filespec.cpp

linux下的一款播放器

/* ***** BEGIN LICENSE BLOCK *****
 * Source last modified: $Id: filespec.cpp,v 1.1.1.1.50.4 2004/07/09 01:44:23 hubbe Exp $
 * 
 * Portions Copyright (c) 1995-2004 RealNetworks, Inc. All Rights Reserved.
 * 
 * The contents of this file, and the files included with this file,
 * are subject to the current version of the RealNetworks Public
 * Source License (the "RPSL") available at
 * http://www.helixcommunity.org/content/rpsl unless you have licensed
 * the file under the current version of the RealNetworks Community
 * Source License (the "RCSL") available at
 * http://www.helixcommunity.org/content/rcsl, in which case the RCSL
 * will apply. You may also obtain the license terms directly from
 * RealNetworks.  You may not use this file except in compliance with
 * the RPSL or, if you have a valid RCSL with RealNetworks applicable
 * to this file, the RCSL.  Please see the applicable RPSL or RCSL for
 * the rights, obligations and limitations governing use of the
 * contents of the file.
 * 
 * Alternatively, the contents of this file may be used under the
 * terms of the GNU General Public License Version 2 or later (the
 * "GPL") in which case the provisions of the GPL are applicable
 * instead of those above. If you wish to allow use of your version of
 * this file only under the terms of the GPL, and not to allow others
 * to use your version of this file under the terms of either the RPSL
 * or RCSL, indicate your decision by deleting the provisions above
 * and replace them with the notice and other provisions required by
 * the GPL. If you do not delete the provisions above, a recipient may
 * use your version of this file under the terms of any one of the
 * RPSL, the RCSL or the GPL.
 * 
 * This file is part of the Helix DNA Technology. RealNetworks is the
 * developer of the Original Code and owns the copyrights in the
 * portions it created.
 * 
 * This file, and the files included with this file, is distributed
 * and made available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY
 * KIND, EITHER EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS
 * ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET
 * ENJOYMENT OR NON-INFRINGEMENT.
 * 
 * Technology Compatibility Kit Test Suite(s) Location:
 *    http://www.helixcommunity.org/content/tck
 * 
 * Contributor(s):
 * 
 * ***** END LICENSE BLOCK ***** */

#include "hxstring.h"
#include "filespec.h"

#define MAX_PATH_COMPONENTS 256

//////////////////////////////////////////////////////////
//
// Utility base class -- CHXPathParser
//
//////////////////////////////////////////////////////////

CHXPathParser::CHXPathParser()
: m_bEmpty(TRUE)
, m_bIsValid(FALSE)
{
}

CHXPathParser &CHXPathParser::operator=(const CHXPathParser &other)
{
    if(!other.IsSet())
    {
	m_bEmpty = TRUE;
	m_path = "";
    }
    else
	ParsePath(other.m_path);

    return *this;
}

BOOL CHXPathParser::operator==(const CHXPathParser &other)
{
    // for now, just returns if the paths are identical
    // in the future, should normalize paths (i.e. remove duplicate slashes, resolve ..\..\.. type issues
    return m_path.CompareNoCase(other.m_path) == 0;
}

BOOL CHXPathParser::operator!=(const CHXPathParser &other)
{
    // for now, just returns if the paths are not identical
    // in the future, should normalize paths (i.e. remove duplicate slashes, resolve ..\..\.. type issues
    return !(*this == other);
}

CHXString CHXPathParser::GetPathName() const
{
    return m_path;
}

BOOL CHXPathParser::IsSet() const
{
    return !m_bEmpty;
}

void CHXPathParser::UnSet()
{
	m_path = "";
	m_bEmpty = TRUE;
}

void CHXPathParser::ParsePath(const char *psz)
{
    m_path = psz;

    int i, nStart, nLength;
    int nPathLength = m_path.GetLength();

    m_bIsValid = TRUE; // possibly set to false later in this method
    m_bCannotBeFile = FALSE;
    m_bAbsolute = TRUE;
    m_bEmpty = FALSE;

    m_nVolumeLength = 0;
    m_nParentLength = 0;
    m_nSeparatorLength = 0;
    m_nNameLength = 0;
    m_nExtensionSeparatorLength = 0;
    m_nExtensionLength = 0;

    if(psz == NULL || m_path.IsEmpty())
    {
	m_bIsValid = FALSE;
	m_bCannotBeFile = TRUE;
	m_bEmpty = TRUE;

	return;
    }

    // first, parse the local disk name, if present
    if(nPathLength >= 2 && m_path[1] == ':')
    {
	// local disk/volume
	m_nVolumeLength = 2;
	nStart = 2;
    }
    else
    {
	m_nVolumeLength = 0;
	nStart = 0;
    }

    // now, break the rest of the path up into components based on slashes
    // Here is an example of how the path will be broken up.  The carats point
    // to the start of each component.  The separator length will be the
    // number of slashes following the carat, and the name will be the remaining
    // characters in that component.
    //
    // \\hostname\bla\bla\bla\file.txt
    // ^         ^   ^   ^   ^ 
    //
    // In the case of a trailing slash:
    //
    // \bla\bla\
    // ^   ^   ^
    //

    int anStart[MAX_PATH_COMPONENTS];
    int anSeparatorLen[MAX_PATH_COMPONENTS];
    int anNameLen[MAX_PATH_COMPONENTS];
    int nNumComponents = 0;

    while(nStart < nPathLength && nNumComponents < MAX_PATH_COMPONENTS)
    {
	int nNumSep, nNameLen;

	// count the number of separators starting at position nStart
	for(nNumSep = 0; 
		nStart + nNumSep < nPathLength && 
			(m_path[nStart + nNumSep] == '\\' || 
			 m_path[nStart + nNumSep] == '/');
		nNumSep++);

	// count the number of non-separators starting at position nStart + nNumSep
	for(nNameLen = 0; 
		nStart + nNumSep + nNameLen < nPathLength && 
			(m_path[nStart + nNumSep + nNameLen] != '\\' &&
			 m_path[nStart + nNumSep + nNameLen] != '/');
		nNameLen++);

	anStart[nNumComponents] = nStart;
	anSeparatorLen[nNumComponents] = nNumSep;
	anNameLen[nNumComponents] = nNameLen;

	nNumComponents++;

	nStart += nNumSep + nNameLen;
    }

    // now we are ready to interpret the results
    if(nNumComponents == 0)
    {
	// no components at all.  If there was a volume, then this is a relative
	// path on the volume [and cannot be a file].  If there was no volume, then
	// this is invalid
	if(m_nVolumeLength > 0)
	{
	    m_bAbsolute = FALSE;
	    m_bCannotBeFile = TRUE;
	}
	else
	    m_bIsValid = FALSE;
    }
    else
    {
	// we will now start using nStart as the component number of the start of the actual path [excluding volume]

	nStart = 0;

	// here, we look for a possible \\hostname type of volume
	if(anSeparatorLen[0] > 1)
	{
	    if(m_nVolumeLength > 0)
	    {
		// this catches these invalid paths: C:\\\\temp, C:\\hostname\bla
		// the problem with the second one is that it has both a local and network volume
		// the problem with the first one is it has too many slashes to be an absolute path
		m_bIsValid = FALSE;

		// however, we continue parsing the path, as if this was ok
		nStart = 0;
	    }
	    else if(anSeparatorLen[0] > 2)
	    {
		// this catches these invalid paths: \\\\hostname\bla
		m_bIsValid = FALSE;

		// however, we continue parsing the path, as if this was ok,
		// and if it was not a hostname
		nStart = 0;
	    }
	    else
	    {
		// this catches these *valid* paths: \\hostname\bla
		m_nVolumeLength = anSeparatorLen[0] + anNameLen[0];
		nStart = 1;
	    }
	}


	// now that we have dealt with all possible volumes, nStart points to the first component in the
	// actual path.  There are still several possibilities:
	//
	// "" [i.e. no more components]
	// \
	// bla\
	// bla.txt
	// bla\bla.txt
	// \bla\
	// \bla.txt
	// \bla\bla.txt

	// these cannot be files: "", "bla\", "\bla\bla\"

	if(nNumComponents == nStart || anNameLen[nNumComponents - 1] == 0)
	    m_bCannotBeFile = TRUE;

	// these are not valid: "\\\\\file.txt",

	if(nNumComponents > nStart && anSeparatorLen[nStart] > 1)
	    m_bIsValid = FALSE;

	// these are absolute: "\bla\file.txt"
	// there is one special case: the full path "\\hostname" is absolute

	if((nNumComponents > nStart && anSeparatorLen[nStart] >= 1) || m_path[0] == '\\' || m_path[0] == '/')
	    m_bAbsolute = TRUE;
	else
	    m_bAbsolute = FALSE;

	if(nNumComponents == nStart + 1 && anNameLen[nStart] == 0)
	{
	    // the path is simply: "\"
	    m_nParentLength = anSeparatorLen[nStart];
	    nStart = nPathLength;
	    nLength = 0;
	}
	else if(nNumComponents > nStart)
	{
	    // remove the last component if it is just a slash
	    if(nNumComponents > nStart && anNameLen[nNumComponents-1] == 0)
		nNumComponents--;

	    if(nNumComponents == nStart + 1)
	    {
		// just one component
		m_nParentLength = anSeparatorLen[nStart];

		// back to using nStart as an index into the path.
		// note that we must set nLength first, since it
		// uses nStart as the index
		nLength = anNameLen[nStart];
		nStart = anStart[nStart] + anSeparatorLen[nStart];
	    }
	    else
	    {
		// more than one component
		m_nParentLength = anStart[nNumComponents - 1] - m_nVolumeLength;
		m_nSeparatorLength = anSeparatorLen[nNumComponents - 1];

		// back to using nStart as an index into the path
		nLength = anNameLen[nNumComponents - 1];
		nStart = anStart[nNumComponents - 1] + anSeparatorLen[nNumComponents - 1];
	    }
	}
	else
	{
	    // no more components
	    nStart = nPathLength;
	    nLength = 0;
	}

	// now, use nStart and nLength as the portion of the path to look at for the name
	// now we break it up into name, extension separator, and extension
	for(i = nStart + nLength - 1; i >= nStart; i--)
	    if(m_path[i] == '.')
		break;

	if(i < nStart)
	    m_nNameLength = nLength;
	else
	{
	    m_nNameLength = i - nStart;
	    m_nExtensionSeparatorLength = 1;
	    m_nExtensionLength = nStart + nLength - i - 1;
	}