:: # Copyright 2013, Big Switch Networks, Inc.
:: #
:: # LoxiGen is licensed under the Eclipse Public License, version 1.0 (EPL), with
:: # the following special exception:
:: #
:: # LOXI Exception
:: #
:: # As a special exception to the terms of the EPL, you may distribute libraries
:: # generated by LoxiGen (LoxiGen Libraries) under the terms of your choice, provided
:: # that copyright and licensing notices generated by LoxiGen are not altered or removed
:: # from the LoxiGen Libraries and the notice provided below is (i) included in
:: # the LoxiGen Libraries, if distributed in source code form and (ii) included in any
:: # documentation for the LoxiGen Libraries, if distributed in binary form.
:: #
:: # Notice: "Copyright 2013, Big Switch Networks, Inc. This library was generated by the LoxiGen Compiler."
:: #
:: # You may not use this file except in compliance with the EPL or LOXI Exception. You may obtain
:: # a copy of the EPL at:
:: #
:: # http://www.eclipse.org/legal/epl-v10.html
:: #
:: # Unless required by applicable law or agreed to in writing, software
:: # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
:: # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
:: # EPL for the specific language governing permissions and limitations
:: # under the EPL.
::
OFReader = {}
OFReader.new = function(buf, offset)
    local self = {}
    offset = offset or 0

    self.read = function(len)
        local r = buf(offset, len)
        offset = offset + len
        return r
    end

    self.read_all = function()
        local r = buf(offset, buf:len() - offset)
        offset = buf:len()
        return r
    end

    self.peek = function(off, len)
        return buf(offset + off, len)
    end

    self.peek_all = function(off)
        return buf(offset + off, buf:len() - offset - off)
    end

    self.skip = function(len)
        offset = offset + len
    end

    self.is_empty = function()
        return offset == buf:len()
    end

    self.slice = function(len)
        r = OFReader.new(buf(offset, len))
        offset = offset + len
        return r
    end
    
    self.skip_align = function()
        offset = math.floor((offset + 7)/8)*8
    end

    return self
end
