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#!/usr/bin/env python
#
# Copyright 2010 Ettus Research LLC
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
"""
The vrt packer/unpacker code generator:
This script will generate the pack and unpack routines that convert
metatdata into vrt headers and vrt headers into metadata.
The generated code infers jump tables to speed-up the parsing time.
"""
TMPL_TEXT = """
#import time
/***********************************************************************
* This file was generated by $file on $time.strftime("%c")
**********************************************************************/
\#include <uhd/transport/vrt.hpp>
\#include <uhd/utils/byteswap.hpp>
\#include <boost/detail/endian.hpp>
\#include <stdexcept>
//define the endian macros to convert integers
\#ifdef BOOST_BIG_ENDIAN
\#define BE_MACRO(x) (x)
\#define LE_MACRO(x) uhd::byteswap(x)
\#else
\#define BE_MACRO(x) uhd::byteswap(x)
\#define LE_MACRO(x) (x)
\#endif
using namespace uhd;
using namespace uhd::transport;
########################################################################
#def gen_code($XE_MACRO, $suffix)
########################################################################
########################################################################
## setup predicates
########################################################################
#set $sid_p = 0b00001
#set $cid_p = 0b00010
#set $tsi_p = 0b00100
#set $tsf_p = 0b01000
#set $tlr_p = 0b10000
void vrt::pack_$(suffix)(
const tx_metadata_t &metadata, //input
boost::uint32_t *header_buff, //output
size_t &num_header_words32, //output
size_t num_payload_words32, //input
size_t &num_packet_words32, //output
size_t packet_count, //input
double tick_rate //input
){
boost::uint32_t vrt_hdr_flags = 0;
boost::uint8_t pred = 0;
if (metadata.has_stream_id) pred |= $hex($sid_p);
if (metadata.has_time_spec) pred |= $hex($tsi_p | $tsf_p);
switch(pred){
#for $pred in range(2**5)
case $pred:
#set $num_header_words = 1
#set $flags = 0
########## Stream ID ##########
#if $pred & $sid_p
header_buff[$num_header_words] = $(XE_MACRO)(metadata.stream_id);
#set $num_header_words += 1
#set $flags |= (0x1 << 28);
#end if
########## Class ID ##########
#if $pred & $cid_p
header_buff[$num_header_words] = 0;
#set $num_header_words += 1
header_buff[$num_header_words] = 0;
#set $num_header_words += 1
#set $flags |= (0x1 << 27);
#end if
########## Integer Time ##########
#if $pred & $tsi_p
header_buff[$num_header_words] = $(XE_MACRO)(boost::uint32_t(metadata.time_spec.get_full_secs()));
#set $num_header_words += 1
#set $flags |= (0x3 << 22);
#end if
########## Fractional Time ##########
#if $pred & $tsf_p
header_buff[$num_header_words] = 0;
#set $num_header_words += 1
header_buff[$num_header_words] = $(XE_MACRO)(boost::uint32_t(metadata.time_spec.get_tick_count(tick_rate)));
#set $num_header_words += 1
#set $flags |= (0x1 << 20);
#end if
########## Trailer ##########
#if $pred & $tlr_p
#set $flags |= (0x1 << 26);
#set $num_trailer_words = 1;
#else
#set $num_trailer_words = 0;
#end if
########## Variables ##########
num_header_words32 = $num_header_words;
num_packet_words32 = $($num_header_words + $num_trailer_words) + num_payload_words32;
vrt_hdr_flags = $hex($flags);
break;
#end for
}
//set the burst flags
if (metadata.start_of_burst) vrt_hdr_flags |= $hex(0x1 << 25);
if (metadata.end_of_burst) vrt_hdr_flags |= $hex(0x1 << 24);
//fill in complete header word
header_buff[0] = $(XE_MACRO)(boost::uint32_t(0
| vrt_hdr_flags
| ((packet_count & 0xf) << 16)
| (num_packet_words32 & 0xffff)
));
}
void vrt::unpack_$(suffix)(
rx_metadata_t &metadata, //output
const boost::uint32_t *header_buff, //input
size_t &num_header_words32, //output
size_t &num_payload_words32, //output
size_t num_packet_words32, //input
size_t &packet_count, //output
double tick_rate //input
){
//clear the metadata
metadata = rx_metadata_t();
boost::uint32_t secs = 0, ticks = 0;
//extract vrt header
boost::uint32_t vrt_hdr_word = $(XE_MACRO)(header_buff[0]);
size_t packet_words32 = vrt_hdr_word & 0xffff;
packet_count = (vrt_hdr_word >> 16) & 0xf;
//failure cases
if (packet_words32 == 0 or num_packet_words32 < packet_words32)
throw std::runtime_error("bad vrt header or packet fragment");
if (vrt_hdr_word & (0x7 << 29))
throw std::runtime_error("unsupported vrt packet type");
boost::uint8_t pred = 0;
if(vrt_hdr_word & $hex(0x1 << 28)) pred |= $hex($sid_p);
if(vrt_hdr_word & $hex(0x1 << 27)) pred |= $hex($cid_p);
if(vrt_hdr_word & $hex(0x3 << 22)) pred |= $hex($tsi_p);
if(vrt_hdr_word & $hex(0x3 << 20)) pred |= $hex($tsf_p);
if(vrt_hdr_word & $hex(0x1 << 26)) pred |= $hex($tlr_p);
switch(pred){
#for $pred in range(2**5)
case $pred:
#set $has_time_spec = False
#set $num_header_words = 1
########## Stream ID ##########
#if $pred & $sid_p
metadata.has_stream_id = true;
metadata.stream_id = $(XE_MACRO)(header_buff[$num_header_words]);
#set $num_header_words += 1
#end if
########## Class ID ##########
#if $pred & $cid_p
#set $num_header_words += 1
#set $num_header_words += 1
#end if
########## Integer Time ##########
#if $pred & $tsi_p
#set $has_time_spec = True
secs = $(XE_MACRO)(header_buff[$num_header_words]);
#set $num_header_words += 1
#end if
########## Fractional Time ##########
#if $pred & $tsf_p
#set $has_time_spec = True
#set $num_header_words += 1
ticks = $(XE_MACRO)(header_buff[$num_header_words]);
#set $num_header_words += 1
#end if
#if $has_time_spec
metadata.has_time_spec = true;
metadata.time_spec = time_spec_t(secs, ticks, tick_rate);
#end if
########## Trailer ##########
#if $pred & $tlr_p
#set $num_trailer_words = 1;
#else
#set $num_trailer_words = 0;
#end if
########## Variables ##########
num_header_words32 = $num_header_words;
num_payload_words32 = packet_words32 - $($num_header_words + $num_trailer_words);
break;
#end for
}
}
########################################################################
#end def
########################################################################
$gen_code("BE_MACRO", "be")
$gen_code("LE_MACRO", "le")
"""
def parse_tmpl(_tmpl_text, **kwargs):
from Cheetah.Template import Template
return str(Template(_tmpl_text, kwargs))
if __name__ == '__main__':
import sys
open(sys.argv[1], 'w').write(parse_tmpl(TMPL_TEXT, file=__file__))
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