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 1.335 2006/02/16 18:16:37 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>

/*
** The following constant value is used by the SQLITE_BIGENDIAN and

  sqlite3* db, 
  const char *zName, 
  int enc, 
  void* pCtx,
  int(*xCompare)(void*,int,const void*,int,const void*)
){
  CollSeq *pColl;
  int enc2;
  
  if( sqlite3SafetyCheck(db) ){
    return SQLITE_MISUSE;
  }

  /* If SQLITE_UTF16 is specified as the encoding type, transform this
  ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
  ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
  */
  enc2 = enc & ~SQLITE_UTF16_ALIGNED;
  if( enc2==SQLITE_UTF16 ){
    enc2 = SQLITE_UTF16NATIVE;
  }


  if( (enc2&~3)!=0 ){
    sqlite3Error(db, SQLITE_ERROR, "unknown encoding");



    return SQLITE_ERROR;
  }

  /* Check if this call is removing or replacing an existing collation 
  ** sequence. If so, and there are active VMs, return busy. If there
  ** are no active VMs, invalidate any pre-compiled statements.
  */
  pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, strlen(zName), 0);
  if( pColl && pColl->xCmp ){
    if( db->activeVdbeCnt ){
      sqlite3Error(db, SQLITE_BUSY, 
        "Unable to delete/modify collation sequence due to active statements");
      return SQLITE_BUSY;
    }
    sqlite3ExpirePreparedStatements(db);
  }

  pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, strlen(zName), 1);
  if( pColl ){
    pColl->xCmp = xCompare;
    pColl->pUser = pCtx;
    pColl->enc = enc2 | (enc & SQLITE_UTF16_ALIGNED);
  }
  sqlite3Error(db, SQLITE_OK, 0);
  return SQLITE_OK;
}


/*

    rc = SQLITE_ERROR;
  }
  sqlite3Error(db, rc, (zErrMsg?"%s":0), zErrMsg);
  sqliteFree(zErrMsg);
  return sqlite3ApiExit(db, rc);
}
#endif

**    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 1.163 2006/02/16 18:16:37 drh Exp $
*/
#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

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

void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
void sqlite3_result_value(sqlite3_context*, sqlite3_value*);

/*
** These are the allowed values for the eTextRep argument to
** sqlite3_create_collation and sqlite3_create_function.
*/
#define SQLITE_UTF8           1
#define SQLITE_UTF16LE        2
#define SQLITE_UTF16BE        3
#define SQLITE_UTF16          4    /* Use native byte order */
#define SQLITE_ANY            5    /* sqlite3_create_function only */
#define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */

/*
** These two functions are used to add new collation sequences to the
** sqlite3 handle specified as the first argument. 
**
** The name of the new collation sequence is specified as a UTF-8 string
** for sqlite3_create_collation() and a UTF-16 string for

/*
** 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 1.484 2006/02/16 18:16:37 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** Extra interface definitions for those who need them
*/

** Defer sourcing vdbe.h and btree.h until after the "u8" and 
** "BusyHandler typedefs.
*/
#include "vdbe.h"
#include "btree.h"
#include "pager.h"







#ifdef SQLITE_MEMDEBUG
/*
** The following global variables are used for testing and debugging
** only.  They only work if SQLITE_MEMDEBUG is defined.
*/
extern int sqlite3_nMalloc;      /* Number of sqliteMalloc() calls */
extern int sqlite3_nFree;        /* Number of sqliteFree() calls */

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the printf() interface to SQLite.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test1.c,v 1.207 2006/02/16 18:16:37 drh Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include "os.h"
#include <stdlib.h>
#include <string.h>

  if( sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
  return TCL_OK;

bad_args:
  Tcl_WrongNumArgs(interp, 1, objv, "DB");
  return TCL_ERROR;
}

/*
** tclcmd:   add_alignment_test_collations  DB
**
** Add two new collating sequences to the database DB
**
**     utf16_aligned
**     utf16_unaligned
**
** Both collating sequences use the same sort order as BINARY.
** The only difference is that the utf16_aligned collating
** sequence is declared with the SQLITE_UTF16_ALIGNED flag.
** Both collating functions increment the unaligned utf16 counter
** whenever they see a string that begins on an odd byte boundary.
*/
static int unaligned_string_counter = 0;
static int alignmentCollFunc(
  void *NotUsed,
  int nKey1, const void *pKey1,
  int nKey2, const void *pKey2
){
  int rc, n;
  n = nKey1<nKey2 ? nKey1 : nKey2;
  if( nKey1>0 && 1==(1&(int)pKey1) ) unaligned_string_counter++;
  if( nKey2>0 && 1==(1&(int)pKey2) ) unaligned_string_counter++;
  rc = memcmp(pKey1, pKey2, n);
  if( rc==0 ){
    rc = nKey1 - nKey2;
  }
  return rc;
}
static int add_alignment_test_collations(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  sqlite3 *db;
  if( objc>=2 ){
    if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
    sqlite3_create_collation(db, "utf16_unaligned",
        SQLITE_UTF16, 
        0, alignmentCollFunc);
    sqlite3_create_collation(db, "utf16_aligned",
        SQLITE_UTF16 | SQLITE_UTF16_ALIGNED, 
        0, alignmentCollFunc);
  }
  return SQLITE_OK;
}
#endif /* !defined(SQLITE_OMIT_UTF16) */

/*
** Usage: add_test_function <db ptr> <utf8> <utf16le> <utf16be>
**
** This function is used to test that SQLite selects the correct user
** function callback when multiple versions (for different text encodings)
** are available.

#endif

#ifndef SQLITE_OMIT_UTF16
     { "sqlite3_column_bytes16",    test_stmt_int,   sqlite3_column_bytes16   },
     { "sqlite3_column_text16",     test_stmt_utf16, sqlite3_column_text16    },
     { "sqlite3_column_decltype16", test_stmt_utf16, sqlite3_column_decltype16},
     { "sqlite3_column_name16",     test_stmt_utf16, sqlite3_column_name16    },
     { "add_alignment_test_collations", add_alignment_test_collations, 0      },
#ifdef SQLITE_ENABLE_COLUMN_METADATA
{"sqlite3_column_database_name16",
  test_stmt_utf16, sqlite3_column_database_name16},
{"sqlite3_column_table_name16", test_stmt_utf16, sqlite3_column_table_name16},
{"sqlite3_column_origin_name16", test_stmt_utf16, sqlite3_column_origin_name16},
#endif
#endif

      (char*)&sqlite3_open_file_count, TCL_LINK_INT);
  Tcl_LinkVar(interp, "sqlite_current_time", 
      (char*)&sqlite3_current_time, TCL_LINK_INT);
  Tcl_LinkVar(interp, "sqlite_os_trace",
      (char*)&sqlite3_os_trace, TCL_LINK_INT);
  Tcl_LinkVar(interp, "sqlite3_tsd_count",
      (char*)&sqlite3_tsd_count, TCL_LINK_INT);
  Tcl_LinkVar(interp, "unaligned_string_counter",
      (char*)&unaligned_string_counter, TCL_LINK_INT);
#if OS_UNIX && defined(SQLITE_TEST) && defined(THREADSAFE) && THREADSAFE
  Tcl_LinkVar(interp, "threadsOverrideEachOthersLocks",
      (char*)&threadsOverrideEachOthersLocks, TCL_LINK_INT);
#endif
#ifndef SQLITE_OMIT_UTF16
  Tcl_LinkVar(interp, "sqlite_last_needed_collation",
      (char*)&pzNeededCollation, TCL_LINK_STRING|TCL_LINK_READ_ONLY);

  int rc;
  if( !(pMem->flags&MEM_Str) || pMem->enc==desiredEnc ){
    return SQLITE_OK;
  }
#ifdef SQLITE_OMIT_UTF16
  return SQLITE_ERROR;
#else


  /* MemTranslate() may return SQLITE_OK or SQLITE_NOMEM. If NOMEM is returned,
  ** then the encoding of the value may not have changed.
  */
  rc = sqlite3VdbeMemTranslate(pMem, desiredEnc);
  assert(rc==SQLITE_OK    || rc==SQLITE_NOMEM);
  assert(rc==SQLITE_OK    || pMem->enc!=desiredEnc);

    ** the user deletes the collation sequence after the vdbe program is
    ** compiled (this was not always the case).
    */
    assert( !pColl || pColl->xCmp );

    if( pColl ){
      if( pMem1->enc==pColl->enc ){
        /* The strings are already in the correct encoding.  Call the
        ** comparison function directly */
        return pColl->xCmp(pColl->pUser,pMem1->n,pMem1->z,pMem2->n,pMem2->z);
      }else{
        u8 origEnc = pMem1->enc;
        const void *v1, *v2;
        int n1, n2;
        /* Convert the strings into the encoding that the comparison
        ** function expects */
        v1 = sqlite3ValueText((sqlite3_value*)pMem1, pColl->enc);
        n1 = v1==0 ? 0 : pMem1->n;
        assert( n1==sqlite3ValueBytes((sqlite3_value*)pMem1, pColl->enc) );
        v2 = sqlite3ValueText((sqlite3_value*)pMem2, pColl->enc);

        n2 = v2==0 ? 0 : pMem2->n;
        assert( n2==sqlite3ValueBytes((sqlite3_value*)pMem2, pColl->enc) );
        /* Do the comparison */
        rc = pColl->xCmp(pColl->pUser, n1, v1, n2, v2);
        /* Convert the strings back into the database encoding */
        sqlite3ValueText((sqlite3_value*)pMem1, origEnc);

        sqlite3ValueText((sqlite3_value*)pMem2, origEnc);
        return rc;
      }
    }
    /* If a NULL pointer was passed as the collate function, fall through
    ** to the blob case and use memcmp().  */
  }

#endif

/* This function is only available internally, it is not part of the
** external API. It works in a similar way to sqlite3_value_text(),
** except the data returned is in the encoding specified by the second
** parameter, which must be one of SQLITE_UTF16BE, SQLITE_UTF16LE or
** SQLITE_UTF8.
**
** (2006-02-16:)  The enc value can be or-ed with SQLITE_UTF16_ALIGNED.
** If that is the case, then the result must be aligned on an even byte
** boundary.
*/
const void *sqlite3ValueText(sqlite3_value* pVal, u8 enc){
  if( !pVal ) return 0;
  assert( (enc&3)==(enc&~SQLITE_UTF16_ALIGNED) );

  if( pVal->flags&MEM_Null ){
    return 0;
  }
  assert( (MEM_Blob>>3) == MEM_Str );
  pVal->flags |= (pVal->flags & MEM_Blob)>>3;
  if( pVal->flags&MEM_Str ){
    sqlite3VdbeChangeEncoding(pVal, enc & ~SQLITE_UTF16_ALIGNED);
    if( (enc & SQLITE_UTF16_ALIGNED)!=0 && 1==(1&(int)pVal->z) ){
      assert( (pVal->flags & (MEM_Ephem|MEM_Static))!=0 );
      if( sqlite3VdbeMemMakeWriteable(pVal)!=SQLITE_OK ){
        return 0;
      }
    }
  }else if( !(pVal->flags&MEM_Blob) ){
    sqlite3VdbeMemStringify(pVal, enc);
    assert( 0==(1&(int)pVal->z) );
  }
  assert(pVal->enc==(enc & ~SQLITE_UTF16_ALIGNED) || sqlite3MallocFailed() );
  if( pVal->enc==(enc & ~SQLITE_UTF16_ALIGNED) ){
    return pVal->z;
  }else{
    return 0;
  }
}

/*
** Create a new sqlite3_value object.
*/
sqlite3_value* sqlite3ValueNew(void){
  Mem *p = sqliteMalloc(sizeof(*p));

# 2006 February 16
#
# 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 contains code to verify that the SQLITE_UTF16_ALIGNED
# flag passed into the sqlite3_create_collation() function insures
# that all strings passed to that function are aligned on an even
# byte boundary.
#
# $Id: utf16align.test,v 1.1 2006/02/16 18:16:38 drh Exp $

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

# Skip this entire test if we do not support UTF16
#
ifcapable !utf16 {
  finish_test
  return
}

# Create a database with a UTF16 encoding.  Put in lots of string
# data of varying lengths.
#
do_test utf16align-1.0 {
  set unaligned_string_counter 0
  add_alignment_test_collations [sqlite3_connection_pointer db]
  execsql {
    PRAGMA encoding=UTF16;
    CREATE TABLE t1(
      id INTEGER PRIMARY KEY,
      spacer TEXT,
      a TEXT COLLATE utf16_aligned,
      b TEXT COLLATE utf16_unaligned
    );
    INSERT INTO t1(a) VALUES("abc");
    INSERT INTO t1(a) VALUES("defghi");
    INSERT INTO t1(a) VALUES("jklmnopqrstuv");
    INSERT INTO t1(a) VALUES("wxyz0123456789-");
    UPDATE t1 SET b=a||'-'||a;
    INSERT INTO t1(a,b) SELECT a||b, b||a FROM t1;
    INSERT INTO t1(a,b) SELECT a||b, b||a FROM t1;
    INSERT INTO t1(a,b) SELECT a||b, b||a FROM t1;
    INSERT INTO t1(a,b) VALUES('one','two');
    INSERT INTO t1(a,b) SELECT a, b FROM t1;
    UPDATE t1 SET spacer = CASE WHEN rowid&1 THEN 'x' ELSE 'xx' END;
    SELECT count(*) FROM t1;
  }
} 66
do_test utf16align-1.1 {
  set unaligned_string_counter
} 0

# Creating an index that uses the unaligned collation.  We should see
# some unaligned strings passed to the collating function.
#
do_test utf16align-1.2 {
  execsql {
    CREATE INDEX t1i1 ON t1(spacer, b);
  }
  # puts $unaligned_string_counter
  expr {$unaligned_string_counter>0}
} 1

# Create another index that uses the aligned collation.  This time
# there should be no unaligned accesses
#
do_test utf16align-1.3 {
  set unaligned_string_counter 0
  execsql {
    CREATE INDEX t1i2 ON t1(spacer, a);
  }
  expr {$unaligned_string_counter>0}
} 0
integrity_check utf16align-1.4

finish_test