SQLite

/*
** 2004 April 6
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** $Id: btree.c,v 1.451 2008/04/03 21:46:57 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** See the header comment on "btreeInt.h" for additional information.
** Including a description of file format and an overview of operation.
*/
#include "btreeInt.h"

  assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  pInfo->pCell = pCell;
  assert( pPage->leaf==0 || pPage->leaf==1 );
  n = pPage->childPtrSize;
  assert( n==4-4*pPage->leaf );
  if( pPage->hasData ){
    n += getVarint32(&pCell[n], &nPayload);
  }else{
    nPayload = 0;
  }
  pInfo->nData = nPayload;
  if( pPage->intKey ){
    n += getVarint(&pCell[n], (u64 *)&pInfo->nKey);
  }else{
    u32 x;
    n += getVarint32(&pCell[n], &x);
    pInfo->nKey = x;
    nPayload += x;
  }
  pInfo->nPayload = nPayload;
  pInfo->nHeader = n;
  if( nPayload<=pPage->maxLocal ){
    /* This is the (easy) common case where the entire payload fits

      pCur->info.nSize = 0;
      pCur->validNKey = 1;
      if( pPage->intKey ){
        u8 *pCell;
        pCell = findCell(pPage, pCur->idx) + pPage->childPtrSize;
        if( pPage->hasData ){
          u32 dummy;
          pCell += getVarint32(pCell, &dummy);
        }
        getVarint(pCell, (u64*)&nCellKey);
        if( nCellKey==nKey ){
          c = 0;
        }else if( nCellKey<nKey ){
          c = -1;
        }else{

/*
** 2004 April 6
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** $Id: btreeInt.h,v 1.20 2008/03/29 16:01:04 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.

*/
#if SQLITE_TEST
# define TRACE(X)   if( sqlite3BtreeTrace ){ printf X; fflush(stdout); }
#else
# define TRACE(X)
#endif

/*
** Routines to read and write variable-length integers.  These used to
** be defined locally, but now we use the varint routines in the util.c
** file.
*/
#define getVarint    sqlite3GetVarint
#define getVarint32(A,B)  ((*B=*(A))<=0x7f?1:sqlite3GetVarint32(A,B))
#define putVarint    sqlite3PutVarint

/* The database page the PENDING_BYTE occupies. This page is never used.
** TODO: This macro is very similary to PAGER_MJ_PGNO() in pager.c. They
** should possibly be consolidated (presumably in pager.h).
**
** If disk I/O is omitted (meaning that the database is stored purely
** in memory) then there is no pending byte.
*/

/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.694 2008/04/17 17:02:02 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** Include the configuration header output by 'configure' if it was run
** (otherwise we get an empty default).

int sqlite3AtoF(const char *z, double*);
char *sqlite3_snprintf(int,char*,const char*,...);
int sqlite3GetInt32(const char *, int*);
int sqlite3FitsIn64Bits(const char *, int);
int sqlite3Utf16ByteLen(const void *pData, int nChar);
int sqlite3Utf8CharLen(const char *pData, int nByte);
int sqlite3Utf8Read(const u8*, const u8*, const u8**);






int sqlite3PutVarint(unsigned char*, u64);
int sqlite3PutVarint32(unsigned char*, u32);
int sqlite3GetVarint(const unsigned char *, u64 *);
int sqlite3GetVarint32(const unsigned char *, u32 *);
int sqlite3VarintLen(u64 v);
























void sqlite3IndexAffinityStr(Vdbe *, Index *);
void sqlite3TableAffinityStr(Vdbe *, Table *);
char sqlite3CompareAffinity(Expr *pExpr, char aff2);
int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity);
char sqlite3ExprAffinity(Expr *pExpr);
int sqlite3Atoi64(const char*, i64*);
void sqlite3Error(sqlite3*, int, const char*,...);

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the btree.c module in SQLite.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test3.c,v 1.94 2008/03/25 17:23:33 drh Exp $
*/
#include "sqliteInt.h"
#include "btreeInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

){
  return TCL_OK;
}

/*
** usage:   varint_test  START  MULTIPLIER  COUNT  INCREMENT
**
** This command tests the sqlite3PutVarint() and sqlite3GetVarint()
** routines, both for accuracy and for speed.
**
** An integer is written using PutVarint() and read back with
** GetVarint() and varified to be unchanged.  This repeats COUNT
** times.  The first integer is START*MULTIPLIER.  Each iteration
** increases the integer by INCREMENT.
**
** This command returns nothing if it works.  It returns an error message
** if something goes wrong.
*/
static int btree_varint_test(

  if( Tcl_GetInt(interp, argv[2], (int*)&mult) ) return TCL_ERROR;
  if( Tcl_GetInt(interp, argv[3], (int*)&count) ) return TCL_ERROR;
  if( Tcl_GetInt(interp, argv[4], (int*)&incr) ) return TCL_ERROR;
  in = start;
  in *= mult;
  for(i=0; i<count; i++){
    char zErr[200];
    n1 = sqlite3PutVarint(zBuf, in);
    if( n1>9 || n1<1 ){
      sprintf(zErr, "PutVarint returned %d - should be between 1 and 9", n1);
      Tcl_AppendResult(interp, zErr, 0);
      return TCL_ERROR;
    }
    n2 = sqlite3GetVarint(zBuf, &out);
    if( n1!=n2 ){
      sprintf(zErr, "PutVarint returned %d and GetVarint returned %d", n1, n2);
      Tcl_AppendResult(interp, zErr, 0);
      return TCL_ERROR;
    }
    if( in!=out ){
      sprintf(zErr, "Wrote 0x%016llx and got back 0x%016llx", in, out);
      Tcl_AppendResult(interp, zErr, 0);
      return TCL_ERROR;
    }
    if( (in & 0xffffffff)==in ){
      u32 out32;
      n2 = sqlite3GetVarint32(zBuf, &out32);
      out = out32;
      if( n1!=n2 ){
        sprintf(zErr, "PutVarint returned %d and GetVarint32 returned %d", 
                  n1, n2);
        Tcl_AppendResult(interp, zErr, 0);
        return TCL_ERROR;
      }
      if( in!=out ){
        sprintf(zErr, "Wrote 0x%016llx and got back 0x%016llx from GetVarint32",
            in, out);
        Tcl_AppendResult(interp, zErr, 0);
        return TCL_ERROR;
      }
    }

    /* In order to get realistic timings, run getVarint 19 more times.
    ** This is because getVarint is called about 20 times more often
    ** than putVarint.
    */
    for(j=0; j<19; j++){
      sqlite3GetVarint(zBuf, &out);
    }
    in += incr;
  }
  return TCL_OK;
}

/*

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** 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 1.733 2008/04/18 11:31:13 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
** The following global variable is incremented every time a cursor

** Convert the given register into a string if it isn't one
** already. Return non-zero if a malloc() fails.
*/
#define Stringify(P, enc) \
   if(((P)->flags&(MEM_Str|MEM_Blob))==0 && sqlite3VdbeMemStringify(P,enc)) \
     { goto no_mem; }

/*
** The header of a record consists of a sequence variable-length integers.
** These integers are almost always small and are encoded as a single byte.
** The following macro takes advantage this fact to provide a fast decode
** of the integers in a record header.  It is faster for the common case
** where the integer is a single byte.  It is a little slower when the
** integer is two or more bytes.  But overall it is faster.
**
** The following expressions are equivalent:
**
**     x = sqlite3GetVarint32( A, &B );
**
**     x = GetVarint( A, B );
**
*/
#define GetVarint(A,B)  ((B = *(A))<=0x7f ? 1 : sqlite3GetVarint32(A, &B))

/*
** An ephemeral string value (signified by the MEM_Ephem flag) contains
** a pointer to a dynamically allocated string where some other entity
** is responsible for deallocating that string.  Because the register
** does not control the string, it might be deleted without the register
** knowing it.
**

      }else{
        pC->aRow = 0;
      }
    }
    /* The following assert is true in all cases accept when
    ** the database file has been corrupted externally.
    **    assert( zRec!=0 || avail>=payloadSize || avail>=9 ); */
    szHdrSz = GetVarint((u8*)zData, offset);

    /* The KeyFetch() or DataFetch() above are fast and will get the entire
    ** record header in most cases.  But they will fail to get the complete
    ** record header if the record header does not fit on a single page
    ** in the B-Tree.  When that happens, use sqlite3VdbeMemFromBtree() to
    ** acquire the complete header text.
    */

    ** arrays.  aType[i] will contain the type integer for the i-th
    ** column and aOffset[i] will contain the offset from the beginning
    ** of the record to the start of the data for the i-th column
    */
    for(i=0; i<nField; i++){
      if( zIdx<zEndHdr ){
        aOffset[i] = offset;
        zIdx += GetVarint(zIdx, aType[i]);
        offset += sqlite3VdbeSerialTypeLen(aType[i]);
      }else{
        /* If i is less that nField, then there are less fields in this
        ** record than SetNumColumns indicated there are columns in the
        ** table. Set the offset for any extra columns not present in
        ** the record to 0. This tells code below to store a NULL
        ** instead of deserializing a value from the record.

  pOut = &p->aMem[pOp->p3];
  if( sqlite3VdbeMemGrow(pOut, nByte, 0) ){
    goto no_mem;
  }
  zNewRecord = (u8 *)pOut->z;

  /* Write the record */
  i = sqlite3PutVarint32(zNewRecord, nHdr);
  for(pRec=pData0; pRec<=pLast; pRec++){
    serial_type = sqlite3VdbeSerialType(pRec, file_format);
    i += sqlite3PutVarint32(&zNewRecord[i], serial_type);      /* serial type */
  }
  for(pRec=pData0; pRec<=pLast; pRec++){  /* serial data */
    i += sqlite3VdbeSerialPut(&zNewRecord[i], nByte-i, pRec, file_format);
  }
  assert( i==nByte );

  assert( pOp->p3>0 && pOp->p3<=p->nMem );

**
*************************************************************************
** This file contains code used for creating, destroying, and populating
** a VDBE (or an "sqlite3_stmt" as it is known to the outside world.)  Prior
** to version 2.8.7, all this code was combined into the vdbe.c source file.
** But that file was getting too big so this subroutines were split out.
**
** $Id: vdbeaux.c,v 1.378 2008/04/24 08:36:51 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include "vdbeInt.h"

      }
      return len;
    }
  }
  return 0;
}

/*
** The header of a record consists of a sequence variable-length integers.
** These integers are almost always small and are encoded as a single byte.
** The following macro takes advantage this fact to provide a fast decode
** of the integers in a record header.  It is faster for the common case
** where the integer is a single byte.  It is a little slower when the
** integer is two or more bytes.  But overall it is faster.
**
** The following expressions are equivalent:
**
**     x = sqlite3GetVarint32( A, &B );
**
**     x = GetVarint( A, B );
**
*/
#define GetVarint(A,B)  ((B = *(A))<=0x7f ? 1 : sqlite3GetVarint32(A, &B))

/*
** Given the nKey-byte encoding of a record in pKey[], parse the
** record into a UnpackedRecord structure.  Return a pointer to
** that structure.
**
** The calling function might provide szSpace bytes of memory

    p = pSpace;
    p->needFree = 0;
  }
  p->pKeyInfo = pKeyInfo;
  p->nField = pKeyInfo->nField + 1;
  p->needDestroy = 1;
  p->aMem = pMem = &((Mem*)p)[1];
  idx = GetVarint(aKey, szHdr);
  d = szHdr;
  i = 0;
  while( idx<szHdr && i<p->nField ){
    u32 serial_type;

    idx += GetVarint( aKey+idx, serial_type);
    if( d>=nKey && sqlite3VdbeSerialTypeLen(serial_type)>0 ) break;
    pMem->enc = pKeyInfo->enc;
    pMem->db = pKeyInfo->db;
    pMem->flags = 0;
    pMem->zMalloc = 0;
    d += sqlite3VdbeSerialGet(&aKey[d], serial_type, pMem);
    pMem++;

  pKeyInfo = pPKey2->pKeyInfo;
  mem1.enc = pKeyInfo->enc;
  mem1.db = pKeyInfo->db;
  mem1.flags = 0;
  mem1.zMalloc = 0;
  
  idx1 = GetVarint(aKey1, szHdr1);
  d1 = szHdr1;
  nField = pKeyInfo->nField;
  while( idx1<szHdr1 && i<pPKey2->nField ){
    u32 serial_type1;

    /* Read the serial types for the next element in each key. */
    idx1 += GetVarint( aKey1+idx1, serial_type1 );
    if( d1>=nKey1 && sqlite3VdbeSerialTypeLen(serial_type1)>0 ) break;

    /* Extract the values to be compared.
    */
    d1 += sqlite3VdbeSerialGet(&aKey1[d1], serial_type1, &mem1);

    /* Do the comparison

** an integer rowid).  This routine returns the number of bytes in
** that integer.
*/
int sqlite3VdbeIdxRowidLen(const u8 *aKey){
  u32 szHdr;        /* Size of the header */
  u32 typeRowid;    /* Serial type of the rowid */

  sqlite3GetVarint32(aKey, &szHdr);
  sqlite3GetVarint32(&aKey[szHdr-1], &typeRowid);
  return sqlite3VdbeSerialTypeLen(typeRowid);
}
  

/*
** pCur points at an index entry created using the OP_MakeRecord opcode.
** Read the rowid (the last field in the record) and store it in *rowid.

  m.flags = 0;
  m.db = 0;
  m.zMalloc = 0;
  rc = sqlite3VdbeMemFromBtree(pCur, 0, nCellKey, 1, &m);
  if( rc ){
    return rc;
  }
  sqlite3GetVarint32((u8*)m.z, &szHdr);
  sqlite3GetVarint32((u8*)&m.z[szHdr-1], &typeRowid);
  lenRowid = sqlite3VdbeSerialTypeLen(typeRowid);
  sqlite3VdbeSerialGet((u8*)&m.z[m.n-lenRowid], typeRowid, &v);
  *rowid = v.u.i;
  sqlite3VdbeMemRelease(&m);
  return SQLITE_OK;
}