/****************************************************************************
** $Id$
**
** Localization database support.
**
** Created : 980906
**
** Copyright (C) 1998-2000 Trolltech AS.  All rights reserved.
**
** This file is part of the kernel module of the Qt GUI Toolkit.
**
** This file may be distributed under the terms of the Q Public License
** as defined by Trolltech AS of Norway and appearing in the file
** LICENSE.QPL included in the packaging of this file.
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.
**
** Licensees holding valid Qt Enterprise Edition or Qt Professional Edition
** licenses may use this file in accordance with the Qt Commercial License
** Agreement provided with the Software.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
** See http://www.trolltech.com/pricing.html or email sales@trolltech.com for
**   information about Qt Commercial License Agreements.
** See http://www.trolltech.com/qpl/ for QPL licensing information.
** See http://www.trolltech.com/gpl/ for GPL licensing information.
**
** Contact info@trolltech.com if any conditions of this licensing are
** not clear to you.
**
**********************************************************************/

// needed for bsearch (at least for Borland)
#include "qplatformdefs.h"

#include "qtranslator.h"

#ifndef QT_NO_TRANSLATION

#include "qfileinfo.h"

#if defined(Q_OS_UNIX)
#define QT_USE_MMAP
#endif

#if defined(QT_USE_MMAP)

// for mmap
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <errno.h>

// for htonl
#include <netinet/in.h>

// for close
#include <unistd.h>

#else
// appropriate stuff here
#endif

// for qsort
#include <stdlib.h>

// other qt stuff necessary for the implementation
#include "qintdict.h"
#include "qstring.h"
#include "qapplication.h"
#include "qfile.h"
#include "qbuffer.h"
#include "qdatastream.h"
#include "qmap.h"
#include "qtl.h"

/*
$ mcookie
3cb86418caef9c95cd211cbf60a1bddd
$
*/

static const int magic_length = 16;
static const uchar magic[magic_length] = { // magic number for the file
    0x3c, 0xb8, 0x64, 0x18, 0xca, 0xef, 0x9c, 0x95,
    0xcd, 0x21, 0x1c, 0xbf, 0x60, 0xa1, 0xbd, 0xdd
};

static bool match( const char* found, const char* target )
{
    /*
      Here arises the subtle distinction between a null string (means
      "any") and an empty string (means empty).
    */
    return found == 0 || qstrcmp(found, target) == 0;
}

#if defined(Q_C_CALLBACKS)
extern "C" {
#endif

/*
  Yes, unfortunately, we have code here that depends on endianness.  The
  candidate is big endian (it comes from a .qm file) whereas the target
  endianness depends on the system Qt is running on.
*/
#ifdef Q_OS_TEMP
static int __cdecl cmp_uint32_little( const void* target, const void* candidate )
#else
static int cmp_uint32_little( const void* target, const void* candidate )
#endif
{
    const uchar* t = (const uchar*) target;
    const uchar* c = (const uchar*) candidate;
    return t[3] != c[0] ? (int) t[3] - (int) c[0]
	   : t[2] != c[1] ? (int) t[2] - (int) c[1]
	   : t[1] != c[2] ? (int) t[1] - (int) c[2]
	   : (int) t[0] - (int) c[3];
}

#ifdef Q_OS_TEMP
static int __cdecl cmp_uint32_big( const void* target, const void* candidate )
#else
static int cmp_uint32_big( const void* target, const void* candidate )
#endif
{
    const uchar* t = (const uchar*) target;
    const uchar* c = (const uchar*) candidate;
    return t[0] != c[0] ? (int) t[0] - (int) c[0]
	   : t[1] != c[1] ? (int) t[1] - (int) c[1]
	   : t[2] != c[2] ? (int) t[2] - (int) c[2]
	   : (int) t[3] - (int) c[3];
}

#if defined(Q_C_CALLBACKS)
}
#endif

static int systemWordSize = 0;
static bool systemBigEndian;

static uint elfHash( const char * name )
{
    const uchar *k;
    uint h = 0;
    uint g;

    if ( name ) {
	k = (const uchar*)name;
	while ( *k ) {
	    h = (h << 4) + *k++;
	    if ( (g = (h & 0xf0000000)) != 0 )
		h ^= g >> 24;
	    h &= ~g;
	}
    }

    if ( !h )
	h = 1;

    return h;
}


class QTranslatorPrivate {
public:
    struct Offset {
	Offset() { h=0; o=0; }
	Offset( const QTranslatorMessage& m, int offset )
	{ h = m.hash(); o = offset; } // ### qChecksum

	bool operator<( const Offset&k ) const { return ( h != k.h )
							     ? h < k.h
							     : o < k.o; }

	uint h;
	uint o;
    };

    enum { Contexts = 0x2f, Hashes = 0x42, Messages = 0x69 } Tag;

    QTranslatorPrivate() :
	unmapPointer( 0 ), unmapLength( 0 ),
	messageArray( 0 ), offsetArray( 0 ), contextArray( 0 )
#ifndef QT_NO_TRANSLATION_BUILDER
	,messages( 0 )
#endif
    { }
    // QTranslator must finalize this before deallocating it.

    // for mmap'ed files, this is what needs to be unmapped.
    char * unmapPointer;
    unsigned int unmapLength;


    // for squeezed but non-file data, this is what needs to be deleted
    QByteArray * messageArray;
    QByteArray * offsetArray;
    QByteArray * contextArray;

#ifndef QT_NO_TRANSLATION_BUILDER
    QMap<QTranslatorMessage, void *> * messages;
#endif
};


/*! \class QTranslator

  \brief The QTranslator class provides internationalization support for text
  output.

  \ingroup i18n
  \ingroup environment
  \mainclass

  An object of this class contains a set of QTranslatorMessage
  objects, each of which specifies a translation from a source
  language to a target language.  QTranslator provides functions to
  look up such translations, add new ones, remove them, load and save them,
  etc.

  The most common use of QTranslator is expected to be loading a
  translator file made using \link linguist-manual.book Qt
  Linguist\endlink, installing it using
  QApplication::installTranslator(), and using it via QObject::tr(),
  like this:

  \code
  int main( int argc, char ** argv )
  {
      QApplication app( argc, argv );

      QTranslator translator( 0 );
      translator.load( "french.qm", "." );
      app.installTranslator( &translator );

      MyWidget m;
      app.setMainWidget( &m );
      m.show();

      return app.exec();
  }
  \endcode

  Most applications will never need to do anything else with this
  class.  However, applications that work on translator files need the
  other functions in this class.

  It is possible to do lookup using findMessage() (as tr() and
  QApplication::translate() do) and contains(), insert a new
  translation message using insert(), and remove it using remove().

  Because end-user programs and translation tools have rather different
  requirements, QTranslator can use stripped translator files in a way
  that uses a minimum of memory and provides very little functionality
  other than findMessage().

  Thus, load() may not load enough information to make anything more
  than findMessage() work.  save() has an argument indicating whether
  to save just this minimum of information or to save everything.

  "Everything" means that for each translation item the following
  information is kept:

  \list
   \i The \e {translated text} - the return value from tr().
   \i The input key:
    \list
     \i The \e {source text} - usually the argument to tr().
     \i The \e context - usually the class name for the tr() caller.
     \i The \e comment - a comment that helps disambiguate different uses
	of the same text in the same context.
    \endlist
  \endlist

  The minimum for each item is just the information necessary for
  findMessage() to return the right text.  This may include the source,
  context and comment, but usually it is just a hash value and the
  translated text.

  For example, the "Cancel" in a dialog might have "Anuluj" when the
  program runs in Polish (in this case the source text would be
  "Cancel"). The context would (normally) be the dialog's class name;
  there would normally be no comment, and the translated text would be
  "Anuluj".

  But it's not always so simple. The Spanish version of a printer
  dialog with settings for two-sided printing and binding would
  probably require both "Activado" and "Activada" as translations for
  "Enabled".  In this case the source text would be "Enabled" in both
  cases and the context would be the dialog's class name, but the two
  items would have disambiguating comments such as "two-sided
  printing" for one and "binding" for the other.  The comment enables
  the translator to choose the appropriate gender for the Spanish
  version, and enables Qt to distinguish between translations.

  Note that when QTranslator loads a stripped file, most functions do
  not work.  The functions that do work with stripped files are
  explicitly documented as such.

  \sa QTranslatorMessage QApplication::installTranslator()
  QApplication::removeTranslator() QObject::tr() QApplication::translate()
*/

/*! \enum QTranslator::SaveMode
  This enum type defines how QTranslator can write translation files.
  There are two modes:

  \value Everything  files are saved with all contents
  \value Stripped  files are saved with just what's needed for end-users

  Note that when QTranslator loads a stripped file, most functions do
  not work.  The functions that do work with stripped files are
  explicitly documented as such.
*/

/*!
    Constructs an empty message file object that is not connected to
    any file. The object has parent \a parent and name \a name.
*/

QTranslator::QTranslator( QObject * parent, const char * name )
    : QObject( parent, name )
{
    d = new QTranslatorPrivate;
}


/*!  Destroys the object and frees any allocated resources.
*/

QTranslator::~QTranslator()
{
    if ( qApp )
	qApp->removeTranslator( this );
    clear();
    delete d;
}


extern bool qt_detectRTLLanguage();

/*!  Loads \a filename, which may be an absolute file name or relative
  to \a directory.  The previous contents of this translator object is
  discarded.

  If the full file name does not exist, other file names
  are tried in the following order:

  \list 1
   \i File name with \a suffix appended (".qm" if the suffix is QString::null).
   \i File name with text after a character in \a search_delimiters stripped
      ("_." is the default for \a search_delimiters if it is QString::null).
   \i File name stripped and \a suffix appended.
   \i File name stripped further, etc.
  \endlist

  For example, an application running in the fr_CA locale
  (French-speaking Canada) might call load("foo.fr_ca", "/opt/foolib"),
  which would then try to open these files:

  \list 1
   \i /opt/foolib/foo.fr_ca
   \i /opt/foolib/foo.fr_ca.qm
   \i /opt/foolib/foo.fr
   \i /opt/foolib/foo.fr.qm
   \i /opt/foolib/foo
   \i /opt/foolib/foo.qm
  \endlist

  \sa save()
*/

bool QTranslator::load( const QString & filename, const QString & directory,
			const QString & search_delimiters,
			const QString & suffix )
{
    clear();

    QString prefix;

    if ( filename[0] == '/'
#ifdef Q_WS_WIN
	 || (filename[0] && filename[1] == ':') || filename[0] == '\\'
#endif
	 )
	prefix = QString::fromLatin1( "" );
    else
	prefix = directory;

    if ( prefix.length() ) {
	if ( prefix[int(prefix.length()-1)] != '/' )
	    prefix += QChar( '/' );
    }

    QString fname = filename;
    QString realname;
    QString delims;
    delims = search_delimiters.isNull() ?
	     QString::fromLatin1( "_." ) : search_delimiters;

    for ( ;; ) {
	QFileInfo fi;

	realname = prefix + fname;
	fi.setFile( realname );
	if ( fi.isReadable() )
	    break;

	realname += suffix.isNull() ? QString::fromLatin1( ".qm" ) : suffix;
	fi.setFile( realname );
	if ( fi.isReadable() )
	    break;

	int rightmost = 0;
	for ( int i = 0; i < (int)delims.length(); i++ ) {
	    int k = fname.findRev( delims[i] );
	    if ( k > rightmost )
		rightmost = k;
	}

	// no truncations? fail
	if ( rightmost == 0 )
	    return FALSE;

	fname.truncate( rightmost );
    }

    // realname is now the fully qualified name of a readable file.

#if defined(QT_USE_MMAP)
    // unix (if mmap supported)

#ifndef MAP_FILE
#define MAP_FILE 0
#endif
#ifndef MAP_FAILED
#define MAP_FAILED -1
#endif

    //const char * lang = getenv( "LANG" );

    int f;

    f = ::open( QFile::encodeName(realname), O_RDONLY );
    if ( f < 0 ) {
	// qDebug( "can't open %s: %s", realname.ascii(), strerror( errno ) );
	return FALSE;
    }

    struct stat st;
    if ( fstat( f, &st ) ) {
	// qDebug( "can't stat %s: %s", realname.ascii(), strerror( errno ) );
	return FALSE;
    }
    char * tmp;
    tmp = (char*)mmap( 0, st.st_size, // any address, whole file
		       PROT_READ, // read-only memory
		       MAP_FILE | MAP_PRIVATE, // swap-backed map from file
		       f, 0 ); // from offset 0 of f
    if ( !tmp || tmp == (char*)MAP_FAILED ) {
	// qDebug( "can't mmap %s: %s", filename.ascii(), strerror( errno ) );
	// #### could revert to file io?
	return FALSE;
    }

    ::close( f );

    d->unmapPointer = tmp;
    d->unmapLength = st.st_size;
#else
    // windows, or unix without mmap
    QFile f(realname);
    if ( !f.exists() )
	return FALSE;
    d->unmapLength = f.size();
    d->unmapPointer = new char[d->unmapLength]; // ### really not
    bool ok = FALSE;
    if ( f.open(IO_ReadOnly) ) {
	ok = d->unmapLength ==
	     (uint)f.readBlock( d->unmapPointer, d->unmapLength );
	f.close();
    }
    if ( !ok ) {
	delete [] d->unmapPointer;
	d->unmapPointer = 0;
	return FALSE;
    }
#endif

    // now that we've read it and all, check that it has the right
    // magic number, and forget all about it if it doesn't.
    if ( memcmp( (const void *)(d->unmapPointer), magic, magic_length ) ) {
	clear();
	return FALSE;
    }
    // prepare to read.
    QByteArray tmpArray;
    tmpArray.setRawData( d->unmapPointer, d->unmapLength );
    QDataStream s( tmpArray, IO_ReadOnly );
    if ( !s.device()->at(magic_length) )
	return FALSE;

    // read.
    Q_UINT8 tag = 0;
    Q_UINT32 length = 0;
    s >> tag >> length;
    while ( tag && length ) {
	if ( tag == QTranslatorPrivate::Contexts && !d->contextArray ) {
	    d->contextArray = new QByteArray;
	    d->contextArray->setRawData( tmpArray.data()+s.device()->at(),
					 length );
	} else if ( tag == QTranslatorPrivate::Hashes && !d->offsetArray ) {
	    d->offsetArray = new QByteArray;
	    d->offsetArray->setRawData( tmpArray.data()+s.device()->at(),
					length );
	} else if ( tag == QTranslatorPrivate::Messages && !d->messageArray ) {
	    d->messageArray = new QByteArray;
	    d->messageArray->setRawData( tmpArray.data()+s.device()->at(),
					 length );
	}
	if ( !s.device()->at(s.device()->at() + length) )
	    return FALSE;
	tag = 0;
	length = 0;
	if ( !s.atEnd() )
	    s >> tag >> length;
    }

    tmpArray.resetRawData( d->unmapPointer, d->unmapLength );
    QApplication::setReverseLayout( qt_detectRTLLanguage() );
    return TRUE;
}

#ifndef QT_NO_TRANSLATION_BUILDER

/*!  Saves this message file to \a filename, overwriting the previous
  contents of \a filename.  If \a mode is \c Everything (the
  default), all the information is preserved.  If \a mode is \c Stripped,
  any information that is not necessary for findMessage() is stripped
  away.

  \sa load()
*/

bool QTranslator::save( const QString & filename, SaveMode mode )
{
    QFile f( filename );
    if ( f.open( IO_WriteOnly ) ) {
	squeeze( mode );

	QDataStream s( &f );
	s.writeRawBytes( (const char *)magic, magic_length );
	Q_UINT8 tag;

	if ( d->offsetArray != 0 ) {
	    tag = (Q_UINT8) QTranslatorPrivate::Hashes;
	    Q_UINT32 oas = (Q_UINT32) d->offsetArray->size();
	    s << tag << oas;
	    s.writeRawBytes( d->offsetArray->data(), oas );
	}
	if ( d->messageArray != 0 ) {
	    tag = (Q_UINT8) QTranslatorPrivate::Messages;
	    Q_UINT32 mas = (Q_UINT32) d->messageArray->size();
	    s << tag << mas;
	    s.writeRawBytes( d->messageArray->data(), mas );
	}
	if ( d->contextArray != 0 ) {
	    tag = (Q_UINT8) QTranslatorPrivate::Contexts;
	    Q_UINT32 cas = (Q_UINT32) d->contextArray->size();
	    s << tag << cas;
	    s.writeRawBytes( d->contextArray->data(), cas );
	}
	return TRUE;
    }
    return FALSE;
}

#endif

/*!  Empties this translator of all contents.

  This function works with stripped translator files.
*/

void QTranslator::clear()
{
    bool wasUsed = d->unmapPointer || 
		   d->unmapLength || 
		   d->messageArray || 
		   d->offsetArray || 
		   d->contextArray;

    if ( d->unmapPointer && d->unmapLength ) {
#if defined(QT_USE_MMAP)
	munmap( d->unmapPointer, d->unmapLength );
#else
	delete [] d->unmapPointer;
#endif
	d->unmapPointer = 0;
	d->unmapLength = 0;
	if ( d->messageArray )
	    d->messageArray->resetRawData( d->messageArray->data(),
					   d->messageArray->size() );
	if ( d->offsetArray )
	    d->offsetArray->resetRawData( d->offsetArray->data(),
					  d->offsetArray->size() );
	if ( d->contextArray )
	    d->contextArray->resetRawData( d->contextArray->data(),
					   d->contextArray->size() );
    }
    delete d->messageArray;
    d->messageArray = 0;
    delete d->offsetArray;
    d->offsetArray = 0;
    delete d->contextArray;
    d->contextArray = 0;
#ifndef QT_NO_TRANSLATION_BUILDER
    delete d->messages;
    d->messages = 0;
#endif

    if ( wasUsed )
	QApplication::setReverseLayout( qt_detectRTLLanguage() );
}

#ifndef QT_NO_TRANSLATION_BUILDER

/*! Converts this message file to the compact format used to store
  message files on disk.

  You should never need to call this directly; save() and other functions call
  it as necessary. \a mode is for internal use.

  \sa save() unsqueeze()
*/

void QTranslator::squeeze( SaveMode mode )
{
    if ( !d->messages ) {
	if ( mode == Stripped )
	    unsqueeze();
	else
	    return;
    }

    QMap<QTranslatorMessage, void *> * messages = d->messages;

    d->messages = 0;
    clear();

    d->messageArray = new QByteArray;
    d->offsetArray = new QByteArray;

    QMap<QTranslatorPrivate::Offset, void *> offsets;

    QDataStream ms( *d->messageArray, IO_WriteOnly );
    QMap<QTranslatorMessage, void *>::Iterator it = messages->begin(), next;
    int cpPrev = 0, cpNext = 0;
    for ( it = messages->begin(); it != messages->end(); ++it ) {
	cpPrev = cpNext;
	next = it;
	++next;
	if ( next == messages->end() )
	    cpNext = 0;
	else
	    cpNext = (int) it.key().commonPrefix( next.key() );
	offsets.replace( QTranslatorPrivate::Offset(it.key(),
			 ms.device()->at()), (void*)0 );
	it.key().write( ms, mode == Stripped,
			(QTranslatorMessage::Prefix) QMAX(cpPrev, cpNext + 1) );
    }

    d->offsetArray->resize( 0 );
    QMap<QTranslatorPrivate::Offset, void *>::Iterator offset;
    offset = offsets.begin();
    QDataStream ds( *d->offsetArray, IO_WriteOnly );
    while ( offset != offsets.end() ) {
	QTranslatorPrivate::Offset k = offset.key();
	++offset;
	ds << (Q_UINT32)k.h << (Q_UINT32)k.o;
    }

    if ( mode == Stripped ) {
	QAsciiDict<int> contextSet( 1511 );
	int baudelaire;

	for ( it = messages->begin(); it != messages->end(); ++it )
	    contextSet.replace( it.key().context(), &baudelaire );

	Q_UINT16 hTableSize;
	if ( contextSet.count() < 200 )
	    hTableSize = ( contextSet.count() < 60 ) ? 151 : 503;
	else if ( contextSet.count() < 2500 )
	    hTableSize = ( contextSet.count() < 750 ) ? 1511 : 5003;
	else
	    hTableSize = 15013;

	QIntDict<char> hDict( hTableSize );
	QAsciiDictIterator<int> c = contextSet;
	while ( c.current() != 0 ) {
	    hDict.insert( (long) (elfHash(c.currentKey()) % hTableSize),
			  c.currentKey() );
	    ++c;
	}

	/*
	  The contexts found in this translator are stored in a hash table to
	  provide fast look-up.  The context array has the following format:

	      Q_UINT16 hTableSize;
	      Q_UINT16 hTable[hTableSize];
	      Q_UINT8  contextPool[...];

	  The context pool stores the contexts as Pascal strings:

	      Q_UINT8  len;
	      Q_UINT8  data[len];

	  Let's consider the look-up of context "FunnyDialog".  A hash value
	  between 0 and hTableSize - 1 is computed, say h.  If hTable[h] is 0,
	  "FunnyDialog" is not covered by this translator.  Else, we check in
	  the contextPool at offset 2 * hTable[h] to see if "FunnyDialog" is one
	  of the contexts stored there, until we find it or we meet the empty
	  string.
	*/
	d->contextArray = new QByteArray;
	d->contextArray->resize( 2 + (hTableSize << 1) );
	QDataStream t( *d->contextArray, IO_WriteOnly );
	Q_UINT16 *hTable = new Q_UINT16[hTableSize];
	memset( hTable, 0, hTableSize * sizeof(Q_UINT16) );

	t << hTableSize;
	t.device()->at( 2 + (hTableSize << 1) );
	t << (Q_UINT16) 0; // the entry at offset 0 cannot be used
	uint upto = 2;

	for ( int i = 0; i < hTableSize; i++ ) {
	    const char *con = hDict.find( i );
	    if ( con == 0 ) {
		hTable[i] = 0;
	    } else {
		hTable[i] = (Q_UINT16) ( upto >> 1 );
		do {
		    uint len = (uint) qstrlen( con );
		    len = QMIN( len, 255 );
		    t << (Q_UINT8) len;
		    t.writeRawBytes( con, len );
		    upto += 1 + len;
		    hDict.remove( i );
		} while ( (con = hDict.find(i)) != 0 );
		do {
		    t << (Q_UINT8) 0; // empty string (at least one)
		    upto++;
		} while ( (upto & 0x1) != 0 ); // offsets have to be even
	    }
	}
	t.device()->at( 2 );
	for ( int j = 0; j < hTableSize; j++ )
	    t << hTable[j];
	delete [] hTable;

	if ( upto > 131072 ) {
	    qWarning( "QTranslator::squeeze: Too many contexts" );
	    delete d->contextArray;
	    d->contextArray = 0;
	}
    }
    delete messages;
}


/*!  Converts this message file into an easily modifiable data structure, less
  compact than the format used in the files.

  You should never need to call this function; it is called by insert() and
  friends as necessary.

  \sa squeeze()
*/

void QTranslator::unsqueeze()
{
    if ( d->messages )
	return;

    d->messages = new QMap<QTranslatorMessage, void *>;
    if ( !d->messageArray )
	return;

    QDataStream s( *d->messageArray, IO_ReadOnly );
    for ( ;; ) {
	QTranslatorMessage m( s );
	if ( m.hash() == 0 )
	    break;
	d->messages->insert( m, (void *) 0 );
    }
}


/*!  Returns TRUE if this message file contains a message with the key
  (\a context, \a sourceText, \a comment); otherwise returns FALSE.

  This function works with stripped translator files.

  (This is is a one-liner that calls find().)
*/

bool QTranslator::contains( const char* context, const char* sourceText,
			    const char* comment ) const
{
    return findMessage( context, sourceText, comment ).translation() != QString::null;
}


/*!  Inserts \a message into this message file.

  This function does \e not work with stripped translator files.  It
  may seem to, but that is not dependable.

  \sa remove()
*/

void QTranslator::insert( const QTranslatorMessage& message )
{
    unsqueeze();
    d->messages->remove( message ); // safer
    d->messages->insert( message, (void *) 0 );
}


/*!
  \fn void QTranslator::insert( const char *, const char *, const QString & )
  \overload
  \obsolete
*/

/*!  Removes \a message from this translator.

  This function works with stripped translator files.

  \sa insert()
*/

void QTranslator::remove( const QTranslatorMessage& message )
{
    unsqueeze();
    d->messages->remove( message );
}


/*!
  \fn void QTranslator::remove( const char *, const char * )
  \overload
  \obsolete

  Removes the translation associated to the key (\a context, \a sourceText,
  "") from this translator.
*/
#endif

/*!
  \fn QString QTranslator::find( const char*, const char*, const char* ) const
  \obsolete

  Please use findMessage() instead.

  Returns the translation for the key (\a context, \a sourceText,
  \a comment) or QString::null if there is none in this translator.
*/

/*!  Returns the QTranslatorMessage for the key
  (\a context, \a sourceText, \a comment).
*/

QTranslatorMessage QTranslator::findMessage( const char* context,
					     const char* sourceText,
					     const char* comment ) const
{
    if ( context == 0 )
	context = "";
    if ( sourceText == 0 )
	sourceText = "";
    if ( comment == 0 )
	comment = "";

#ifndef QT_NO_TRANSLATION_BUILDER
    if ( d->messages ) {
	QMap<QTranslatorMessage, void *>::ConstIterator it
	    = d->messages->find( QTranslatorMessage(context, sourceText,
				 comment) );
	if ( it == d->messages->end() )
	    return QTranslatorMessage();
	return it.key();
    }
#endif

    if ( !d->offsetArray )
	return QTranslatorMessage();

    /*
      Check if the context belongs to this QTranslator.  If many translators are
      installed, this step is necessary.
    */
    if ( d->contextArray ) {
	Q_UINT16 hTableSize = 0;
	QDataStream t( *d->contextArray, IO_ReadOnly );
	t >> hTableSize;
	uint g = elfHash( context ) % hTableSize;
	t.device()->at( 2 + (g << 1) );
	Q_UINT16 off;
	t >> off;
	if ( off == 0 )
	    return QTranslatorMessage();
	t.device()->at( 2 + (hTableSize << 1) + (off << 1) );

	Q_UINT8 len;
	char con[256];
	for ( ;; ) {
	    t >> len;
	    if ( len == 0 )
		return QTranslatorMessage();
	    t.readRawBytes( con, len );
	    con[len] = '\0';
	    if ( qstrcmp(con, context) == 0 )
		break;
	}
    }

    Q_UINT32 h = elfHash( QCString(sourceText) + comment );

    Q_UINT32 rh;
    Q_UINT32 ro;

    size_t numItems = d->offsetArray->size() / ( 2 * sizeof(Q_UINT32) );
    if ( !numItems )
	return QTranslatorMessage();

    if ( systemWordSize == 0 )
	qSysInfo( &systemWordSize, &systemBigEndian );
    char *r = (char *) bsearch( &h, d->offsetArray->data(), numItems,
				2 * sizeof(Q_UINT32),
				systemBigEndian ? cmp_uint32_big
				: cmp_uint32_little );
    if ( r == 0 )
	return QTranslatorMessage();

    // go back on equal key
    while ( r != d->offsetArray->data() && cmp_uint32_big(r - 8, r) == 0 )
	r -= 8;

    QDataStream s( *d->offsetArray, IO_ReadOnly );
    s.device()->at( r - d->offsetArray->data() );

    s >> rh >> ro;

    QDataStream ms( *d->messageArray, IO_ReadOnly );
    while ( rh == h ) {
	ms.device()->at( ro );
	QTranslatorMessage m( ms );
	if ( match(m.context(), context)
		&& match(m.sourceText(), sourceText)
		&& match(m.comment(), comment) )
	    return m;
	if ( s.atEnd() )
	    return QTranslatorMessage();
	s >> rh >> ro;
    }

    return QTranslatorMessage();
}

#ifndef QT_NO_TRANSLATION_BUILDER

/*!  Returns a list of the messages in the translator.  This function is
  rather slow; because it is seldom called, it's optimized for simplicity and
  small size, not speed.

  Note that if you want to iterate over the list, you should
  iterate over a copy, e.g.
    \code
    QValueList<QTranslatorMessage> list = myTranslator.messages();
    QValueList<QTranslatorMessage>::Iterator it = list.begin();
    while( it != list.end() ) {
	myProcessing( *it );
	++it;
    }
    \endcode
*/

QValueList<QTranslatorMessage> QTranslator::messages() const
{
    ((QTranslator *) this)->unsqueeze();
    QValueList<QTranslatorMessage> result;
    QMap<QTranslatorMessage, void *>::ConstIterator it;
    for ( it = d->messages->begin(); it != d->messages->end(); ++it )
	result.append( it.key() );
    return result;
}

#endif

/*! \class QTranslatorMessage qtranslator.h

  \preliminary

  \brief The QTranslatorMessage class contains a translator message and its
  properties.

  \ingroup i18n
  \ingroup environment

  This class is of no interest to most applications, just for
  translation tools such as
  \link linguist-manual.book Qt Linguist\endlink. It is
  provided simply to make the API complete and regular.

  For a QTranslator object, a lookup key is a triple (\e context, \e
  {source text}, \e comment) that uniquely identifies a message.  An
  extended key is a quadruple (\e hash, \e context, \e {source
  text}, \e comment), where \e hash is computed from the source text
  and the comment.  Unless you plan to read and write messages
  yourself, you need not worry about the hash value.

  QTranslatorMessage stores this triple or quadruple and the relevant
  translation if there is any.

  \sa QTranslator
*/

/*!  Constructs a translator message with the extended key (0, 0, 0, 0) and
  QString::null as translation.
*/

QTranslatorMessage::QTranslatorMessage()
    : h( 0 ), cx( 0 ), st( 0 ), cm( 0 )
{
}


/*!  Constructs an translator message with the extended key
  (\e h, \a context, \a sourceText, \a comment), where \e h is computed from
  \a sourceText and \a comment, and possibly with a \a translation.
*/

QTranslatorMessage::QTranslatorMessage( const char * context,
					const char * sourceText,
					const char * comment,
					const QString& translation )
    : cx( context ), st( sourceText ), cm( comment ), tn( translation )
{
    /*
      0 means we don't know, "" means we know it's empty.
    */
    if ( cx == (const char*)0 )
	cx = "";
    if ( st == (const char*)0 )
	st = "";
    if ( cm == (const char*)0 )
	cm = "";
    h = elfHash( st + cm );
}


/*!  Constructs a translator message read from a \a stream.  The resulting
  message may have any combination of content.

  \sa QTranslator::save()
 */

QTranslatorMessage::QTranslatorMessage( QDataStream & stream )
    : cx( 0 ), st( 0 ), cm( 0 )
{
    QString str16;
    char tag;
    Q_UINT8 obs1;

    for ( ;; ) {
	tag = 0;
	if ( !stream.atEnd() )
	    stream.readRawBytes( &tag, 1 );
	switch( (Tag)tag ) {
	case Tag_End:
	    if ( h == 0 )
		h = elfHash( st + cm );
	    return;
	case Tag_SourceText16: // obsolete
	    stream >> str16;
	    st = str16.latin1();
	    break;
	case Tag_Translation:
	    stream >> tn;
	    break;
	case Tag_Context16: // obsolete
	    stream >> str16;
	    cx = str16.latin1();
	    break;
	case Tag_Hash:
	    stream >> h;
	    break;
	case Tag_SourceText:
	    stream >> st;
	    break;
	case Tag_Context:
	    stream >> cx;
	    if ( cx == "" ) // for compatibility
		cx = 0;
	    break;
	case Tag_Comment:
	    stream >> cm;
	    break;
	case Tag_Obsolete1: // obsolete
	    stream >> obs1;
	    break;
	default:
	    h = 0;
	    st = 0;
	    cx = 0;
	    cm = 0;
	    tn = QString::null;
	    return;
	}
    }
}


/*!  Constructs a copy of translator message \a m.
*/

QTranslatorMessage::QTranslatorMessage( const QTranslatorMessage & m )
    : cx( m.cx ), st( m.st ), cm( m.cm ), tn( m.tn )
{
    h = m.h;
}


/*!  Assigns message \a m to this translator message and returns a
 reference to this translator message.
*/

QTranslatorMessage & QTranslatorMessage::operator=(
	const QTranslatorMessage & m )
{
    h = m.h;
    cx = m.cx;
    st = m.st;
    cm = m.cm;
    tn = m.tn;
    return *this;
}


/*! \fn uint QTranslatorMessage::hash() const

  Returns the hash value used internally to represent the lookup key.  This
  value is zero only if this translator message was constructed from a stream
  containing invalid data.

  The hashing function is unspecified, but it will remain unchanged in future
  versions of Qt.
*/

/*! \fn const char *QTranslatorMessage::context() const

  Returns the context for this message (e.g. "MyDialog").
*/

/*! \fn const char *QTranslatorMessage::sourceText() const

  Returns the source text of this message (e.g. "&Save").
*/

/*! \fn const char *QTranslatorMessage::comment() const

  Returns the comment for this message (e.g. "File|Save").
*/

/*! \fn void QTranslatorMessage::setTranslation( const QString & translation )

  Sets the translation of the source text to \a translation.

  \sa translation()
*/

/*! \fn QString QTranslatorMessage::translation() const

  Returns the translation of the source text (e.g., "&Sauvegarder").

  \sa setTranslation()
*/

/*! \enum QTranslatorMessage::Prefix

  Let (\e h, \e c, \e s, \e m) be the extended key.  The possible prefixes are

  \value NoPrefix  no prefix
  \value Hash  only (\e h)
  \value HashContext  only (\e h, \e c)
  \value HashContextSourceText  only (\e h, \e c, \e s)
  \value HashContextSourceTextComment  the whole extended key, (\e h, \e c,
       \e s, \e m)

  \sa write() commonPrefix()
*/

/*!
    Writes this translator message to the \a stream.  If \a strip is
    FALSE (the default), all the information in the message is
    written.  If \a strip is TRUE, only the part of the extended key
    specified by \a prefix is written with the translation (\c
    HashContextSourceTextComment by default).

  \sa commonPrefix()
*/

void QTranslatorMessage::write( QDataStream & stream, bool strip,
				Prefix prefix ) const
{
    char tag;

    tag = (char)Tag_Translation;
    stream.writeRawBytes( &tag, 1 );
    stream << tn;

    bool mustWriteHash = TRUE;
    if ( !strip )
	prefix = HashContextSourceTextComment;

    switch ( prefix ) {
    case HashContextSourceTextComment:
	tag = (char)Tag_Comment;
	stream.writeRawBytes( &tag, 1 );
	stream << cm;
	// fall through
    case HashContextSourceText:
	tag = (char)Tag_SourceText;
	stream.writeRawBytes( &tag, 1 );
	stream << st;
	// fall through
    case HashContext:
	tag = (char)Tag_Context;
	stream.writeRawBytes( &tag, 1 );
	stream << cx;
	// fall through
    default:
	if ( mustWriteHash ) {
	    tag = (char)Tag_Hash;
	    stream.writeRawBytes( &tag, 1 );
	    stream << h;
	}
    }

    tag = (char)Tag_End;
    stream.writeRawBytes( &tag, 1 );
}


/*!  Returns the widest lookup prefix that is common to this translator message
  and message \a m.

  For example, if the extended key is for this message is (42, "PrintDialog",
  "Yes", "Print?") and that for \a m is (42, "PrintDialog", "No", "Print?"),
  this function returns \c HashContext.

  \sa write()
*/

QTranslatorMessage::Prefix QTranslatorMessage::commonPrefix(
	const QTranslatorMessage& m ) const
{
    if ( h != m.h )
	return NoPrefix;
    if ( cx != m.cx )
	return Hash;
    if ( st != m.st )
	return HashContext;
    if ( cm != m.cm )
	return HashContextSourceText;
    return HashContextSourceTextComment;
}


/*!  Returns TRUE if the extended key of this object is equal to that of \a m;
  otherwise returns FALSE.
*/

bool QTranslatorMessage::operator==( const QTranslatorMessage& m ) const
{
    return h == m.h && cx == m.cx && st == m.st && cm == m.cm;
}


/*! \fn bool QTranslatorMessage::operator!=( const QTranslatorMessage& m ) const

  Returns TRUE if the extended key of this object is different from that of
  \a m; otherwise returns FALSE.
*/


/*!  Returns TRUE if the extended key of this object is lexicographically before
  than that of \a m; otherwise returns FALSE.
*/

bool QTranslatorMessage::operator<( const QTranslatorMessage& m ) const
{
    return h != m.h ? h < m.h
	   : ( cx != m.cx ? cx < m.cx
	     : (st != m.st ? st < m.st : cm < m.cm) );
}


/*! \fn bool QTranslatorMessage::operator<=( const QTranslatorMessage& m ) const

  Returns TRUE if the extended key of this object is lexicographically before
  that of \a m or if they are equal; otherwise returns FALSE.
*/

/*! \fn bool QTranslatorMessage::operator>( const QTranslatorMessage& m ) const

  Returns TRUE if the extended key of this object is lexicographically after
  that of \a m; otherwise returns FALSE.
*/

/*! \fn bool QTranslatorMessage::operator>=( const QTranslatorMessage& m ) const

  Returns TRUE if the extended key of this object is lexicographically after
  that of \a m or if they are equal; otherwise returns FALSE.
*/

#endif // QT_NO_TRANSLATION
