};

/*
 * Internal Core Utilities
 */
static const char *xvfs_relativePath(Tcl_Obj *path, struct xvfs_tclfs_instance_info *info) {
	const char *pathStr, *rootStr;
	const char *pathFinal;
	int pathLen, rootLen;

	pathStr = Tcl_GetStringFromObj(path, &pathLen);
	rootStr = Tcl_GetStringFromObj(info->mountpoint, &rootLen);

	if (pathLen < rootLen) {
		return(NULL);

	}

	/* XXX:TODO: Should this use the native OS path separator ? */
	if (pathStr[rootLen] != '/') {
		return(NULL);
	}

	pathFinal = pathStr + rootLen + 1;
	pathLen  -= rootLen + 1;

	if (pathLen == 1 && memcmp(pathFinal, ".", 1) == 0) {
		return("");
	}

	while (pathLen >= 2 && memcmp(pathFinal, "./", 2) == 0) {
		pathFinal += 2;
		pathLen   -= 2;
	}

	return(pathFinal);
}

static const char *xvfs_perror(int xvfs_error) {
	if (xvfs_error >= 0) {
		return("Not an error");
	}

	switch (xvfs_error) {
		case XVFS_RV_ERR_ENOENT:
			return("No such file or directory");
		case XVFS_RV_ERR_EINVAL:
			return("Invalid argument");
		case XVFS_RV_ERR_EISDIR:
			return("Is a directory");
		case XVFS_RV_ERR_ENOTDIR:
			return("Not a directory");
		case XVFS_RV_ERR_EFAULT:
			return("Bad address");
		case XVFS_RV_ERR_INTERNAL:
			return("Internal error");
		default:
			return("Unknown error");
	}
}


static int xvfs_errorToErrno(int xvfs_error) {
	if (xvfs_error >= 0) {
		return(0);
	}

	switch (xvfs_error) {
		case XVFS_RV_ERR_ENOENT:
			return(ENOENT);
		case XVFS_RV_ERR_EINVAL:
			return(EINVAL);
		case XVFS_RV_ERR_EISDIR:
			return(EISDIR);
		case XVFS_RV_ERR_ENOTDIR:
			return(ENOTDIR);
		case XVFS_RV_ERR_EFAULT:
			return(EFAULT);
		case XVFS_RV_ERR_INTERNAL:
			return(EINVAL);
		default:
			return(ERANGE);
	}
}

/*
 * Xvfs Memory Channel

	if (mode & O_WRONLY) {
		return(NULL);
	}

	return(xvfs_tclfs_openChannel(Tcl_NewStringObj(pathStr, -1), instanceInfo));
}

static int xvfs_tclfs_verifyType(Tcl_Obj *path, Tcl_GlobTypeData *types, struct xvfs_tclfs_instance_info *instanceInfo) {
	const char *pathStr;
	Tcl_StatBuf fileInfo;
	int statRetVal;

	statRetVal = xvfs_tclfs_stat(path, &fileInfo, instanceInfo);
	if (statRetVal != 0) {
		return(0);
	}

	if (!types) {
		return(1);
	}

	if (types->perm != TCL_GLOB_PERM_RONLY) {
		if (types->perm & (TCL_GLOB_PERM_W | TCL_GLOB_PERM_X | TCL_GLOB_PERM_HIDDEN)) {
			return(0);
		}
	}

	if (types->type & (TCL_GLOB_TYPE_BLOCK | TCL_GLOB_TYPE_CHAR | TCL_GLOB_TYPE_PIPE | TCL_GLOB_TYPE_SOCK | TCL_GLOB_TYPE_LINK)) {
		return(0);
	}

	if ((types->type & TCL_GLOB_TYPE_DIR) == TCL_GLOB_TYPE_DIR) {
		if (!(fileInfo.st_mode & 040000)) {
			return(0);
		}
	}

	if ((types->type & TCL_GLOB_TYPE_FILE) == TCL_GLOB_TYPE_FILE) {
		if (!(fileInfo.st_mode & 0100000)) {
			return(0);
		}
	}

	if ((types->type & TCL_GLOB_TYPE_MOUNT) == TCL_GLOB_TYPE_MOUNT) {
		pathStr = xvfs_relativePath(path, instanceInfo);
		if (!pathStr) {
			return(0);
		}

		if (strlen(pathStr) != 0) {
			return(0);
		}
	}

	return(1);
}

static int xvfs_tclfs_matchInDir(Tcl_Interp *interp, Tcl_Obj *resultPtr, Tcl_Obj *path, const char *pattern, Tcl_GlobTypeData *types, struct xvfs_tclfs_instance_info *instanceInfo) {
	const char *pathStr;
	const char **children, *child;
	Tcl_WideInt childrenCount, idx;
	Tcl_Obj *childObj;
	int tclRetVal;

	if (pattern == NULL) {
		if (xvfs_tclfs_verifyType(path, types, instanceInfo)) {
			return(TCL_OK);
		}

		return(TCL_ERROR);
	}

	pathStr = xvfs_relativePath(path, instanceInfo);
	if (!pathStr) {
		if (interp) {
			Tcl_SetResult(interp, (char *) xvfs_perror(XVFS_RV_ERR_ENOENT), NULL);
		}

		return(TCL_ERROR);
	}

	childrenCount = 0;
	children = instanceInfo->fsInfo->getChildrenProc(pathStr, &childrenCount);
	if (childrenCount < 0) {
		if (interp) {
			Tcl_SetResult(interp, (char *) xvfs_perror(childrenCount), NULL);
		}

		return(TCL_ERROR);
	}

	for (idx = 0; idx < childrenCount; idx++) {
		child = children[idx];

		if (!Tcl_StringMatch(child, pattern)) {
			continue;
		}

		childObj = Tcl_DuplicateObj(path);
		Tcl_AppendStringsToObj(childObj, "/", child, NULL);
		Tcl_IncrRefCount(childObj);

		if (!xvfs_tclfs_verifyType(childObj, types, instanceInfo)) {
			Tcl_DecrRefCount(childObj);

			continue;
		}

		tclRetVal = Tcl_ListObjAppendElement(interp, resultPtr, childObj);
		Tcl_DecrRefCount(childObj);

		if (tclRetVal != TCL_OK) {
			return(tclRetVal);
		}
	}

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

#if defined(XVFS_MODE_STANDALONE) || defined(XVFS_MODE_FLEXIBLE)
/*
 * Tcl_Filesystem handlers for the standalone implementation
 */
static struct xvfs_tclfs_instance_info xvfs_tclfs_standalone_info;

static Tcl_Obj *xvfs_tclfs_standalone_listVolumes(void) {
	return(xvfs_tclfs_listVolumes(&xvfs_tclfs_standalone_info));
}

static Tcl_Channel xvfs_tclfs_standalone_openFileChannel(Tcl_Interp *interp, Tcl_Obj *path, int mode, int permissions) {
	return(xvfs_tclfs_openFileChannel(interp, path, mode, permissions, &xvfs_tclfs_standalone_info));
}

static int xvfs_tclfs_standalone_matchInDir(Tcl_Interp *interp, Tcl_Obj *resultPtr, Tcl_Obj *pathPtr, const char *pattern, Tcl_GlobTypeData *types) {
	return(xvfs_tclfs_matchInDir(interp, resultPtr, pathPtr, pattern, types, &xvfs_tclfs_standalone_info));
}

/*
 * There are three (3) modes of operation for Xvfs_Register:
 *    1. standalone -- We register our own Tcl_Filesystem
 *                     and handle requests under `//xvfs:/<fsName>`
 *    2. client -- A single Tcl_Filesystem is registered for the
 *                 interp to handle requests under `//xvfs:/` which

	xvfs_tclfs_standalone_fs.createInternalRepProc      = NULL;
	xvfs_tclfs_standalone_fs.normalizePathProc          = NULL;
	xvfs_tclfs_standalone_fs.filesystemPathTypeProc     = NULL;
	xvfs_tclfs_standalone_fs.filesystemSeparatorProc    = NULL;
	xvfs_tclfs_standalone_fs.statProc                   = xvfs_tclfs_standalone_stat;
	xvfs_tclfs_standalone_fs.accessProc                 = NULL;
	xvfs_tclfs_standalone_fs.openFileChannelProc        = xvfs_tclfs_standalone_openFileChannel;
	xvfs_tclfs_standalone_fs.matchInDirectoryProc       = xvfs_tclfs_standalone_matchInDir;
	xvfs_tclfs_standalone_fs.utimeProc                  = NULL;
	xvfs_tclfs_standalone_fs.linkProc                   = NULL;
	xvfs_tclfs_standalone_fs.listVolumesProc            = xvfs_tclfs_standalone_listVolumes;
	xvfs_tclfs_standalone_fs.fileAttrStringsProc        = NULL;
	xvfs_tclfs_standalone_fs.fileAttrsGetProc           = NULL;
	xvfs_tclfs_standalone_fs.fileAttrsSetProc           = NULL;
	xvfs_tclfs_standalone_fs.createDirectoryProc        = NULL;