1 files changed, 737 insertions, 0 deletions

diff --git a/src/unstable/myriadfs.cpp b/src/unstable/myriadfs.cpp
new file mode 100644
index 0000000..ab9ca74
--- /dev/null
+++ b/src/unstable/myriadfs.cpp
@@ -0,0 +1,737 @@
+/*
+ * Copyright (C) 2007-2023 Xagasoft, All rights reserved.
+ *
+ * This file is part of the libbu++ library and is released under the
+ * terms of the license contained in the file LICENSE.
+ */
+
+#include "bu/config.h"
+#include "bu/myriadfs.h"
+#include "bu/myriadstream.h"
+
+#include <string.h>
+#include <unistd.h>
+#include <time.h>
+
+#include "bu/sio.h"
+using Bu::sio;
+using Bu::Fmt;
+
+namespace Bu { subExceptionDef( MyriadFsException ) }
+
+#define Myriad_Fs_MAGIC_CODE        ((char *)"\xa7\x18\x8b\x39")
+
+Bu::MyriadFs::MyriadFs( Bu::Stream &rStore, int iBlockSize ) :
+    rStore( rStore ),
+    mStore( rStore, iBlockSize ),
+    iUser( 0 ),
+    iGroup( 0 )
+{
+#ifndef WIN32
+    iUser = getuid();
+    iGroup = getgid();
+#endif
+
+    if( mStore.exists( 1 ) )
+    {
+        // Check to see if this is a MyriadFs stream.
+        Bu::MyriadStream ms = mStore.open( 1, Bu::Myriad::Read );
+        char sMagic[4];
+        if( ms.read( sMagic, 4 ) < 4 )
+            throw MyriadFsException("The provided stream does not appear to be "
+                "a MyriadFs stream.");
+        if( ::strncmp( sMagic, Myriad_Fs_MAGIC_CODE, 4 ) )
+            throw MyriadFsException("The provided stream does not appear to be "
+                "a MyriadFs stream.");
+    
+        int8_t iVer;
+        ms.read( &iVer, 1 );
+
+        int32_t iNumNodes;
+        ms.read( &iNumNodes, 4 );
+        for( int32_t j = 0; j < iNumNodes; j++ )
+        {
+            int32_t iNode;
+            int32_t iPos;
+            ms.read( &iNode, 4 );
+            ms.read( &iPos, 4 );
+            hNodeIndex.insert( iNode, iPos );
+        }
+    }
+    else
+    {
+        // Create initial header stream
+        {
+            Bu::MyriadStream ms = mStore.open(
+                1, Bu::Myriad::WriteNew|Bu::Myriad::Exclusive );
+            ms.write( Myriad_Fs_MAGIC_CODE, 4 );
+            int8_t iVer = 1;
+            int32_t iTmp = 1;
+            ms.write( &iVer, 1 );
+            ms.write( &iTmp, 4 ); // iNumNodes
+            iTmp = 0;
+            ms.write( &iTmp, 4 ); // iInode
+            ms.write( &iTmp, 4 ); // iPosition
+            hNodeIndex.insert( 0, 0 );
+        }
+
+        // Create initial inode stream, with one root node.
+        {
+            Bu::MyriadStream ms = mStore.open(
+                2, Bu::Myriad::WriteNew|Bu::Myriad::Exclusive );
+            RawStat rs;
+            rs.iNode = 0;
+            rs.iUser = iUser;
+            rs.iGroup = iGroup;
+            rs.uPerms = 0755|typeDir;
+            rs.iLinks = 1;
+            rs.uStreamIndex = 3;
+            rs.iCTime = rs.iMTime = rs.iATime = time(NULL);
+            ms.write( &rs, sizeof(RawStat) );
+        }
+
+        // Create inode 0's storage stream.
+        {
+            Bu::MyriadStream ms = mStore.open(
+                3, Bu::Myriad::WriteNew|Bu::Myriad::Exclusive );
+            int32_t iTmp32 = 0;
+            ms.write( &iTmp32, 4 );     // iChildCount
+        }
+    }
+}
+
+Bu::MyriadFs::~MyriadFs()
+{
+    writeHeader();
+}
+
+void Bu::MyriadFs::stat( const Bu::String &sPath, Bu::MyriadFs::Stat &rBuf )
+{
+    int32_t iParent;
+    int32_t iNode = lookupInode( sPath, iParent );
+    Bu::MyriadStream is = mStore.open( 2, Bu::Myriad::Read );
+    stat( iNode, rBuf, is );
+}
+
+Bu::MyriadStream Bu::MyriadFs::open( const Bu::String &sPath, int iMode,
+        uint16_t uPerms )
+{
+    int32_t iParent = -1;
+    int32_t iNode;
+    try
+    {
+        iNode = lookupInode( sPath, iParent );
+//        sio << "File found." << sio.nl;
+        // The file was found
+        Bu::MyriadStream ms = openByInode( iNode );
+        if( (iMode&Truncate) ) 
+        {
+            ms.setSize( 0 );
+        }
+        return ms;
+    }
+    catch( Bu::MyriadFsException &e )
+    {
+        if( iParent < 0 )
+            throw;
+
+        // This means that an intermediate path component couldn't be found
+        if( e.getErrorCode() == 1 )
+            throw;
+
+        // The file wasn't found, but the path leading up to it was.
+        // first, figure out the final path element...
+        Bu::String sName = filePart( sPath );
+//        sio << "End filename: " << sName << sio.nl;
+//        sio << "Parent inode: " << iParent << sio.nl;
+        iNode = create( iParent, sName, (uPerms&permMask)|typeRegFile, 0 );
+//        sio << "New iNode: " << iNode << sio.nl;
+        return openByInode( iNode );
+    }
+}
+
+void Bu::MyriadFs::create( const Bu::String &sPath, uint16_t iPerms )
+{
+    create( sPath, iPerms, 0 );
+}
+
+void Bu::MyriadFs::create( const Bu::String &sPath, uint16_t iPerms,
+        uint16_t iDevHi, uint16_t iDevLo )
+{
+    create( sPath, iPerms, ((uint32_t)iDevHi<<16)|(uint32_t)iDevLo );
+}
+
+void Bu::MyriadFs::create( const Bu::String &sPath, uint16_t iPerms,
+        uint32_t uSpecial )
+{
+    int32_t iParent = -1;
+//    int32_t iNode;
+    try
+    {
+        /*iNode =*/ lookupInode( sPath, iParent );
+//        sio << "File found." << sio.nl;
+    }
+    catch( Bu::MyriadFsException &e )
+    {
+        if( iParent < 0 )
+            throw;
+
+        // This means that an intermediate path component couldn't be found
+        if( e.getErrorCode() == 1 )
+            throw;
+
+        // The file wasn't found, but the path leading up to it was.
+        // first, figure out the final path element...
+        Bu::String sName = filePart( sPath );
+//        sio << "End filename: " << sName << sio.nl;
+//        sio << "Parent inode: " << iParent << sio.nl;
+        /*iNode =*/ create( iParent, sName, iPerms, uSpecial );
+//        sio << "New iNode: " << iNode << sio.nl;
+    }
+    // The file was found
+    //throw Bu::MyriadFsException("Path already exists.");
+}
+
+void Bu::MyriadFs::mkDir( const Bu::String &sPath, uint16_t iPerms )
+{
+    create( sPath, (iPerms&permMask)|typeDir, 0 );
+}
+
+void Bu::MyriadFs::mkSymLink( const Bu::String &sTarget,
+        const Bu::String &sPath )
+{
+    int32_t iParent = -1;
+    int32_t iNode;
+    try
+    {
+        iNode = lookupInode( sPath, iParent );
+    }
+    catch( Bu::MyriadFsException &e )
+    {
+        if( iParent < 0 )
+            throw;
+
+        // This means that an intermediate path component couldn't be found
+        if( e.getErrorCode() == 1 )
+            throw;
+
+        // The file wasn't found, but the path leading up to it was.
+        // first, figure out the final path element...
+        Bu::String sName = filePart( sPath );
+//       sio << "End filename: " << sName << sio.nl;
+//        sio << "Parent inode: " << iParent << sio.nl;
+        iNode = create( iParent, sName, 0777|typeSymLink, 0 );
+//        sio << "New iNode: " << iNode << sio.nl;
+        MyriadStream ms = openByInode( iNode );
+        ms.write( sTarget );
+        return;
+    }
+    throw Bu::MyriadFsException("Path already exists.");
+}
+
+void Bu::MyriadFs::mkHardLink( const Bu::String &sTarget,
+        const Bu::String &sPath )
+{
+    int32_t iParent = -1;
+    int32_t iNode;
+    
+    iNode = lookupInode( sTarget, iParent );
+
+    try
+    {
+        lookupInode( sPath, iParent );
+        throw Bu::MyriadFsException("Path already exists.");
+    }
+    catch( Bu::MyriadFsException &e )
+    {
+        if( iParent < 0 )
+            throw;
+
+        // This means that an intermediate path component couldn't be found
+        if( e.getErrorCode() == 1 )
+            throw;
+
+        // The file wasn't found, but the path leading up to it was.
+        // first, figure out the final path element...
+        Bu::String sName = filePart( sPath );
+//        sio << "End filename: " << sName << sio.nl;
+//        sio << "Parent inode: " << iParent << sio.nl;
+        addToDir( iParent, iNode, sName );
+        MyriadStream is = mStore.open( 2, Bu::Myriad::ReadWrite );
+        RawStat rs;
+        readInode( iNode, rs, is );
+        rs.iLinks++;
+        writeInode( rs, is );
+    }
+}
+
+Bu::String Bu::MyriadFs::readSymLink( const Bu::String &sPath )
+{
+    int32_t iParent = -1;
+    int32_t iNode;
+    iNode = lookupInode( sPath, iParent );
+    MyriadStream ms = openByInode( iNode );
+    Bu::String sRet;
+    sRet.setSize( ms.getSize() );
+    ms.read( sRet.getStr(), ms.getSize() );
+    return sRet;
+}
+
+Bu::MyriadFs::Dir Bu::MyriadFs::readDir( const Bu::String &sPath )
+{
+    int32_t iParent = -1;
+    int32_t iNode = lookupInode( sPath, iParent );
+    return readDir( iNode );
+}
+
+void Bu::MyriadFs::setTimes( const Bu::String &sPath, int64_t iATime,
+        int64_t iMTime )
+{
+    int32_t iParent = -1;
+    int32_t iNode;
+
+    iNode = lookupInode( sPath, iParent );
+    
+    setTimes( iNode, iATime, iMTime );
+}
+
+void Bu::MyriadFs::unlink( const Bu::String &sPath )
+{
+    int32_t iParent = -1;
+//  int32_t iNode;
+
+    /*iNode =*/ lookupInode( sPath, iParent );
+
+    Dir lDir = readDir( iParent );
+
+    Bu::String sName = filePart( sPath );
+
+    for( Dir::iterator i = lDir.begin(); i; i++ )
+    {
+        if( sName == (*i).sName )
+        {
+            RawStat rs;
+            readInode( (*i).iNode, rs );
+            if( (rs.uPerms&typeMask) == typeDir )
+            {
+                MyriadStream msDir = mStore.open(
+                    rs.uStreamIndex, Bu::Myriad::Read
+                    );
+                int32_t iCount;
+                msDir.read( &iCount, 4 );
+                if( iCount > 0 )
+                {
+                    throw Bu::MyriadFsException("Directory not empty.");
+                }
+            }
+            if( --rs.iLinks == 0 )
+            {
+                destroyNode( (*i).iNode );
+            }
+            else
+            {
+                writeInode( rs );
+            }
+            lDir.erase( i );
+            break;
+        }
+    }
+    
+    Bu::MyriadStream ms = openByInode( iParent );
+    int32_t iNumChildren = lDir.getSize();
+    ms.write( &iNumChildren, 4 );
+    for( Dir::iterator i = lDir.begin(); i; i++ )
+    {
+        ms.write( &(*i).iNode, 4 );
+        uint8_t iSize = (*i).sName.getSize();
+        ms.write( &iSize, 1 );
+        ms.write( (*i).sName.getStr(), iSize );
+    }
+    ms.setSize( ms.tell() );
+}
+
+void Bu::MyriadFs::setFileSize( const Bu::String &sPath, int32_t iSize )
+{
+    int32_t iParent = -1;
+    int32_t iNode;
+    iNode = lookupInode( sPath, iParent );
+    MyriadStream ms = openByInode( iNode );
+    ms.setSize( iSize );
+}
+
+void Bu::MyriadFs::rename( const Bu::String &sFrom, const Bu::String &sTo )
+{
+    mkHardLink( sFrom, sTo );
+    unlink( sFrom );
+}
+
+dev_t Bu::MyriadFs::devToSys( uint32_t uDev )
+{
+    return (((uDev&0xFFFF0000)>>8)&0xFF00) | ((uDev&0xFF));
+}
+
+uint32_t Bu::MyriadFs::sysToDev( dev_t uDev )
+{
+    return (((uint32_t)uDev&0xFF00)<<8) | ((uint32_t)uDev&0xFF);
+}
+
+int32_t Bu::MyriadFs::lookupInode( const Bu::String &sPath, int32_t &iParent )
+{
+    if( sPath == "/" )
+    {
+        return 0;
+    }
+    if( sPath[0] == '/' )
+    {
+        // Absolute lookup
+        return lookupInode( sPath.begin()+1, 0, iParent );
+    }
+    else
+    {
+        // Relative lookup
+        throw Bu::ExceptionBase(
+            "Relative lookups in MyriadFs are not working yet.");
+    }
+}
+
+int32_t Bu::MyriadFs::lookupInode( Bu::String::const_iterator iStart,
+        int32_t iNode, int32_t &iParent )
+{
+    iParent = iNode;
+
+    Bu::String::const_iterator iEnd = iStart.find('/');
+    Bu::String sTok( iStart, iEnd );
+
+//  sio << "Direcotry component: " << sTok << sio.nl;
+
+    Dir lDir = readDir( iNode );
+
+    for( Dir::iterator i = lDir.begin(); i; i++ )
+    {
+        if( (*i).sName == sTok )
+        {
+            // We found an item
+            if( !iEnd )
+            {
+                // It's the last one in the requested path, return it
+                return (*i).iNode;
+            }
+            else
+            {
+                // Not the last one in our path, double check it's a dir
+                if( ((*i).uPerms&typeMask) == typeDir )
+                {
+                    return lookupInode( iEnd+1, (*i).iNode, iParent );
+                }
+                else
+                {
+                    iParent = -1;
+                    throw Bu::MyriadFsException(
+                        "Element '%s' in given path is not a directory.",
+                        sTok.getStr() );
+                }
+            }
+        }
+    }
+
+    if( iEnd )
+        throw Bu::MyriadFsException( 1, "Path not found");
+    else
+        throw Bu::MyriadFsException( 2, "Path not found");
+}
+
+void Bu::MyriadFs::readInode( int32_t iNode, RawStat &rs, MyriadStream &rIs )
+{
+    rIs.setPos( hNodeIndex.get( iNode )*sizeof(RawStat) );
+    if( rIs.read( &rs, sizeof(RawStat) ) < (int)sizeof(RawStat) )
+        throw Bu::MyriadFsException("Filesystem corruption detected.");
+    if( rs.iNode != iNode )
+        throw Bu::MyriadFsException("Filesystem corruption detected.");
+}
+
+void Bu::MyriadFs::readInode( int32_t iNode, RawStat &rs )
+{
+    MyriadStream ms = mStore.open( 2, Bu::Myriad::Read );
+    readInode( iNode, rs, ms );
+}
+
+void Bu::MyriadFs::writeInode( const RawStat &rs,
+        MyriadStream &rOs )
+{
+    rOs.setSize( hNodeIndex.getSize()*sizeof(RawStat) );
+    rOs.setPos( hNodeIndex.get( rs.iNode )*sizeof(RawStat) );
+    if( rOs.write( &rs, sizeof(RawStat) ) < (int)sizeof(RawStat) )
+        throw Bu::MyriadFsException("Error writing inode to header stream.");
+}
+
+void Bu::MyriadFs::writeInode( const RawStat &rs )
+{
+    MyriadStream ms = mStore.open( 2, Bu::Myriad::Write );
+    writeInode( rs, ms );
+}
+
+Bu::MyriadFs::Dir Bu::MyriadFs::readDir( int32_t iNode )
+{
+    Bu::MyriadStream ms = openByInode( iNode );
+    int32_t iNumChildren = 0;
+    ms.read( &iNumChildren, 4 );
+    
+    Bu::MyriadStream is = mStore.open( 2, Bu::Myriad::Read );
+    Dir lDir;
+    // sio << "Reading dir " << iNode << ", " << iNumChildren << " entries:" << sio.nl;
+    for( int32_t j = 0; j < iNumChildren; j++ )
+    {
+        int32_t iChildNode = 0;
+        if( ms.read( &iChildNode, 4 ) < 4 )
+        {
+            throw Bu::MyriadFsException(
+                "Failed to read iChildNode from directory.");
+        }
+        Stat s;
+        stat( iChildNode, s, is );
+        uint8_t uLen;
+        if( ms.read( &uLen, 1 ) < 1 )
+        {
+            throw Bu::MyriadFsException(
+                "Failed to read uLen from directory.");
+        }
+        s.sName.setSize( uLen );
+        if( ms.read( s.sName.getStr(), uLen ) < uLen )
+        {
+            throw Bu::MyriadFsException(
+                "Failed to read sName from directory.");
+        }
+        lDir.append( s );
+
+//      sio << "    " << s.sName << sio.nl;
+    }
+
+    return lDir;
+}
+
+Bu::MyriadStream Bu::MyriadFs::openByInode( int32_t iNode )
+{
+    RawStat rs;
+    readInode( iNode, rs );
+    switch( (rs.uPerms&typeMask) )
+    {
+        case typeDir:
+        case typeSymLink:
+        case typeRegFile:
+            return mStore.open( rs.uStreamIndex, Bu::Myriad::ReadWrite );
+
+        default:
+            throw Bu::MyriadFsException(
+                "inode incorrect type for low-level openByInode.");
+    }
+}
+
+void Bu::MyriadFs::addToDir( int32_t iDir, int32_t iNode,
+        const Bu::String &sName )
+{
+    if( sName.getSize() > 255 )
+    {
+        throw Bu::MyriadFsException("Filename too long, max is 255 bytes.");
+    }
+    Bu::MyriadStream ms = openByInode( iDir );
+    int32_t iNumChildren = 0;
+    ms.read( &iNumChildren, 4 );
+    iNumChildren++;
+    ms.setPos( 0 );
+    ms.write( &iNumChildren, 4 );
+    ms.setPosEnd( 0 );
+    ms.write( &iNode, 4 );
+    uint8_t uLen = sName.getSize();
+    ms.write( &uLen, 1 );
+    ms.write( sName.getStr(), uLen );
+}
+
+int32_t Bu::MyriadFs::create( int32_t iParent, const Bu::String &sName,
+        uint16_t uPerms, uint32_t uSpecial )
+{
+    int32_t iNode = allocInode( uPerms, uSpecial );
+    addToDir( iParent, iNode, sName );
+    return iNode;
+}
+
+int32_t Bu::MyriadFs::allocInode( uint16_t uPerms, uint32_t uSpecial )
+{
+    int32_t iNode = 0;
+    for(; iNode < 0xfffffff; iNode++ )
+    {
+        if( !hNodeIndex.has( iNode ) )
+        {
+            hNodeIndex.insert( iNode, hNodeIndex.getSize() );
+            RawStat rs;
+            rs.iNode = iNode;
+            rs.iUser = iUser;
+            rs.iGroup = iGroup;
+            rs.uPerms = uPerms;
+            rs.iLinks = 1;
+            switch( (uPerms&typeMask) )
+            {
+                case typeRegFile:
+                case typeSymLink:
+                    {
+                        Bu::MyriadStream ms = mStore.create(
+                            Bu::Myriad::Create
+                            );
+                        rs.uStreamIndex = ms.getId();
+                    }
+                    break;
+                
+                case typeDir:
+                    {
+                        Bu::MyriadStream ms = mStore.create(
+                            Bu::Myriad::Create
+                            );
+                        rs.uStreamIndex = ms.getId();
+                    }
+//                    sio << "Creating directory node, storage: "
+//                        << rs.uStreamIndex << sio.nl;
+                    {
+                        Bu::MyriadStream msDir = mStore.open(
+                            rs.uStreamIndex, Bu::Myriad::Write
+                            );
+                        uint32_t uSize = 0;
+                        msDir.write( &uSize, 4 );
+                    }
+                    break;
+
+                case typeChrDev:
+                case typeBlkDev:
+                    rs.uStreamIndex = uSpecial;
+                    break;
+
+                default:
+                    rs.uStreamIndex = 0;
+                    break;
+            }
+            rs.iATime = time(NULL);
+            rs.iMTime = time(NULL);
+            rs.iCTime = time(NULL);
+            writeInode( rs );
+
+            return iNode;
+        }
+    }
+
+    throw Bu::MyriadFsException(
+        "No inode could be allocated.  You've run out!");
+}
+
+void Bu::MyriadFs::stat( int32_t iNode, Stat &rBuf, MyriadStream &rIs )
+{
+    RawStat rs;
+    readInode( iNode, rs, rIs );
+    rBuf.iNode = iNode;
+    rBuf.iUser = rs.iUser;
+    rBuf.iGroup = rs.iGroup;
+    rBuf.uPerms = rs.uPerms;
+    rBuf.iLinks = rs.iLinks;
+    rBuf.iATime = rs.iATime;
+    rBuf.iMTime = rs.iMTime;
+    rBuf.iCTime = rs.iCTime;
+    rBuf.uDev = 0;
+    rBuf.iSize = 0;
+    switch( (rBuf.uPerms&typeMask) )
+    {
+        case typeRegFile:
+        case typeSymLink:
+            rBuf.iSize = mStore.getSize( rs.uStreamIndex );
+            break;
+
+        case typeChrDev:
+        case typeBlkDev:
+            rBuf.uDev = rs.uStreamIndex;
+            break;
+
+        default:
+            rBuf.iSize = 0;
+            break;
+    }
+}
+
+void Bu::MyriadFs::writeHeader()
+{
+    Bu::MyriadStream ms = mStore.open( 1, Bu::Myriad::Write );
+    ms.write( Myriad_Fs_MAGIC_CODE, 4 );
+    int8_t iVer = 1;
+    int32_t iNumNodes = hNodeIndex.getSize();
+    ms.write( &iVer, 1 );
+    ms.write( &iNumNodes, 4 ); // iNumNodes
+    for( NodeIndex::iterator i = hNodeIndex.begin(); i; i++ )
+    {
+        int32_t iNode = i.getKey();
+        int32_t iPosition = i.getValue();
+        ms.write( &iNode, 4 );
+        ms.write( &iPosition, 4 );
+    }
+
+    // Truncate the stream afterwards so we don't use up too much space.
+    ms.setSize( ms.tell() );
+}
+
+void Bu::MyriadFs::setTimes( int32_t iNode, int64_t iATime, int64_t iMTime )
+{
+    RawStat rs;
+    Bu::MyriadStream is = mStore.open( 2, Bu::Myriad::ReadWrite );
+
+    readInode( iNode, rs, is );
+    rs.iATime = iATime;
+    rs.iMTime = iMTime;
+    writeInode( rs, is );
+}
+
+void Bu::MyriadFs::destroyNode( int32_t iNode )
+{
+    if( iNode == 0 )
+        throw Bu::MyriadFsException("You cannot destroy the root.");
+
+    uint32_t iPosition;
+    RawStat rsOld;
+
+    Bu::MyriadStream is = mStore.open( 2, Bu::Myriad::ReadWrite );
+
+    // This will be overwritten with the last node
+    iPosition = hNodeIndex.get( iNode );
+    readInode( iNode, rsOld, is );
+    
+    switch( (rsOld.uPerms&typeMask) )
+    {
+        case typeRegFile:
+        case typeDir:
+        case typeSymLink:
+            mStore.erase( rsOld.uStreamIndex );
+            break;
+    }
+
+    hNodeIndex.erase( iNode );
+
+    // Read the last node, can't use the helpers, because we don't know the
+    // iNode yet.
+    if( iPosition != hNodeIndex.getSize() )
+    {
+        // If this is the last node, then we don't need to do anything, but
+        // this case handles what to do if we aren't on the last node
+        RawStat rs;
+        is.setPos( (hNodeIndex.getSize())*sizeof(RawStat) );
+        is.read( &rs, sizeof(RawStat) );
+
+        hNodeIndex.get( rs.iNode ) = iPosition;
+        writeInode( rs, is );
+    }
+
+    is.setSize( hNodeIndex.getSize() * sizeof(RawStat) );
+}
+
+Bu::String Bu::MyriadFs::filePart( const Bu::String &sPath )
+{
+    Bu::String::const_iterator iStart = sPath.begin();
+    if( *iStart == '/' )
+        iStart++;
+    for( Bu::String::const_iterator iEnd = iStart.find('/'); iEnd;
+         iStart = iEnd+1, iEnd = iStart.find('/') ) { }
+    return Bu::String( iStart, sPath.end() );
+}
+