SQLite

1.0.26

** sqlite and the code that does the actually reading and writing
** of information to the disk.
**
** This file uses GDBM as the database backend.  It should be
** relatively simple to convert to a different database such
** as NDBM, SDBM, or BerkeleyDB.
**
** $Id: dbbe.c,v 1.24 2001/03/20 12:55:14 drh Exp $
*/
#include "sqliteInt.h"
#include <unistd.h>

/*
** This routine opens a new database.  It looks at the first
** few characters of the database name to try to determine what

  if( strncmp(zName, "memory:", 7)==0 ){
    extern Dbbe *sqliteMemOpen(const char*,int,int,char**);
    return sqliteMemOpen(&zName[7], writeFlag, createFlag, pzErrMsg);
  }
  return sqliteGdbmOpen(zName, writeFlag, createFlag, pzErrMsg);
}

/*
** Open a temporary file.  The file should be deleted when closed.
**
** Note that we can't use the old Unix trick of opening the file
** and then immediately unlinking the file.  That works great
** under Unix, but fails when we try to port to Windows.
*/
int sqliteDbbeOpenTempFile(const char *zDir, Dbbe *pBe, FILE **ppFile){
  char *zFile;         /* Full name of the temporary file */
  char zBuf[50];       /* Base name of the temporary file */
  int i;               /* Loop counter */
  int limit;           /* Prevent an infinite loop */
  int rc = SQLITE_OK;  /* Value returned by this function */

  for(i=0; i<pBe->nTemp; i++){
    if( pBe->apTemp[i]==0 ) break;
  }
  if( i>=pBe->nTemp ){
    pBe->nTemp++;
    pBe->apTemp = sqliteRealloc(pBe->apTemp, pBe->nTemp*sizeof(FILE*) );
    pBe->azTemp = sqliteRealloc(pBe->azTemp, pBe->nTemp*sizeof(char*) );
  }
  if( pBe->apTemp==0 ){
    *ppFile = 0;
    return SQLITE_NOMEM;
  }
  limit = 4;
  zFile = 0;
  do{
    sqliteRandomName(zBuf, "/_temp_file_");
    sqliteFree(zFile);
    zFile = 0;
    sqliteSetString(&zFile, zDir, zBuf, 0);
  }while( access(zFile,0)==0 && limit-- >= 0 );
#if OS_WIN
  *ppFile = pBe->apTemp[i] = fopen(zFile, "w+b");
#else
  *ppFile = pBe->apTemp[i] = fopen(zFile, "w+");
#endif
  if( pBe->apTemp[i]==0 ){
    rc = SQLITE_ERROR;
    sqliteFree(zFile);
    pBe->azTemp[i] = 0;
  }else{
    pBe->azTemp[i] = zFile;
  }
  return rc;
}

/*
** Close a temporary file opened using sqliteGdbmOpenTempFile()
*/
void sqliteDbbeCloseTempFile(Dbbe *pBe, FILE *f){
  int i;
  for(i=0; i<pBe->nTemp; i++){
    if( pBe->apTemp[i]==f ){
      unlink(pBe->azTemp[i]);
      sqliteFree(pBe->azTemp[i]);
      pBe->apTemp[i] = 0;
      pBe->azTemp[i] = 0;
      break;
    }
  }
  fclose(f);
}

/*
** Close all temporary files that happen to still be open.
** This routine is called when the database is being closed.
*/
void sqliteDbbeCloseAllTempFiles(Dbbe *pBe){
  int i;
  for(i=0; i<pBe->nTemp; i++){
    if( pBe->apTemp[i]!=0 ){
      unlink(pBe->azTemp[i]);
      fclose(pBe->apTemp[i]);
      sqliteFree(pBe->azTemp[i]);
      pBe->apTemp[i] = 0;
      pBe->azTemp[i] = 0;
      break;
    }
  }
  sqliteFree(pBe->azTemp);
  sqliteFree(pBe->apTemp);
}

/*
** Translate the name of an SQL table (or index) into the name 
** of a file that holds the key/data pairs for that table or
** index.  Space to hold the filename is obtained from
** sqliteMalloc() and must be freed by the calling function.
**
** zDir is the name of the directory in which the file should

** This file defines the interface to the database backend (Dbbe).
**
** The database backend is designed to be as general as possible
** so that it can easily be replaced by a different backend.
** This library was originally designed to support the following
** backends: GDBM, NDBM, SDBM, Berkeley DB.
**
** $Id: dbbe.h,v 1.10 2001/01/15 22:51:10 drh Exp $
*/
#ifndef _SQLITE_DBBE_H_
#define _SQLITE_DBBE_H_
#include <stdio.h>

/*
** The database backend supports two opaque structures.  A Dbbe is

  /* Write an entry into a table.  If another entry already exists with
  ** the same key, the old entry is discarded first.
  */
  int (*Put)(DbbeCursor*, int nKey, char *pKey, int nData, char *pData);

  /* Remove an entry from the table */
  int (*Delete)(DbbeCursor*, int nKey, char *pKey);

  /* Open a file suitable for temporary storage */
  int (*OpenTempFile)(Dbbe*, FILE**);

  /* Close a temporary file */
  void (*CloseTempFile)(Dbbe *, FILE *);
};

/*
** This is the structure returned by sqliteDbbeOpen().  It contains
** information common to all the different backend drivers.
**
** The information in this structure (with the exception the method
** pointers in the Dbbe.x field) is intended to be visible to
** the backend drivers only.  Users should not access or modify
** this structure in any way other than the read the method pointers
** in Dbbe.x.
*/
struct Dbbe {
  struct DbbeMethods *x; /* Backend-specific methods for database access */
  int nTemp;             /* Number of temporary files created */
  FILE **apTemp;         /* Space to hold temporary file pointers */
  char **azTemp;         /* Names of the temporary files */
};

#endif /* defined(_SQLITE_DBBE_H_) */

** sqlite and the code that does the actually reading and writing
** of information to the disk.
**
** This file uses GDBM as the database backend.  It should be
** relatively simple to convert to a different database such
** as NDBM, SDBM, or BerkeleyDB.
**
** $Id: dbbegdbm.c,v 1.3 2001/01/15 22:51:10 drh Exp $
*/
#include "sqliteInt.h"
#include <gdbm.h>
#include <sys/stat.h>
#include <unistd.h>
#include <ctype.h>
#include <time.h>

  BeFile *pFile, *pNext;
  for(pFile=pBe->pOpen; pFile; pFile=pNext){
    pNext = pFile->pNext;
    gdbm_close(pFile->dbf);
    memset(pFile, 0, sizeof(*pFile));   
    sqliteFree(pFile);
  }
  sqliteDbbeCloseAllTempFiles(pDbbe);
  memset(pBe, 0, sizeof(*pBe));
  sqliteFree(pBe);
}

/*
** Translate the name of an SQL table (or index) into the name 
** of a file that holds the key/data pairs for that table or

  key.dsize = nKey;
  key.dptr = pKey;
  rc = gdbm_delete(pCursr->pFile->dbf, key);
  if( rc ) rc = SQLITE_ERROR;
  return rc;
}

/*
** Open a temporary file.  The file is located in the same directory
** as the rest of the database.
*/
static int sqliteGdbmOpenTempFile(Dbbe *pDbbe, FILE **ppFile){
  Dbbex *pBe = (Dbbex*)pDbbe;
  return sqliteDbbeOpenTempFile(pBe->zDir, pDbbe, ppFile);
}

/*
** This variable contains pointers to all of the access methods
** used to implement the GDBM backend.
*/
static struct DbbeMethods gdbmMethods = {
  /* n         Close */   sqliteGdbmClose,
  /*      OpenCursor */   sqliteGdbmOpenCursor,

  /*       KeyLength */   sqliteGdbmKeyLength,
  /*      DataLength */   sqliteGdbmDataLength,
  /*         NextKey */   sqliteGdbmNextKey,
  /*          Rewind */   sqliteGdbmRewind,
  /*             New */   sqliteGdbmNew,
  /*             Put */   sqliteGdbmPut,
  /*          Delete */   sqliteGdbmDelete,
  /*    OpenTempFile */   sqliteGdbmOpenTempFile,
  /*   CloseTempFile */   sqliteDbbeCloseTempFile
};


/*
** This routine opens a new database.  For the GDBM driver
** implemented here, the database name is the name of the directory
** containing all the files of the database.

** This file contains code to implement the database backend (DBBE)
** for sqlite.  The database backend is the interface between
** sqlite and the code that does the actually reading and writing
** of information to the disk.
**
** This file uses an in-memory hash table as the database backend. 
**
** $Id: dbbemem.c,v 1.10 2001/03/20 12:57:57 drh Exp $
*/
#include "sqliteInt.h"
#include <sys/stat.h>
#include <unistd.h>
#include <ctype.h>
#include <time.h>

  MTable *pTble;
  ArrayElem *j;
  for(j=ArrayFirst(&pBe->tables); j; j=ArrayNext(j)){
    pTble = ArrayData(j);
    deleteMTable(pTble);
  }
  ArrayClear(&pBe->tables);
  sqliteDbbeCloseAllTempFiles(pDbbe);
  memset(pBe, 0, sizeof(*pBe));
  sqliteFree(pBe);
}

/*
** Translate the name of an SQL table (or index) into its
** canonical name.

  data = ArrayInsert(&pCursr->pTble->data, key, data);
  if( data.p ){
    sqliteFree(data.p);
  }
  return SQLITE_OK;
}

/*
** Open a temporary file.  The file is located in the current working
** directory.
*/
static int sqliteMemOpenTempFile(Dbbe *pDbbe, FILE **ppFile){
#if OS_UNIX
  const char *zTemps[] = { "/usr/tmp", "/var/tmp", "/tmp", "/temp", 0};
#endif
#if OS_WIN
  const char *zTemps[] = { "/temp", "c:/temp", "c:", "d:", "e:", 0};
#endif
  const char *zDir;
  int i;
  struct stat statbuf;
  for(i=0; zTemps[i]; i++){
    zDir = zTemps[i];
    if( stat(zDir, &statbuf)==0 && S_ISDIR(statbuf.st_mode) 
      && access(zDir, W_OK|X_OK)==0 ){
        break;
    }
  }
  if( zDir==0 ) zDir = ".";
  return sqliteDbbeOpenTempFile(zDir, pDbbe, ppFile);
}

/*
** This variable contains pointers to all of the access methods
** used to implement the MEMORY backend.
*/
static struct DbbeMethods memoryMethods = {
  /* n         Close */   sqliteMemClose,
  /*      OpenCursor */   sqliteMemOpenCursor,

  /*       KeyLength */   sqliteMemKeyLength,
  /*      DataLength */   sqliteMemDataLength,
  /*         NextKey */   sqliteMemNextKey,
  /*          Rewind */   sqliteMemRewind,
  /*             New */   sqliteMemNew,
  /*             Put */   sqliteMemPut,
  /*          Delete */   sqliteMemDelete,
  /*    OpenTempFile */   sqliteMemOpenTempFile,
  /*   CloseTempFile */   sqliteDbbeCloseTempFile
};

/*
** This routine opens a new database.  For the GDBM driver
** implemented here, the database name is the name of the directory
** containing all the files of the database.
**

**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle DELETE FROM statements.
**
** $Id: delete.c,v 1.7 2001/01/15 22:51:10 drh Exp $
*/
#include "sqliteInt.h"

/*
** Process a DELETE FROM statement.
*/
void sqliteDeleteFrom(

  }

  /* Begin generating code.
  */
  v = sqliteGetVdbe(pParse);
  if( v==0 ) goto delete_from_cleanup;















  /* Begin the database scan
  */
  sqliteVdbeAddOp(v, OP_ListOpen, 0, 0, 0, 0);
  pWInfo = sqliteWhereBegin(pParse, pTabList, pWhere, 1);
  if( pWInfo==0 ) goto delete_from_cleanup;

  /* Remember the key of every item to be deleted.
  */
  sqliteVdbeAddOp(v, OP_ListWrite, 0, 0, 0, 0);

  /* End the database scan loop.
  */
  sqliteWhereEnd(pWInfo);

  /* Delete every item whose key was written to the list during the
  ** database scan.  We have to delete items after the scan is complete
  ** because deleting an item can change the scan order.
  */
  base = pParse->nTab;
  sqliteVdbeAddOp(v, OP_ListRewind, 0, 0, 0, 0);
  sqliteVdbeAddOp(v, OP_OpenTbl, base, 1, pTab->zName, 0);
  for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
    sqliteVdbeAddOp(v, OP_OpenIdx, base+i, 1, pIdx->zName, 0);
  }
  end = sqliteVdbeMakeLabel(v);
  addr = sqliteVdbeAddOp(v, OP_ListRead, 0, end, 0, 0);
  if( pTab->pIndex ){
    sqliteVdbeAddOp(v, OP_Dup, 0, 0, 0, 0);
    sqliteVdbeAddOp(v, OP_Fetch, base, 0, 0, 0);
    for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
      int j;
      sqliteVdbeAddOp(v, OP_Dup, 0, 0, 0, 0);
      for(j=0; j<pIdx->nColumn; j++){
        sqliteVdbeAddOp(v, OP_Field, base, pIdx->aiColumn[j], 0, 0);
      }
      sqliteVdbeAddOp(v, OP_MakeKey, pIdx->nColumn, 0, 0, 0);
      sqliteVdbeAddOp(v, OP_DeleteIdx, base+i, 0, 0, 0);
    }
  }
  sqliteVdbeAddOp(v, OP_Delete, base, 0, 0, 0);
  sqliteVdbeAddOp(v, OP_Goto, 0, addr, 0, 0);
  sqliteVdbeAddOp(v, OP_ListClose, 0, 0, 0, end);


delete_from_cleanup:
  sqliteIdListDelete(pTabList);
  sqliteExprDelete(pWhere);
  return;
}

** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.36 2001/01/20 19:52:50 drh Exp $
*/
#include "sqlite.h"
#include "dbbe.h"
#include "vdbe.h"
#include "parse.h"
#include <gdbm.h>
#include <stdio.h>

void sqliteExprResolveInSelect(Parse*, Expr*);
int sqliteExprAnalyzeAggregates(Parse*, Expr*);
void sqliteParseInfoReset(Parse*);
Vdbe *sqliteGetVdbe(Parse*);
int sqliteRandomByte(void);
int sqliteRandomInteger(void);
void sqliteRandomName(char*,char*);
int sqliteDbbeOpenTempFile(const char*, Dbbe*, FILE**);
void sqliteDbbeCloseTempFile(Dbbe*, FILE*);
void sqliteDbbeCloseAllTempFiles(Dbbe*);
char *sqliteDbbeNameToFile(const char*,const char*,const char*);

** inplicit conversion from one 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 1.52 2001/02/19 23:23:39 drh Exp $
*/
#include "sqliteInt.h"
#include <unistd.h>
#include <ctype.h>

/*
** SQL is translated into a sequence of instructions to be

};
struct SetElem {
  SetElem *pHash;        /* Next element with the same hash on zKey */
  SetElem *pNext;        /* Next element in a list of them all */
  char zKey[1];          /* Value of this key */
};















/*
** An instance of the virtual machine
*/
struct Vdbe {
  sqlite *db;         /* The whole database */
  Dbbe *pBe;          /* Opaque context structure used by DB backend */
  FILE *trace;        /* Write an execution trace here, if not NULL */

  int nStackAlloc;    /* Size of the stack */
  Stack *aStack;      /* The operand stack, except string values */
  char **zStack;      /* Text or binary values of the stack */
  char **azColName;   /* Becomes the 4th parameter to callbacks */
  int nCursor;        /* Number of slots in aCsr[] */
  Cursor *aCsr;       /* On element of this array for each open cursor */
  int nList;          /* Number of slots in apList[] */
  FILE **apList;      /* An open file for each list */
  int nSort;          /* Number of slots in apSort[] */
  Sorter **apSort;    /* An open sorter list */
  FILE *pFile;        /* At most one open file handler */
  int nField;         /* Number of file fields */
  char **azField;     /* Data for each file field */
  char *zLine;        /* A single line from the input file */
  int nLineAlloc;     /* Number of spaces allocated for zLine */

    for(i=oldAlloc; i<p->nStackAlloc; i++){
      p->zStack[i] = 0;
      p->aStack[i].flags = 0;
    }
  }
  return 0;
}












/*
** Clean up the VM after execution.
**
** This routine will automatically close any cursors, list, and/or
** sorters that were left open.
*/

      sqliteFree(p->aMem[i].z);
    }
  }
  sqliteFree(p->aMem);
  p->aMem = 0;
  p->nMem = 0;
  for(i=0; i<p->nList; i++){
    if( p->apList[i] ){
      p->pBe->x->CloseTempFile(p->pBe, p->apList[i]);
      p->apList[i] = 0;
    }
  }
  sqliteFree(p->apList);
  p->apList = 0;
  p->nList = 0;
  for(i=0; i<p->nSort; i++){
    Sorter *pSorter;
    while( (pSorter = p->apSort[i])!=0 ){

      case OP_Reorganize: {
        pBex->ReorganizeTable(pBe, pOp->p3);
        break;
      }

      /* Opcode: ListOpen P1 * *
      **
      ** Open a file used for temporary storage of integer table keys.  P1

      ** will server as a handle to this temporary file for future
      ** interactions.  If another temporary file with the P1 handle is
      ** already opened, the prior file is closed and a new one opened
      ** in its place.
      */
      case OP_ListOpen: {
        int i = pOp->p1;
        VERIFY( if( i<0 ) goto bad_instruction; )
        if( i>=p->nList ){
          int j;
          p->apList = sqliteRealloc( p->apList, (i+1)*sizeof(FILE*) );
          if( p->apList==0 ){ p->nList = 0; goto no_mem; }
          for(j=p->nList; j<=i; j++) p->apList[j] = 0;
          p->nList = i+1;
        }else if( p->apList[i] ){
          pBex->CloseTempFile(pBe, p->apList[i]);
        }
        rc = pBex->OpenTempFile(pBe, &p->apList[i]);
        if( rc!=SQLITE_OK ){
          sqliteSetString(pzErrMsg, "unable to open a temporary file", 0);
        }
        break;
      }

      /* Opcode: ListWrite P1 * *
      **
      ** Write the integer on the top of the stack
      ** into the temporary storage file P1.
      */
      case OP_ListWrite: {
        int i = pOp->p1;

        VERIFY( if( i<0 ) goto bad_instruction; )
        VERIFY( if( p->tos<0 ) goto not_enough_stack; )
        if( VERIFY( i<p->nList && ) p->apList[i]!=0 ){






          int val;


          Integerify(p, p->tos);
          val = aStack[p->tos].i;
          POPSTACK;
          fwrite(&val, sizeof(int), 1, p->apList[i]);
        }
        break;
      }

      /* Opcode: ListRewind P1 * *
      **
      ** Rewind the temporary buffer P1 back to the beginning.
      */
      case OP_ListRewind: {
        int i = pOp->p1;
        VERIFY( if( i<0 ) goto bad_instruction; )
        if( VERIFY( i<p->nList && ) p->apList[i]!=0 ){
          rewind(p->apList[i]);
        }
        break;
      }

      /* Opcode: ListRead P1 P2 *
      **
      ** Attempt to read an integer from temporary storage buffer P1
      ** and push it onto the stack.  If the storage buffer is empty, 
      ** push nothing but instead jump to P2.
      */
      case OP_ListRead: {
        int i = pOp->p1;
        int val, amt;

        VERIFY(if( i<0 || i>=p->nList || p->apList[i]==0 )goto bad_instruction;)
        amt = fread(&val, sizeof(int), 1, p->apList[i]);
        if( amt==1 ){





          p->tos++;
          if( NeedStack(p, p->tos) ) goto no_mem;
          aStack[p->tos].i = val;
          aStack[p->tos].flags = STK_Int;
          zStack[p->tos] = 0;




        }else{
          pc = pOp->p2 - 1;
        }
        break;
      }

      /* Opcode: ListClose P1 * *
      **
      ** Close the temporary storage buffer and discard its contents.
      */
      case OP_ListClose: {
        int i = pOp->p1;
        VERIFY( if( i<0 ) goto bad_instruction; )
        if( VERIFY( i<p->nList && ) p->apList[i]!=0 ){
          pBex->CloseTempFile(pBe, p->apList[i]);
          p->apList[i] = 0;
        }
        break;
      }

      /* Opcode: SortOpen P1 * *
      **
      ** Create a new sorter with index P1
      */

#   drh@hwaci.com
#   http://www.hwaci.com/drh/
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the DELETE FROM statement.
#
# $Id: delete.test,v 1.7 2001/03/20 12:55:14 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Try to delete from a non-existant table.
#
do_test delete-1.1 {

  }
  execsql {SELECT f1 FROM table1 ORDER BY f1}
} {42 44 47 48 50}
do_test delete-5.7 {
  execsql "DELETE FROM table1 WHERE f1!=48"
  execsql {SELECT f1 FROM table1 ORDER BY f1}
} {48}





















































finish_test

}


proc chng {date desc} {
  puts "<DT><B>$date</B></DT>"
  puts "<DD><P><UL>$desc</UL></P></DD>"
}










chng {2001 Mar 20 (1.0.26)} {
<li>A serious bug fixed on Windows.  Windows users should upgrade.
    No impact to Unix.</li>
}

chng {2001 Mar 15 (1.0.25)} {