*    3. flexible -- Attempts to find a core Xvfs instance for the
 *                   process at runtime, if found do #2, otherwise
 *                   fallback to #1
 *
 */
static Tcl_Filesystem xvfs_tclfs_standalone_fs;
static int xvfs_standalone_register(Tcl_Interp *interp, struct Xvfs_FSInfo *fsInfo) {
	int tclRet;
	static int registered = 0;

	/*
	 * Ensure this instance is not already registered
	 */
	if (registered) {
		return(TCL_OK);

	if (fsInfo->protocolVersion != XVFS_PROTOCOL_VERSION) {
		if (interp) {
			Tcl_SetResult(interp, "Protocol mismatch", NULL);
		}
		return(TCL_ERROR);
	}

	xvfs_tclfs_standalone_fs.typeName                   = "xvfsInstance";
	xvfs_tclfs_standalone_fs.structureLength            = sizeof(xvfs_tclfs_standalone_fs);
	xvfs_tclfs_standalone_fs.version                    = TCL_FILESYSTEM_VERSION_1;
	xvfs_tclfs_standalone_fs.pathInFilesystemProc       = xvfs_tclfs_standalone_pathInFilesystem;
	xvfs_tclfs_standalone_fs.dupInternalRepProc         = NULL;
	xvfs_tclfs_standalone_fs.freeInternalRepProc        = NULL;
	xvfs_tclfs_standalone_fs.internalToNormalizedProc   = NULL;
	xvfs_tclfs_standalone_fs.createInternalRepProc      = NULL;

	xvfs_tclfs_standalone_info.fsInfo = fsInfo;
	xvfs_tclfs_standalone_info.mountpoint = Tcl_NewObj();

	Tcl_IncrRefCount(xvfs_tclfs_standalone_info.mountpoint);
	Tcl_AppendStringsToObj(xvfs_tclfs_standalone_info.mountpoint, XVFS_ROOT_MOUNTPOINT, fsInfo->name, NULL);
	
	tclRet = Tcl_FSRegister(NULL, &xvfs_tclfs_standalone_fs);
	if (tclRet != TCL_OK) {
		Tcl_DecrRefCount(xvfs_tclfs_standalone_info.mountpoint);

		if (interp) {
			Tcl_SetResult(interp, "Tcl_FSRegister() failed", NULL);
		}

		return(tclRet);
	}

	xvfs_tclfs_prepareChannelType();

	return(TCL_OK);
}
#endif /* XVFS_MODE_STANDALONE || XVFS_MODE_FLEXIBLE */

	}

	return(xvfs_register(interp, fsInfo));
}
#endif /* XVFS_MODE_FLEXIBLE */

#if defined(XVFS_MODE_SERVER)
static Tcl_Filesystem xvfs_tclfs_dispatch_fs;
static Tcl_HashTable xvfs_tclfs_dispatch_map;

static struct xvfs_tclfs_instance_info *xvfs_tclfs_dispatch_pathToInstanceInfo(Tcl_Obj *path) {
	Tcl_HashEntry *mapEntry;
	struct xvfs_tclfs_instance_info *retval;
	const char *pathStr, *rootStr;
	char *fsName, *fsNameEnds, origSep;
	int pathLen, rootLen;

	XVFS_DEBUG_ENTER;

	XVFS_DEBUG_PRINTF("Looking up path \"%s\" ...", Tcl_GetString(path));
	
	rootStr = XVFS_ROOT_MOUNTPOINT;
	rootLen = strlen(XVFS_ROOT_MOUNTPOINT);

	pathStr = Tcl_GetStringFromObj(path, &pathLen);

	if (pathLen < rootLen) {
		XVFS_DEBUG_PUTS("... failed (length too short)");
		XVFS_DEBUG_LEAVE;
		return(NULL);
	}

	if (memcmp(pathStr, rootStr, rootLen) != 0) {
		XVFS_DEBUG_PUTS("... failed (incorrect prefix)");
		XVFS_DEBUG_LEAVE;
		return(NULL);
	}

	fsName = ((char *) pathStr) + rootLen;

	fsNameEnds = strchr(fsName, '/');
	if (fsNameEnds) {
		origSep = *fsNameEnds;
		*fsNameEnds = '\0';
	}

	XVFS_DEBUG_PRINTF("... fsName = %s...", fsName);

	mapEntry = Tcl_FindHashEntry(&xvfs_tclfs_dispatch_map, fsName);

	if (fsNameEnds) {
		*fsNameEnds = origSep;
	}

	if (mapEntry) {
		retval = (struct xvfs_tclfs_instance_info *) Tcl_GetHashValue(mapEntry);
		XVFS_DEBUG_PRINTF("... found a registered filesystem: %p", retval);
	} else {
		retval = NULL;
		XVFS_DEBUG_PUTS("... found no registered filesystem.");
	}

	XVFS_DEBUG_LEAVE;
	return(retval);
}

static int xvfs_tclfs_dispatch_pathInFilesystem(Tcl_Obj *path, ClientData *dataPtr) {
	static struct xvfs_tclfs_instance_info *instanceInfo;

	instanceInfo = xvfs_tclfs_dispatch_pathToInstanceInfo(path);
	if (!instanceInfo) {
		return(-1);
	}

	return(xvfs_tclfs_pathInFilesystem(path, dataPtr, instanceInfo));
}

static int xvfs_tclfs_dispatch_stat(Tcl_Obj *path, Tcl_StatBuf *statBuf) {
	struct xvfs_tclfs_instance_info *instanceInfo;

	instanceInfo = xvfs_tclfs_dispatch_pathToInstanceInfo(path);
	if (!instanceInfo) {
		return(0);
	}

	return(xvfs_tclfs_stat(path, statBuf, instanceInfo));
}

static int xvfs_tclfs_dispatch_access(Tcl_Obj *path, int mode) {
	struct xvfs_tclfs_instance_info *instanceInfo;

	instanceInfo = xvfs_tclfs_dispatch_pathToInstanceInfo(path);
	if (!instanceInfo) {
		return(-1);
	}

	return(xvfs_tclfs_access(path, mode, instanceInfo));
}

static Tcl_Channel xvfs_tclfs_dispatch_openFileChannel(Tcl_Interp *interp, Tcl_Obj *path, int mode, int permissions) {
	struct xvfs_tclfs_instance_info *instanceInfo;

	instanceInfo = xvfs_tclfs_dispatch_pathToInstanceInfo(path);
	if (!instanceInfo) {
		return(NULL);
	}

	return(xvfs_tclfs_openFileChannel(interp, path, mode, permissions, instanceInfo));
}

static int xvfs_tclfs_dispatch_matchInDir(Tcl_Interp *interp, Tcl_Obj *resultPtr, Tcl_Obj *pathPtr, const char *pattern, Tcl_GlobTypeData *types) {
	struct xvfs_tclfs_instance_info *instanceInfo;

	instanceInfo = xvfs_tclfs_dispatch_pathToInstanceInfo(pathPtr);
	if (!instanceInfo) {
		return(TCL_ERROR);
	}

	return(xvfs_tclfs_matchInDir(interp, resultPtr, pathPtr, pattern, types, instanceInfo));
}

static int xvfs_tclfs_dispatch_init(Tcl_Interp *interp) {
	static int registered = 0;
	int tclRet;

	/* XXX:TODO: Make this thread-safe */
	if (registered) {
		return(TCL_OK);
	}
	registered = 1;

	xvfs_tclfs_dispatch_fs.typeName                   = "xvfsDispatch";
	xvfs_tclfs_dispatch_fs.structureLength            = sizeof(xvfs_tclfs_dispatch_fs);
	xvfs_tclfs_dispatch_fs.version                    = TCL_FILESYSTEM_VERSION_1;
	xvfs_tclfs_dispatch_fs.pathInFilesystemProc       = xvfs_tclfs_dispatch_pathInFilesystem;
	xvfs_tclfs_dispatch_fs.dupInternalRepProc         = NULL;
	xvfs_tclfs_dispatch_fs.freeInternalRepProc        = NULL;
	xvfs_tclfs_dispatch_fs.internalToNormalizedProc   = NULL;
	xvfs_tclfs_dispatch_fs.createInternalRepProc      = NULL;
	xvfs_tclfs_dispatch_fs.normalizePathProc          = NULL;
	xvfs_tclfs_dispatch_fs.filesystemPathTypeProc     = NULL;
	xvfs_tclfs_dispatch_fs.filesystemSeparatorProc    = NULL;
	xvfs_tclfs_dispatch_fs.statProc                   = xvfs_tclfs_dispatch_stat;
	xvfs_tclfs_dispatch_fs.accessProc                 = xvfs_tclfs_dispatch_access;
	xvfs_tclfs_dispatch_fs.openFileChannelProc        = xvfs_tclfs_dispatch_openFileChannel;
	xvfs_tclfs_dispatch_fs.matchInDirectoryProc       = xvfs_tclfs_dispatch_matchInDir;
	xvfs_tclfs_dispatch_fs.utimeProc                  = NULL;
	xvfs_tclfs_dispatch_fs.linkProc                   = NULL;
	xvfs_tclfs_dispatch_fs.listVolumesProc            = NULL;
	xvfs_tclfs_dispatch_fs.fileAttrStringsProc        = NULL;
	xvfs_tclfs_dispatch_fs.fileAttrsGetProc           = NULL;
	xvfs_tclfs_dispatch_fs.fileAttrsSetProc           = NULL;
	xvfs_tclfs_dispatch_fs.createDirectoryProc        = NULL;
	xvfs_tclfs_dispatch_fs.removeDirectoryProc        = NULL;
	xvfs_tclfs_dispatch_fs.deleteFileProc             = NULL;
	xvfs_tclfs_dispatch_fs.copyFileProc               = NULL;
	xvfs_tclfs_dispatch_fs.renameFileProc             = NULL;
	xvfs_tclfs_dispatch_fs.copyDirectoryProc          = NULL;
	xvfs_tclfs_dispatch_fs.lstatProc                  = NULL;
	xvfs_tclfs_dispatch_fs.loadFileProc               = NULL;
	xvfs_tclfs_dispatch_fs.getCwdProc                 = NULL;
	xvfs_tclfs_dispatch_fs.chdirProc                  = NULL;

	tclRet = Tcl_FSRegister(NULL, &xvfs_tclfs_dispatch_fs);
	if (tclRet != TCL_OK) {
		if (interp) {
			Tcl_SetResult(interp, "Tcl_FSRegister() failed", NULL);
		}

		return(tclRet);
	}

	/*
	 * Initialize the channel type we will use for I/O
	 */
	xvfs_tclfs_prepareChannelType();

	/*
	 * Initialize the map to lookup paths to registered
	 * filesystems
	 */
	Tcl_InitHashTable(&xvfs_tclfs_dispatch_map, TCL_STRING_KEYS);

	return(TCL_OK);
}

int Xvfs_Register(Tcl_Interp *interp, struct Xvfs_FSInfo *fsInfo) {
	Tcl_HashEntry *mapEntry;
	struct xvfs_tclfs_instance_info *instanceInfo;
	int dispatchInitRet;
	int new;

	dispatchInitRet = xvfs_tclfs_dispatch_init(interp);
	if (dispatchInitRet != TCL_OK) {
		return(dispatchInitRet);
	}

	/*
	 * Verify this is for a protocol we support
	 */
	if (fsInfo->protocolVersion != XVFS_PROTOCOL_VERSION) {
		if (interp) {
			Tcl_SetResult(interp, "Protocol mismatch", NULL);
		}
		return(TCL_ERROR);
	}

	/*
	 * Create the structure needed
	 */
	instanceInfo = (struct xvfs_tclfs_instance_info *) Tcl_Alloc(sizeof(*instanceInfo));
	instanceInfo->fsInfo = fsInfo;
	instanceInfo->mountpoint = Tcl_ObjPrintf("%s%s", XVFS_ROOT_MOUNTPOINT, fsInfo->name);
	Tcl_IncrRefCount(instanceInfo->mountpoint);

	/*
	 * Register a hash table entry for this name
	 */
	new = 0;
	mapEntry = Tcl_CreateHashEntry(&xvfs_tclfs_dispatch_map, fsInfo->name, &new);
	Tcl_SetHashValue(mapEntry, instanceInfo);

	return(TCL_OK);
}
#endif /* XVFS_MODE_SERVER */