SQLite

**
*************************************************************************
** 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 1.126 2003/04/17 22:57:54 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>

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

  if( db->pVdbe==0 ){ db->nChange = 0; }
  memset(&sParse, 0, sizeof(sParse));
  sParse.db = db;
  sParse.xCallback = xCallback;
  sParse.pArg = pArg;
  sParse.useDb = -1;
  sParse.useCallback = ppVm==0;
#ifndef SQLITE_OMIT_TRACE
  if( db->xTrace ) db->xTrace(db->pTraceArg, zSql);
#endif
  sqliteRunParser(&sParse, zSql, pzErrMsg);
  if( sqlite_malloc_failed ){
    sqliteSetString(pzErrMsg, "out of memory", 0);
    sParse.rc = SQLITE_NOMEM;
    sqliteRollbackAll(db);
    sqliteResetInternalSchema(db, 0);
    db->flags &= ~SQLITE_InTrans;

** is returned.  
**
** A NULL trace function means that no tracing is executes.  A non-NULL
** trace is a pointer to a function that is invoked at the start of each
** sqlite_exec().
*/
void *sqlite_trace(sqlite *db, void (*xTrace)(void*,const char*), void *pArg){
#ifndef SQLITE_OMIT_TRACE
  void *pOld = db->pTraceArg;
  db->xTrace = xTrace;
  db->pTraceArg = pArg;
  return pOld;
#else
  return 0;
#endif
}

/*
** Register functions to be invoked when a transaction is started or when
** a transaction commits.  If either function returns non-zero, then the
** corresponding operation aborts with a constraint error.
**
** EXPERIMENTAL.  This API is under evaluation and is not yet an
** official part of the SQLite interface.  This means it could change
** or be deleted in future releases.
*/
void *sqlite_begin_hook(
  sqlite *db,
  int (*xCallback)(void*),
  void *pArg
){
  void *pOld = db->pBeginArg;
  db->xBeginCallback = xCallback;
  db->pBeginArg = pArg;
  return pOld;
}
void *sqlite_commit_hook(
  sqlite *db,
  int (*xCallback)(void*),
  void *pArg
){
  void *pOld = db->pCommitArg;
  db->xCommitCallback = xCallback;
  db->pCommitArg = pArg;
  return pOld;
}

/*
** This routine is called to create a connection to a database BTree
** driver.  If zFilename is the name of a file, then that file is
** opened and used.  If zFilename is the magic name ":memory:" then
** the database is stored in memory (and is thus forgotten as soon as

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the SQLite library
** presents to client programs.
**
** @(#) $Id: sqlite.h.in,v 1.45 2003/04/22 20:30:39 drh Exp $
*/
#ifndef _SQLITE_H_
#define _SQLITE_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

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

** when this routine is called, that is like encountering an error or
** an interrupt.  (See sqlite_interrupt().)  Incomplete updates may be
** rolled back and transactions cancelled,  depending on the circumstances,
** and the result code returned will be SQLITE_ABORT.
*/
int sqlite_finalize(sqlite_vm*, char **pzErrMsg);

/*** EXPERIMENTAL ***
** 
** Register a callback function to be invoked whenever a new transaction
** is started or committed.  The pArg argument is passed through to the
** callback.  If the callback function returns non-zero, then the operation
** is aborted with a constraint error.
**
** If another function was previously registered, its pArg value is returned.
** Otherwise NULL is returned.
**
** Registering a NULL function disables the callback.
*/
void *sqlite_begin_hook(sqlite*, int(*)(void*), void*);
void *sqlite_commit_hook(sqlite*, int(*)(void*), void*);

#ifdef __cplusplus
}  /* End of the 'extern "C"' block */
#endif

#endif /* _SQLITE_H_ */

/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.178 2003/04/22 20:30:39 drh Exp $
*/
#include "config.h"
#include "sqlite.h"
#include "hash.h"
#include "vdbe.h"
#include "parse.h"
#include "btree.h"

** When building SQLite for embedded systems where memory is scarce,
** you can define one or more of the following macros to omit extra
** features of the library and thus keep the size of the library to
** a minimum.
*/
/* #define SQLITE_OMIT_AUTHORIZATION  1 */
/* #define SQLITE_OMIT_INMEMORYDB     1 */
/* #define SQLITE_OMIT_TRACE          1 */
/* #define SQLITE_OMIT_VACUUM         1 */

/*
** Integers of known sizes.  These typedefs might change for architectures
** where the sizes very.  Preprocessor macros are available so that the
** types can be conveniently redefined at compile-type.  Like this:
**
**         cc '-DUINTPTR_TYPE=long long int' ...
*/
#ifndef UINT32_TYPE
# define UINT32_TYPE unsigned int
#endif
#ifndef UINT16_TYPE
# define UINT16_TYPE unsigned short int
#endif
#ifndef UINT8_TYPE
# define UINT8_TYPE unsigned char
#endif
#ifndef INT8_TYPE
# define INT8_TYPE signed char
#endif
#ifndef INTPTR_TYPE
# if SQLITE_PTR_SZ==4
#   define INTPTR_TYPE int
# else
#   define INTPTR_TYPE long long
# endif
#endif
typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */
typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */
typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */
typedef INT8_TYPE i8;              /* 1-byte signed integer */
typedef INTPTR_TYPE ptr;           /* Big enough to hold a pointer */
typedef unsigned INTPTR_TYPE uptr; /* Big enough to hold a pointer */

/*
** This macro casts a pointer to an integer.  Useful for doing
** pointer arithmetic.
*/

  u8 want_to_close;             /* Close after all VDBEs are deallocated */
  int next_cookie;              /* Next value of aDb[0].schema_cookie */
  int cache_size;               /* Number of pages to use in the cache */
  int temp_store;               /* 1=file, 2=memory, 0=compile-time default */
  int nTable;                   /* Number of tables in the database */
  void *pBusyArg;               /* 1st Argument to the busy callback */
  int (*xBusyCallback)(void *,const char*,int);  /* The busy callback */
  void *pBeginArg;              /* Argument to the xBeginCallback() */
  int (*xBeginCallback)(void*); /* Invoked at every transaction start */
  void *pCommitArg;             /* Argument to xCommitCallback() */   
  int (*xCommitCallback)(void*);/* Invoked at every commit. */
  Hash aFunc;                   /* All functions that can be in SQL exprs */
  int lastRowid;                /* ROWID of most recent insert */
  int priorNewRowid;            /* Last randomly generated ROWID */
  int onError;                  /* Default conflict algorithm */
  int magic;                    /* Magic number for detect library misuse */
  int nChange;                  /* Number of rows changed */
  struct Vdbe *pVdbe;           /* List of active virtual machines */

** be the right operand of an IN operator.  Or, if a scalar SELECT appears
** in an expression the opcode is TK_SELECT and Expr.pSelect is the only
** operand.
*/
struct Expr {
  u8 op;                 /* Operation performed by this node */
  u8 dataType;           /* Either SQLITE_SO_TEXT or SQLITE_SO_NUM */
  i8 iDb;                /* Database referenced by this expression */
  u8 flags;              /* Various flags.  See below */
  Expr *pLeft, *pRight;  /* Left and right subnodes */
  ExprList *pList;       /* A list of expressions used as function arguments
                         ** or in "<expr> IN (<expr-list)" */
  Token token;           /* An operand token */
  Token span;            /* Complete text of the expression */
  int iTable, iColumn;   /* When op==TK_COLUMN, then this expr node means the

/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** A TCL Interface to SQLite
**
** $Id: tclsqlite.c,v 1.47 2003/04/22 20:30:39 drh Exp $
*/
#ifndef NO_TCL     /* Omit this whole file if TCL is unavailable */

#include "sqliteInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

** that has been opened by the SQLite TCL interface.
*/
typedef struct SqliteDb SqliteDb;
struct SqliteDb {
  sqlite *db;           /* The "real" database structure */
  Tcl_Interp *interp;   /* The interpreter used for this database */
  char *zBusy;          /* The busy callback routine */
  char *zBegin;         /* The begin-transaction callback routine */
  char *zCommit;        /* The commit-transaction callback routine */
  char *zAuth;          /* The authorization callback routine */
  SqlFunc *pFunc;       /* List of SQL functions */
  int rc;               /* Return code of most recent sqlite_exec() */
};

/*
** An instance of this structure passes information thru the sqlite

    SqlFunc *pFunc = pDb->pFunc;
    pDb->pFunc = pFunc->pNext;
    Tcl_Free((char*)pFunc);
  }
  if( pDb->zBusy ){
    Tcl_Free(pDb->zBusy);
  }
  if( pDb->zBegin ){
    Tcl_Free(pDb->zBegin);
  }
  if( pDb->zCommit ){
    Tcl_Free(pDb->zCommit);
  }
  if( pDb->zAuth ){
    Tcl_Free(pDb->zAuth);
  }
  Tcl_Free((char*)pDb);
}

  if( rc!=TCL_OK || atoi(Tcl_GetStringResult(pDb->interp)) ){
    return 0;
  }
  return 1;
}

/*
** This routine is called when a new transaction is started.  The
** TCL script in pDb->zBegin is executed.  If it returns non-zero or
** if it throws an exception, the transaction is aborted.
*/
static int DbBeginHandler(void *cd){
  SqliteDb *pDb = (SqliteDb*)cd;
  int rc;

  rc = Tcl_Eval(pDb->interp, pDb->zBegin);
  if( rc!=TCL_OK || atoi(Tcl_GetStringResult(pDb->interp)) ){
    return 1;
  }
  return 0;
}

/*
** This routine is called when a transaction is committed.  The
** TCL script in pDb->zCommit is executed.  If it returns non-zero or
** if it throws an exception, the transaction is rolled back instead
** of being committed.
*/
static int DbCommitHandler(void *cd){
  SqliteDb *pDb = (SqliteDb*)cd;
  int rc;

  rc = Tcl_Eval(pDb->interp, pDb->zCommit);

  if( rc!=TCL_OK || atoi(Tcl_GetStringResult(pDb->interp)) ){
    return 1;
  }
  return 0;
}

/*
** This routine is called to evaluate an SQL function implemented
** using TCL script.
*/
static void tclSqlFunc(sqlite_func *context, int argc, const char **argv){

** and calls that connection "db1".  The second command causes this
** subroutine to be invoked.
*/
static int DbObjCmd(void *cd, Tcl_Interp *interp, int objc,Tcl_Obj *const*objv){
  SqliteDb *pDb = (SqliteDb*)cd;
  int choice;
  static const char *DB_strs[] = {
    "authorizer",         "begin_hook",        "busy",
    "changes",            "close",             "commit_hook",
    "complete",           "errorcode",         "eval",
    "function",           "last_insert_rowid", "timeout",
    0                    
  };
  enum DB_enum {
    DB_AUTHORIZER,        DB_BEGIN_HOOK,       DB_BUSY,
    DB_CHANGES,           DB_CLOSE,            DB_COMMIT_HOOK,
    DB_COMPLETE,          DB_ERRORCODE,        DB_EVAL,
    DB_FUNCTION,          DB_LAST_INSERT_ROWID,DB_TIMEOUT,
  };

  if( objc<2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "SUBCOMMAND ...");
    return TCL_ERROR;
  }
  if( Tcl_GetIndexFromObj(interp, objv[1], DB_strs, "option", 0, &choice) ){

  ** If this method is invoked with no arguments, the current authorization
  ** callback string is returned.
  */
  case DB_AUTHORIZER: {
    if( objc>3 ){
      Tcl_WrongNumArgs(interp, 2, objv, "?CALLBACK?");
    }else if( objc==2 ){
      if( pDb->zBegin ){
        Tcl_AppendResult(interp, pDb->zAuth, 0);
      }
    }else{
      char *zAuth;
      int len;
      if( pDb->zAuth ){
        Tcl_Free(pDb->zAuth);

        pDb->interp = interp;
        sqlite_set_authorizer(pDb->db, auth_callback, pDb);
      }else{
        sqlite_set_authorizer(pDb->db, 0, 0);
      }
#endif
    }
    break;
  }


  /*    $db begin_callback ?CALLBACK?
  **
  ** Invoke the given callback at the beginning of every SQL transaction.
  ** If the callback throws an exception or returns non-zero, then the
  ** transaction is aborted.  If CALLBACK is an empty string, the callback
  ** is disabled.
  */
  case DB_BEGIN_HOOK: {
    if( objc>3 ){
      Tcl_WrongNumArgs(interp, 2, objv, "?CALLBACK?");
    }else if( objc==2 ){
      if( pDb->zBegin ){
        Tcl_AppendResult(interp, pDb->zBegin, 0);
      }
    }else{
      char *zBegin;
      int len;
      if( pDb->zBegin ){
        Tcl_Free(pDb->zBegin);
      }
      zBegin = Tcl_GetStringFromObj(objv[2], &len);
      if( zBegin && len>0 ){
        pDb->zBegin = Tcl_Alloc( len + 1 );
        strcpy(pDb->zBegin, zBegin);
      }else{
        pDb->zBegin = 0;
      }
      if( pDb->zBegin ){
        pDb->interp = interp;
        sqlite_begin_hook(pDb->db, DbBeginHandler, pDb);
      }else{
        sqlite_begin_hook(pDb->db, 0, 0);
      }
    }
    break;
  }

  /*    $db busy ?CALLBACK?
  **
  ** Invoke the given callback if an SQL statement attempts to open
  ** a locked database file.

  /*    $db close
  **
  ** Shutdown the database
  */
  case DB_CLOSE: {
    Tcl_DeleteCommand(interp, Tcl_GetStringFromObj(objv[0], 0));
    break;
  }

  /*    $db commit_hook ?CALLBACK?
  **
  ** Invoke the given callback just before committing every SQL transaction.
  ** If the callback throws an exception or returns non-zero, then the
  ** transaction is aborted.  If CALLBACK is an empty string, the callback
  ** is disabled.
  */
  case DB_COMMIT_HOOK: {
    if( objc>3 ){
      Tcl_WrongNumArgs(interp, 2, objv, "?CALLBACK?");
    }else if( objc==2 ){
      if( pDb->zCommit ){
        Tcl_AppendResult(interp, pDb->zCommit, 0);
      }
    }else{
      char *zCommit;
      int len;
      if( pDb->zCommit ){
        Tcl_Free(pDb->zCommit);
      }
      zCommit = Tcl_GetStringFromObj(objv[2], &len);
      if( zCommit && len>0 ){
        pDb->zCommit = Tcl_Alloc( len + 1 );
        strcpy(pDb->zCommit, zCommit);
      }else{
        pDb->zCommit = 0;
      }
      if( pDb->zCommit ){
        pDb->interp = interp;
        sqlite_commit_hook(pDb->db, DbCommitHandler, pDb);
      }else{
        sqlite_commit_hook(pDb->db, 0, 0);
      }
    }
    break;
  }

  /*    $db complete SQL
  **
  ** Return TRUE if SQL is a complete SQL statement.  Return FALSE if
  ** additional lines of input are needed.  This is similar to the

      Tcl_WrongNumArgs(interp, 2, objv, "MILLISECONDS");
      return TCL_ERROR;
    }
    if( Tcl_GetIntFromObj(interp, objv[2], &ms) ) return TCL_ERROR;
    sqlite_busy_timeout(pDb->db, ms);
    break;
  }





































  } /* End of the SWITCH statement */
  return TCL_OK;
}

/*
**   sqlite DBNAME FILENAME ?MODE?
**

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.218 2003/04/17 12:44:25 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** The makefile scans this source file and creates the following
** array of string constants which are the names of all VDBE opcodes.

      default: {
        goto abort_due_to_error;
      }
    }
  }
  db->aDb[i].inTrans = 1;
  p->undoTransOnError = 1;
  if( db->xBeginCallback!=0 && i==1 && rc==SQLITE_OK ){
    if( sqliteSafetyOff(db) ) goto abort_due_to_misuse; 
    if( db->xBeginCallback(db->pBeginArg)!=0 ){
      rc = SQLITE_CONSTRAINT;
    }
    if( sqliteSafetyOn(db) ) goto abort_due_to_misuse;
  }
  break;
}

/* Opcode: Commit * * *
**
** Cause all modifications to the database that have been made since the
** last Transaction to actually take effect.  No additional modifications
** are allowed until another transaction is started.  The Commit instruction
** deletes the journal file and releases the write lock on the database.
** A read lock continues to be held if there are still cursors open.
*/
case OP_Commit: {
  int i;
  if( db->xCommitCallback!=0 ){
    if( sqliteSafetyOff(db) ) goto abort_due_to_misuse; 
    if( db->xCommitCallback(db->pCommitArg)!=0 ){
      rc = SQLITE_CONSTRAINT;
    }
    if( sqliteSafetyOn(db) ) goto abort_due_to_misuse;
  }
  for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
    if( db->aDb[i].inTrans ){
      rc = sqliteBtreeCommit(db->aDb[i].pBt);
      db->aDb[i].inTrans = 0;
    }
  }
  if( rc==SQLITE_OK ){

# 2003 April 3
#
# 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.
#
#***********************************************************************
# This file implements regression tests for TCL interface to the
# SQLite library. 
#
# The focus of the tests in this file is the  following interface:
#
#      sqlite_begin_hook
#      sqlite_commit_hook
#
# $Id: hook.test,v 1.1 2003/04/03 15:46:05 drh Exp $

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

do_test hook-1.1 {
  db begin_hook
} {}
do_test hook-1.2 {
  db commit_hook
} {}

do_test hook-2.1 {
  set begin_cnt 0
  proc begin_hook {} {
    incr ::begin_cnt
    return 0
  }
  db begin_hook begin_hook
  db begin_hook
} {begin_hook}
do_test hook-2.2 {
  set begin_cnt
} {0}
do_test hook-2.3 {
  execsql {
    CREATE TABLE t1(a,b);
  }
  set begin_cnt
} {1}
do_test hook-2.4 {
  execsql {
    INSERT INTO t1 VALUES(1,2);
    INSERT INTO t1 SELECT a+1, b+1 FROM t1;
    INSERT INTO t1 SELECT a+2, b+2 FROM t1;
  }
  set begin_cnt
} {4}
do_test hook-2.5 {
  execsql {
    SELECT * FROM t1
  }
} {1 2 2 3 3 4 4 5}
do_test hook-2.6 {
  set begin_cnt
} {4}
do_test hook-2.7 {
  proc begin_hook {} {
    incr ::begin_cnt
    return 1
  }
  catchsql {
    INSERT INTO t1 VALUES(9,10);
  }
} {1 {constraint failed}}
do_test hook-2.8 {
  set begin_cnt
} {5}
do_test hook-2.9 {
  execsql {
    SELECT * FROM t1;
  }
} {1 2 2 3 3 4 4 5}
do_test hook-2.10 {
  db begin_hook {}
  db begin_hook
} {}
do_test hook-2.11 {
  execsql {
    INSERT INTO t1 VALUES(9,10);
    SELECT * FROM t1
  }
} {1 2 2 3 3 4 4 5 9 10}

do_test hook-3.1 {
  set commit_cnt 0
  proc commit_hook {} {
    incr ::commit_cnt
    return 0
  }
  db commit_hook ::commit_hook
  db commit_hook
} {::commit_hook}
do_test hook-3.2 {
  set commit_cnt
} {0}
do_test hook-3.3 {
  execsql {
    CREATE TABLE t2(a,b);
  }
  set commit_cnt
} {1}
do_test hook-3.4 {
  execsql {
    INSERT INTO t2 VALUES(1,2);
    INSERT INTO t2 SELECT a+1, b+1 FROM t2;
    INSERT INTO t2 SELECT a+2, b+2 FROM t2;
  }
  set commit_cnt
} {4}
do_test hook-3.5 {
  set commit_cnt {}
  proc commit_hook {} {
    set ::commit_cnt [execsql {SELECT * FROM t2}]
    return 0
  }
  execsql {
    INSERT INTO t2 VALUES(5,6);
  }
  set commit_cnt
} {1 2 2 3 3 4 4 5 5 6}
do_test hook-3.6 {
  set commit_cnt {}
  proc commit_hook {} {
    set ::commit_cnt [execsql {SELECT * FROM t2}]
    return 1
  }
  catchsql {
    INSERT INTO t2 VALUES(6,7);
  }
} {1 {constraint failed}}
do_test hook-3.7 {
  set commit_cnt
} {1 2 2 3 3 4 4 5 5 6 6 7}
do_test hook-3.8 {
  execsql {SELECT * FROM t2}
} {1 2 2 3 3 4 4 5 5 6}


finish_test

# This file implements regression tests for TCL interface to the
# SQLite library. 
#
# Actually, all tests are based on the TCL interface, so the main
# interface is pretty well tested.  This file contains some addition
# tests for fringe issues that the main test suite does not cover.
#
# $Id: tclsqlite.test,v 1.12 2003/04/22 20:30:40 drh Exp $

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

# Check the error messages generated by tclsqlite
#
do_test tcl-1.1 {
  set v [catch {sqlite bogus} msg]
  lappend v $msg
} {1 {wrong # args: should be "sqlite HANDLE FILENAME ?MODE?"}}
do_test tcl-1.2 {
  set v [catch {db bogus} msg]
  lappend v $msg
} {1 {bad option "bogus": must be authorizer, begin_hook, busy, changes, close, commit_hook, complete, errorcode, eval, function, last_insert_rowid, or timeout}}
do_test tcl-1.3 {
  execsql {CREATE TABLE t1(a int, b int)}
  execsql {INSERT INTO t1 VALUES(10,20)}
  set v [catch {
    db eval {SELECT * FROM t1} data {
      error "The error message"
    }