SQLite

/*
** 2004 April 6
**
** 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 1.216 2004/11/10 11:55:11 danielk1977 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.

    return SQLITE_PERM;   /* Did not open this cursor for writing */
  }
  if( checkReadLocks(pBt, pCur->pgnoRoot, pCur) ){
    return SQLITE_LOCKED; /* The table pCur points to has a read lock */
  }
  rc = sqlite3pager_write(pPage->aData);
  if( rc ) return rc;

  /* Locate the cell within it's page and leave pCell pointing to the
  ** data. The clearCell() call frees any overflow pages associated with the
  ** cell. The cell itself is still intact.
  */
  pCell = findCell(pPage, pCur->idx);
  if( !pPage->leaf ){
    pgnoChild = get4byte(pCell);
  }
  clearCell(pPage, pCell);

  if( !pPage->leaf ){
    /*
    ** The entry we are about to delete is not a leaf so if we do not
    ** do something we will leave a hole on an internal page.
    ** We have to fill the hole by moving in a cell from a leaf.  The
    ** next Cell after the one to be deleted is guaranteed to exist and
    ** to be a leaf so we can use it.

**     BTREE_INTKEY|BTREE_LEAFDATA     Used for SQL tables with rowid keys
**     BTREE_ZERODATA                  Used for SQL indices
*/
int sqlite3BtreeCreateTable(Btree *pBt, int *piTable, int flags){
  MemPage *pRoot;
  Pgno pgnoRoot;
  int rc;

  if( pBt->inTrans!=TRANS_WRITE ){
    /* Must start a transaction first */
    return pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR;
  }
  if( pBt->readOnly ){
    return SQLITE_READONLY;
  }

  /* It is illegal to create a table if any cursors are open on the
  ** database. This is because in auto-vacuum mode the backend may
  ** need to move a database page to make room for the new root-page.
  ** If an open cursor was using the page a problem would occur.
  */
  if( pBt->pCursor ){
    return SQLITE_LOCKED;
  }

#ifdef SQLITE_OMIT_AUTOVACUUM
  rc = allocatePage(pBt, &pRoot, &pgnoRoot, 1, 0);
  if( rc ) return rc;
#else
  if( pBt->autoVacuum ){
    Pgno pgnoMove;      /* Move a page here to make room for the root-page */
    MemPage *pPageMove; /* The page to move to. */

** the move.  If no page gets moved, *piMoved is set to 0.
** The last root page is recorded in meta[3] and the value of
** meta[3] is updated by this procedure.
*/
int sqlite3BtreeDropTable(Btree *pBt, int iTable, int *piMoved){
  int rc;
  MemPage *pPage = 0;


  if( pBt->inTrans!=TRANS_WRITE ){
    return pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR;
  }

  /* It is illegal to drop a table if any cursors are open on the
  ** database. This is because in auto-vacuum mode the backend may
  ** need to move another root-page to fill a gap left by the deleted
  ** root page. If an open cursor was using this page a problem would 
  ** occur.
  */
  if( pBt->pCursor ){

    return SQLITE_LOCKED;

  }

  rc = getPage(pBt, (Pgno)iTable, &pPage);
  if( rc ) return rc;
  rc = sqlite3BtreeClearTable(pBt, iTable);
  if( rc ) return rc;

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.275 2004/11/10 11:55:12 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Check to see if the schema for the database needs

    ** generate.
    */
    sqlite3OpenMasterTable(v, iDb);
    sqlite3VdbeAddOp(v, OP_NewRecno, 0, 0);
    sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
    sqlite3VdbeAddOp(v, OP_String8, 0, 0);
    sqlite3VdbeAddOp(v, OP_PutIntKey, 0, 0);
    sqlite3VdbeAddOp(v, OP_Close, 0, 0);
  }
}

/*
** Add a new column to the table currently being constructed.
**
** The parser calls this routine once for each column declaration

    Vdbe *v;
    char *zType;    /* "view" or "table" */
    char *zType2;   /* "VIEW" or "TABLE" */
    char *zStmt;    /* Text of the CREATE TABLE or CREATE VIEW statement */

    v = sqlite3GetVdbe(pParse);
    if( v==0 ) return;

    sqlite3VdbeAddOp(v, OP_Close, 0, 0);

    /* Create the rootpage for the new table and push it onto the stack.
    ** A view has no rootpage, so just push a zero onto the stack for
    ** views.  Initialize zType at the same time.
    */
    if( p->pSelect==0 ){
      /* A regular table */
      sqlite3VdbeAddOp(v, OP_CreateTable, p->iDb, 0);
      zType = "table";
      zType2 = "TABLE";
    }else{
      /* A view */
      sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
      zType = "view";
      zType2 = "VIEW";
    }



    /* If this is a CREATE TABLE xx AS SELECT ..., execute the SELECT
    ** statement to populate the new table. The root-page number for the
    ** new table is on the top of the vdbe stack.
    **
    ** Once the SELECT has been coded by sqlite3Select(), it is in a
    ** suitable state to query for the column names and types to be used
    ** by the new table.

** This file contains the C functions that implement date and time
** functions for SQLite.  
**
** There is only one exported symbol in this file - the function
** sqlite3RegisterDateTimeFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: date.c,v 1.40 2004/11/10 11:55:12 danielk1977 Exp $
**
** NOTES:
**
** SQLite processes all times and dates as Julian Day numbers.  The
** dates and times are stored as the number of days since noon
** in Greenwich on November 24, 4714 B.C. according to the Gregorian
** calendar system.

  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  time_t t;
  char *zFormat = (char *)sqlite3_user_data(context);
  char zBuf[20];


#ifdef SQLITE_TEST
  /* This test variable is located in os_XXX.c */
extern int sqlite3_current_time;
#endif
  time(&t);
#ifdef SQLITE_TEST
  if( sqlite3_current_time ){
    t = sqlite3_current_time;
  }
#endif

  sqlite3OsEnterMutex();
  strftime(zBuf, 20, zFormat, gmtime(&t));
  sqlite3OsLeaveMutex();

  sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
}
#endif

/*
** This function registered all of the above C functions as SQL
** functions.  This should be the only routine in this file with

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the btree.c module in SQLite.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test3.c,v 1.57 2004/11/10 11:55:12 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "pager.h"
#include "btree.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

    case SQLITE_IOERR:      zName = "SQLITE_IOERR";       break;
    case SQLITE_CORRUPT:    zName = "SQLITE_CORRUPT";     break;
    case SQLITE_NOTFOUND:   zName = "SQLITE_NOTFOUND";    break;
    case SQLITE_FULL:       zName = "SQLITE_FULL";        break;
    case SQLITE_CANTOPEN:   zName = "SQLITE_CANTOPEN";    break;
    case SQLITE_PROTOCOL:   zName = "SQLITE_PROTOCOL";    break;
    case SQLITE_EMPTY:      zName = "SQLITE_EMPTY";       break;
    case SQLITE_LOCKED:     zName = "SQLITE_LOCKED";      break;
    default:                zName = "SQLITE_Unknown";     break;
  }
  return zName;
}

/*
** Usage:   btree_open FILENAME NCACHE FLAGS

**
** 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 1.425 2004/11/10 11:55:13 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*

** a zero is pushed onto the stack.  If AUTOVACUUM is disabled at 
** then a zero is pushed onto the stack.
**
** See also: Clear
*/
case OP_Destroy: {
  int iMoved;
  if( db->activeVdbeCnt>1 ){
    rc = SQLITE_LOCKED;
  }else{
    assert( db->activeVdbeCnt==1 );
    rc = sqlite3BtreeDropTable(db->aDb[pOp->p2].pBt, pOp->p1, &iMoved);
    pTos++;
    pTos->flags = MEM_Int;
    pTos->i = iMoved;
  #ifndef SQLITE_OMIT_AUTOVACUUM
    if( rc==SQLITE_OK && iMoved!=0 ){
      sqlite3RootPageMoved(&db->aDb[pOp->p2], iMoved, pOp->p1);
    }
  #endif
  }
  break;
}

/* Opcode: Clear P1 P2 *
**
** Delete all contents of the database table or index whose root page
** in the database file is given by P1.  But, unlike Destroy, do not

# 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.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is btree database backend
#
# $Id: btree.test,v 1.32 2004/11/10 11:55:14 danielk1977 Exp $


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

# Basic functionality.  Open and close a database.
#

do_test btree-6.6 {
  btree_close_cursor $::c2
} {}
do_test btree-6.6.1 {
  lindex [btree_pager_stats $::b1] 1
} {1}
do_test btree-6.7 {
  btree_close_cursor $::c1
  btree_drop_table $::b1 $::t2
} {}
do_test btree-6.7.1 {
  lindex [btree_get_meta $::b1] 0
} {1}
do_test btree-6.8 {
  set ::t2 [btree_create_table $::b1 0]

  btree_move_to $::c2 {}
  btree_key $::c2
} {}

# If we drop table 1 it just clears the table.  Table 1 always exists.
#
do_test btree-6.10 {
  btree_close_cursor $::c2
  btree_drop_table $::b1 1
  set ::c2 [btree_cursor $::b1 $::t2 1]
  set ::c1 [btree_cursor $::b1 1 1]
  btree_first $::c1
  btree_eof $::c1
} {1}
do_test btree-6.11 {
  btree_commit $::b1
  select_all $::c1

# 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.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the CREATE TABLE statement.
#
# $Id: table.test,v 1.33 2004/11/10 11:55:15 danielk1977 Exp $

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

# Create a basic table and verify it is added to sqlite_master
#
do_test table-1.1 {

} {}
do_test table-12.2 {
  execsql {
    SELECT sql FROM sqlite_master WHERE tbl_name = 't8'
  }
} {{CREATE TABLE t8(b number(5,10),h,i integer,j BLOB)}}

#--------------------------------------------------------------------
# Test cases table-13.*
#
# Test the ability to have default values of CURRENT_TIME, CURRENT_DATE
# and CURRENT_TIMESTAMP.
#
do_test table-13.1 {
  execsql {
    CREATE TABLE tablet8(
       a integer primary key,

foreach {date time} {
  1976-07-04 12:00:00
  1994-04-16 14:00:00
  2000-01-01 00:00:00
  2003-12-31 12:34:56
} {
  incr i
  set sqlite_current_time [clock scan "$date $time" -gmt 1]
  # set sqlite_current_time [execsql "SELECT strftime('%s','$date $time')"]

  do_test table-13.2.$i {
    execsql "
      INSERT INTO tablet8(a) VALUES($i);
      SELECT tm, dt, dttm FROM tablet8 WHERE a=$i;
    "
  } [list $time $date [list $date $time]]
}
set sqlite_current_time 0

#--------------------------------------------------------------------
# Test cases table-14.*
#
# Test that a table cannot be created or dropped while other virtual
# machines are active. This is required because otherwise when in 
# auto-vacuum mode the btree-layer may need to move the root-pages of 
# a table for which there is an open cursor.
#

# Try to create a table from within a callback:
do_test table-14.1 {
  set rc [
    catch {
      db eval {SELECT * FROM tablet8 LIMIT 1} {} {
        db eval {CREATE TABLE t9(a, b, c)}
      }
    } msg
  ]
  set result [list $rc $msg]
} {1 {database table is locked}}

do_test table-14.2 {
  execsql {
    CREATE TABLE t9(a, b, c)
  }
} {}

# Try to drop a table from within a callback:
do_test table-14.3 {
  set rc [
    catch {
      db eval {SELECT * FROM tablet8 LIMIT 1} {} {
        db eval {DROP TABLE t9;}
      }
    } msg
  ] 
  set result [list $rc $msg]
} {1 {database table is locked}}

# Now attach a database and ensure that a table can be created in the 
# attached database whilst in a callback from a query on the main database.
do_test table-14.4 {
  file delete -force test2.db
  file delete -force test2.db-journal
  execsql {
    attach 'test2.db' as aux;
  }
  db eval {SELECT * FROM tablet8 LIMIT 1} {} {
    db eval {CREATE TABLE aux.t1(a, b, c)}
  }
} {}

# On the other hand, it should be impossible to drop a table when any VMs 
# are active. This is because VerifyCookie instructions may have already
# been executed, and btree root-pages may not move after this (which a
# delete table might do).
do_test table-14.4 {
  set rc [
    catch {
      db eval {SELECT * FROM tablet8 LIMIT 1} {} {
        db eval {DROP TABLE aux.t1;}
      }
    } msg
  ] 
  set result [list $rc $msg]
} {1 {database table is locked}}

finish_test