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 1.145 2004/01/15 02:44:03 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>

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

*/
void *sqlite_trace(sqlite *db, void (*xTrace)(void*,const char*), void *pArg){
  void *pOld = db->pTraceArg;
  db->xTrace = xTrace;
  db->pTraceArg = pArg;
  return pOld;
}

/*** EXPERIMENTAL ***
**
** Register a function to be invoked when a transaction comments.
** If either function returns non-zero, then the commit becomes a
** rollback.
*/
void *sqlite_commit_hook(
  sqlite *db,               /* Attach the hook to this database */
  int (*xCallback)(void*),  /* Function to invoke on each commit */
  void *pArg                /* Argument to the function */
){
  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
** the connection is closed.)  If zFilename is NULL then the database

**    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 1.54 2004/01/15 02:44:03 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++.

** To remove the progress callback altogether, pass NULL as the third
** argument to this function.
**
** If the progress callback returns a result other than 0, then the current 
** query is immediately terminated and any database changes rolled back. If the
** query was part of a larger transaction, then the transaction is not rolled
** back and remains active. The sqlite_exec() call returns SQLITE_ABORT. 
**
******* THIS IS AN EXPERIMENTAL API AND IS SUBJECT TO CHANGE ******
*/
void sqlite_progress_handler(sqlite*, int, int(*)(void*), void*);

/*
** Register a callback function to be invoked whenever a new transaction
** is committed.  The pArg argument is passed through to the callback.
** callback.  If the callback function returns non-zero, then the commit
** is converted into a rollback.
**
** If another function was previously registered, its pArg value is returned.
** Otherwise NULL is returned.
**
** Registering a NULL function disables the callback.
**
******* THIS IS AN EXPERIMENTAL API AND IS SUBJECT TO CHANGE ******
*/
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 1.208 2004/01/15 02:44:03 drh Exp $
*/
#include "config.h"
#include "sqlite.h"
#include "hash.h"
#include "vdbe.h"
#include "parse.h"
#include "btree.h"

  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 *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 */

/*
** 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 1.54 2004/01/15 02:44:03 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 *zCommit;        /* The commit hook callback routine */
  char *zTrace;         /* The trace callback routine */
  char *zProgress;      /* The progress callback routine */
  char *zAuth;          /* The authorization callback routine */
  SqlFunc *pFunc;       /* List of SQL functions */
  int rc;               /* Return code of most recent sqlite_exec() */
};

  Tcl_DStringInit(&str);
  Tcl_DStringAppend(&str, pDb->zTrace, -1);
  Tcl_DStringAppendElement(&str, zSql);
  Tcl_Eval(pDb->interp, Tcl_DStringValue(&str));
  Tcl_DStringFree(&str);
  Tcl_ResetResult(pDb->interp);
}

/*
** 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){
  SqlFunc *p = sqlite_user_data(context);

** 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",         "busy",              "changes",
    "close",              "commit_hook",       "complete",
    "errorcode",          "eval",              "function",
    "last_insert_rowid",  "onecolumn",         "progress",
    "timeout",            "trace",             0
  };
  enum DB_enum {
    DB_AUTHORIZER,        DB_BUSY,             DB_CHANGES,
    DB_CLOSE,             DB_COMMIT_HOOK,      DB_COMPLETE,
    DB_ERRORCODE,         DB_EVAL,             DB_FUNCTION,
    DB_LAST_INSERT_ROWID, DB_ONECOLUMN,        DB_PROGRESS,
    DB_TIMEOUT,           DB_TRACE,            

  };

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

  **
  ** 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
  ** built-in "info complete" command of Tcl.
  */

**
** 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 1.251 2004/01/15 02:44:03 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*

** 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 ){

# 2004 Jan 14
#
# 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_commit_hook
#
# $Id: hook.test,v 1.3 2004/01/15 02:44:03 drh Exp $

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

do_test hook-1.2 {
  db commit_hook
} {}


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 1.17 2004/01/15 02:44:04 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, busy, changes, close, commit_hook, complete, errorcode, eval, function, last_insert_rowid, onecolumn, progress, timeout, or trace}}
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"
    }