SQLite

# The library that programs using readline() must link against.
#
LIBREADLINE = @TARGET_READLINE_LIBS@

# Object files for the SQLite library.
#
LIBOBJ = build.o dbbe.o dbbegdbm.o dbbemem.o delete.o expr.o insert.o \
         main.o parse.o printf.o select.o table.o tokenize.o update.o \
         util.o vdbe.o where.o tclsqlite.o

# All of the source code files.
#
SRC = \
  $(TOP)/src/build.c \
  $(TOP)/src/dbbe.c \
  $(TOP)/src/dbbegdbm.c \
  $(TOP)/src/dbbemem.c \
  $(TOP)/src/dbbe.h \
  $(TOP)/src/dbbemem.c \
  $(TOP)/src/delete.c \
  $(TOP)/src/expr.c \
  $(TOP)/src/insert.c \
  $(TOP)/src/main.c \
  $(TOP)/src/parse.y \
  $(TOP)/src/printf.c \

  $(TOP)/src/select.c \
  $(TOP)/src/shell.c \
  $(TOP)/src/sqlite.h.in \
  $(TOP)/src/sqliteInt.h \
  $(TOP)/src/table.c \
  $(TOP)/src/tclsqlite.c \
  $(TOP)/src/tokenize.c \

expr.o:	$(TOP)/src/expr.c $(HDR)
	$(TCC) $(GDBM_FLAGS) -c $(TOP)/src/expr.c

insert.o:	$(TOP)/src/insert.c $(HDR)
	$(TCC) $(GDBM_FLAGS) -c $(TOP)/src/insert.c




select.o:	$(TOP)/src/select.c $(HDR)
	$(TCC) $(GDBM_FLAGS) -c $(TOP)/src/select.c

table.o:	$(TOP)/src/table.c $(HDR)
	$(TCC) $(GDBM_FLAGS) -c $(TOP)/src/table.c

update.o:	$(TOP)/src/update.c $(HDR)

1.0.18

** 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 1.21 2000/10/19 14:10:09 drh Exp $
*/
#include "sqliteInt.h"

/*
** This routine opens a new database.  It looks at the first
** few characters of the database name to try to determine what
** kind of database to open.  If the first characters are "gdbm:",

  }
  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);
}

** 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 1.8 2000/10/19 01:49:02 drh Exp $
*/
#ifndef _SQLITE_DBBE_H_
#define _SQLITE_DBBE_H_
#include <stdio.h>

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

** The DbbeCursor structure holds some state information, such as
** the key and data from the last retrieval.  For this reason, 
** the backend must allow the creation of multiple independent
** DbbeCursor structures for each table in the database.
*/
typedef struct Dbbe Dbbe;
typedef struct DbbeCursor DbbeCursor;


/*
** Open a complete database.
**
** If the database name begins with "gdbm:" the GDBM driver is used.
** If the name begins with "memory:" the in-memory driver is used.
** The default driver is GDBM.
*/
Dbbe *sqliteDbbeOpen(const char *zName, int write, int create, char **pzErr);

/*
** This is the structure returned by sqliteDbbeOpen().  It contains pointers
** to all access routines for the database backend.



*/
struct Dbbe {
  /* Close the whole database. */
  void (*Close)(Dbbe*);

  /* Open a cursor into particular file of a previously opened database.
  ** Create the file if it doesn't already exist and writeable!=0.  zName
  ** is the base name of the file to be opened.  This routine will add
  ** an appropriate path and extension to the filename to locate the 

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

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



















#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 1.1 2000/10/19 01:49:02 drh Exp $
*/
#include "sqliteInt.h"
#include <gdbm.h>
#include <sys/stat.h>
#include <unistd.h>
#include <ctype.h>
#include <time.h>

  GDBM_FILE dbf;          /* The file itself */
  int nRef;               /* Number of references */
  int delOnClose;         /* Delete when closing */
  int writeable;          /* Opened for writing */
  BeFile *pNext, *pPrev;  /* Next and previous on list of open files */
};

/*
** The following structure holds the current state of the RC4 algorithm.
** We use RC4 as a random number generator.  Each call to RC4 gives
** a random 8-bit number.
**
** Nothing in this file or anywhere else in SQLite does any kind of
** encryption.  The RC4 algorithm is being used as a PRNG (pseudo-random
** number generator) not as an encryption device.
*/
struct rc4 {
  int i, j;
  int s[256];
};

/*
** The following structure contains all information used by GDBM
** database driver.  This is a subclass of the Dbbe structure.
*/
typedef struct Dbbex Dbbex;
struct Dbbex {
  Dbbe dbbe;         /* The base class */
  char *zDir;        /* The directory containing the database */
  int write;         /* True for write permission */
  BeFile *pOpen;     /* List of open files */
  int nTemp;         /* Number of temporary files created */
  FILE **apTemp;     /* Space to hold temporary file pointers */
  char **azTemp;     /* Names of the temporary files */
  struct rc4 rc4;    /* The random number generator */
};

/*
** An cursor into a database file is an instance of the following structure.
** There can only be a single BeFile structure for each disk file, but
** there can be multiple DbbeCursor structures.  Each DbbeCursor represents
** a cursor pointing to a particular part of the open BeFile.  The
** BeFile.nRef field hold a count of the number of DbbeCursor structures
** associated with the same disk file.
*/
struct DbbeCursor {
  Dbbex *pBe;        /* The database of which this record is a part */
  BeFile *pFile;     /* The database file for this table */
  datum key;         /* Most recently used key */
  datum data;        /* Most recent data */
  int needRewind;    /* Next key should be the first */
  int readPending;   /* The fetch hasn't actually been done yet */
};

/*
** Initialize the RC4 PRNG.  "seed" is a pointer to some random
** data used to initialize the PRNG.  
*/
static void rc4init(struct rc4 *p, char *seed, int seedlen){
  int i;
  char k[256];
  p->j = 0;
  p->i = 0;
  for(i=0; i<256; i++){
    p->s[i] = i;
    k[i] = seed[i%seedlen];
  }
  for(i=0; i<256; i++){
    int t;
    p->j = (p->j + p->s[i] + k[i]) & 0xff;
    t = p->s[p->j];
    p->s[p->j] = p->s[i];
    p->s[i] = t;
  }
}

/*
** Get a single 8-bit random value from the RC4 PRNG.
*/
static int rc4byte(struct rc4 *p){
  int t;
  p->i = (p->i + 1) & 0xff;
  p->j = (p->j + p->s[p->i]) & 0xff;
  t = p->s[p->i];
  p->s[p->i] = p->s[p->j];
  p->s[p->j] = t;
  t = p->s[p->i] + p->s[p->j];
  return t & 0xff;

}

/*
** The "mkdir()" function only takes one argument under Windows.
*/
#if OS_WIN
# define mkdir(A,B) mkdir(A)
#endif

  int i;
  for(pFile=pBe->pOpen; pFile; pFile=pNext){
    pNext = pFile->pNext;
    gdbm_close(pFile->dbf);
    memset(pFile, 0, sizeof(*pFile));   
    sqliteFree(pFile);
  }
  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);
  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
** index.  Space to hold the filename is obtained from
** sqliteMalloc() and must be freed by the calling function.
*/
static char *sqliteFileOfTable(Dbbex *pBe, const char *zTable){
  char *zFile = 0;
  int i;
  sqliteSetString(&zFile, pBe->zDir, "/", zTable, ".tbl", 0);
  if( zFile==0 ) return 0;
  for(i=strlen(pBe->zDir)+1; zFile[i]; i++){
    int c = zFile[i];
    if( isupper(c) ){
      zFile[i] = tolower(c);
    }else if( !isalnum(c) && c!='-' && c!='_' && c!='.' ){
      zFile[i] = '+';
    }
  }
  return zFile;
}

/*
** Generate a random filename with the given prefix.  The new filename
** is written into zBuf[].  The calling function must insure that
** zBuf[] is big enough to hold the prefix plus 20 or so extra
** characters.
**
** Very random names are chosen so that the chance of a
** collision with an existing filename is very very small.
*/
static void randomName(struct rc4 *pRc4, char *zBuf, char *zPrefix){
  int i, j;
  static const char zRandomChars[] = "abcdefghijklmnopqrstuvwxyz0123456789";
  strcpy(zBuf, zPrefix);
  j = strlen(zBuf);
  for(i=0; i<15; i++){
    int c = rc4byte(pRc4) % (sizeof(zRandomChars) - 1);
    zBuf[j++] = zRandomChars[c];
  }
  zBuf[j] = 0;
}

/*
** Open a new table cursor.  Write a pointer to the corresponding
** DbbeCursor structure into *ppCursr.  Return an integer success
** code:
**
**    SQLITE_OK          It worked!
**

      if( !writeable || pBe->write ){
        pFile->dbf = gdbm_open(zFile, 0, rw_mask, mode, 0);
      }else{
        pFile->dbf = 0;
      }
    }else{
      int limit;
      struct rc4 *pRc4;
      char zRandom[50];
      pRc4 = &pBe->rc4;
      zFile = 0;
      limit = 5;
      do {
        randomName(&pBe->rc4, zRandom, "_temp_table_");
        sqliteFree(zFile);
        zFile = sqliteFileOfTable(pBe, zRandom);
        pFile->dbf = gdbm_open(zFile, 0, rw_mask, mode, 0);
      }while( pFile->dbf==0 && limit-- >= 0);
      pFile->delOnClose = 1;
    }
    pFile->writeable = writeable;

** Get a new integer key.
*/
static int sqliteGdbmNew(DbbeCursor *pCursr){
  int iKey;
  datum key;
  int go = 1;
  int i;
  struct rc4 *pRc4;

  if( pCursr->pFile==0 || pCursr->pFile->dbf==0 ) return 1;
  pRc4 = &pCursr->pBe->rc4;
  while( go ){
    iKey = 0;
    for(i=0; i<4; i++){
      iKey = (iKey<<8) + rc4byte(pRc4);
    }
    if( iKey==0 ) continue;
    key.dptr = (char*)&iKey;
    key.dsize = 4;
    go = gdbm_exists(pCursr->pFile->dbf, key);
  }
  return iKey;
}   

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

/*
** 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.
*/
static int sqliteGdbmOpenTempFile(Dbbe *pDbbe, 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 */
  Dbbex *pBe = (Dbbex*)pDbbe;

  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{
    randomName(&pBe->rc4, zBuf, "/_temp_file_");
    sqliteFree(zFile);

    zFile = 0;
    sqliteSetString(&zFile, pBe->zDir, zBuf, 0);
  }while( access(zFile,0)==0 && limit-- >= 0 );
  *ppFile = pBe->apTemp[i] = fopen(zFile, "w+");
  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()
*/
static void sqliteGdbmCloseTempFile(Dbbe *pDbbe, FILE *f){
  int i;
  Dbbex *pBe = (Dbbex*)pDbbe;
  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);
}


/*
** 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.
**

  }
  sqliteFree(zMaster);
  pNew = sqliteMalloc(sizeof(Dbbex) + strlen(zName) + 1);
  if( pNew==0 ){
    sqliteSetString(pzErrMsg, "out of memory", 0);
    return 0;
  }
  pNew->dbbe.Close = sqliteGdbmClose;
  pNew->dbbe.OpenCursor = sqliteGdbmOpenCursor;
  pNew->dbbe.DropTable = sqliteGdbmDropTable;
  pNew->dbbe.ReorganizeTable = sqliteGdbmReorganizeTable;
  pNew->dbbe.CloseCursor = sqliteGdbmCloseCursor;
  pNew->dbbe.Fetch = sqliteGdbmFetch;
  pNew->dbbe.Test = sqliteGdbmTest;
  pNew->dbbe.CopyKey = sqliteGdbmCopyKey;
  pNew->dbbe.CopyData = sqliteGdbmCopyData;
  pNew->dbbe.ReadKey = sqliteGdbmReadKey;
  pNew->dbbe.ReadData = sqliteGdbmReadData;
  pNew->dbbe.KeyLength = sqliteGdbmKeyLength;
  pNew->dbbe.DataLength = sqliteGdbmDataLength;
  pNew->dbbe.NextKey = sqliteGdbmNextKey;
  pNew->dbbe.Rewind = sqliteGdbmRewind;
  pNew->dbbe.New = sqliteGdbmNew;
  pNew->dbbe.Put = sqliteGdbmPut;
  pNew->dbbe.Delete = sqliteGdbmDelete;
  pNew->dbbe.OpenTempFile = sqliteGdbmOpenTempFile;
  pNew->dbbe.CloseTempFile = sqliteGdbmCloseTempFile;
  pNew->zDir = (char*)&pNew[1];
  strcpy(pNew->zDir, zName);
  pNew->write = writeFlag;
  pNew->pOpen = 0;
  time(&statbuf.st_ctime);
  rc4init(&pNew->rc4, (char*)&statbuf, sizeof(statbuf));
  return &pNew->dbbe;
}

** 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 1.5 2000/12/10 18:23:50 drh Exp $
*/
#include "sqliteInt.h"
#include <sys/stat.h>
#include <unistd.h>
#include <ctype.h>
#include <time.h>

typedef struct MTable MTable;
struct MTable {
  char *zName;            /* Name of the table */
  int delOnClose;         /* Delete when closing */
  Array data;             /* The data in this stable */
};

/*
** The following structure holds the current state of the RC4 algorithm.
** We use RC4 as a random number generator.  Each call to RC4 gives
** a random 8-bit number.
**
** Nothing in this file or anywhere else in SQLite does any kind of
** encryption.  The RC4 algorithm is being used as a PRNG (pseudo-random
** number generator) not as an encryption device.
*/
struct rc4 {
  int i, j;
  int s[256];
};

/*
** The following structure contains all information used by GDBM
** database driver.  This is a subclass of the Dbbe structure.
*/
typedef struct Dbbex Dbbex;
struct Dbbex {
  Dbbe dbbe;         /* The base class */
  Array tables;      /* All tables of the database */
  int nTemp;         /* Number of temporary files created */
  FILE **apTemp;     /* Space to hold temporary file pointers */
  char **azTemp;     /* Names of the temporary files */
  struct rc4 rc4;    /* The random number generator */
};

/*
** An cursor into a database file is an instance of the following structure.
** There can only be a single MTable structure for each disk file, but
** there can be multiple DbbeCursor structures.  Each DbbeCursor represents
** a cursor pointing to a particular part of the open MTable.  The
** MTable.nRef field hold a count of the number of DbbeCursor structures
** associated with the same disk file.
*/
struct DbbeCursor {
  Dbbex *pBe;        /* The database of which this record is a part */
  MTable *pTble;     /* The database file for this table */
  ArrayElem *elem;   /* Most recently accessed record */
  int needRewind;    /* Next key should be the first */
};

/*
** Initialize the RC4 PRNG.  "seed" is a pointer to some random
** data used to initialize the PRNG.  
*/
static void rc4init(struct rc4 *p, char *seed, int seedlen){
  int i;
  char k[256];
  p->j = 0;
  p->i = 0;
  for(i=0; i<256; i++){
    p->s[i] = i;
    k[i] = seed[i%seedlen];
  }
  for(i=0; i<256; i++){
    int t;
    p->j = (p->j + p->s[i] + k[i]) & 0xff;
    t = p->s[p->j];
    p->s[p->j] = p->s[i];
    p->s[i] = t;
  }
}

/*
** Get a single 8-bit random value from the RC4 PRNG.
*/
static int rc4byte(struct rc4 *p){
  int t;
  p->i = (p->i + 1) & 0xff;
  p->j = (p->j + p->s[p->i]) & 0xff;
  t = p->s[p->i];
  p->s[p->i] = p->s[p->j];
  p->s[p->j] = t;
  t = p->s[p->i] + p->s[p->j];
  return t & 0xff;
}

/*
** Forward declaration
*/
static void sqliteMemCloseCursor(DbbeCursor *pCursr);

/*
** Erase all the memory of an MTable

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

/*
** Generate a random filename with the given prefix.  The new filename
** is written into zBuf[].  The calling function must insure that
** zBuf[] is big enough to hold the prefix plus 20 or so extra
** characters.
**
** Very random names are chosen so that the chance of a
** collision with an existing filename is very very small.
*/
static void randomName(struct rc4 *pRc4, char *zBuf, char *zPrefix){
  int i, j;
  static const char zRandomChars[] = "abcdefghijklmnopqrstuvwxyz0123456789";
  strcpy(zBuf, zPrefix);
  j = strlen(zBuf);
  for(i=0; i<15; i++){
    int c = rc4byte(pRc4) % (sizeof(zRandomChars) - 1);
    zBuf[j++] = zRandomChars[c];
  }
  zBuf[j] = 0;
}

/*
** Translate the name of an SQL table (or index) into its
** canonical name.
** 
** Space to hold the canonical name is obtained from
** sqliteMalloc() and must be freed by the calling function.
*/

** Get a new integer key.
*/
static int sqliteMemNew(DbbeCursor *pCursr){
  int iKey;
  Datum key;
  int go = 1;
  int i;
  struct rc4 *pRc4;

  pRc4 = &pCursr->pBe->rc4;
  while( go ){
    iKey = 0;
    for(i=0; i<4; i++){
      iKey = (iKey<<8) + rc4byte(pRc4);
    }
    if( iKey==0 ) continue;
    key.p = (char*)&iKey;
    key.n = 4;
    go = ArrayFindElement(&pCursr->pTble->data, key)!=0;
  }
  return iKey;
}   

  if( data.p ){
    sqliteFree(data.p);
  }
  return SQLITE_OK;
}

/*
** 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.
*/


static int sqliteMemOpenTempFile(Dbbe *pDbbe, FILE **ppTble){
  char *zName;         /* 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 */
  Dbbex *pBe = (Dbbex*)pDbbe;

  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 ){
    *ppTble = 0;
    return SQLITE_NOMEM;
  }
  limit = 4;
  zName = 0;
  do{
    randomName(&pBe->rc4, zBuf, "/tmp/_temp_file_");
    sqliteFree(zName);
    zName = 0;
    sqliteSetString(&zName, zBuf, 0);
  }while( access(zName,0)==0 && limit-- >= 0 );
  *ppTble = pBe->apTemp[i] = fopen(zName, "w+");
  if( pBe->apTemp[i]==0 ){
    rc = SQLITE_ERROR;
    sqliteFree(zName);
    pBe->azTemp[i] = 0;
  }else{
    pBe->azTemp[i] = zName;
  }
  return rc;
}

/*
** Close a temporary file opened using sqliteMemOpenTempFile()
*/
static void sqliteMemCloseTempFile(Dbbe *pDbbe, FILE *f){
  int i;
  Dbbex *pBe = (Dbbex*)pDbbe;
  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);
}


/*
** 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.
**
** If successful, a pointer to the Dbbe structure is returned.
** If there are errors, an appropriate error message is left
** in *pzErrMsg and NULL is returned.
*/
Dbbe *sqliteMemOpen(
  const char *zName,     /* The name of the database */
  int writeFlag,         /* True if we will be writing to the database */
  int createFlag,        /* True to create database if it doesn't exist */
  char **pzErrMsg        /* Write error messages (if any) here */
){
  Dbbex *pNew;
  long now;

  pNew = sqliteMalloc( sizeof(*pNew) );
  if( pNew==0 ){
    sqliteSetString(pzErrMsg, "out of memory", 0);
    return 0;
  }
  ArrayInit(&pNew->tables);
  pNew->dbbe.Close = sqliteMemClose;
  pNew->dbbe.OpenCursor = sqliteMemOpenCursor;
  pNew->dbbe.DropTable = sqliteMemDropTable;
  pNew->dbbe.ReorganizeTable = sqliteMemReorganizeTable;
  pNew->dbbe.CloseCursor = sqliteMemCloseCursor;
  pNew->dbbe.Fetch = sqliteMemFetch;
  pNew->dbbe.Test = sqliteMemTest;
  pNew->dbbe.CopyKey = sqliteMemCopyKey;
  pNew->dbbe.CopyData = sqliteMemCopyData;
  pNew->dbbe.ReadKey = sqliteMemReadKey;
  pNew->dbbe.ReadData = sqliteMemReadData;
  pNew->dbbe.KeyLength = sqliteMemKeyLength;
  pNew->dbbe.DataLength = sqliteMemDataLength;
  pNew->dbbe.NextKey = sqliteMemNextKey;
  pNew->dbbe.Rewind = sqliteMemRewind;
  pNew->dbbe.New = sqliteMemNew;
  pNew->dbbe.Put = sqliteMemPut;
  pNew->dbbe.Delete = sqliteMemDelete;
  pNew->dbbe.OpenTempFile = sqliteMemOpenTempFile;
  pNew->dbbe.CloseTempFile = sqliteMemCloseTempFile;
  time(&now);
  rc4init(&pNew->rc4, (char*)&now, sizeof(now));
  return &pNew->dbbe;
}

**
*************************************************************************
** 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 1.22 2000/12/10 18:23:50 drh Exp $
*/
#include "sqliteInt.h"

/*
** This is the callback routine for the code that initializes the
** database.  Each callback contains text of a CREATE TABLE or
** CREATE INDEX statement that must be parsed to yield the internal

}

/*
** Close an existing SQLite database
*/
void sqlite_close(sqlite *db){
  int i;
  db->pBe->Close(db->pBe);
  for(i=0; i<N_HASH; i++){
    Table *pNext, *pList = db->apTblHash[i];
    db->apTblHash[i] = 0;
    while( pList ){
      pNext = pList->pHash;
      pList->pHash = 0;
      sqliteDeleteTable(db, pList);

** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.33 2000/12/10 18:23:51 drh Exp $
*/
#include "sqlite.h"
#include "dbbe.h"
#include "vdbe.h"
#include "parse.h"
#include <gdbm.h>
#include <stdio.h>

int sqliteExprCompare(Expr*, Expr*);
int sqliteFuncId(Token*);
int sqliteExprResolveIds(Parse*, IdList*, Expr*);
void sqliteExprResolveInSelect(Parse*, Expr*);
int sqliteExprAnalyzeAggregates(Parse*, Expr*);
void sqliteParseInfoReset(Parse*);
Vdbe *sqliteGetVdbe(Parse*);

** 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 1.49 2000/12/10 18:35:20 drh Exp $
*/
#include "sqliteInt.h"
#include <unistd.h>
#include <ctype.h>

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

static void Cleanup(Vdbe *p){
  int i;
  PopStack(p, p->tos+1);
  sqliteFree(p->azColName);
  p->azColName = 0;
  for(i=0; i<p->nCursor; i++){
    if( p->aCsr[i].pCursor ){
      p->pBe->CloseCursor(p->aCsr[i].pCursor);
      p->aCsr[i].pCursor = 0;
    }
  }
  sqliteFree(p->aCsr);
  p->aCsr = 0;
  p->nCursor = 0;
  for(i=0; i<p->nMem; i++){
    if( p->aMem[i].s.flags & STK_Dyn ){
      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->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++){

  void *pBusyArg,            /* 1st argument to the busy callback */
  int (*xBusy)(void*,const char*,int)  /* Called when a file is busy */
){
  int pc;                    /* The program counter */
  Op *pOp;                   /* Current operation */
  int rc;                    /* Value to return */
  Dbbe *pBe = p->pBe;        /* The backend driver */

  sqlite *db = p->db;        /* The database */
  char **zStack;
  Stack *aStack;
  char zBuf[100];            /* Space to sprintf() and integer */


  /* No instruction ever pushes more than a single element onto the

        if( i>=p->nCursor ){
          int j;
          p->aCsr = sqliteRealloc( p->aCsr, (i+1)*sizeof(Cursor) );
          if( p->aCsr==0 ){ p->nCursor = 0; goto no_mem; }
          for(j=p->nCursor; j<=i; j++) p->aCsr[j].pCursor = 0;
          p->nCursor = i+1;
        }else if( p->aCsr[i].pCursor ){
          pBe->CloseCursor(p->aCsr[i].pCursor);
        }
        do {
          rc = pBe->OpenCursor(pBe,pOp->p3,pOp->p2,&p->aCsr[i].pCursor);
          switch( rc ){
            case SQLITE_BUSY: {
              if( xBusy==0 || (*xBusy)(pBusyArg, pOp->p3, ++busy)==0 ){
                sqliteSetString(pzErrMsg,"table ", pOp->p3, " is locked", 0);
                busy = 0;
              }
              break;

      **
      ** Close a cursor previously opened as P1.  If P1 is not
      ** currently open, this instruction is a no-op.
      */
      case OP_Close: {
        int i = pOp->p1;
        if( i>=0 && i<p->nCursor && p->aCsr[i].pCursor ){
          pBe->CloseCursor(p->aCsr[i].pCursor);
          p->aCsr[i].pCursor = 0;
        }
        break;
      }

      /* Opcode: Fetch P1 * *
      **
      ** Pop the top of the stack and use its value as a key to fetch
      ** a record from cursor P1.  The key/data pair is held
      ** in the P1 cursor until needed.
      */
      case OP_Fetch: {
        int i = pOp->p1;
        int tos = p->tos;
        VERIFY( if( tos<0 ) goto not_enough_stack; )
        if( i>=0 && i<p->nCursor && p->aCsr[i].pCursor ){
          if( aStack[tos].flags & STK_Int ){
            pBe->Fetch(p->aCsr[i].pCursor, sizeof(int), 
                           (char*)&aStack[tos].i);
          }else{
            if( Stringify(p, tos) ) goto no_mem;
            pBe->Fetch(p->aCsr[i].pCursor, aStack[tos].n, 
                           zStack[tos]);
          }
          p->nFetch++;
        }
        POPSTACK;
        break;
      }

      case OP_Found: {
        int i = pOp->p1;
        int tos = p->tos;
        int alreadyExists = 0;
        VERIFY( if( tos<0 ) goto not_enough_stack; )
        if( VERIFY( i>=0 && i<p->nCursor && ) p->aCsr[i].pCursor ){
          if( aStack[tos].flags & STK_Int ){
            alreadyExists = pBe->Test(p->aCsr[i].pCursor, sizeof(int), 
                                          (char*)&aStack[tos].i);
          }else{
            if( Stringify(p, tos) ) goto no_mem;
            alreadyExists = pBe->Test(p->aCsr[i].pCursor,aStack[tos].n, 
                                           zStack[tos]);
          }
        }
        if( pOp->opcode==OP_Found ){
          if( alreadyExists ) pc = pOp->p2 - 1;
        }else{
          if( !alreadyExists ) pc = pOp->p2 - 1;

      */
      case OP_New: {
        int i = pOp->p1;
        int v;
        if( VERIFY( i<0 || i>=p->nCursor || ) p->aCsr[i].pCursor==0 ){
          v = 0;
        }else{
          v = pBe->New(p->aCsr[i].pCursor);
        }
        VERIFY( NeedStack(p, p->tos+1); )
        p->tos++;
        aStack[p->tos].i = v;
        aStack[p->tos].flags = STK_Int;
        break;
      }

            if( Stringify(p, nos) ) goto no_mem;
            nKey = aStack[nos].n;
            zKey = zStack[nos];
          }else{
            nKey = sizeof(int);
            zKey = (char*)&aStack[nos].i;
          }
          pBe->Put(p->aCsr[i].pCursor, nKey, zKey,
                        aStack[tos].n, zStack[tos]);
        }
        POPSTACK;
        POPSTACK;
        break;
      }

            nKey = sizeof(int);
            zKey = (char*)&aStack[tos].i;
          }else{
            if( Stringify(p, tos) ) goto no_mem;
            nKey = aStack[tos].n;
            zKey = zStack[tos];
          }
          pBe->Delete(p->aCsr[i].pCursor, nKey, zKey);
        }
        POPSTACK;
        break;
      }

      /* Opcode: KeyAsData P1 P2 *
      **

        int tos = ++p->tos;
        DbbeCursor *pCrsr;
        char *z;

        VERIFY( if( NeedStack(p, tos) ) goto no_mem; )
        if( VERIFY( i>=0 && i<p->nCursor && ) (pCrsr = p->aCsr[i].pCursor)!=0 ){
          if( p->aCsr[i].keyAsData ){
            amt = pBe->KeyLength(pCrsr);
            if( amt<=sizeof(int)*(p2+1) ){
              aStack[tos].flags = STK_Null;
              break;
            }
            pAddr = (int*)pBe->ReadKey(pCrsr, sizeof(int)*p2);
            if( *pAddr==0 ){
              aStack[tos].flags = STK_Null;
              break;
            }
            z = pBe->ReadKey(pCrsr, *pAddr);
          }else{
            amt = pBe->DataLength(pCrsr);
            if( amt<=sizeof(int)*(p2+1) ){
              aStack[tos].flags = STK_Null;
              break;
            }
            pAddr = (int*)pBe->ReadData(pCrsr, sizeof(int)*p2);
            if( *pAddr==0 ){
              aStack[tos].flags = STK_Null;
              break;
            }
            z = pBe->ReadData(pCrsr, *pAddr);
          }
          zStack[tos] = z;
          aStack[tos].n = strlen(z) + 1;
          aStack[tos].flags = STK_Str;
        }
        break;
      }

      case OP_Key: {
        int i = pOp->p1;
        int tos = ++p->tos;
        DbbeCursor *pCrsr;

        VERIFY( if( NeedStack(p, p->tos) ) goto no_mem; )
        if( VERIFY( i>=0 && i<p->nCursor && ) (pCrsr = p->aCsr[i].pCursor)!=0 ){
          char *z = pBe->ReadKey(pCrsr, 0);
          if( p->aCsr[i].keyAsData ){
            zStack[tos] = z;
            aStack[tos].flags = STK_Str;
            aStack[tos].n = pBe->KeyLength(pCrsr);
          }else{
            memcpy(&aStack[tos].i, z, sizeof(int));
            aStack[tos].flags = STK_Int;
          }
        }
        break;
      }

      /* Opcode: Rewind P1 * *
      **
      ** The next use of the Key or Field or Next instruction for P1 
      ** will refer to the first entry in the database file.
      */
      case OP_Rewind: {
        int i = pOp->p1;
        if( VERIFY( i>=0 && i<p->nCursor && ) p->aCsr[i].pCursor!=0 ){
          pBe->Rewind(p->aCsr[i].pCursor);
        }
        break;
      }

      /* Opcode: Next P1 P2 *
      **
      ** Advance P1 to the next key/data pair in the file.  Or, if there are no
      ** more key/data pairs, rewind P1 and jump to location P2.
      */
      case OP_Next: {
        int i = pOp->p1;
        if( VERIFY( i>=0 && i<p->nCursor && ) p->aCsr[i].pCursor!=0 ){
          if( pBe->NextKey(p->aCsr[i].pCursor)==0 ){
            pc = pOp->p2 - 1;
          }else{
            p->nFetch++;
          }
        }
        break;
      }

        VERIFY( if( NeedStack(p, p->tos) ) goto no_mem; )
        zStack[tos] = 0;
        if( VERIFY( i>=0 && i<p->nCursor && ) (pCrsr = p->aCsr[i].pCursor)!=0 ){
          int *aIdx;
          int nIdx;
          int j, k;
          nIdx = pBe->DataLength(pCrsr)/sizeof(int);
          aIdx = (int*)pBe->ReadData(pCrsr, 0);
          if( nIdx>1 ){
            k = *(aIdx++);
            if( k>nIdx-1 ) k = nIdx-1;
          }else{
            k = nIdx;
          }
          for(j=p->aCsr[i].index; j<k; j++){

        VERIFY( if( nos<0 ) goto not_enough_stack; )
        if( VERIFY( i>=0 && i<p->nCursor && ) (pCrsr = p->aCsr[i].pCursor)!=0 ){
          int r;
          int newVal;
          Integerify(p, nos);
          newVal = aStack[nos].i;
          if( Stringify(p, tos) ) goto no_mem;
          r = pBe->Fetch(pCrsr, aStack[tos].n, zStack[tos]);
          if( r==0 ){
            /* Create a new record for this index */
            pBe->Put(pCrsr, aStack[tos].n, zStack[tos],
                          sizeof(int), (char*)&newVal);
          }else{
            /* Extend the existing record */
            int nIdx;
            int *aIdx;
            int k;
            
            nIdx = pBe->DataLength(pCrsr)/sizeof(int);
            if( nIdx==1 ){
              aIdx = sqliteMalloc( sizeof(int)*4 );
              if( aIdx==0 ) goto no_mem;
              aIdx[0] = 2;
              pBe->CopyData(pCrsr, 0, sizeof(int), (char*)&aIdx[1]);
              aIdx[2] = newVal;
              pBe->Put(pCrsr, aStack[tos].n, zStack[tos],
                    sizeof(int)*4, (char*)aIdx);
              sqliteFree(aIdx);
            }else{
              aIdx = (int*)pBe->ReadData(pCrsr, 0);
              k = aIdx[0];
              if( k<nIdx-1 ){
                aIdx[k+1] = newVal;
                aIdx[0]++;
                pBe->Put(pCrsr, aStack[tos].n, zStack[tos],
                    sizeof(int)*nIdx, (char*)aIdx);
              }else{
                nIdx *= 2;
                aIdx = sqliteMalloc( sizeof(int)*nIdx );
                if( aIdx==0 ) goto no_mem;
                pBe->CopyData(pCrsr, 0, sizeof(int)*(k+1), (char*)aIdx);
                aIdx[k+1] = newVal;
                aIdx[0]++;
                pBe->Put(pCrsr, aStack[tos].n, zStack[tos],
                      sizeof(int)*nIdx, (char*)aIdx);
                sqliteFree(aIdx);
              }
            }              
          }
        }
        POPSTACK;

          int nIdx;
          int j, k;
          int r;
          int oldVal;
          Integerify(p, nos);
          oldVal = aStack[nos].i;
          if( Stringify(p, tos) ) goto no_mem;
          r = pBe->Fetch(pCrsr, aStack[tos].n, zStack[tos]);
          if( r==0 ) break;
          nIdx = pBe->DataLength(pCrsr)/sizeof(int);
          aIdx = (int*)pBe->ReadData(pCrsr, 0);
          if( (nIdx==1 && aIdx[0]==oldVal) || (aIdx[0]==1 && aIdx[1]==oldVal) ){
            pBe->Delete(pCrsr, aStack[tos].n, zStack[tos]);
          }else{
            k = aIdx[0];
            for(j=1; j<=k && aIdx[j]!=oldVal; j++){}
            if( j>k ) break;
            aIdx[j] = aIdx[k];
            aIdx[k] = 0;
            aIdx[0]--;
            if( aIdx[0]*3 + 1 < nIdx ){
              nIdx /= 2;
            }
            pBe->Put(pCrsr, aStack[tos].n, zStack[tos], 
                          sizeof(int)*nIdx, (char*)aIdx);
          }
        }
        POPSTACK;
        POPSTACK;
        break;
      }

      /* Opcode: Destroy * * P3
      **
      ** Drop the disk file whose name is P3.  All key/data pairs in
      ** the file are deleted and the file itself is removed
      ** from the disk.
      */
      case OP_Destroy: {
        pBe->DropTable(pBe, pOp->p3);
        break;
      }

      /* Opcode: Reorganize * * P3
      **
      ** Compress, optimize, and tidy up the GDBM file named by P3.
      */
      case OP_Reorganize: {
        pBe->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

        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] ){
          pBe->CloseTempFile(pBe, p->apList[i]);
        }
        rc = pBe->OpenTempFile(pBe, &p->apList[i]);
        if( rc!=SQLITE_OK ){
          sqliteSetString(pzErrMsg, "unable to open a temporary file", 0);
        }
        break;
      }

      /* Opcode: ListWrite 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 ){
          pBe->CloseTempFile(pBe, p->apList[i]);
          p->apList[i] = 0;
        }
        break;
      }

      /* Opcode: SortOpen P1 * *
      **