GNU Radio 3.6.5 C++ API

file_meta_sink.h

Go to the documentation of this file.
00001 /* -*- c++ -*- */
00002 /*
00003  * Copyright 2012 Free Software Foundation, Inc.
00004  *
00005  * This file is part of GNU Radio
00006  *
00007  * GNU Radio is free software; you can redistribute it and/or modify
00008  * it under the terms of the GNU General Public License as published by
00009  * the Free Software Foundation; either version 3, or (at your option)
00010  * any later version.
00011  *
00012  * GNU Radio is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015  * GNU General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU General Public License
00018  * along with GNU Radio; see the file COPYING.  If not, write to
00019  * the Free Software Foundation, Inc., 51 Franklin Street,
00020  * Boston, MA 02110-1301, USA.
00021  */
00022 
00023 #ifndef INCLUDED_BLOCKS_FILE_META_SINK_H
00024 #define INCLUDED_BLOCKS_FILE_META_SINK_H
00025 
00026 #include <blocks/api.h>
00027 #include <gr_sync_block.h>
00028 
00029 namespace gr {
00030   namespace blocks {
00031 
00032     const char METADATA_VERSION = 0;
00033     const size_t METADATA_HEADER_SIZE = 149;
00034 
00035     enum gr_file_types {
00036       GR_FILE_BYTE=0,
00037       GR_FILE_CHAR=0,
00038       GR_FILE_SHORT=1,
00039       GR_FILE_INT,
00040       GR_FILE_LONG,
00041       GR_FILE_LONG_LONG,
00042       GR_FILE_FLOAT,
00043       GR_FILE_DOUBLE,
00044     };
00045 
00046     /*!
00047      * \brief Write stream to file with meta-data headers.
00048      * \ingroup file_operators_blk
00049      *
00050      * \details
00051      * These files represent data as binary information in between
00052      * meta-data headers. The headers contain information about the
00053      * type of data and properties of the data in the next segment of
00054      * samples. The information includes:
00055      *
00056      *   rx_rate (double): sample rate of data.
00057      *   rx_time (uint64_t, double): time stamp of first sample in segment.
00058      *   size (uint32_t): item size in bytes.
00059      *   type (gr_file_types as int32_t): data type.
00060      *   cplx (bool): Is data complex?
00061      *   strt (uint64_t): Starting byte of data in this segment.
00062      *   bytes (uint64_t): Size in bytes of data in this segment.
00063      *
00064      * Tags can be sent to the file to update the information, which
00065      * will create a new header. Headers are found by searching from
00066      * the first header (at position 0 in the file) and reading where
00067      * the data segment starts plus the data segment size. Following
00068      * will either be a new header or EOF.
00069      */
00070     class BLOCKS_API file_meta_sink : virtual public gr_sync_block
00071     {
00072     public:
00073       // gr::blocks::file_meta_sink::sptr
00074       typedef boost::shared_ptr<file_meta_sink> sptr;
00075 
00076       /*!
00077        * \brief Create a meta-data file sink.
00078        *
00079        * \param itemsize (size_t): Size of data type.
00080        * \param filename (string): Name of file to write data to.
00081        * \param samp_rate (double): Sample rate of data. If sample rate will be
00082        *    set by a tag, such as rx_tag from a UHD source, this is
00083        *    basically ignored.
00084        * \param relative_rate (double): Rate chance from source of sample
00085        *    rate tag to sink.
00086        * \param type (gr_file_types): Data type (int, float, etc.)
00087        * \param complex (bool): If data stream is complex
00088        * \param max_segment_size (size_t): Length of a single segment
00089        *    before the header is repeated (in items).
00090        * \param extra_dict (string): a serialized PMT dictionary of extra
00091        *    information. Currently not supported.
00092        * \param detached_header (bool): Set to true to store the header
00093        *    info in a separate file (named filename.hdr)
00094        */
00095       static sptr make(size_t itemsize, const std::string &filename,
00096                        double samp_rate=1, double relative_rate=1,
00097                        gr_file_types type=GR_FILE_FLOAT, bool complex=true,
00098                        size_t max_segment_size=1000000,
00099                        const std::string &extra_dict="",
00100                        bool detached_header=false);
00101 
00102       virtual bool open(const std::string &filename) = 0;
00103       virtual void close() = 0;
00104       virtual void do_update() = 0;
00105 
00106       virtual void set_unbuffered(bool unbuffered) = 0;
00107     };
00108 
00109   } /* namespace blocks */
00110 } /* namespace gr */
00111 
00112 #endif /* INCLUDED_BLOCKS_FILE_META_SINK_H */