GNU Radio C++ API Reference g90d26cb
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tagged_stream_block.h
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1/* -*- c++ -*- */
2/*
3 * Copyright 2013 Free Software Foundation, Inc.
4 * Copyright 2025 Marcus Müller <mmueller@gnuradio.org>
5 *
6 * This file is part of GNU Radio
7 *
8 * SPDX-License-Identifier: GPL-3.0-or-later
9 *
10 */
11
12#ifndef INCLUDED_GR_RUNTIME_TAGGED_STREAM_BLOCK_H
13#define INCLUDED_GR_RUNTIME_TAGGED_STREAM_BLOCK_H
14
15#include <gnuradio/api.h>
16#include <gnuradio/block.h>
17
18namespace gr {
19
20/*!
21 * \brief Block that operates on PDUs in form of tagged streams
22 * \ingroup base_blk
23 *
24 * Override work to provide the signal processing implementation.
25 */
27{
28private:
30 d_length_tag_key; //!< This is the key for the tag that stores the PDU length
32 d_n_input_items_reqd; //!< How many input items do I need to process the next PDU?
33
34protected:
36 tagged_stream_block(void) {} // allows pure virtual interface sub-classes
37 tagged_stream_block(const std::string& name,
38 gr::io_signature::sptr input_signature,
39 gr::io_signature::sptr output_signature,
40 const std::string& length_tag_key);
41
42 /*!
43 * \brief Given a [start,end), returns a vector of all tags in the range.
44 *
45 * \see block::get_tags_in_range
46 *
47 * Does the same as block::get_tags_in_range, but omits the length_tag_key-tagged
48 * tags.
49 *
50 * In context of a class derived from tagged_stream_block, `get_tags_in_range` gets
51 * resolved to this implementation. Cast to the `gr::block` base class to access the
52 * original (i.e., length tag key-including) `block::get_tags_in_range`.
53 *
54 * \param v a vector reference to return tags into
55 * \param which_input an integer of which input stream to pull from
56 * \param abs_start a uint64 count of the start of the range of interest
57 * \param abs_end a uint64 count of the end of the range of interest
58 */
60 unsigned int which_input,
61 uint64_t abs_start,
62 uint64_t abs_end);
63 /*!
64 * \brief Given a [start,end), returns a vector of all tags in the range.
65 *
66 * \see block::get_tags_in_range
67 *
68 * Does the same as block::get_tags_in_range, but omits the length_tag_key-tagged
69 * tags.
70 *
71 * In context of a class derived from tagged_stream_block, `get_tags_in_range` gets
72 * resolved to this implementation. Cast to the `gr::block` base class to access the
73 * original (i.e., length tag key-including) `block::get_tags_in_range`.
74 *
75 * \param v a vector reference to return tags into
76 * \param which_input an integer of which input stream to pull from
77 * \param abs_start a uint64 count of the start of the range of interest
78 * \param abs_end a uint64 count of the end of the range of interest
79 * \param key a PMT symbol key to filter only tags of this key
80 */
82 unsigned int which_input,
83 uint64_t abs_start,
84 uint64_t abs_end,
85 const pmt::pmt_t& key);
86 /*!
87 * \brief Gets all tags within the relative window of the current call to work.
88 *
89 * \see block::get_tags_in_window
90 *
91 * Does the same as block::get_tags_in_window, but omits the length_tag_key-tagged
92 * tags.
93 *
94 * In context of a class derived from tagged_stream_block, `get_tags_in_window` gets
95 * resolved to this implementation. Cast to the `gr::block` base class to access the
96 * original (i.e., length tag key-including) `block::get_tags_in_window`.
97 *
98 *
99 * \param v a vector reference to return tags into
100 * \param which_input an integer of which input stream to pull from
101 * \param rel_start a uint64 count of the start of the range of interest
102 * \param rel_end a uint64 count of the end of the range of interest
103 */
105 unsigned int which_input,
106 uint64_t rel_start,
107 uint64_t rel_end);
108
109 /*!
110 * \brief Gets all tags within the relative window of the current call to work,
111 * matching \p key
112 *
113 * \see block::get_tags_in_window
114 *
115 * Does the same as block::get_tags_in_window, but omits the length_tag_key-tagged
116 * tags.
117 *
118 * In context of a class derived from tagged_stream_block, `get_tags_in_window` gets
119 * resolved to this implementation. Cast to the `gr::block` base class to access the
120 * original (i.e., length tag key-including) `block::get_tags_in_window`.
121 *
122 * \param v a vector reference to return tags into
123 * \param which_input an integer of which input stream to pull from
124 * \param rel_start a uint64 count of the start of the range of interest
125 * \param rel_end a uint64 count of the end of the range of interest
126 * \param key a PMT symbol key to filter only tags of this key
127 */
129 unsigned int which_input,
130 uint64_t rel_start,
131 uint64_t rel_end,
132 const pmt::pmt_t& key);
133
134 /*!
135 * \brief Parse all tags on the first sample of a PDU, return the
136 * number of items per input and prune the length tags.
137 *
138 * In most cases, you don't need to override this, unless the
139 * number of items read is not directly coded in one single tag.
140 *
141 * Default behaviour:
142 * - Go through all input ports
143 * - On every input port, search for the tag with the key specified in \p
144 * length_tag_key
145 * - Copy that value as an int to the corresponding position in \p n_input_items_reqd
146 * - Remove the length tag.
147 *
148 * \param[in] tags All the tags found on the first item of every input port.
149 * \param[out] n_input_items_reqd Number of items which will be read from every input
150 */
152 gr_vector_int& n_input_items_reqd);
153
154 /*!
155 * \brief Calculate the number of output items.
156 *
157 * This is basically the inverse function to forecast(): Given a
158 * number of input items, it returns the maximum number of output
159 * items.
160 *
161 * You most likely need to override this function, unless your
162 * block is a sync block or integer interpolator/decimator.
163 */
164 virtual int calculate_output_stream_length(const gr_vector_int& ninput_items);
165
166 /*!
167 * \brief Set the new length tags on the output stream
168 *
169 * Default behaviour: Set a tag with key \p length_tag_key and the
170 * number of produced items on every output port.
171 *
172 * For anything else, override this.
173 *
174 * \param n_produced Length of the new PDU
175 * \param n_ports Number of output ports
176 */
177 virtual void update_length_tags(int n_produced, int n_ports);
178
179public:
180 /*! \brief Don't override this.
181 */
182 void /* final */ forecast(int noutput_items,
183 gr_vector_int& ninput_items_required) override;
184
185 bool check_topology(int ninputs, int /* noutputs */) override;
186
187 /*!
188 * - Reads the number of input items from the tags using parse_length_tags()
189 * - Checks there's enough data on the input and output buffers
190 * - If not, inform the scheduler and do nothing
191 * - Calls work() with the exact number of items per PDU
192 * - Updates the tags using update_length_tags()
193 */
194 int general_work(int noutput_items,
195 gr_vector_int& ninput_items,
196 gr_vector_const_void_star& input_items,
197 gr_vector_void_star& output_items) override;
198
199 /*!
200 * \brief Just like gr::block::general_work, but makes sure the input is valid
201 *
202 * The user must override work to define the signal processing
203 * code. Check the documentation for general_work() to see what
204 * happens here.
205 *
206 * Like gr::sync_block, this calls consume() for you (it consumes
207 * ninput_items[i] items from the i-th port).
208 *
209 * A note on tag propagation: The PDU length tags are handled by
210 * other functions, but all other tags are handled just as in any
211 * other \p gr::block. So, most likely, you either set the tag
212 * propagation policy to TPP_DONT and handle the tag propagation
213 * manually, or you propagate tags through the scheduler and don't
214 * do anything here.
215 *
216 * \param noutput_items The size of the writable output buffer
217 * \param ninput_items The exact size of the items on every input for this particular
218 * PDU. These will be consumed if a length tag key is provided! \param input_items See
219 * gr::block \param output_items See gr::block
220 */
221 virtual int work(int noutput_items,
222 gr_vector_int& ninput_items,
223 gr_vector_const_void_star& input_items,
224 gr_vector_void_star& output_items) = 0;
225};
226
227} /* namespace gr */
228
229#endif /* INCLUDED_GR_RUNTIME_TAGGED_STREAM_BLOCK_H */
The abstract base class for all 'terminal' processing blocks.
Definition gnuradio-runtime/include/gnuradio/block.h:65
std::shared_ptr< io_signature > sptr
Definition io_signature.h:52
Block that operates on PDUs in form of tagged streams.
Definition tagged_stream_block.h:27
std::string d_length_tag_key_str
Definition tagged_stream_block.h:35
int general_work(int noutput_items, gr_vector_int &ninput_items, gr_vector_const_void_star &input_items, gr_vector_void_star &output_items) override
void get_tags_in_window(std::vector< tag_t > &v, unsigned int which_input, uint64_t rel_start, uint64_t rel_end)
Gets all tags within the relative window of the current call to work.
void get_tags_in_range(std::vector< tag_t > &v, unsigned int which_input, uint64_t abs_start, uint64_t abs_end)
Given a [start,end), returns a vector of all tags in the range.
tagged_stream_block(const std::string &name, gr::io_signature::sptr input_signature, gr::io_signature::sptr output_signature, const std::string &length_tag_key)
tagged_stream_block(void)
Definition tagged_stream_block.h:36
void get_tags_in_range(std::vector< tag_t > &v, unsigned int which_input, uint64_t abs_start, uint64_t abs_end, const pmt::pmt_t &key)
Given a [start,end), returns a vector of all tags in the range.
bool check_topology(int ninputs, int) override
Confirm that ninputs and noutputs is an acceptable combination.
virtual int calculate_output_stream_length(const gr_vector_int &ninput_items)
Calculate the number of output items.
virtual void parse_length_tags(const std::vector< std::vector< tag_t > > &tags, gr_vector_int &n_input_items_reqd)
Parse all tags on the first sample of a PDU, return the number of items per input and prune the lengt...
void forecast(int noutput_items, gr_vector_int &ninput_items_required) override
Don't override this.
virtual void update_length_tags(int n_produced, int n_ports)
Set the new length tags on the output stream.
void get_tags_in_window(std::vector< tag_t > &v, unsigned int which_input, uint64_t rel_start, uint64_t rel_end, const pmt::pmt_t &key)
Gets all tags within the relative window of the current call to work, matching key.
virtual int work(int noutput_items, gr_vector_int &ninput_items, gr_vector_const_void_star &input_items, gr_vector_void_star &output_items)=0
Just like gr::block::general_work, but makes sure the input is valid.
#define GR_RUNTIME_API
Definition gnuradio-runtime/include/gnuradio/api.h:18
GNU Radio logging wrapper.
Definition basic_block.h:29
std::shared_ptr< pmt_base > pmt_t
typedef for shared pointer (transparent reference counting).
Definition pmt.h:85
Definition cc_common.h:35