SQLite

/*
** 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.
**
*************************************************************************
** $Id: btree.c,v 1.61 2002/05/15 11:44:14 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.

  PageOne *pP1;
  int rc;
  if( !pBt->inTrans ){
    return SQLITE_ERROR;  /* Must start a transaction first */
  }
  pP1 = pBt->page1;
  rc = sqlitepager_write(pP1);
  if( rc ) return rc;   
  memcpy(pP1->aMeta, &aMeta[1], sizeof(pP1->aMeta));
  return SQLITE_OK;
}

/******************************************************************************
** The complete implementation of the BTree subsystem is above this line.
** All the code the follows is for testing and troubleshooting the BTree

**     COPY
**     VACUUM
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**     PRAGMA
**
** $Id: build.c,v 1.89 2002/05/15 11:44:14 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called after a single SQL statement has been
** parsed and we want to execute the VDBE code to implement 

    assert( pOld==0 || pOld==p );
  }
  sqliteHashClear(&db->idxDrop);

  /* Remove any triggers that haven't been commited yet */
  for(pElem = sqliteHashFirst(&db->trigHash); pElem; 
      pElem = (pElem?sqliteHashNext(pElem):0)) {
    Trigger *pTrigger = sqliteHashData(pElem);
    if( !pTrigger->isCommit ){
      Table *pTbl = sqliteFindTable(db, pTrigger->table);
      if( pTbl ){
        if( pTbl->pTrigger == pTrigger ){
          pTbl->pTrigger = pTrigger->pNext;
        }else{
          Trigger *cc = pTbl->pTrigger;
          while( cc ){
            if (cc->pNext == pTrigger) {
              cc->pNext = cc->pNext->pNext;
              break;
            }
            cc = cc->pNext;
          }
          assert(cc);
        }
      }
      sqliteHashInsert(&db->trigHash, pTrigger->name,
              1 + strlen(pTrigger->name), 0);
      sqliteDeleteTrigger(pTrigger);
      pElem = sqliteHashFirst(&db->trigHash);
    }
  }

  /* Any triggers that were dropped - put 'em back in place */
  for(pElem = sqliteHashFirst(&db->trigDrop); pElem; 
      pElem = sqliteHashNext(pElem)) {
    Trigger * pTrigger = sqliteHashData(pElem);
    Table * tab = sqliteFindTable(db, pTrigger->table);
    sqliteHashInsert(&db->trigHash, pTrigger->name, 
        strlen(pTrigger->name) + 1, pTrigger);

    pTrigger->pNext = tab->pTrigger;
    tab->pTrigger = pTrigger;
  }

  sqliteHashClear(&db->trigDrop);
  db->flags &= ~SQLITE_InternChanges;

      sqliteVdbeAddOpList(v, ArraySize(indexListPreface), indexListPreface);
      while(pIdx){
        sqliteVdbeAddOp(v, OP_Integer, i, 0);
        sqliteVdbeAddOp(v, OP_String, 0, 0);
        sqliteVdbeChangeP3(v, -1, pIdx->zName, P3_STATIC);
        sqliteVdbeAddOp(v, OP_Integer, pIdx->onError!=OE_None, 0);
        sqliteVdbeAddOp(v, OP_Callback, 3, 0);
        ++i;
        pIdx = pIdx->pNext;
      }
    }
  }else

#ifndef NDEBUG
  if( sqliteStrICmp(zLeft, "parser_trace")==0 ){
    extern void sqliteParserTrace(FILE*, char *);

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle DELETE FROM statements.
**
** $Id: delete.c,v 1.32 2002/05/15 11:44:14 drh Exp $
*/
#include "sqliteInt.h"


/*
** Given a table name, find the corresponding table and make sure the
** table is writeable.  Generate an error and return NULL if not.  If

  {
    Table * pTab;
    char * zTab = sqliteTableNameFromToken(pTableName);

    if(zTab != 0) {
      pTab = sqliteFindTable(pParse->db, zTab);
      if (pTab) {
        row_triggers_exist = 
          sqliteTriggersExist(pParse, pTab->pTrigger, 
              TK_DELETE, TK_BEFORE, TK_ROW, 0) ||
          sqliteTriggersExist(pParse, pTab->pTrigger, 
              TK_DELETE, TK_AFTER, TK_ROW, 0);
      }
      sqliteFree(zTab);
      if (row_triggers_exist &&  pTab->pSelect ) {
        /* Just fire VIEW triggers */
        sqliteViewTriggers(pParse, pTab, pWhere, OE_Replace, 0);
        return;
      }
    }
  }

  /* Locate the table which we want to delete.  This table has to be
  ** put in an IdList structure because some of the subroutines we
  ** will be calling are designed to work with multiple tables and expect

      openOp = pTab->isTemp ? OP_OpenAux : OP_Open;
      sqliteVdbeAddOp(v, openOp, base, pTab->tnum);
      sqliteVdbeAddOp(v, OP_MoveTo, base, 0);
      sqliteVdbeAddOp(v, OP_OpenTemp, oldIdx, 0);

      sqliteVdbeAddOp(v, OP_Integer, 13, 0);
      for (ii = 0; ii < pTab->nCol; ii++) {
        if (ii == pTab->iPKey) 
          sqliteVdbeAddOp(v, OP_Recno, base, 0);
        else
          sqliteVdbeAddOp(v, OP_Column, base, ii);
      }
      sqliteVdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
      sqliteVdbeAddOp(v, OP_PutIntKey, oldIdx, 0);
      sqliteVdbeAddOp(v, OP_Close, base, 0);
      sqliteVdbeAddOp(v, OP_Rewind, oldIdx, 0);

      sqliteCodeRowTrigger(pParse, TK_DELETE, 0, TK_BEFORE, pTab, -1, 
          oldIdx, (pParse->trigStack)?pParse->trigStack->orconf:OE_Default);
    }

    pParse->nTab = base + 1;
    openOp = pTab->isTemp ? OP_OpenWrAux : OP_OpenWrite;
    sqliteVdbeAddOp(v, openOp, base, pTab->tnum);
    for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
      sqliteVdbeAddOp(v, openOp, pParse->nTab++, pIdx->tnum);
    }

    if (!row_triggers_exist) 
      addr = sqliteVdbeAddOp(v, OP_ListRead, 0, end);

    sqliteGenerateRowDelete(v, pTab, base, pParse->trigStack?0:1);

    if (row_triggers_exist) {
      for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
        sqliteVdbeAddOp(v, OP_Close, base + i, pIdx->tnum);
      }
      sqliteVdbeAddOp(v, OP_Close, base, 0);
      sqliteCodeRowTrigger(pParse, TK_DELETE, 0, TK_AFTER, pTab, -1, 
          oldIdx, (pParse->trigStack)?pParse->trigStack->orconf:OE_Default);
    }

    sqliteVdbeAddOp(v, OP_Goto, 0, addr);
    sqliteVdbeResolveLabel(v, end);
    sqliteVdbeAddOp(v, OP_ListReset, 0, 0);

    if (!row_triggers_exist) {
      for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
        sqliteVdbeAddOp(v, OP_Close, base + i, pIdx->tnum);
      }
      sqliteVdbeAddOp(v, OP_Close, base, 0);
      pParse->nTab = base;
    }
  }
  sqliteEndWriteOperation(pParse);

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle INSERT statements in SQLite.
**
** $Id: insert.c,v 1.54 2002/05/15 11:44:14 drh Exp $
*/
#include "sqliteInt.h"

/*
** This routine is call to handle SQL of the following forms:
**
**    insert into TABLE (IDLIST) values(EXPRLIST)

  /* Ensure that:
  *  (a) the table is not read-only, 
  *  (b) that if it is a view then ON INSERT triggers exist
  */
  row_triggers_exist = 
    sqliteTriggersExist(pParse, pTab->pTrigger, TK_INSERT, 
        TK_BEFORE, TK_ROW, 0) ||
    sqliteTriggersExist(pParse, pTab->pTrigger, TK_INSERT, TK_AFTER, TK_ROW, 0);
  if( pTab->readOnly || (pTab->pSelect && !row_triggers_exist) ){
    sqliteSetString(&pParse->zErrMsg, 
      pTab->pSelect ? "view " : "table ",
      zTab,
      " may not be modified", 0);
    pParse->nErr++;

  if (row_triggers_exist) {

    /* build the new.* reference row */
    sqliteVdbeAddOp(v, OP_Integer, 13, 0);
    for(i=0; i<pTab->nCol; i++){
      if( pColumn==0 ){
        j = i;
      }else{
        for(j=0; j<pColumn->nId; j++){
          if( pColumn->a[j].idx==i ) break;
        }
      }
      if( pColumn && j>=pColumn->nId ){
        sqliteVdbeAddOp(v, OP_String, 0, 0);
        sqliteVdbeChangeP3(v, -1, pTab->aCol[i].zDflt, P3_STATIC);
      }else if( srcTab>=0 ){
        sqliteVdbeAddOp(v, OP_Column, srcTab, j); 
      }else{
        sqliteExprCode(pParse, pList->a[j].pExpr);
      }
    }
    sqliteVdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
    sqliteVdbeAddOp(v, OP_PutIntKey, newIdx, 0);
    sqliteVdbeAddOp(v, OP_Rewind, newIdx, 0);

    /* Fire BEFORE triggers */
    if (
    sqliteCodeRowTrigger(pParse, TK_INSERT, 0, TK_BEFORE, pTab, newIdx, -1, 
        onError)
       ) goto insert_cleanup;

    /* Open the tables and indices for the INSERT */
    if (!pTab->pSelect) {
      base = pParse->nTab;
      openOp = pTab->isTemp ? OP_OpenWrAux : OP_OpenWrite;
      sqliteVdbeAddOp(v, openOp, base, pTab->tnum);
      sqliteVdbeChangeP3(v, -1, pTab->zName, P3_STATIC);
      for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
        sqliteVdbeAddOp(v, openOp, idx+base, pIdx->tnum);
        sqliteVdbeChangeP3(v, -1, pIdx->zName, P3_STATIC);
      }
      pParse->nTab += idx;
    }
  }

  /* Push the record number for the new entry onto the stack.  The
  ** record number is a randomly generate integer created by NewRecno
  ** except when the table has an INTEGER PRIMARY KEY column, in which
  ** case the record number is the same as that column. 
  */
  if (!pTab->pSelect) {
    if( keyColumn>=0 ){
      if( srcTab>=0 ){
        sqliteVdbeAddOp(v, OP_Column, srcTab, keyColumn);
      }else{
        int addr;
        sqliteExprCode(pParse, pList->a[keyColumn].pExpr);

        /* If the PRIMARY KEY expression is NULL, then use OP_NewRecno
         ** to generate a unique primary key value.
         */
        addr = sqliteVdbeAddOp(v, OP_Dup, 0, 1);
        sqliteVdbeAddOp(v, OP_NotNull, 0, addr+4);
        sqliteVdbeAddOp(v, OP_Pop, 1, 0);
        sqliteVdbeAddOp(v, OP_NewRecno, base, 0);
      }
      sqliteVdbeAddOp(v, OP_MustBeInt, 0, 0);
    }else{
      sqliteVdbeAddOp(v, OP_NewRecno, base, 0);
    }

    /* Push onto the stack, data for all columns of the new entry, beginning
     ** with the first column.
     */
    for(i=0; i<pTab->nCol; i++){
      if( i==pTab->iPKey ){
        /* The value of the INTEGER PRIMARY KEY column is always a NULL.
         ** Whenever this column is read, the record number will be substituted
         ** in its place.  So will fill this column with a NULL to avoid
         ** taking up data space with information that will never be used. */
        sqliteVdbeAddOp(v, OP_String, 0, 0);
        continue;
      }
      if( pColumn==0 ){
        j = i;
      }else{
        for(j=0; j<pColumn->nId; j++){
          if( pColumn->a[j].idx==i ) break;
        }
      }
      if( pColumn && j>=pColumn->nId ){
        sqliteVdbeAddOp(v, OP_String, 0, 0);
        sqliteVdbeChangeP3(v, -1, pTab->aCol[i].zDflt, P3_STATIC);
      }else if( srcTab>=0 ){
        sqliteVdbeAddOp(v, OP_Column, srcTab, j); 
      }else{
        sqliteExprCode(pParse, pList->a[j].pExpr);
      }
    }

    /* Generate code to check constraints and generate index keys and
     ** do the insertion.
     */
    endOfLoop = sqliteVdbeMakeLabel(v);

  }

  if (row_triggers_exist) {
    /* Close all tables opened */
    if (!pTab->pSelect) {
      sqliteVdbeAddOp(v, OP_Close, base, 0);
      for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
        sqliteVdbeAddOp(v, OP_Close, idx+base, 0);
      }
    }

    /* Code AFTER triggers */
    if (
        sqliteCodeRowTrigger(pParse, TK_INSERT, 0, TK_AFTER, pTab, newIdx, -1, 
          onError)
       ) goto insert_cleanup;
  }

  /* The bottom of the loop, if the data source is a SELECT statement
   */
  sqliteVdbeResolveLabel(v, endOfLoop);
  if( srcTab>=0 ){

**
*************************************************************************
** 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 1.73 2002/05/15 11:44:14 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"

/*
** This is the callback routine for the code that initializes the
** database.  See sqliteInit() below for additional information.

  for (pElem=sqliteHashFirst(&temp2); pElem; pElem=sqliteHashNext(pElem)){
    Trigger * pTrigger = sqliteHashData(pElem);
    Table *pTab = sqliteFindTable(db, pTrigger->table);
    assert(pTab);
    if (pTab->isTemp) { 
      sqliteHashInsert(&db->trigHash, pTrigger->name, strlen(pTrigger->name), 
          pTrigger);
    } else {
      sqliteDeleteTrigger(pTrigger);
    }
  }
  sqliteHashClear(&temp2);

  sqliteHashInit(&db->tblHash, SQLITE_HASH_STRING, 0);

        if( zSql[1]!='-' ){
          isComplete = 0;
          break;
        }
        while( *zSql && *zSql!='\n' ){ zSql++; }
        if( *zSql==0 ) return isComplete;
        break;
      }
      default: {
        if (seenCreate && !sqliteStrNICmp(zSql, "trigger", 7)){
          while (sqliteStrNICmp(zSql, "end", 3)){
            if (!*++zSql) return 0;
          }
        }
        if (!sqliteStrNICmp(zSql, "create", 6)) {
          zSql = zSql + 5;
          seenCreate = 1;
        }else{
          seenCreate = 0;
        }
        isComplete = 0;
        break;
      }
    }
    zSql++;
  }
  return isComplete;

};
typedef char MD5Context[88];

/*
 * Note: this code is harmless on little-endian machines.
 */
static void byteReverse (unsigned char *buf, unsigned longs){
        uint32 t;
        do {
                t = (uint32)((unsigned)buf[3]<<8 | buf[2]) << 16 |
                            ((unsigned)buf[1]<<8 | buf[0]);
                *(uint32 *)buf = t;
                buf += 4;
        } while (--longs);
}
/* The four core functions - F1 is optimized somewhat */

/* #define F1(x, y, z) (x & y | ~x & z) */
#define F1(x, y, z) (z ^ (x & (y ^ z)))
#define F2(x, y, z) F1(z, x, y)
#define F3(x, y, z) (x ^ y ^ z)
#define F4(x, y, z) (y ^ (x | ~z))

/* This is the central step in the MD5 algorithm. */
#define MD5STEP(f, w, x, y, z, data, s) \
        ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )

/*
 * The core of the MD5 algorithm, this alters an existing MD5 hash to
 * reflect the addition of 16 longwords of new data.  MD5Update blocks
 * the data and converts bytes into longwords for this routine.
 */
static void MD5Transform(uint32 buf[4], const uint32 in[16]){
        register uint32 a, b, c, d;

        a = buf[0];
        b = buf[1];
        c = buf[2];
        d = buf[3];

        MD5STEP(F1, a, b, c, d, in[ 0]+0xd76aa478,  7);
        MD5STEP(F1, d, a, b, c, in[ 1]+0xe8c7b756, 12);
        MD5STEP(F1, c, d, a, b, in[ 2]+0x242070db, 17);
        MD5STEP(F1, b, c, d, a, in[ 3]+0xc1bdceee, 22);
        MD5STEP(F1, a, b, c, d, in[ 4]+0xf57c0faf,  7);
        MD5STEP(F1, d, a, b, c, in[ 5]+0x4787c62a, 12);
        MD5STEP(F1, c, d, a, b, in[ 6]+0xa8304613, 17);
        MD5STEP(F1, b, c, d, a, in[ 7]+0xfd469501, 22);
        MD5STEP(F1, a, b, c, d, in[ 8]+0x698098d8,  7);
        MD5STEP(F1, d, a, b, c, in[ 9]+0x8b44f7af, 12);
        MD5STEP(F1, c, d, a, b, in[10]+0xffff5bb1, 17);
        MD5STEP(F1, b, c, d, a, in[11]+0x895cd7be, 22);
        MD5STEP(F1, a, b, c, d, in[12]+0x6b901122,  7);
        MD5STEP(F1, d, a, b, c, in[13]+0xfd987193, 12);
        MD5STEP(F1, c, d, a, b, in[14]+0xa679438e, 17);
        MD5STEP(F1, b, c, d, a, in[15]+0x49b40821, 22);

        MD5STEP(F2, a, b, c, d, in[ 1]+0xf61e2562,  5);
        MD5STEP(F2, d, a, b, c, in[ 6]+0xc040b340,  9);
        MD5STEP(F2, c, d, a, b, in[11]+0x265e5a51, 14);
        MD5STEP(F2, b, c, d, a, in[ 0]+0xe9b6c7aa, 20);
        MD5STEP(F2, a, b, c, d, in[ 5]+0xd62f105d,  5);
        MD5STEP(F2, d, a, b, c, in[10]+0x02441453,  9);
        MD5STEP(F2, c, d, a, b, in[15]+0xd8a1e681, 14);
        MD5STEP(F2, b, c, d, a, in[ 4]+0xe7d3fbc8, 20);
        MD5STEP(F2, a, b, c, d, in[ 9]+0x21e1cde6,  5);
        MD5STEP(F2, d, a, b, c, in[14]+0xc33707d6,  9);
        MD5STEP(F2, c, d, a, b, in[ 3]+0xf4d50d87, 14);
        MD5STEP(F2, b, c, d, a, in[ 8]+0x455a14ed, 20);
        MD5STEP(F2, a, b, c, d, in[13]+0xa9e3e905,  5);
        MD5STEP(F2, d, a, b, c, in[ 2]+0xfcefa3f8,  9);
        MD5STEP(F2, c, d, a, b, in[ 7]+0x676f02d9, 14);
        MD5STEP(F2, b, c, d, a, in[12]+0x8d2a4c8a, 20);

        MD5STEP(F3, a, b, c, d, in[ 5]+0xfffa3942,  4);
        MD5STEP(F3, d, a, b, c, in[ 8]+0x8771f681, 11);
        MD5STEP(F3, c, d, a, b, in[11]+0x6d9d6122, 16);
        MD5STEP(F3, b, c, d, a, in[14]+0xfde5380c, 23);
        MD5STEP(F3, a, b, c, d, in[ 1]+0xa4beea44,  4);
        MD5STEP(F3, d, a, b, c, in[ 4]+0x4bdecfa9, 11);
        MD5STEP(F3, c, d, a, b, in[ 7]+0xf6bb4b60, 16);
        MD5STEP(F3, b, c, d, a, in[10]+0xbebfbc70, 23);
        MD5STEP(F3, a, b, c, d, in[13]+0x289b7ec6,  4);
        MD5STEP(F3, d, a, b, c, in[ 0]+0xeaa127fa, 11);
        MD5STEP(F3, c, d, a, b, in[ 3]+0xd4ef3085, 16);
        MD5STEP(F3, b, c, d, a, in[ 6]+0x04881d05, 23);
        MD5STEP(F3, a, b, c, d, in[ 9]+0xd9d4d039,  4);
        MD5STEP(F3, d, a, b, c, in[12]+0xe6db99e5, 11);
        MD5STEP(F3, c, d, a, b, in[15]+0x1fa27cf8, 16);
        MD5STEP(F3, b, c, d, a, in[ 2]+0xc4ac5665, 23);

        MD5STEP(F4, a, b, c, d, in[ 0]+0xf4292244,  6);
        MD5STEP(F4, d, a, b, c, in[ 7]+0x432aff97, 10);
        MD5STEP(F4, c, d, a, b, in[14]+0xab9423a7, 15);
        MD5STEP(F4, b, c, d, a, in[ 5]+0xfc93a039, 21);
        MD5STEP(F4, a, b, c, d, in[12]+0x655b59c3,  6);
        MD5STEP(F4, d, a, b, c, in[ 3]+0x8f0ccc92, 10);
        MD5STEP(F4, c, d, a, b, in[10]+0xffeff47d, 15);
        MD5STEP(F4, b, c, d, a, in[ 1]+0x85845dd1, 21);
        MD5STEP(F4, a, b, c, d, in[ 8]+0x6fa87e4f,  6);
        MD5STEP(F4, d, a, b, c, in[15]+0xfe2ce6e0, 10);
        MD5STEP(F4, c, d, a, b, in[ 6]+0xa3014314, 15);
        MD5STEP(F4, b, c, d, a, in[13]+0x4e0811a1, 21);
        MD5STEP(F4, a, b, c, d, in[ 4]+0xf7537e82,  6);
        MD5STEP(F4, d, a, b, c, in[11]+0xbd3af235, 10);
        MD5STEP(F4, c, d, a, b, in[ 2]+0x2ad7d2bb, 15);
        MD5STEP(F4, b, c, d, a, in[ 9]+0xeb86d391, 21);

        buf[0] += a;
        buf[1] += b;
        buf[2] += c;
        buf[3] += d;
}

/*
 * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
 * initialization constants.
 */
static void MD5Init(MD5Context *pCtx){
        struct Context *ctx = (struct Context *)pCtx;
        ctx->buf[0] = 0x67452301;
        ctx->buf[1] = 0xefcdab89;
        ctx->buf[2] = 0x98badcfe;
        ctx->buf[3] = 0x10325476;
        ctx->bits[0] = 0;
        ctx->bits[1] = 0;
}

/*
 * Update context to reflect the concatenation of another buffer full
 * of bytes.
 */
static 
void MD5Update(MD5Context *pCtx, const unsigned char *buf, unsigned int len){
        struct Context *ctx = (struct Context *)pCtx;
        uint32 t;

        /* Update bitcount */

        t = ctx->bits[0];
        if ((ctx->bits[0] = t + ((uint32)len << 3)) < t)
                ctx->bits[1]++; /* Carry from low to high */
        ctx->bits[1] += len >> 29;

        t = (t >> 3) & 0x3f;    /* Bytes already in shsInfo->data */

        /* Handle any leading odd-sized chunks */

        if ( t ) {
                unsigned char *p = (unsigned char *)ctx->in + t;

                t = 64-t;
                if (len < t) {
                        memcpy(p, buf, len);
                        return;
                }
                memcpy(p, buf, t);
                byteReverse(ctx->in, 16);
                MD5Transform(ctx->buf, (uint32 *)ctx->in);
                buf += t;
                len -= t;
        }

        /* Process data in 64-byte chunks */

        while (len >= 64) {
                memcpy(ctx->in, buf, 64);
                byteReverse(ctx->in, 16);
                MD5Transform(ctx->buf, (uint32 *)ctx->in);
                buf += 64;
                len -= 64;
        }

        /* Handle any remaining bytes of data. */

        memcpy(ctx->in, buf, len);
}

/*
 * Final wrapup - pad to 64-byte boundary with the bit pattern 
 * 1 0* (64-bit count of bits processed, MSB-first)
 */
static void MD5Final(unsigned char digest[16], MD5Context *pCtx){
        struct Context *ctx = (struct Context *)pCtx;
        unsigned count;
        unsigned char *p;

        /* Compute number of bytes mod 64 */
        count = (ctx->bits[0] >> 3) & 0x3F;

        /* Set the first char of padding to 0x80.  This is safe since there is
           always at least one byte free */
        p = ctx->in + count;
        *p++ = 0x80;

        /* Bytes of padding needed to make 64 bytes */
        count = 64 - 1 - count;

        /* Pad out to 56 mod 64 */
        if (count < 8) {
                /* Two lots of padding:  Pad the first block to 64 bytes */
                memset(p, 0, count);
                byteReverse(ctx->in, 16);
                MD5Transform(ctx->buf, (uint32 *)ctx->in);

                /* Now fill the next block with 56 bytes */
                memset(ctx->in, 0, 56);
        } else {
                /* Pad block to 56 bytes */
                memset(p, 0, count-8);
        }
        byteReverse(ctx->in, 14);

        /* Append length in bits and transform */
        ((uint32 *)ctx->in)[ 14 ] = ctx->bits[0];
        ((uint32 *)ctx->in)[ 15 ] = ctx->bits[1];

        MD5Transform(ctx->buf, (uint32 *)ctx->in);
        byteReverse((unsigned char *)ctx->buf, 4);
        memcpy(digest, ctx->buf, 16);
        memset(ctx, 0, sizeof(ctx));    /* In case it's sensitive */
}

/*
** Convert a digest into base-16.  digest should be declared as
** "unsigned char digest[16]" in the calling function.  The MD5
** digest is stored in the first 16 bytes.  zBuf should
** be "char zBuf[33]".

    **   xtype                       The class of the conversion.
    **   infop                       Pointer to the appropriate info struct.
    */
    switch( xtype ){
      case etORDINAL:
      case etRADIX:
        if( flag_long )  longvalue = va_arg(ap,long);
        else             longvalue = va_arg(ap,int);
#ifdef etCOMPATIBILITY
        /* For the format %#x, the value zero is printed "0" not "0x0".
        ** I think this is stupid. */
        if( longvalue==0 ) flag_alternateform = 0;
#else
        /* More sensible: turn off the prefix for octal (to prevent "00"),
        ** but leave the prefix for hex. */
        if( longvalue==0 && infop->base==8 ) flag_alternateform = 0;
#endif
        if( infop->flag_signed ){
          if( *(long*)&longvalue<0 ){
            longvalue = -*(long*)&longvalue;
            prefix = '-';
          }else if( flag_plussign )  prefix = '+';
          else if( flag_blanksign )  prefix = ' ';
          else                       prefix = 0;
        }else                        prefix = 0;
        if( flag_zeropad && precision<width-(prefix!=0) ){
          precision = width-(prefix!=0);
        }
        bufpt = &buf[etBUFSIZE];
        if( xtype==etORDINAL ){
          long a,b;
          a = longvalue%10;
          b = longvalue%100;
          bufpt -= 2;
          if( a==0 || a>3 || (b>10 && b<14) ){

          register int base;
          cset = infop->charset;
          base = infop->base;
          do{                                           /* Convert to ascii */
            *(--bufpt) = cset[longvalue%base];
            longvalue = longvalue/base;
          }while( longvalue>0 );
        }
        length = (long)&buf[etBUFSIZE]-(long)bufpt;
        for(idx=precision-length; idx>0; idx--){
          *(--bufpt) = '0';                             /* Zero pad */
        }
        if( prefix ) *(--bufpt) = prefix;               /* Add sign */
        if( flag_alternateform && infop->prefix ){      /* Add "0" or "0x" */
          char *pre, x;
          pre = infop->prefix;
          if( *bufpt!=pre[0] ){
            for(pre=infop->prefix; (x=(*pre))!=0; pre++) *(--bufpt) = x;
          }
        }
        length = (long)&buf[etBUFSIZE]-(long)bufpt;
        break;
      case etFLOAT:
      case etEXP:
      case etGENERIC:
        realvalue = va_arg(ap,double);
#ifndef etNOFLOATINGPOINT
        if( precision<0 ) precision = 6;         /* Set default precision */
        if( precision>etBUFSIZE-10 ) precision = etBUFSIZE-10;
        if( realvalue<0.0 ){
          realvalue = -realvalue;
          prefix = '-';
        }else{
          if( flag_plussign )          prefix = '+';
          else if( flag_blanksign )    prefix = ' ';
          else                         prefix = 0;
        }
        if( infop->type==etGENERIC && precision>0 ) precision--;
        rounder = 0.0;
#ifdef COMPATIBILITY
        /* Rounding works like BSD when the constant 0.4999 is used.  Wierd! */
        for(idx=precision, rounder=0.4999; idx>0; idx--, rounder*=0.1);
#else
        /* It makes more sense to use 0.5 */

          while( realvalue<1e-8 && k++<100 ){ realvalue *= 1e8; exp-=8; }
          while( realvalue<1.0 && k++<100 ){ realvalue *= 10.0; exp--; }
          if( k>=100 ){
            bufpt = "NaN";
            length = 3;
            break;
          }
        }
        bufpt = buf;
        /*
        ** If the field type is etGENERIC, then convert to either etEXP
        ** or etFLOAT, as appropriate.
        */
        flag_exp = xtype==etEXP;
        if( xtype!=etFLOAT ){
          realvalue += rounder;
          if( realvalue>=10.0 ){ realvalue *= 0.1; exp++; }
        }
        if( xtype==etGENERIC ){
          flag_rtz = !flag_alternateform;
          if( exp<-4 || exp>precision ){
            xtype = etEXP;
          }else{
            precision = precision - exp;
            xtype = etFLOAT;
          }
        }else{
          flag_rtz = 0;
        }
        /*
        ** The "exp+precision" test causes output to be of type etEXP if
        ** the precision is too large to fit in buf[].
        */
        nsd = 0;
        if( xtype==etFLOAT && exp+precision<etBUFSIZE-30 ){
          flag_dp = (precision>0 || flag_alternateform);

          while( (precision--)>0 ) *(bufpt++) = et_getdigit(&realvalue,&nsd);
          *(bufpt--) = 0;                           /* Null terminate */
          if( flag_rtz && flag_dp ){     /* Remove trailing zeros and "." */
            while( bufpt>=buf && *bufpt=='0' ) *(bufpt--) = 0;
            if( bufpt>=buf && *bufpt=='.' ) *(bufpt--) = 0;
          }
          bufpt++;                            /* point to next free slot */
        }else{    /* etEXP or etGENERIC */
          flag_dp = (precision>0 || flag_alternateform);
          if( prefix ) *(bufpt++) = prefix;   /* Sign */
          *(bufpt++) = et_getdigit(&realvalue,&nsd);  /* First digit */
          if( flag_dp ) *(bufpt++) = '.';     /* Decimal point */
          while( (precision--)>0 ) *(bufpt++) = et_getdigit(&realvalue,&nsd);
          bufpt--;                            /* point to last digit */
          if( flag_rtz && flag_dp ){          /* Remove tail zeros */
            while( bufpt>=buf && *bufpt=='0' ) *(bufpt--) = 0;
            if( bufpt>=buf && *bufpt=='.' ) *(bufpt--) = 0;
          }
          bufpt++;                            /* point to next free slot */
          if( exp || flag_exp ){
            *(bufpt++) = infop->charset[0];
            if( exp<0 ){ *(bufpt++) = '-'; exp = -exp; } /* sign of exp */
            else       { *(bufpt++) = '+'; }
            if( exp>=100 ){
              *(bufpt++) = (exp/100)+'0';                /* 100's digit */
              exp %= 100;
            }
            *(bufpt++) = exp/10+'0';                     /* 10's digit */
            *(bufpt++) = exp%10+'0';                     /* 1's digit */
          }
        }
        /* The converted number is in buf[] and zero terminated. Output it.
        ** Note that the number is in the usual order, not reversed as with
        ** integer conversions. */
        length = (long)bufpt-(long)buf;
        bufpt = buf;

        /* Special case:  Add leading zeros if the flag_zeropad flag is

        break;
      case etCHARLIT:
      case etCHARX:
        c = buf[0] = (xtype==etCHARX ? va_arg(ap,int) : *++fmt);
        if( precision>=0 ){
          for(idx=1; idx<precision; idx++) buf[idx] = c;
          length = precision;
        }else{
          length =1;
        }
        bufpt = buf;
        break;
      case etSTRING:
        zMem = bufpt = va_arg(ap,char*);
        if( bufpt==0 ) bufpt = "(null)";
        length = strlen(bufpt);
        if( precision>=0 && precision<length ) length = precision;

      register int nspace;
      nspace = width-length;
      if( nspace>0 ){
        if( flag_center ){
          nspace = nspace/2;
          width -= nspace;
          flag_leftjustify = 1;
        }
        count += nspace;
        while( nspace>=etSPACESIZE ){
          (*func)(arg,spaces,etSPACESIZE);
          nspace -= etSPACESIZE;
        }
        if( nspace>0 ) (*func)(arg,spaces,nspace);
      }

/*
** All copyright on this work is disclaimed by the author.

*/

#include "sqliteInt.h"

/*
** This is called by the parser when it sees a CREATE TRIGGER statement
*/

void sqliteCreateTrigger(
  Parse *pParse,      /* The parse context of the CREATE TRIGGER statement */
  Token *nm,          /* The name of the trigger */
  int tr_tm,          /* One of TK_BEFORE, TK_AFTER */
  int op,             /* One of TK_INSERT, TK_UPDATE, TK_DELETE */
  IdList *cols,       /* column list if this is an UPDATE OF trigger */
  Token *tbl,         /* The name of the table/view the trigger applies to */
  int foreach,        /* One of TK_ROW or TK_STATEMENT */
  Expr *pWhen,        /* WHEN clause */
  TriggerStep *steps, /* The triggered program */
  char const *cc,     /* The string data to make persistent */

  int len
){
  Trigger *nt;
  Table   *tab;
  int offset;
  TriggerStep *ss;

  /* Check that: 
  ** 1. the trigger name does not already exist.
  ** 2. the table (or view) does exist.
  */
  {
    char *tmp_str = sqliteStrNDup(nm->z, nm->n);
    if( sqliteHashFind(&(pParse->db->trigHash), tmp_str, nm->n + 1) ){
      sqliteSetNString(&pParse->zErrMsg, "trigger ", -1,
          nm->z, nm->n, " already exists", -1, 0);
      sqliteFree(tmp_str);
      pParse->nErr++;
      goto trigger_cleanup;
    }
    sqliteFree(tmp_str);
  }
  {
    char *tmp_str = sqliteStrNDup(tbl->z, tbl->n);
    tab = sqliteFindTable(pParse->db, tmp_str);
    sqliteFree(tmp_str);
    if( !tab ){
      sqliteSetNString(&pParse->zErrMsg, "no such table: ", -1,
          tbl->z, tbl->n, 0);
      pParse->nErr++;
      goto trigger_cleanup;
    }
  }

  /* Build the Trigger object */
  nt = (Trigger*)sqliteMalloc(sizeof(Trigger));

  nt->name = sqliteStrNDup(nm->z, nm->n);
  nt->table = sqliteStrNDup(tbl->z, tbl->n);
  nt->op = op;
  nt->tr_tm = tr_tm;
  nt->pWhen = pWhen;
  nt->pColumns = cols;
  nt->foreach = foreach;

    sqliteExprMoveStrings(ss->pWhere, offset);
    sqliteExprListMoveStrings(ss->pExprList, offset);

    ss = ss->pNext;
  }

  /* if we are not initializing, and this trigger is not on a TEMP table, 
  ** build the sqlite_master entry
  */
  if( !pParse->initFlag && !tab->isTemp ){

    /* Make an entry in the sqlite_master table */
    sqliteBeginWriteOperation(pParse);

    sqliteVdbeAddOp(pParse->pVdbe,        OP_OpenWrite, 0, 2);
    sqliteVdbeChangeP3(pParse->pVdbe, -1, MASTER_NAME,           P3_STATIC);
    sqliteVdbeAddOp(pParse->pVdbe,        OP_NewRecno,  0, 0);

  tmp_name = sqliteStrNDup(trigname->z, trigname->n);

  /* ensure that the trigger being dropped exists */
  trig = sqliteHashFind(&(pParse->db->trigHash), tmp_name, trigname->n + 1); 
  if (!trig) {
    sqliteSetNString(&pParse->zErrMsg, "no such trigger: ", -1,
        tmp_name, -1, 0);
    sqliteFree(tmp_name);
    return;
  }

  /*
   * If this is not an "explain", do the following:
   * 1. Remove the trigger from its associated table structure
   * 2. Move the trigger from the trigHash hash to trigDrop
   */
  if (!pParse->explain) {
    /* 1 */
    tbl = sqliteFindTable(pParse->db, trig->table);
    assert(tbl);
    if (tbl->pTrigger == trig) 
      tbl->pTrigger = trig->pNext;
    else {
      Trigger * cc = tbl->pTrigger;
      while (cc) {
        if (cc->pNext == trig) {
          cc->pNext = cc->pNext->pNext;
          break;
        }
        cc = cc->pNext;
      }
      assert(cc);
    }

    /* 2 */
    sqliteHashInsert(&(pParse->db->trigHash), tmp_name, 
        trigname->n + 1, NULL);
    sqliteHashInsert(&(pParse->db->trigDrop), trig->name, 
        trigname->n + 1, trig);
  }

  /* Unless this is a trigger on a TEMP TABLE, generate code to destroy the
   * database record of the trigger */
  if (!tbl->isTemp) {
    int base;
    static VdbeOp dropTrigger[] = {

      { OP_Close,      0, 0,        0},
    };

    if (!nested) 
      sqliteBeginWriteOperation(pParse);

    base = sqliteVdbeAddOpList(pParse->pVdbe, 
        ArraySize(dropTrigger), dropTrigger);
    sqliteVdbeChangeP3(pParse->pVdbe, base+2, tmp_name, 0);

    if (!nested)
      changeCookie(pParse->db);

    sqliteVdbeChangeP1(pParse->pVdbe, base+9, pParse->db->next_cookie);

  int i, e;
  if (!ii) return 1;
  if (!ee) return 1;

  for (i = 0; i < ii->nId; i++) 
    for (e = 0; e < ee->nExpr; e++) 
      if (!sqliteStrICmp(ii->a[i].zName, ee->a[e].zName))
        return 1;

  return 0; 
}

/* A global variable that is TRUE if we should always set up temp tables for
 * for triggers, even if there are no triggers to code. This is used to test 
 * how much overhead the triggers algorithm is causing.

  Trigger * tt;

  if (always_code_trigger_setup) return 1;

  tt = pTrigger;
  while (tt) {
    if (tt->op == op && tt->tr_tm == tr_tm && tt->foreach == foreach &&
        checkColumnOverLap(tt->pColumns, pChanges)) {
      TriggerStack * ss;
      ss = pParse->trigStack;
      while (ss && ss->pTrigger != pTrigger) ss = ss->pNext;
      if (!ss) return 1;
    }
    tt = tt->pNext;
  }

  return 0;
}

static int codeTriggerProgram(
        Parse *pParse,
        TriggerStep * program,
        int onError)
{
    TriggerStep * step = program;
    int orconf;

    while (step) {
        int saveNTab = pParse->nTab;
        orconf = (onError == OE_Default)?step->orconf:onError;
        pParse->trigStack->orconf = orconf;
        switch(step->op) {
            case TK_SELECT: {
                int tmp_tbl = pParse->nTab++;
                sqliteVdbeAddOp(pParse->pVdbe, OP_OpenTemp, tmp_tbl, 0);
                sqliteVdbeAddOp(pParse->pVdbe, OP_KeyAsData, tmp_tbl, 1);
                sqliteSelect(pParse, step->pSelect, 
                        SRT_Union, tmp_tbl, 0, 0, 0);
                sqliteVdbeAddOp(pParse->pVdbe, OP_Close, tmp_tbl, 0);
                pParse->nTab--;
                break;
                            }
            case TK_UPDATE: {
                sqliteVdbeAddOp(pParse->pVdbe, OP_PushList, 0, 0);
                sqliteUpdate(pParse, &step->target, 
                        sqliteExprListDup(step->pExprList), 
                        sqliteExprDup(step->pWhere), orconf);
                sqliteVdbeAddOp(pParse->pVdbe, OP_PopList, 0, 0);
                break;
                            }
            case TK_INSERT: {
                sqliteInsert(pParse, &step->target, 
                        sqliteExprListDup(step->pExprList), 
                        sqliteSelectDup(step->pSelect), 
                        sqliteIdListDup(step->pIdList), orconf);
                break;
                            }
            case TK_DELETE: {
                sqliteVdbeAddOp(pParse->pVdbe, OP_PushList, 0, 0);
                sqliteDeleteFrom(pParse, &step->target, 
                        sqliteExprDup(step->pWhere)
                        );
                sqliteVdbeAddOp(pParse->pVdbe, OP_PopList, 0, 0);
                break;
                            }
            default:
                            assert(0);
        } 
        pParse->nTab = saveNTab;
        step = step->pNext;
    }

    return 0;
}

int sqliteCodeRowTrigger(
        Parse * pParse,  /* Parse context */
        int op,          /* One of TK_UPDATE, TK_INSERT, TK_DELETE */
        ExprList * changes, /* Changes list for any UPDATE OF triggers */
        int tr_tm,       /* One of TK_BEFORE, TK_AFTER */
        Table * tbl,     /* The table to code triggers from */
        int newTable,    /* The indice of the "new" row to access */
        int oldTable,    /* The indice of the "old" row to access */
        int onError)     /* ON CONFLICT policy */
{
  Trigger * pTrigger;
  TriggerStack * pTriggerStack;


  assert(op == TK_UPDATE || op == TK_INSERT || op == TK_DELETE);
  assert(tr_tm == TK_BEFORE || tr_tm == TK_AFTER);

  assert(newTable != -1 || oldTable != -1);

  pTrigger = tbl->pTrigger;
  while (pTrigger) {
    int fire_this = 0;

    /* determine whether we should code this trigger */
    if (pTrigger->op == op && pTrigger->tr_tm == tr_tm && 
        pTrigger->foreach == TK_ROW) {
      fire_this = 1;
      pTriggerStack = pParse->trigStack;
      while (pTriggerStack) {
        if (pTriggerStack->pTrigger == pTrigger) fire_this = 0;
        pTriggerStack = pTriggerStack->pNext;
      }
      if (op == TK_UPDATE && pTrigger->pColumns &&
          !checkColumnOverLap(pTrigger->pColumns, changes))
        fire_this = 0;
    }

    if (fire_this) {
      int endTrigger;
      IdList dummyTablist;
      Expr * whenExpr;

      pTriggerStack->pNext = pParse->trigStack;
      pParse->trigStack = pTriggerStack;

      /* code the WHEN clause */
      endTrigger = sqliteVdbeMakeLabel(pParse->pVdbe);
      whenExpr = sqliteExprDup(pTrigger->pWhen);
      if (sqliteExprResolveIds(pParse, 0, &dummyTablist, 0, whenExpr)) {
        pParse->trigStack = pParse->trigStack->pNext;
        sqliteFree(pTriggerStack);
        sqliteExprDelete(whenExpr);
        return 1;
      }
      sqliteExprIfFalse(pParse, whenExpr, endTrigger);
      sqliteExprDelete(whenExpr);

      codeTriggerProgram(pParse, pTrigger->step_list, onError); 

      /* Pop the entry off the trigger stack */

    if( aXRef==0 ) goto trigger_cleanup;
    for (ii = 0; ii < pTab->nCol; ii++)
      aXRef[ii] = -1;

    for(ii=0; ii<pChanges->nExpr; ii++){
      int jj;
      if( sqliteExprResolveIds(pParse, oldIdx, theSelect.pSrc , 0, 
            pChanges->a[ii].pExpr) )
        goto trigger_cleanup;

      if( sqliteExprCheck(pParse, pChanges->a[ii].pExpr, 0, 0) )
        goto trigger_cleanup;

      for(jj=0; jj<pTab->nCol; jj++){
        if( sqliteStrICmp(pTab->aCol[jj].zName, pChanges->a[ii].zName)==0 ){
          aXRef[jj] = ii;
          break;
        }
      }
      if( jj>=pTab->nCol ){
        sqliteSetString(&pParse->zErrMsg, "no such column: ", 
            pChanges->a[ii].zName, 0);
        pParse->nErr++;
        goto trigger_cleanup;
      }
    }

    sqliteVdbeAddOp(v, OP_Integer, 13, 0);

    for (ii = 0; ii < pTab->nCol; ii++)
      if( aXRef[ii] < 0 ) 
        sqliteVdbeAddOp(v, OP_Column, oldIdx, ii);
      else
        sqliteExprCode(pParse, pChanges->a[aXRef[ii]].pExpr);

    sqliteVdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
    sqliteVdbeAddOp(v, OP_PutIntKey, newIdx, 0);
    sqliteVdbeAddOp(v, OP_Rewind, newIdx, 0);

    sqliteCodeRowTrigger(pParse, TK_UPDATE, pChanges, TK_BEFORE, 
        pTab, newIdx, oldIdx, onError);
    sqliteCodeRowTrigger(pParse, TK_UPDATE, pChanges, TK_AFTER, 
        pTab, newIdx, oldIdx, onError);
  } else {
    sqliteCodeRowTrigger(pParse, TK_DELETE, 0, TK_BEFORE, pTab, -1, oldIdx, 
        onError);
    sqliteCodeRowTrigger(pParse, TK_DELETE, 0, TK_AFTER, pTab, -1, oldIdx, 
        onError);
  }

  sqliteVdbeAddOp(v, OP_Next, oldIdx, startOfLoop);

  sqliteVdbeResolveLabel(v, endOfLoop);
  sqliteEndWriteOperation(pParse);

trigger_cleanup:
  sqliteFree(aXRef);
  sqliteExprListDelete(pChanges);
  sqliteExprDelete(pWhere);
  sqliteExprListDelete(theSelect.pEList);
  sqliteIdListDelete(theSelect.pSrc);
  sqliteExprDelete(theSelect.pWhere);
  return;
}

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle UPDATE statements.
**
** $Id: update.c,v 1.38 2002/05/15 11:44:15 drh Exp $
*/
#include "sqliteInt.h"

/*
** Process an UPDATE statement.
*/
void sqliteUpdate(

   */
  {
    char * zTab = sqliteTableNameFromToken(pTableName);

    if(zTab != 0) {
      pTab = sqliteFindTable(pParse->db, zTab);
      if (pTab) {
        row_triggers_exist = 
          sqliteTriggersExist(pParse, pTab->pTrigger, 
              TK_UPDATE, TK_BEFORE, TK_ROW, pChanges) ||
          sqliteTriggersExist(pParse, pTab->pTrigger, 
              TK_UPDATE, TK_AFTER, TK_ROW, pChanges);
      }
      sqliteFree(zTab);
      if (row_triggers_exist &&  pTab->pSelect ) {
        /* Just fire VIEW triggers */
        sqliteViewTriggers(pParse, pTab, pWhere, onError, pChanges);
        return;
      }
    }
  }

  /* Locate the table which we want to update.  This table has to be
  ** put in an IdList structure because some of the subroutines we
  ** will be calling are designed to work with multiple tables and expect

    sqliteVdbeAddOp(v, OP_Dup, 0, 0);
    sqliteVdbeAddOp(v, OP_Open, base, pTab->tnum);
    sqliteVdbeAddOp(v, OP_MoveTo, base, 0);

    sqliteVdbeAddOp(v, OP_Integer, 13, 0);
    for (ii = 0; ii < pTab->nCol; ii++) {
        if (ii == pTab->iPKey) 
            sqliteVdbeAddOp(v, OP_Recno, base, 0);
        else
            sqliteVdbeAddOp(v, OP_Column, base, ii);
    }
    sqliteVdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
    sqliteVdbeAddOp(v, OP_PutIntKey, oldIdx, 0);

    sqliteVdbeAddOp(v, OP_Integer, 13, 0);
    for (ii = 0; ii < pTab->nCol; ii++){
      if( aXRef[ii] < 0 ){

    sqliteVdbeAddOp(v, OP_PutIntKey, newIdx, 0);
    sqliteVdbeAddOp(v, OP_Close, base, 0);

    sqliteVdbeAddOp(v, OP_Rewind, oldIdx, 0);
    sqliteVdbeAddOp(v, OP_Rewind, newIdx, 0);

    if (sqliteCodeRowTrigger(pParse, TK_UPDATE, pChanges, TK_BEFORE, pTab, 
          newIdx, oldIdx, onError)) goto update_cleanup;
  }

  /* Rewind the list of records that need to be updated and
  ** open every index that needs updating.  Note that if any
  ** index could potentially invoke a REPLACE conflict resolution 
  ** action, then we need to open all indices because we might need
  ** to be deleting some records.

  if( db->flags & SQLITE_CountRows && !pParse->trigStack){
    sqliteVdbeAddOp(v, OP_AddImm, 1, 0);
  }

  if (row_triggers_exist) {
    for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
      if( openAll || aIdxUsed[i] )
        sqliteVdbeAddOp(v, OP_Close, base+i+1, 0);
    }
    sqliteVdbeAddOp(v, OP_Close, base, 0);
    pParse->nTab = base;

    if (sqliteCodeRowTrigger(pParse, TK_UPDATE, pChanges, TK_AFTER, pTab, 
          newIdx, oldIdx, onError)) goto update_cleanup;
  }

  /* Repeat the above with the next record to be updated, until
  ** all record selected by the WHERE clause have been updated.
  */
  sqliteVdbeAddOp(v, OP_Goto, 0, addr);
  sqliteVdbeChangeP2(v, addr, sqliteVdbeCurrentAddr(v));
  sqliteVdbeAddOp(v, OP_ListReset, 0, 0);

  /* Close all tables if there were no FOR EACH ROW triggers */
  if (!row_triggers_exist) {
    for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
      if( openAll || aIdxUsed[i] ){
        sqliteVdbeAddOp(v, OP_Close, base+i+1, 0);
      }
    }
    sqliteVdbeAddOp(v, OP_Close, base, 0);
    pParse->nTab = base;
  } else {
    sqliteVdbeAddOp(v, OP_Close, newIdx, 0);
    sqliteVdbeAddOp(v, OP_Close, oldIdx, 0);

** 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 1.143 2002/05/15 11:44:15 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

** Save the current Vdbe list such that it can be restored by a PopList 
** opcode. The list is empty after this is executed.
*/
case OP_PushList: {
  p->keylistStackDepth++;
  assert(p->keylistStackDepth > 0);
  p->keylistStack = sqliteRealloc(p->keylistStack, 
          sizeof(Keylist *) * p->keylistStackDepth);
  p->keylistStack[p->keylistStackDepth - 1] = p->pList;
  p->pList = 0;
  break;
}

/* Opcode: PopList * * * 
**

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  Also found here are subroutines
** to generate VDBE code to evaluate expressions.
**
** $Id: where.c,v 1.43 2002/05/15 11:44:15 drh Exp $
*/
#include "sqliteInt.h"

/*
** The query generator uses an array of instances of this structure to
** help it analyze the subexpressions of the WHERE clause.  Each WHERE
** clause subexpression is separated from the others by an AND operator.

  nExpr = exprSplit(ARRAYSIZE(aExpr), aExpr, pWhere);

  /* Analyze all of the subexpressions.
  */
  for(i=0; i<nExpr; i++){
    exprAnalyze(base, &aExpr[i]);
    if (pParse->trigStack && pParse->trigStack->newIdx >= 0) {
        aExpr[i].prereqRight = 
            aExpr[i].prereqRight & ~(1 << pParse->trigStack->newIdx - base);
        aExpr[i].prereqLeft = 
            aExpr[i].prereqLeft & ~(1 << pParse->trigStack->newIdx - base);
        aExpr[i].prereqAll = 
            aExpr[i].prereqAll & ~(1 << pParse->trigStack->newIdx - base);
    }
    if (pParse->trigStack && pParse->trigStack->oldIdx >= 0) {
        aExpr[i].prereqRight = 
            aExpr[i].prereqRight & ~(1 << pParse->trigStack->oldIdx - base);
        aExpr[i].prereqLeft = 
            aExpr[i].prereqLeft & ~(1 << pParse->trigStack->oldIdx - base);
        aExpr[i].prereqAll = 
            aExpr[i].prereqAll & ~(1 << pParse->trigStack->oldIdx - base);
    }
  }

  /* Figure out a good nesting order for the tables.  aOrder[0] will
  ** be the index in pTabList of the outermost table.  aOrder[1] will
  ** be the first nested loop and so on.  aOrder[pTabList->nId-1] will
  ** be the innermost loop.