available on the local
+** b-tree page.  Write the number of available bytes into *pAmt.
 **
 ** The pointer returned is ephemeral.  The key/data may move
 ** or be destroyed on the next call to any Btree routine.
 **
 ** These routines is used to get quick access to key and data
 ** in the common case where no overflow pages are used.
-**
-** It is a fatal error to call these routines with amt values that
-** are larger than the key/data size.
 */
-const void *sqlite3BtreeKeyFetch(BtCursor *pCur, int amt){
-  return (const void*)fetchPayload(pCur, amt, 0);
+const void *sqlite3BtreeKeyFetch(BtCursor *pCur, int *pAmt){
+  return (const void*)fetchPayload(pCur, pAmt, 0);
 }
-const void *sqlite3BtreeDataFetch(BtCursor *pCur, int amt){
-  return (const void*)fetchPayload(pCur, amt, 1);
+const void *sqlite3BtreeDataFetch(BtCursor *pCur, int *pAmt){
+  return (const void*)fetchPayload(pCur, pAmt, 1);
 }
 
 
@@ -2077,15 +2065,19 @@ int sqlite3BtreeMoveto(BtCursor *pCur, const void *pKey, i64 nKey, int *pRes){
         }else{
           c = 0;
         }
-      }else if( (pCellKey = sqlite3BtreeKeyFetch(pCur, nCellKey))!=0 ){
-        c = pCur->xCompare(pCur->pArg, nCellKey, pCellKey, nKey, pKey);
       }else{
-        u8 *pCellKey = sqliteMalloc( nCellKey );
-        if( pCellKey==0 ) return SQLITE_NOMEM;
-        rc = sqlite3BtreeKey(pCur, 0, nCellKey, pCellKey);
-        c = pCur->xCompare(pCur->pArg, nCellKey, pCellKey, nKey, pKey);
-        sqliteFree(pCellKey);
-        if( rc ) return rc;
+        int available;
+        pCellKey = fetchPayload(pCur, &available, 0);
+        if( available>=nCellKey ){
+          c = pCur->xCompare(pCur->pArg, nCellKey, pCellKey, nKey, pKey);
+        }else{
+          pCellKey = sqliteMallocRaw( nCellKey );
+          if( pCellKey==0 ) return SQLITE_NOMEM;
+          rc = sqlite3BtreeKey(pCur, 0, nCellKey, pCellKey);
+          c = pCur->xCompare(pCur->pArg, nCellKey, pCellKey, nKey, pKey);
+          sqliteFree(pCellKey);
+          if( rc ) return rc;
+        }
       }
       if( c==0 ){
         if( pPage->leafData && !pPage->leaf ){
diff --git a/src/btree.h b/src/btree.h
index 78fc61c59..639e55bcd 100644
--- a/src/btree.h
+++ b/src/btree.h
@@ -13,7 +13,7 @@
 ** subsystem.  See comments in the source code for a detailed description
 ** of what each interface routine does.
 **
-** @(#) $Id: btree.h,v 1.48 2004/05/18 10:06:25 danielk1977 Exp $
+** @(#) $Id: btree.h,v 1.49 2004/05/30 20:46:09 drh Exp $
 */
 #ifndef _BTREE_H_
 #define _BTREE_H_
@@ -92,8 +92,8 @@ int sqlite3BtreeFlags(BtCursor*);
 int sqlite3BtreePrevious(BtCursor*, int *pRes);
 int sqlite3BtreeKeySize(BtCursor*, i64 *pSize);
 int sqlite3BtreeKey(BtCursor*, u32 offset, u32 amt, void*);
-const void *sqlite3BtreeKeyFetch(BtCursor*, int amt);
-const void *sqlite3BtreeDataFetch(BtCursor*, int amt);
+const void *sqlite3BtreeKeyFetch(BtCursor*, int *pAmt);
+const void *sqlite3BtreeDataFetch(BtCursor*, int *pAmt);
 int sqlite3BtreeDataSize(BtCursor*, u32 *pSize);
 int sqlite3BtreeData(BtCursor*, u32 offset, u32 amt, void*);
 
diff --git a/src/test3.c b/src/test3.c
index 0ee59bbcf..a402b3146 100644
--- a/src/test3.c
+++ b/src/test3.c
@@ -13,7 +13,7 @@
 ** is not included in the SQLite library.  It is used for automated
 ** testing of the SQLite library.
 **
-** $Id: test3.c,v 1.38 2004/05/18 15:57:42 drh Exp $
+** $Id: test3.c,v 1.39 2004/05/30 20:46:09 drh Exp $
 */
 #include "sqliteInt.h"
 #include "pager.h"
@@ -986,6 +986,7 @@ static int btree_fetch_key(
 ){
   BtCursor *pCur;
   int n;
+  int amt;
   u64 nKey;
   const char *zBuf;
   char zStatic[1000];
@@ -998,8 +999,8 @@ static int btree_fetch_key(
   if( Tcl_GetInt(interp, argv[1], (int*)&pCur) ) return TCL_ERROR;
   if( Tcl_GetInt(interp, argv[2], &n) ) return TCL_ERROR;
   sqlite3BtreeKeySize(pCur, &nKey);
-  zBuf = sqlite3BtreeKeyFetch(pCur, n);
-  if( zBuf ){
+  zBuf = sqlite3BtreeKeyFetch(pCur, &amt);
+  if( zBuf && amt>=n ){
     assert( nKey<sizeof(zStatic) );
     if( n>0 ) nKey = n;
     memcpy(zStatic, zBuf, (int)nKey); 
@@ -1023,21 +1024,21 @@ static int btree_fetch_data(
 ){
   BtCursor *pCur;
   int n;
+  int amt;
   u32 nData;
   const char *zBuf;
   char zStatic[1000];
 
   if( argc!=3 ){
     Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
-       " ID AMT
-\"", 0);
+       " ID AMT\"", 0);
     return TCL_ERROR;
   }
   if( Tcl_GetInt(interp, argv[1], (int*)&pCur) ) return TCL_ERROR;
   if( Tcl_GetInt(interp, argv[2], &n) ) return TCL_ERROR;
   sqlite3BtreeDataSize(pCur, &nData);
-  zBuf = sqlite3BtreeDataFetch(pCur, n);
-  if( zBuf ){
+  zBuf = sqlite3BtreeDataFetch(pCur, &amt);
+  if( zBuf && amt>=n ){
     assert( nData<sizeof(zStatic) );
     if( n>0 ) nData = n;
     memcpy(zStatic, zBuf, (int)nData); 
diff --git a/src/util.c b/src/util.c
index 4aea0c802..e8b10a05f 100644
--- a/src/util.c
+++ b/src/util.c
@@ -14,7 +14,7 @@
 ** This file contains functions for allocating memory, comparing
 ** strings, and stuff like that.
 **
-** $Id: util.c,v 1.94 2004/05/28 16:00:22 drh Exp $
+** $Id: util.c,v 1.95 2004/05/30 20:46:09 drh Exp $
 */
 #include "sqliteInt.h"
 #include <stdarg.h>
@@ -1233,26 +1233,22 @@ int sqlite3GetVarint(const unsigned char *p, u64 *v){
   u64 x64;
   int n;
   unsigned char c;
-  c = p[0];
-  if( (c & 0x80)==0 ){
+  if( ((c = p[0]) & 0x80)==0 ){
     *v = c;
     return 1;
   }
   x = c & 0x7f;
-  c = p[1];
-  if( (c & 0x80)==0 ){
+  if( ((c = p[1]) & 0x80)==0 ){
     *v = (x<<7) | c;
     return 2;
   }
   x = (x<<7) | (c&0x7f);
-  c = p[2];
-  if( (c & 0x80)==0 ){
+  if( ((c = p[2]) & 0x80)==0 ){
     *v = (x<<7) | c;
     return 3;
   }
   x = (x<<7) | (c&0x7f);
-  c = p[3];
-  if( (c & 0x80)==0 ){
+  if( ((c = p[3]) & 0x80)==0 ){
     *v = (x<<7) | c;
     return 4;
   }
@@ -1275,13 +1271,32 @@ int sqlite3GetVarint(const unsigned char *p, u64 *v){
 ** Return the number of bytes read.  The value is stored in *v.
 */
 int sqlite3GetVarint32(const unsigned char *p, u32 *v){
-  int n = 1;
-  unsigned char c = p[0];
-  u32 x = c & 0x7f;
-  while( (c & 0x80)!=0 && n<9 ){
-    c = p[n++];
-    x = (x<<7) | (c & 0x7f);
+  u32 x;
+  int n;
+  unsigned char c;
+  if( ((c = p[0]) & 0x80)==0 ){
+    *v = c;
+    return 1;
+  }
+  x = c & 0x7f;
+  if( ((c = p[1]) & 0x80)==0 ){
+    *v = (x<<7) | c;
+    return 2;
   }
+  x = (x<<7) | (c&0x7f);
+  if( ((c = p[2]) & 0x80)==0 ){
+    *v = (x<<7) | c;
+    return 3;
+  }
+  x = (x<<7) | (c&0x7f);
+  if( ((c = p[3]) & 0x80)==0 ){
+    *v = (x<<7) | c;
+    return 4;
+  }
+  n = 4;
+  do{
+    x = (x<<7) | ((c = p[n++])&0x7f);
+  }while( (c & 0x80)!=0 && n<9 );
   *v = x;
   return n;
 }
diff --git a/src/vdbe.c b/src/vdbe.c
index 5346dec90..5b773fb51 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -43,7 +43,7 @@
 ** in this file for details.  If in doubt, do not deviate from existing
 ** commenting and indentation practices when changing or adding code.
 **
-** $Id: vdbe.c,v 1.348 2004/05/30 02:14:18 drh Exp $
+** $Id: vdbe.c,v 1.349 2004/05/30 20:46:09 drh Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -1531,9 +1531,10 @@ case OP_Ge: {
   }
 
   affinity = (pOp->p1>>8)&0xFF;
-  if( affinity=='\0' ) affinity = 'n';
-  applyAffinity(pNos, affinity, db->enc);
-  applyAffinity(pTos, affinity, db->enc);
+  if( affinity ){
+    applyAffinity(pNos, affinity, db->enc);
+    applyAffinity(pTos, affinity, db->enc);
+  }
 
   assert( pOp->p3type==P3_COLLSEQ || pOp->p3==0 );
   res = sqlite3MemCompare(pNos, pTos, (CollSeq*)pOp->p3);
@@ -1889,6 +1890,7 @@ case OP_Column: {
     aType = pC->aType;
     aOffset = pC->aOffset;
   }else{
+    int avail;    /* Number of bytes of available data */
     if( pC && pC->aType ){
       aType = pC->aType;
     }else{
@@ -1903,17 +1905,16 @@ case OP_Column: {
     if( zRec ){
       zData = zRec;
     }else{
-      int sz = payloadSize<5 ? payloadSize : 5;
       if( pC->keyAsData ){
-        zData = (char*)sqlite3BtreeKeyFetch(pCrsr, sz);
+        zData = (char*)sqlite3BtreeKeyFetch(pCrsr, &avail);
       }else{
-        zData = (char*)sqlite3BtreeDataFetch(pCrsr, sz);
+        zData = (char*)sqlite3BtreeDataFetch(pCrsr, &avail);
       }
     }
     idx = sqlite3GetVarint32(zData, &szHdr);
 
     /* Get the complete header text */
-    if( !zRec ){
+    if( !zRec && avail<idx ){
       rc = sqlite3VdbeMemFromBtree(pCrsr, 0, szHdr, pC->keyAsData, &sMem);
       if( rc!=SQLITE_OK ){
         goto abort_due_to_error;
diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index cced21537..0f2b317ed 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -1229,21 +1229,37 @@ int sqlite3VdbeSerialGet(
   assert( serial_type!=0 );
   if( serial_type<=5 ){
     /* Integer and Real */
-    u64 v = 0;
-    int n;
-
-    if( buf[0]&0x80 ){
-      v = -1;
-    }
-    for(n=0; n<len; n++){
-      v = (v<<8) | buf[n];
-    }
-    if( serial_type==5 ){
-      pMem->flags = MEM_Real;
-      pMem->r = *(double*)&v;
-    }else{
+    if( serial_type<=3 ){
+      /* 32-bit integer type.  This is handled by a special case for
+      ** performance reasons. */
+      int v = buf[0];
+      int n;
+      if( v&0x80 ){
+        v |= -256;
+      }
+      for(n=1; n<len; n++){
+        v = (v<<8) | buf[n];
+      }
       pMem->flags = MEM_Int;
-      pMem->i = *(i64*)&v;
+      pMem->i = v;
+      return n;
+    }else{
+      u64 v = 0;
+      int n;
+
+      if( buf[0]&0x80 ){
+        v = -1;
+      }
+      for(n=0; n<len; n++){
+        v = (v<<8) | buf[n];
+      }
+      if( serial_type==5 ){
+        pMem->flags = MEM_Real;
+        pMem->r = *(double*)&v;
+      }else{
+        pMem->flags = MEM_Int;
+        pMem->i = *(i64*)&v;
+      }
     }
   }else if( serial_type>=12 ){
     /* String or blob */
diff --git a/src/vdbemem.c b/src/vdbemem.c
index 69e1c393a..fbc3ef7b7 100644
--- a/src/vdbemem.c
+++ b/src/vdbemem.c
@@ -464,16 +464,17 @@ int sqlite3VdbeMemFromBtree(
   int key,          /* If true, retrieve from the btree key, not data. */
   Mem *pMem         /* OUT: Return data in this Mem structure. */
 ){
-  char *zData;
+  char *zData;      /* Data from the btree layer */
+  int available;    /* Number of bytes available on the local btree page */
 
   if( key ){
-    zData = (char *)sqlite3BtreeKeyFetch(pCur, offset+amt);
+    zData = (char *)sqlite3BtreeKeyFetch(pCur, &available);
   }else{
-    zData = (char *)sqlite3BtreeDataFetch(pCur, offset+amt);
+    zData = (char *)sqlite3BtreeDataFetch(pCur, &available);
   }
 
   pMem->n = amt;
-  if( zData ){
+  if( offset+amt<=available ){
     pMem->z = &zData[offset];
     pMem->flags = MEM_Blob|MEM_Ephem;
   }else{