osmium_read_with_progress.cpp 1.79 KB
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/*

  EXAMPLE osmium_read_with_progress

  Reads the contents of the input file showing a progress bar.

  DEMONSTRATES USE OF:
  * file input
  * ProgressBar utility function

  SIMPLER EXAMPLES you might want to understand first:
  * osmium_read

  LICENSE
  The code in this example file is released into the Public Domain.

*/

#include <cstdlib>  // for std::exit
#include <iostream> // for std::cerr

// Allow any format of input files (XML, PBF, ...)
#include <osmium/io/any_input.hpp>

// Get access to isatty utility function and progress bar utility class.
#include <osmium/util/file.hpp>
#include <osmium/util/progress_bar.hpp>

int main(int argc, char* argv[]) {
    if (argc != 2) {
        std::cerr << "Usage: " << argv[0] << " OSMFILE\n";
        std::exit(1);
    }

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    try {
        // The Reader is initialized here with an osmium::io::File, but could
        // also be directly initialized with a file name.
        osmium::io::File input_file{argv[1]};
        osmium::io::Reader reader{input_file};

        // Initialize progress bar, enable it only if STDERR is a TTY.
        osmium::ProgressBar progress{reader.file_size(), osmium::isatty(2)};

        // OSM data comes in buffers, read until there are no more.
        while (osmium::memory::Buffer buffer = reader.read()) {
            // Update progress bar for each buffer.
            progress.update(reader.offset());
        }

        // Progress bar is done.
        progress.done();

        // You do not have to close the Reader explicitly, but because the
        // destructor can't throw, you will not see any errors otherwise.
        reader.close();
    } catch (const std::exception& e) {
        // All exceptions used by the Osmium library derive from std::exception.
        std::cerr << e.what() << '\n';
        std::exit(1);
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    }
}