1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
|
#!/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
########################################################################
## setup predicates
########################################################################
#set $sid_p = 0b00001
#set $cid_p = 0b00010
#set $tsi_p = 0b00100
#set $tsf_p = 0b01000
#set $tlr_p = 0b10000
/***********************************************************************
* This file was generated by $file on $time.strftime("%c")
**********************************************************************/
\#include <uhd/transport/vrt.hpp>
\#include <boost/asio.hpp> //endianness conversion
\#include <stdexcept>
using namespace uhd;
using namespace uhd::transport;
void vrt::pack(
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] = htonl(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] = htonl(0);
#set $num_header_words += 1
header_buff[$num_header_words] = htonl(0);
#set $num_header_words += 1
#set $flags |= (0x1 << 27);
#end if
########## Integer Time ##########
#if $pred & $tsi_p
header_buff[$num_header_words] = htonl(metadata.time_spec.secs);
#set $num_header_words += 1
#set $flags |= (0x3 << 22);
#end if
########## Fractional Time ##########
#if $pred & $tsf_p
header_buff[$num_header_words] = htonl(0);
#set $num_header_words += 1
header_buff[$num_header_words] = htonl(metadata.time_spec.get_ticks(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] = htonl(vrt_hdr_flags |
((packet_count & 0xf) << 16) |
(num_packet_words32 & 0xffff)
);
}
void vrt::unpack(
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();
//extract vrt header
boost::uint32_t vrt_hdr_word = ntohl(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 $set_has_time_spec = False
#set $num_header_words = 1
########## Stream ID ##########
#if $pred & $sid_p
metadata.has_stream_id = true;
metadata.stream_id = ntohl(header_buff[$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
metadata.has_time_spec = true;
#set $set_has_time_spec = True
metadata.time_spec.secs = ntohl(header_buff[$num_header_words]);
#set $num_header_words += 1
#end if
########## Fractional Time ##########
#if $pred & $tsf_p
#if not $set_has_time_spec
metadata.has_time_spec = true;
#set $set_has_time_spec = True
#end if
#set $num_header_words += 1
metadata.time_spec.set_ticks(ntohl(header_buff[$num_header_words]), tick_rate);
#set $num_header_words += 1
#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
}
}
"""
import sys
from Cheetah.Template import Template
def parse_tmpl(_tmpl_text, **kwargs):
return str(Template(_tmpl_text, kwargs))
if __name__ == '__main__':
open(sys.argv[1], 'w').write(parse_tmpl(TMPL_TEXT, file=__file__))
|
