** This file contains the C functions that implement various SQL
** functions of SQLite.  
**
** There is only one exported symbol in this file - the function
** sqliteRegisterBuildinFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: func.c,v 1.10 2002/02/28 03:14:18 drh Exp $
*/
#include <ctype.h>
#include <math.h>
#include <stdlib.h>
#include <assert.h>
#include "sqliteInt.h"

................................................................................
#ifdef SQLITE_UTF8
  for(len=0, z2=z; *z2; z2++){ if( (0xc0&*z)!=0x80 ) len++; }
#else
  len = strlen(z);
#endif
  if( p1<0 ){
    p1 += len;




  }else if( p1>0 ){
    p1--;
  }
  if( p1+p2>len ){
    p2 = len-p1;
  }
#ifdef SQLITE_UTF8
................................................................................
    if( (z[i]&0xc0)!=0x80 ) p1++;
  }
  for(; i<p1+p2; i++){
    assert( z[i] );
    if( (z[i]&0xc0)!=0x80 ) p2++;
  }
#endif

  sqlite_set_result_string(context, &z[p1], p2);
}

/*
** Implementation of the round() function
*/
static void roundFunc(sqlite_func *context, int argc, const char **argv){

** This file contains the C functions that implement various SQL
** functions of SQLite.  
**
** There is only one exported symbol in this file - the function
** sqliteRegisterBuildinFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: func.c,v 1.11 2002/02/28 03:31:11 drh Exp $
*/
#include <ctype.h>
#include <math.h>
#include <stdlib.h>
#include <assert.h>
#include "sqliteInt.h"

................................................................................
#ifdef SQLITE_UTF8
  for(len=0, z2=z; *z2; z2++){ if( (0xc0&*z)!=0x80 ) len++; }
#else
  len = strlen(z);
#endif
  if( p1<0 ){
    p1 += len;
    if( p1<0 ){
      p2 += p1;
      p1 = 0;
    }
  }else if( p1>0 ){
    p1--;
  }
  if( p1+p2>len ){
    p2 = len-p1;
  }
#ifdef SQLITE_UTF8
................................................................................
    if( (z[i]&0xc0)!=0x80 ) p1++;
  }
  for(; i<p1+p2; i++){
    assert( z[i] );
    if( (z[i]&0xc0)!=0x80 ) p2++;
  }
#endif
  if( p2<0 ) p2 = 0;
  sqlite_set_result_string(context, &z[p1], p2);
}

/*
** Implementation of the round() function
*/
static void roundFunc(sqlite_func *context, int argc, const char **argv){

** type to the other occurs as necessary.
** 
** Most of the code in this file is taken up by the sqliteVdbeExec()
** function which does the work of interpreting a VDBE program.
** But other routines are also provided to help in building up
** a program instruction by instruction.
**
** $Id: vdbe.c,v 1.128 2002/02/28 03:04:48 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** The following global variable is incremented every time a cursor
** moves, either by the OP_MoveTo or the OP_Next opcode.  The test
................................................................................
  "Last",              "Rewind",            "Next",              "Destroy",
  "Clear",             "CreateIndex",       "CreateTable",       "IntegrityCk",
  "IdxPut",            "IdxDelete",         "IdxRecno",          "IdxGT",
  "IdxGE",             "MemLoad",           "MemStore",          "ListWrite",
  "ListRewind",        "ListRead",          "ListReset",         "SortPut",
  "SortMakeRec",       "SortMakeKey",       "Sort",              "SortNext",
  "SortCallback",      "SortReset",         "FileOpen",          "FileRead",
  "FileColumn",        "AggReset",          "AggFocus",          "AggIncr",
  "AggNext",           "AggSet",            "AggGet",            "AggFunc",
  "AggInit",           "SetInsert",         "SetFound",          "SetNotFound",
  "MakeRecord",        "MakeKey",           "MakeIdxKey",        "IncrKey",
  "Goto",              "If",                "Halt",              "ColumnCount",
  "ColumnName",        "Callback",          "NullCallback",      "Integer",
  "String",            "Pop",               "Dup",               "Pull",
  "Push",              "MustBeInt",         "Add",               "AddImm",
  "Subtract",          "Multiply",          "Divide",            "Remainder",
  "BitAnd",            "BitOr",             "BitNot",            "ShiftLeft",
  "ShiftRight",        "AbsValue",          "Precision",         "Min",
  "Max",               "Like",              "Glob",              "Eq",
  "Ne",                "Lt",                "Le",                "Gt",
  "Ge",                "IsNull",            "NotNull",           "Negative",
  "And",               "Or",                "Not",               "Concat",
  "Noop",              "Strlen",            "Substr",            "Function",
  "Limit",           

};

/*
** Given the name of an opcode, return its number.  Return 0 if
** there is no match.
**
** This routine is used for testing and debugging.
................................................................................
divide_by_zero:
  PopStack(p, 2);
  p->tos = nos;
  aStack[nos].flags = STK_Null;
  break;
}

/*
** Opcode: Precision * * *
**
** The top of stack is a floating-point number and the next on stack is
** an integer.  Truncate the floating-point number to a number of digits
** specified by the integer and push the floating-point number back onto
** the stack. 
*/
case OP_Precision: {
  int tos = p->tos;
  int nos = tos - 1;
  int nDigit;
  int len;
  double v;
  char *zNew;

  VERIFY( if( nos<0 ) goto not_enough_stack; )
  Realify(p, tos);
  Integerify(p, nos);
  nDigit = aStack[nos].i;
  if( nDigit<0 ) nDigit = 0;
  if( nDigit>30 ) nDigit = 30;
  v = aStack[tos].r;
  zNew = sqlite_mprintf("%.*f", nDigit, v);
  if( zNew==0 ) goto no_mem;
  POPSTACK;
  Release(p, nos);
  aStack[nos].n = len = strlen(zNew) + 1;
  if( len<=NBFS ){
    strcpy(aStack[nos].z, zNew);
    zStack[nos] = aStack[nos].z;
    aStack[nos].flags = STK_Str;
    sqliteFree(zNew);
  }else{
    zStack[nos] = zNew;
    aStack[nos].flags = STK_Str | STK_Dyn;
  }
  break;
}

/* Opcode: Max * * *
**
** Pop the top two elements from the stack then push back the
** largest of the two.
*/
/* Opcode: Min * * *
**
** Pop the top two elements from the stack then push back the
** smaller of the two. 
*/
case OP_Min:
case OP_Max: {
  int tos = p->tos;
  int nos = tos - 1;
  int a,b;
  int ft, fn;
  int copy = 0;
  VERIFY( if( nos<0 ) goto not_enough_stack; )
  ft = aStack[tos].flags;
  fn = aStack[nos].flags;
  if( pOp->opcode==OP_Max ){
    a = tos;
    b = nos;
  }else{
    a = nos;
    b = tos;
  }
  if( fn & STK_Null ){
    copy = 1;
  }else if( ft & STK_Null ){
    copy = 0;
  }else if( (ft & fn & STK_Int)==STK_Int ){
    copy = aStack[a].i>aStack[b].i;
  }else if( ( (ft|fn) & (STK_Int|STK_Real) ) !=0 ){
    Realify(p, tos);
    Realify(p, nos);
    copy = aStack[a].r>aStack[b].r;
  }else{
    if( Stringify(p, tos) || Stringify(p, nos) ) goto no_mem;
    copy = sqliteCompare(zStack[a],zStack[b])>0;
  }
  if( copy ){
    Release(p, nos);
    aStack[nos] = aStack[tos];
    if( aStack[nos].flags & (STK_Dyn|STK_Static) ){
      zStack[nos] = zStack[tos];
    }else{
      zStack[nos] = aStack[nos].z;
    }
    zStack[tos] = 0;
    aStack[tos].flags = 0;
  }else{
    Release(p, tos);
  }
  p->tos = nos;
  break;
}

/* Opcode: Function P1 * P3
**
** Invoke a user function (P3 is a pointer to a Function structure that
** defines the function) with P1 string arguments taken from the stack.
** Pop all arguments from the stack and push back the result.
**
** See also: AggFunc
................................................................................
    AggInsert(&p->agg, zKey, nKey);
    if( sqlite_malloc_failed ) goto no_mem;
  }
  POPSTACK;
  break; 
}

/* Opcode: AggIncr P1 P2 *
**
** Increase the integer value in the P2-th field of the aggregate
** element current in focus by an amount P1.
*/
case OP_AggIncr: {
  AggElem *pFocus = AggInFocus(p->agg);
  int i = pOp->p2;
  if( pFocus==0 ) goto no_mem;
  if( i>=0 && i<p->agg.nMem ){
    Mem *pMem = &pFocus->aMem[i];
    if( pMem->s.flags!=STK_Int ){
      if( pMem->s.flags & STK_Int ){
        /* Do nothing */
      }else if( pMem->s.flags & STK_Real ){
        pMem->s.i = (int)pMem->s.r;
      }else if( pMem->s.flags & STK_Str ){
        pMem->s.i = atoi(pMem->z);
      }else{
        pMem->s.i = 0;
      }
      if( pMem->s.flags & STK_Dyn ) sqliteFree(pMem->z);
      pMem->z = 0;
      pMem->s.flags = STK_Int;
    }
    pMem->s.i += pOp->p1;
  }
  break;
}

/* Opcode: AggSet * P2 *
**
** Move the top of the stack into the P2-th field of the current
** aggregate.  String values are duplicated into new memory.
*/
case OP_AggSet: {
  AggElem *pFocus = AggInFocus(p->agg);
................................................................................
       sqliteHashFind(&p->aSet[i].hash, zStack[tos], aStack[tos].n)==0 ){
    pc = pOp->p2 - 1;
  }
  POPSTACK;
  break;
}

/* Opcode: Strlen * * *
**
** Interpret the top of the stack as a string.  Replace the top of
** stack with an integer which is the length of the string.
*/
case OP_Strlen: {
  int tos = p->tos;
  int len;
  VERIFY( if( tos<0 ) goto not_enough_stack; )
  if( Stringify(p, tos) ) goto no_mem;
#ifdef SQLITE_UTF8
  {
    char *z = zStack[tos];
    for(len=0; *z; z++){ if( (0xc0&*z)!=0x80 ) len++; }
  }
#else
  len = aStack[tos].n-1;
#endif
  POPSTACK;
  p->tos++;
  aStack[tos].i = len;
  aStack[tos].flags = STK_Int;
  break;
}

/* Opcode: Substr P1 P2 *
**
** This operation pops between 1 and 3 elements from the stack and
** pushes back a single element.  The bottom-most element popped from
** the stack is a string and the element pushed back is also a string.
** The other two elements popped are integers.  The integers are taken
** from the stack only if P1 and/or P2 are 0.  When P1 or P2 are
** not zero, the value of the operand is used rather than the integer
** from the stack.  In the sequel, we will use P1 and P2 to describe
** the two integers, even if those integers are really taken from the
** stack.
**
** The string pushed back onto the stack is a substring of the string
** that was popped.  There are P2 characters in the substring.  The
** first character of the substring is the P1-th character of the
** original string where the left-most character is 1 (not 0).  If P1
** is negative, then counting begins at the right instead of at the
** left.
*/
case OP_Substr: {
  int cnt;
  int start;
  int n;
  char *z;

  if( pOp->p2==0 ){
    VERIFY( if( p->tos<0 ) goto not_enough_stack; )
    Integerify(p, p->tos);
    cnt = aStack[p->tos].i;
    POPSTACK;
  }else{
    cnt = pOp->p2;
  }
  if( pOp->p1==0 ){
    VERIFY( if( p->tos<0 ) goto not_enough_stack; )
    Integerify(p, p->tos);
    start = aStack[p->tos].i;
    POPSTACK;
  }else{
    start = pOp->p1;
  }
  if( start ) start--;
  VERIFY( if( p->tos<0 ) goto not_enough_stack; )
  if( Stringify(p, p->tos) ) goto no_mem;

  /* "n" will be the number of characters in the input string.
  ** For iso8859, the number of characters is the number of bytes.
  ** Buf for UTF-8, some characters can use multiple bytes and the
  ** situation is more complex. 
  */
#ifdef SQLITE_UTF8
  z = zStack[p->tos];
  for(n=0; *z; z++){ if( (0xc0&*z)!=0x80 ) n++; }
#else
  n = aStack[p->tos].n - 1;
#endif
  if( start<0 ){
    start += n + 1;
    if( start<0 ){
      cnt += start;
      start = 0;
    }
  }
  if( start>n ){
    start = n;
  }
  if( cnt<0 ) cnt = 0;
  if( cnt > n ){
    cnt = n;
  }

  /* At this point, "start" is the index of the first character to
  ** extract and "cnt" is the number of characters to extract.  We
  ** need to convert units on these variable from characters into
  ** bytes.  For iso8859, the conversion is a no-op, but for UTF-8
  ** we have to do a little work.
  */
#ifdef SQLITE_UTF8
  {
    int c_start = start;
    int c_cnt = cnt;
    int i;
    z = zStack[p->tos];
    for(start=i=0; i<c_start; i++){
      while( (0xc0&z[++start])==0x80 ){}
    }
    for(cnt=i=0; i<c_cnt; i++){
      while( (0xc0&z[(++cnt)+start])==0x80 ){}
    }
  }
#endif
  z = sqliteMalloc( cnt+1 );
  if( z==0 ) goto no_mem;
  strncpy(z, &zStack[p->tos][start], cnt);
  z[cnt] = 0;
  POPSTACK;
  p->tos++;
  zStack[p->tos] = z;
  aStack[p->tos].n = cnt + 1;
  aStack[p->tos].flags = STK_Str|STK_Dyn;
  break;
}

/* An other opcode is illegal...
*/
default: {
  sprintf(zBuf,"%d",pOp->opcode);
  sqliteSetString(pzErrMsg, "unknown opcode ", zBuf, 0);
  rc = SQLITE_INTERNAL;

** type to the other occurs as necessary.
** 
** Most of the code in this file is taken up by the sqliteVdbeExec()
** function which does the work of interpreting a VDBE program.
** But other routines are also provided to help in building up
** a program instruction by instruction.
**
** $Id: vdbe.c,v 1.129 2002/02/28 03:31:11 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** The following global variable is incremented every time a cursor
** moves, either by the OP_MoveTo or the OP_Next opcode.  The test
................................................................................
  "Last",              "Rewind",            "Next",              "Destroy",
  "Clear",             "CreateIndex",       "CreateTable",       "IntegrityCk",
  "IdxPut",            "IdxDelete",         "IdxRecno",          "IdxGT",
  "IdxGE",             "MemLoad",           "MemStore",          "ListWrite",
  "ListRewind",        "ListRead",          "ListReset",         "SortPut",
  "SortMakeRec",       "SortMakeKey",       "Sort",              "SortNext",
  "SortCallback",      "SortReset",         "FileOpen",          "FileRead",
  "FileColumn",        "AggReset",          "AggFocus",          "AggNext",
  "AggSet",            "AggGet",            "AggFunc",           "AggInit",
  "SetInsert",         "SetFound",          "SetNotFound",       "MakeRecord",
  "MakeKey",           "MakeIdxKey",        "IncrKey",           "Goto",
  "If",                "Halt",              "ColumnCount",       "ColumnName",
  "Callback",          "NullCallback",      "Integer",           "String",
  "Pop",               "Dup",               "Pull",              "Push",
  "MustBeInt",         "Add",               "AddImm",            "Subtract",
  "Multiply",          "Divide",            "Remainder",         "BitAnd",
  "BitOr",             "BitNot",            "ShiftLeft",         "ShiftRight",

  "AbsValue",          "Like",              "Glob",              "Eq",
  "Ne",                "Lt",                "Le",                "Gt",
  "Ge",                "IsNull",            "NotNull",           "Negative",
  "And",               "Or",                "Not",               "Concat",


  "Noop",              "Function",          "Limit",           
};

/*
** Given the name of an opcode, return its number.  Return 0 if
** there is no match.
**
** This routine is used for testing and debugging.
................................................................................
divide_by_zero:
  PopStack(p, 2);
  p->tos = nos;
  aStack[nos].flags = STK_Null;
  break;
}



































































































/* Opcode: Function P1 * P3
**
** Invoke a user function (P3 is a pointer to a Function structure that
** defines the function) with P1 string arguments taken from the stack.
** Pop all arguments from the stack and push back the result.
**
** See also: AggFunc
................................................................................
    AggInsert(&p->agg, zKey, nKey);
    if( sqlite_malloc_failed ) goto no_mem;
  }
  POPSTACK;
  break; 
}































/* Opcode: AggSet * P2 *
**
** Move the top of the stack into the P2-th field of the current
** aggregate.  String values are duplicated into new memory.
*/
case OP_AggSet: {
  AggElem *pFocus = AggInFocus(p->agg);
................................................................................
       sqliteHashFind(&p->aSet[i].hash, zStack[tos], aStack[tos].n)==0 ){
    pc = pOp->p2 - 1;
  }
  POPSTACK;
  break;
}

































































































































/* An other opcode is illegal...
*/
default: {
  sprintf(zBuf,"%d",pOp->opcode);
  sqliteSetString(pzErrMsg, "unknown opcode ", zBuf, 0);
  rc = SQLITE_INTERNAL;

*************************************************************************
** Header file for the Virtual DataBase Engine (VDBE)
**
** This header defines the interface to the virtual database engine
** or VDBE.  The VDBE implements an abstract machine that runs a
** simple program to access and modify the underlying database.
**
** $Id: vdbe.h,v 1.48 2002/02/28 00:41:11 drh Exp $
*/
#ifndef _SQLITE_VDBE_H_
#define _SQLITE_VDBE_H_
#include <stdio.h>

/*
** A single VDBE is an opaque structure named "Vdbe".  Only routines
................................................................................

#define OP_FileOpen           55
#define OP_FileRead           56
#define OP_FileColumn         57

#define OP_AggReset           58
#define OP_AggFocus           59
#define OP_AggIncr            60
#define OP_AggNext            61
#define OP_AggSet             62
#define OP_AggGet             63
#define OP_AggFunc            64
#define OP_AggInit            65

#define OP_SetInsert          66
#define OP_SetFound           67
#define OP_SetNotFound        68

#define OP_MakeRecord         69
#define OP_MakeKey            70
#define OP_MakeIdxKey         71
#define OP_IncrKey            72

#define OP_Goto               73
#define OP_If                 74
#define OP_Halt               75

#define OP_ColumnCount        76
#define OP_ColumnName         77
#define OP_Callback           78
#define OP_NullCallback       79

#define OP_Integer            80
#define OP_String             81
#define OP_Pop                82
#define OP_Dup                83
#define OP_Pull               84
#define OP_Push               85
#define OP_MustBeInt          86

#define OP_Add                87
#define OP_AddImm             88
#define OP_Subtract           89
#define OP_Multiply           90
#define OP_Divide             91
#define OP_Remainder          92
#define OP_BitAnd             93
#define OP_BitOr              94
#define OP_BitNot             95
#define OP_ShiftLeft          96
#define OP_ShiftRight         97
#define OP_AbsValue           98
#define OP_Precision          99
#define OP_Min               100
#define OP_Max               101
#define OP_Like              102
#define OP_Glob              103
#define OP_Eq                104
#define OP_Ne                105
#define OP_Lt                106
#define OP_Le                107
#define OP_Gt                108
#define OP_Ge                109
#define OP_IsNull            110
#define OP_NotNull           111
#define OP_Negative          112
#define OP_And               113
#define OP_Or                114
#define OP_Not               115
#define OP_Concat            116
#define OP_Noop              117
#define OP_Strlen            118
#define OP_Substr            119
#define OP_Function          120

#define OP_Limit             121

#define OP_MAX               121

/*
** Prototypes for the VDBE interface.  See comments on the implementation
** for a description of what each of these routines does.
*/
Vdbe *sqliteVdbeCreate(sqlite*);
void sqliteVdbeCreateCallback(Vdbe*, int*);

*************************************************************************
** Header file for the Virtual DataBase Engine (VDBE)
**
** This header defines the interface to the virtual database engine
** or VDBE.  The VDBE implements an abstract machine that runs a
** simple program to access and modify the underlying database.
**
** $Id: vdbe.h,v 1.49 2002/02/28 03:31:12 drh Exp $
*/
#ifndef _SQLITE_VDBE_H_
#define _SQLITE_VDBE_H_
#include <stdio.h>

/*
** A single VDBE is an opaque structure named "Vdbe".  Only routines
................................................................................

#define OP_FileOpen           55
#define OP_FileRead           56
#define OP_FileColumn         57

#define OP_AggReset           58
#define OP_AggFocus           59

#define OP_AggNext            60
#define OP_AggSet             61
#define OP_AggGet             62
#define OP_AggFunc            63
#define OP_AggInit            64

#define OP_SetInsert          65
#define OP_SetFound           66
#define OP_SetNotFound        67

#define OP_MakeRecord         68
#define OP_MakeKey            69
#define OP_MakeIdxKey         70
#define OP_IncrKey            71

#define OP_Goto               72
#define OP_If                 73
#define OP_Halt               74

#define OP_ColumnCount        75
#define OP_ColumnName         76
#define OP_Callback           77
#define OP_NullCallback       78

#define OP_Integer            79
#define OP_String             80
#define OP_Pop                81
#define OP_Dup                82
#define OP_Pull               83
#define OP_Push               84
#define OP_MustBeInt          85

#define OP_Add                86
#define OP_AddImm             87
#define OP_Subtract           88
#define OP_Multiply           89
#define OP_Divide             90
#define OP_Remainder          91
#define OP_BitAnd             92
#define OP_BitOr              93
#define OP_BitNot             94
#define OP_ShiftLeft          95
#define OP_ShiftRight         96
#define OP_AbsValue           97



#define OP_Like               98
#define OP_Glob               99
#define OP_Eq                100
#define OP_Ne                101
#define OP_Lt                102
#define OP_Le                103
#define OP_Gt                104
#define OP_Ge                105
#define OP_IsNull            106
#define OP_NotNull           107
#define OP_Negative          108
#define OP_And               109
#define OP_Or                110
#define OP_Not               111
#define OP_Concat            112
#define OP_Noop              113


#define OP_Function          114

#define OP_Limit             115

#define OP_MAX               115

/*
** Prototypes for the VDBE interface.  See comments on the implementation
** for a description of what each of these routines does.
*/
Vdbe *sqliteVdbeCreate(sqlite*);
void sqliteVdbeCreateCallback(Vdbe*, int*);