file_meta_source.h

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/* -*- c++ -*- */
/*
 * Copyright 2012 Free Software Foundation, Inc.
 *
 * This file is part of GNU Radio
 *
 * GNU Radio 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, or (at your option)
 * any later version.
 *
 * GNU Radio 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 GNU Radio; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#ifndef INCLUDED_BLOCKS_FILE_META_SOURCE_H
#define INCLUDED_BLOCKS_FILE_META_SOURCE_H

#include <blocks/api.h>
#include <gr_sync_block.h>

namespace gr {
  namespace blocks {

    /*!
     * \brief Reads stream from file with meta-data headers. Headers
     * are parsed into tags.
     * \ingroup file_operators_blk
     *
     * \details
     * The information in the metadata headers includes:
     *
     *   rx_rate (double): sample rate of data.
     *   rx_time (uint64_t, double): time stamp of first sample in segment.
     *   size (uint32_t): item size in bytes.
     *   type (gr_file_types as int32_t): data type.
     *   cplx (bool): Is data complex?
     *   strt (uint64_t): Starting byte of data in this segment.
     *   bytes (uint64_t): Size in bytes of data in this segment.
     *
     * Any item inside of the extra header dictionary is ready out and
     * made into a stream tag.
     */
    class BLOCKS_API file_meta_source : virtual public gr_sync_block
    {
    public:
      // gr::blocks::file_meta_source::sptr
      typedef boost::shared_ptr<file_meta_source> sptr;

      /*!
       * \brief Create a meta-data file source.
       *
       * \param filename (string): Name of file to write data to.
       * \param repeat (bool): Repeats file when EOF is found.
       * \param detached_header (bool): Set to true if header
       *    info is stored in a separate file (usually named filename.hdr)
       * \param hdr_filename (string): Name of detached header file if used.
       *    Defaults to 'filename.hdr' if detached_header is true but this
       *    field is an empty string.
       */
      static sptr make(const std::string &filename,
                       bool repeat=false,
                       bool detached_header=false,
                       const std::string &hdr_filename="");

      virtual bool open(const std::string &filename,
                        const std::string &hdr_filename="") = 0;
      virtual void close() = 0;
      virtual void do_update() = 0;
    };

  } /* namespace blocks */
} /* namespace gr */

#endif /* INCLUDED_BLOCKS_FILE_META_SOURCE_H */