SQLite

** 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 1.51 2004/05/24 12:55:55 danielk1977 Exp $
*/
#include <ctype.h>
#include <math.h>
#include <stdlib.h>
#include <assert.h>
#include "sqliteInt.h"
#include "os.h"

  double sum;     /* Sum of terms */
  int cnt;        /* Number of elements summed */
};

/*
** Routines used to compute the sum or average.
*/
static void sumStep(sqlite_func *context, int argc, const char **argv){
  SumCtx *p;
  if( argc<1 ) return;
  p = sqlite3_aggregate_context(context, sizeof(*p));
  if( p && argv[0] ){
    p->sum += sqlite3AtoF(argv[0], 0);
    p->cnt++;
  }
}
static void sumFinalize(sqlite_func *context){
  SumCtx *p;
  p = sqlite3_aggregate_context(context, sizeof(*p));
  sqlite3_set_result_double(context, p ? p->sum : 0.0);

struct CountCtx {
  int n;
};

/*
** Routines to implement the count() aggregate function.
*/
static void countStep(sqlite_func *context, int argc, const char **argv){
  CountCtx *p;
  p = sqlite3_aggregate_context(context, sizeof(*p));
  if( (argc==0 || argv[0]) && p ){
    p->n++;
  }
}   
static void countFinalize(sqlite_func *context){
  CountCtx *p;
  p = sqlite3_aggregate_context(context, sizeof(*p));
  sqlite3_set_result_int(context, p ? p->n : 0);

  char *z;         /* The best so far */
  char zBuf[28];   /* Space that can be used for storage */
};

/*
** Routines to implement min() and max() aggregate functions.
*/
static void minmaxStep(sqlite_func *context, int argc, const char **argv){
  MinMaxCtx *p;
  int (*xCompare)(const char*, const char*);
  int mask;    /* 0 for min() or 0xffffffff for max() */



  assert( argc==2 );
  if( argv[1][0]=='n' ){
    xCompare = sqlite3Compare;
  }else{
    xCompare = strcmp;
  }
  mask = (int)sqlite3_user_data(context);
  p = sqlite3_aggregate_context(context, sizeof(*p));
  if( p==0 || argc<1 || argv[0]==0 ) return;
  if( p->z==0 || (xCompare(argv[0],p->z)^mask)<0 ){
    int len;
    if( !p->zBuf[0] ){
      sqliteFree(p->z);
    }
    len = strlen(argv[0]);
    if( len < sizeof(p->zBuf)-1 ){
      p->z = &p->zBuf[1];
      p->zBuf[0] = 1;
    }else{
      p->z = sqliteMalloc( len+1 );
      p->zBuf[0] = 0;
      if( p->z==0 ) return;
    }
    strcpy(p->z, argv[0]);
  }
}
static void minMaxFinalize(sqlite_func *context){
  MinMaxCtx *p;
  p = sqlite3_aggregate_context(context, sizeof(*p));
  if( p && p->z ){
    sqlite3_set_result_string(context, p->z, strlen(p->z));

#endif
  };
  static struct {
    char *zName;
    signed char nArg;
    signed char dataType;
    u8 argType;
    void (*xStep)(sqlite_func*,int,const char**);
    void (*xFinalize)(sqlite_func*);
  } aAggs[] = {
    { "min",    1, 0,              0, minmaxStep,   minMaxFinalize },
    { "max",    1, 0,              2, minmaxStep,   minMaxFinalize },
    { "sum",    1, SQLITE_NUMERIC, 0, sumStep,      sumFinalize    },
    { "avg",    1, SQLITE_NUMERIC, 0, sumStep,      avgFinalize    },
    { "count",  0, SQLITE_NUMERIC, 0, countStep,    countFinalize  },

**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: main.c,v 1.186 2004/05/24 12:39:02 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>

/*
** A pointer to this structure is used to communicate information

  p->pUserData = pUserData;
  return 0;
}
int sqlite3_create_aggregate(
  sqlite *db,          /* Add the function to this database connection */
  const char *zName,   /* Name of the function to add */
  int nArg,            /* Number of arguments */
  void (*xStep)(sqlite_func*,int,const char**), /* The step function */
  void (*xFinalize)(sqlite_func*),              /* The finalizer */
  void *pUserData      /* User data */
){
  FuncDef *p;
  int nName;
  if( db==0 || zName==0 || sqlite3SafetyCheck(db) ) return 1;
  if( nArg<-1 || nArg>127 ) return 1;

  return TCL_OK;
}

/*
** During testing, the special md5sum() aggregate function is available.
** inside SQLite.  The following routines implement that function.
*/
static void md5step(sqlite_func *context, int argc, const char **argv){
  MD5Context *p;
  int i;
  if( argc<1 ) return;
  p = sqlite3_aggregate_context(context, sizeof(*p));
  if( p==0 ) return;
  if( sqlite3_aggregate_count(context)==1 ){
    MD5Init(p);
  }
  for(i=0; i<argc; i++){

    if( argv[i] ){
      MD5Update(p, (unsigned char*)argv[i], strlen(argv[i]));
    }
  }
}
static void md5finalize(sqlite_func *context){
  MD5Context *p;
  unsigned char digest[16];
  char zBuf[33];

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the SQLite library
** presents to client programs.
**
** @(#) $Id: sqlite.h.in,v 1.73 2004/05/24 12:39:02 danielk1977 Exp $
*/
#ifndef _SQLITE_H_
#define _SQLITE_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.

  void (*xFunc)(sqlite_func*,int,sqlite3_value **),  /* C code to implement */
  void *pUserData           /* Available via the sqlite3_user_data() call */
);
int sqlite3_create_aggregate(
  sqlite*,                  /* Database where the new function is registered */
  const char *zName,        /* Name of the function */
  int nArg,                 /* Number of arguments */
  void (*xStep)(sqlite_func*,int,const char**), /* Called for each row */
  void (*xFinalize)(sqlite_func*),       /* Called once to get final result */
  void *pUserData           /* Available via the sqlite3_user_data() call */
);

/*
** Use the following routine to define the datatype returned by a
** user-defined function.  The second argument can be one of the

/*
** 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 1.249 2004/05/24 12:55:55 danielk1977 Exp $
*/
#include "config.h"
#include "sqlite.h"
#include "hash.h"
#include "parse.h"
#include <stdio.h>
#include <stdlib.h>

** Each SQL function is defined by an instance of the following
** structure.  A pointer to this structure is stored in the sqlite.aFunc
** hash table.  When multiple functions have the same name, the hash table
** points to a linked list of these structures.
*/
struct FuncDef {
  void (*xFunc)(sqlite_func*,int,sqlite3_value**);  /* Regular function */
  void (*xStep)(sqlite_func*,int,const char**);  /* Aggregate function step */
  void (*xFinalize)(sqlite_func*);           /* Aggregate function finializer */
  signed char nArg;         /* Number of arguments.  -1 means unlimited */
  signed char dataType;     /* Arg that determines datatype.  -1=NUMERIC, */
                            /* -2=TEXT. -3=SQLITE_ARGS */
  u8 includeTypes;          /* Add datatypes to args of xFunc and xStep */
  void *pUserData;          /* User data parameter */
  FuncDef *pNext;           /* Next function with same name */

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the printf() interface to SQLite.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test1.c,v 1.48 2004/05/24 12:39:02 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include "os.h"
#include <stdlib.h>
#include <string.h>

/*
** Routines to implement the x_count() aggregate function.
*/
typedef struct CountCtx CountCtx;
struct CountCtx {
  int n;
};
static void countStep(sqlite_func *context, int argc, const char **argv){
  CountCtx *p;
  p = sqlite3_aggregate_context(context, sizeof(*p));
  if( (argc==0 || argv[0]) && p ){
    p->n++;
  }
}   
static void countFinalize(sqlite_func *context){
  CountCtx *p;
  p = sqlite3_aggregate_context(context, sizeof(*p));
  sqlite3_set_result_int(context, p ? p->n : 0);

**
** 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 1.326 2004/05/24 12:39:02 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*

/* Opcode: Callback P1 * *
**
** Pop P1 values off the stack and form them into an array.  Then
** invoke the callback function using the newly formed array as the
** 3rd parameter.
*/
case OP_Callback: {
#if 0
  int i;
  char **azArgv = p->zArgv;
  Mem *pCol;

  pCol = &pTos[1-pOp->p1];
  assert( pCol>=p->aStack );
  for(i=0; i<pOp->p1; i++, pCol++){
    if( pCol->flags & MEM_Null ){
      azArgv[i] = 0;
    }else{
      Stringify(pCol, db->enc);
      azArgv[i] = pCol->z;
    }
  }

  azArgv[i] = 0;
  p->azResColumn = azArgv;
#endif

  int i;
  assert( p->nResColumn==pOp->p1 );

  for(i=0; i<pOp->p1; i++){
    Mem *pVal = &pTos[0-i];
    SetEncodingFlags(pVal, db->enc);
  }

  int i;
  Mem *pArg;
  sqlite_func ctx;
  sqlite3_value **apVal;
  int n = pOp->p1;

  n = pOp->p1;
  apVal = sqliteMalloc(sizeof(sqlite3_value*)*n);
  assert( apVal || n==0 );

  pArg = &pTos[1-n];
  for(i=0; i<n; i++, pArg++){
    SetEncodingFlags(pArg, db->enc);
    apVal[i] = pArg;
  }

  }

  if( pTos->flags&MEM_Str ){
    SetEncodingFlags(pTos, TEXT_Utf8);
    SetEncoding(pTos, encToFlags(db->enc)|MEM_Term);
  }

  if( apVal ) sqliteFree(apVal);
  break;
}

/* Opcode: BitAnd * * *
**
** Pop the top two elements from the stack.  Convert both elements
** to integers.  Push back onto the stack the bit-wise AND of the

** Ideally, this index would be another parameter, but there are
** no free parameters left.  The integer is popped from the stack.
*/
case OP_AggFunc: {
  int n = pOp->p2;
  int i;
  Mem *pMem, *pRec;
  char **azArgv = p->zArgv;
  sqlite_func ctx;


  assert( n>=0 );
  assert( pTos->flags==MEM_Int );
  pRec = &pTos[-n];
  assert( pRec>=p->aStack );




  for(i=0; i<n; i++, pRec++){
    if( pRec->flags & MEM_Null ){
      azArgv[i] = 0;
    }else{
      Stringify(pRec, db->enc);
      SetEncodingFlags(pRec, db->enc);
      SetEncoding(pRec, MEM_Utf8|MEM_Term);
      azArgv[i] = pRec->z;
    }
  }
  i = pTos->i;
  assert( i>=0 && i<p->agg.nMem );
  ctx.pFunc = (FuncDef*)pOp->p3;
  pMem = &p->agg.pCurrent->aMem[i];
  ctx.s.z = pMem->zShort;  /* Space used for small aggregate contexts */
  ctx.pAgg = pMem->z;
  ctx.cnt = ++pMem->i;
  ctx.isError = 0;
  ctx.isStep = 1;
  (ctx.pFunc->xStep)(&ctx, n, (const char**)azArgv);
  pMem->z = ctx.pAgg;
  pMem->flags = MEM_AggCtx;
  popStack(&pTos, n+1);
  if( ctx.isError ){
    rc = SQLITE_ERROR;
  }
  break;

  int nOpAlloc;       /* Number of slots allocated for aOp[] */
  Op *aOp;            /* Space to hold the virtual machine's program */
  int nLabel;         /* Number of labels used */
  int nLabelAlloc;    /* Number of slots allocated in aLabel[] */
  int *aLabel;        /* Space to hold the labels */
  Mem *aStack;        /* The operand stack, except string values */
  Mem *pTos;          /* Top entry in the operand stack */
  char **zArgv;       /* Text values used by the callback */
  char **azColName;   /* Becomes the 4th parameter to callbacks */
  void **azColName16; /* UTF-16 encoded equivalent of azColName */
  int nCursor;        /* Number of slots in apCsr[] */
  Cursor **apCsr;     /* One element of this array for each open cursor */
  Sorter *pSort;      /* A linked list of objects to be sorted */
  FILE *pFile;        /* At most one open file handler */
  int nField;         /* Number of file fields */

  ** Allocation all the stack space we will ever need.
  */
  if( p->aStack==0 ){
    p->nVar = nVar;
    assert( nVar>=0 );
    n = isExplain ? 10 : p->nOp;
    p->aStack = sqliteMalloc(
      n*(sizeof(p->aStack[0]) + 2*sizeof(char*))     /* aStack and zArgv */
      + p->nVar*sizeof(Mem)                          /* apVar */
    );
    p->zArgv = (char**)&p->aStack[n];
    p->azColName = (char**)&p->zArgv[n];
    p->apVar = (Mem *)&p->azColName[n];
    for(n=0; n<p->nVar; n++){
      p->apVar[n].flags = MEM_Null;
    }
  }

  sqlite3HashInit(&p->agg.hash, SQLITE_HASH_BINARY, 0);