2 # Copyright 2008 Free Software Foundation, Inc.
4 # This file is part of GNU Radio
6 # GNU Radio is free software; you can redistribute it and/or modify
7 # it under the terms of the GNU General Public License as published by
8 # the Free Software Foundation; either version 3, or (at your option)
11 # GNU Radio is distributed in the hope that it will be useful,
12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 # GNU General Public License for more details.
16 # You should have received a copy of the GNU General Public License
17 # along with GNU Radio; see the file COPYING. If not, write to
18 # the Free Software Foundation, Inc., 51 Franklin Street,
19 # Boston, MA 02110-1301, USA.
22 from gnuradio import gr
24 class selector(gr.hier_block2):
25 """A hier2 block with N inputs and M outputs, where data is only forwarded through input n to output m."""
26 def __init__(self, item_size, num_inputs, num_outputs, input_index, output_index):
28 SelectorHelper constructor.
29 @param item_size the size of the gr data stream in bytes
30 @param num_inputs the number of inputs (integer)
31 @param num_outputs the number of outputs (integer)
32 @param input_index the index for the source data
33 @param output_index the index for the destination data
35 gr.hier_block2.__init__(
37 gr.io_signature(num_inputs, num_inputs, item_size),
38 gr.io_signature(num_outputs, num_outputs, item_size),
40 #terminator blocks for unused inputs and outputs
41 self.input_terminators = [gr.null_sink(item_size)] * num_inputs
42 self.output_terminators = [gr.head(item_size, 0)] * num_outputs
45 for i in range(num_inputs): self.connect((self, i), self.input_terminators[i])
46 for i in range(num_outputs): self.connect(gr.null_source(item_size), self.output_terminators[i], (self, i))
47 self.item_size = item_size
48 self.input_index = input_index
49 self.output_index = output_index
50 self.num_inputs = num_inputs
51 self.num_outputs = num_outputs
52 self._connect_current()
54 def _indexes_valid(self):
56 Are the input and output indexes within range of the number of inputs and outputs?
57 @return true if input index and output index are in range
59 return self.input_index in range(self.num_inputs) and self.output_index in range(self.num_outputs)
61 def _connect_current(self):
62 """If the input and output indexes are valid:
63 disconnect the blocks at the input and output index from their terminators,
64 and connect them to one another. Then connect the terminators to one another."""
65 if self._indexes_valid():
66 self.disconnect((self, self.input_index), self.input_terminators[self.input_index])
67 self.disconnect(self.output_terminators[self.output_index], (self, self.output_index))
68 self.copy = gr.skiphead(self.item_size, 0)
69 self.connect((self, self.input_index), self.copy)
70 self.connect(self.copy, (self, self.output_index))
71 self.connect(self.output_terminators[self.output_index], self.input_terminators[self.input_index])
73 def _disconnect_current(self):
74 """If the input and output indexes are valid:
75 disconnect the blocks at the input and output index from one another,
76 and the terminators at the input and output index from one another.
77 Reconnect the blocks to the terminators."""
78 if self._indexes_valid():
79 self.disconnect((self, self.input_index), self.copy)
80 self.disconnect(self.copy, (self, self.output_index))
81 self.disconnect(self.output_terminators[self.output_index], self.input_terminators[self.input_index])
84 self.connect((self, self.input_index), self.input_terminators[self.input_index])
85 self.connect(self.output_terminators[self.output_index], (self, self.output_index))
87 def set_input_index(self, input_index):
89 Change the block to the new input index if the index changed.
90 @param input_index the new input index
92 if self.input_index != input_index:
94 self._disconnect_current()
95 self.input_index = input_index
96 self._connect_current()
99 def set_output_index(self, output_index):
101 Change the block to the new output index if the index changed.
102 @param output_index the new output index
104 if self.output_index != output_index:
106 self._disconnect_current()
107 self.output_index = output_index
108 self._connect_current()
111 class valve(selector):
112 """Wrapper for selector with 1 input and 1 output."""
114 def __init__(self, item_size, open):
116 Constructor for valve.
117 @param item_size the size of the gr data stream in bytes
118 @param open true if initial valve state is open
120 if open: output_index = -1
121 else: output_index = 0
122 selector.__init__(self, item_size, 1, 1, 0, output_index)
124 def set_open(self, open):
126 Callback to set open state.
127 @param open true to set valve state to open
129 if open: output_index = -1
130 else: output_index = 0
131 self.set_output_index(output_index)