Libosmium: include/osmium/io/reader.hpp Source File

Libosmium Fast and flexible C++ library for working with OpenStreetMap data

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reader.hpp
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1#ifndef OSMIUM_IO_READER_HPP
2#define OSMIUM_IO_READER_HPP
3
4/*
5
6This file is part of Osmium (https://osmcode.org/libosmium).
7
8Copyright 2013-2026 Jochen Topf <jochen@topf.org> and others (see README).
9
10Boost Software License - Version 1.0 - August 17th, 2003
11
12Permission is hereby granted, free of charge, to any person or organization
13obtaining a copy of the software and accompanying documentation covered by
14this license (the "Software") to use, reproduce, display, distribute,
15execute, and transmit the Software, and to prepare derivative works of the
16Software, and to permit third-parties to whom the Software is furnished to
17do so, all subject to the following:
18
19The copyright notices in the Software and this entire statement, including
20the above license grant, this restriction and the following disclaimer,
21must be included in all copies of the Software, in whole or in part, and
22all derivative works of the Software, unless such copies or derivative
23works are solely in the form of machine-executable object code generated by
24a source language processor.
25
26THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
29SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
30FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
31ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
32DEALINGS IN THE SOFTWARE.
33
34*/
35
36#include <osmium/io/compression.hpp>
37#include <osmium/io/detail/input_format.hpp>
38#include <osmium/io/detail/queue_util.hpp>
39#include <osmium/io/detail/read_thread.hpp>
40#include <osmium/io/detail/read_write.hpp>
41#include <osmium/io/error.hpp>
42#include <osmium/io/file.hpp>
43#include <osmium/io/header.hpp>
44#include <osmium/memory/buffer.hpp>
45#include <osmium/osm/entity_bits.hpp>
46#include <osmium/thread/pool.hpp>
47#include <osmium/thread/util.hpp>
48#include <osmium/util/config.hpp>
49
50#include <cerrno>
51#include <cstdlib>
52#include <fcntl.h>
53#include <future>
54#include <memory>
55#include <string>
56#include <system_error>
57#include <thread>
58#include <utility>
59
60#ifndef _WIN32
61# include <sys/wait.h>
62#endif
63
64#ifndef _MSC_VER
65# include <unistd.h>
66#endif
67
68namespace osmium {
69
70 namespace io {
71
72 namespace detail {
73
74 inline std::size_t get_input_queue_size() noexcept {
75 return osmium::config::get_max_queue_size("INPUT", 20);
76 }
77
78 inline std::size_t get_osmdata_queue_size() noexcept {
79 return osmium::config::get_max_queue_size("OSMDATA", 20);
80 }
81
82 } // namespace detail
83
90 class Reader {
91
92 // The Reader::read() function reads from a queue of buffers which
93 // can contain nested buffers. These nested buffers will be in
94 // here, because read() can only return a single unnested buffer.
95 osmium::memory::Buffer m_back_buffers;
96
97 osmium::io::File m_file;
98
99 osmium::thread::Pool* m_pool = nullptr;
100
101 std::atomic<std::size_t> m_offset{0};
102
103 detail::ParserFactory::create_parser_type m_creator;
104
105 enum class status {
106 okay = 0, // normal reading
107 error = 1, // some error occurred while reading
108 closed = 2, // close() called
109 eof = 3 // eof of file was reached without error
110 } m_status = status::okay;
111
112 int m_childpid = 0;
113
114 detail::future_string_queue_type m_input_queue;
115
116 int m_fd = -1;
117
118 std::size_t m_file_size = 0;
119
120 std::unique_ptr<osmium::io::Decompressor> m_decompressor;
121
122 osmium::io::detail::ReadThreadManager m_read_thread_manager;
123
124 detail::future_buffer_queue_type m_osmdata_queue;
125 detail::queue_wrapper<osmium::memory::Buffer> m_osmdata_queue_wrapper;
126
127 std::future<osmium::io::Header> m_header_future;
128 osmium::io::Header m_header;
129
130 osmium::thread::thread_handler m_thread;
131
132 osmium::osm_entity_bits::type m_read_which_entities = osmium::osm_entity_bits::all;
133 osmium::io::read_meta m_read_metadata = osmium::io::read_meta::yes;
134 osmium::io::buffers_type m_buffers_kind = osmium::io::buffers_type::any;
135
136 void set_option(osmium::thread::Pool& pool) noexcept {
137 m_pool = &pool;
138 }
139
140 void set_option(osmium::osm_entity_bits::type value) noexcept {
141 m_read_which_entities = value;
142 }
143
144 void set_option(osmium::io::read_meta value) noexcept {
145 // Ignore this setting if we have a history/change file,
146 // because if this is set to "no", we don't see the difference
147 // between visible and deleted objects.
148 if (!m_file.has_multiple_object_versions()) {
149 m_read_metadata = value;
150 }
151 }
152
153 void set_option(osmium::io::buffers_type value) noexcept {
154 m_buffers_kind = value;
155 }
156
157 // This function will run in a separate thread.
158 static void parser_thread(osmium::thread::Pool& pool,
159 int fd,
160 const detail::ParserFactory::create_parser_type& creator,
161 detail::future_string_queue_type& input_queue,
162 detail::future_buffer_queue_type& osmdata_queue,
163 std::promise<osmium::io::Header>&& header_promise,
164 std::atomic<std::size_t>* offset_ptr,
165 osmium::osm_entity_bits::type read_which_entities,
166 osmium::io::read_meta read_metadata,
167 osmium::io::buffers_type buffers_kind,
168 bool want_buffered_pages_removed) {
169 std::promise<osmium::io::Header> promise{std::move(header_promise)};
170 osmium::io::detail::parser_arguments args = {
171 pool,
172 fd,
173 input_queue,
174 osmdata_queue,
175 promise,
176 offset_ptr,
177 read_which_entities,
178 read_metadata,
179 buffers_kind,
180 want_buffered_pages_removed};
181 creator(args)->parse();
182 }
183
184#ifndef _WIN32
196 static int execute(const std::string& command, const std::string& filename, int* childpid) {
197 int pipefd[2];
198 if (pipe(pipefd) < 0) {
199 throw std::system_error{errno, std::system_category(), "opening pipe failed"};
200 }
201 const pid_t pid = fork();
202 if (pid < 0) {
203 throw std::system_error{errno, std::system_category(), "fork failed"};
204 }
205 if (pid == 0) { // child
206 // close all file descriptors except one end of the pipe
207 for (int i = 0; i < 32; ++i) {
208 if (i != pipefd[1]) {
209 ::close(i);
210 }
211 }
212 if (dup2(pipefd[1], 1) < 0) { // put end of pipe as stdout/stdin
213 std::exit(1); // NOLINT(concurrency-mt-unsafe)
214 }
215
216 ::open("/dev/null", O_RDONLY); // stdin
217 ::open("/dev/null", O_WRONLY); // stderr
218 // hack: -g switches off globbing in curl which allows [] to be used in file names
219 // this is important for XAPI URLs
220 // in theory this execute() function could be used for other commands, but it is
221 // only used for curl at the moment, so this is okay.
222 if (::execlp(command.c_str(), command.c_str(), "-g", filename.c_str(), nullptr) < 0) {
223 std::exit(1); // NOLINT(concurrency-mt-unsafe)
224 }
225 }
226 // parent
227 *childpid = pid;
228 ::close(pipefd[1]);
229 return pipefd[0];
230 }
231#endif
232
241 static int open_input_file_or_url(const std::string& filename, int* childpid) {
242 const std::string protocol{filename.substr(0, filename.find_first_of(':'))};
243 if (protocol == "http" || protocol == "https" || protocol == "ftp" || protocol == "file") {
244#ifndef _WIN32
245 return execute("curl", filename, childpid);
246#else
247 throw io_error{"Reading OSM files from the network currently not supported on Windows."};
248#endif
249 }
250 const int fd = osmium::io::detail::open_for_reading(filename);
251#if defined(__linux__) || defined(__FreeBSD__)
252 if (fd >= 0) {
253 // Tell the kernel we are going to read this file sequentially
254 ::posix_fadvise(fd, 0, 0, POSIX_FADV_SEQUENTIAL);
255 }
256#endif
257 return fd;
258 }
259
260 static std::unique_ptr<Decompressor> make_decompressor(const osmium::io::File& file, int fd, std::atomic<std::size_t>* offset_ptr) {
261 const auto& factory = osmium::io::CompressionFactory::instance();
262 std::unique_ptr<Decompressor> decompressor;
263
264 if (file.buffer()) {
265 decompressor = factory.create_decompressor(file.compression(), file.buffer(), file.buffer_size());
266 } else if (file.format() == file_format::pbf) {
267 decompressor = std::unique_ptr<Decompressor>{new DummyDecompressor{}};
268 } else {
269 decompressor = factory.create_decompressor(file.compression(), fd);
270 }
271
272 decompressor->set_offset_ptr(offset_ptr);
273 return decompressor;
274 }
275
276 public:
277
318 template <typename... TArgs>
319 explicit Reader(const osmium::io::File& file, TArgs&&... args) :
320 m_file(file.check()),
321 m_creator(detail::ParserFactory::instance().get_creator_function(m_file)),
322 m_input_queue(detail::get_input_queue_size(), "raw_input"),
323 m_fd(m_file.buffer() ? -1 : open_input_file_or_url(m_file.filename(), &m_childpid)),
324 m_file_size(m_fd > 2 ? osmium::file_size(m_fd) : 0),
325 m_decompressor(make_decompressor(m_file, m_fd, &m_offset)),
326 m_read_thread_manager(*m_decompressor, m_input_queue),
327 m_osmdata_queue(detail::get_osmdata_queue_size(), "parser_results"),
328 m_osmdata_queue_wrapper(m_osmdata_queue) {
329
330 (void)std::initializer_list<int>{(set_option(std::forward<TArgs>(args)), 0)...};
331
332 if (!m_pool) {
333 m_pool = &thread::Pool::default_instance();
334 }
335
336 std::promise<osmium::io::Header> header_promise;
337 m_header_future = header_promise.get_future();
338
339 const auto cpc = osmium::config::clean_page_cache_after_read();
340 if (cpc >= 0) {
341 m_decompressor->set_want_buffered_pages_removed(true);
342 }
343
344 const int fd_for_parser = m_decompressor->is_real() ? -1 : m_fd;
345 m_thread = osmium::thread::thread_handler{parser_thread, std::ref(*m_pool), fd_for_parser, std::ref(m_creator),
346 std::ref(m_input_queue), std::ref(m_osmdata_queue),
347 std::move(header_promise), &m_offset, m_read_which_entities,
348 m_read_metadata, m_buffers_kind,
349 m_decompressor->want_buffered_pages_removed()};
350 }
351
352 template <typename... TArgs>
353 explicit Reader(const std::string& filename, TArgs&&... args) :
354 Reader(osmium::io::File(filename), std::forward<TArgs>(args)...) {
355 }
356
357 template <typename... TArgs>
358 explicit Reader(const char* filename, TArgs&&... args) :
359 Reader(osmium::io::File(filename), std::forward<TArgs>(args)...) {
360 }
361
362 Reader(const Reader&) = delete;
363 Reader& operator=(const Reader&) = delete;
364
365 Reader(Reader&&) = delete;
366 Reader& operator=(Reader&&) = delete;
367
368 ~Reader() noexcept {
369 try {
370 close();
371 } catch (...) { // NOLINT(bugprone-empty-catch)
372 // Ignore any exceptions because destructor must not throw.
373 }
374 }
375
384 void close() {
385 m_status = status::closed;
386
387 m_read_thread_manager.stop();
388
389 m_osmdata_queue_wrapper.shutdown();
390
391 try {
392 m_read_thread_manager.close();
393 } catch (...) { // NOLINT(bugprone-empty-catch)
394 // Ignore any exceptions.
395 }
396
397#ifndef _WIN32
398 if (m_childpid) {
399 int status = 0;
400 const pid_t pid = ::waitpid(m_childpid, &status, 0);
401#pragma GCC diagnostic push
402#pragma GCC diagnostic ignored "-Wold-style-cast"
403 if (pid < 0 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) { // NOLINT(hicpp-signed-bitwise)
404 throw std::system_error{errno, std::system_category(), "subprocess returned error"};
405 }
406#pragma GCC diagnostic pop
407 m_childpid = 0;
408 }
409#endif
410 }
411
418 osmium::io::Header header() {
419 if (m_status == status::error) {
420 throw io_error{"Can not get header from reader when in status 'error'"};
421 }
422
423 try {
424 if (m_header_future.valid()) {
425 m_header = m_header_future.get();
426 }
427 } catch (...) {
428 close();
429 m_status = status::error;
430 throw;
431 }
432
433 return m_header;
434 }
435
444 osmium::memory::Buffer read() {
445 osmium::memory::Buffer buffer;
446
447 // If there are buffers on the stack, return those first.
448 if (m_back_buffers) {
449 if (m_back_buffers.has_nested_buffers()) {
450 buffer = std::move(*m_back_buffers.get_last_nested());
451 } else {
452 buffer = std::move(m_back_buffers);
453 m_back_buffers = osmium::memory::Buffer{};
454 }
455 return buffer;
456 }
457
458 if (m_status != status::okay) {
459 throw io_error{"Can not read from reader when in status 'closed', 'eof', or 'error'"};
460 }
461
462 if (m_read_which_entities == osmium::osm_entity_bits::nothing) {
463 m_status = status::eof;
464 return buffer;
465 }
466
467 try {
468 // m_input_format.read() can return an invalid buffer to signal EOF,
469 // or a valid buffer with or without data. A valid buffer
470 // without data is not an error, it just means we have to
471 // keep getting the next buffer until there is one with data.
472 while (true) {
473 buffer = m_osmdata_queue_wrapper.pop();
474 if (detail::at_end_of_data(buffer)) {
475 m_status = status::eof;
476 m_read_thread_manager.close();
477 return buffer;
478 }
479 if (buffer.has_nested_buffers()) {
480 m_back_buffers = std::move(buffer);
481 buffer = std::move(*m_back_buffers.get_last_nested());
482 }
483 if (buffer.committed() > 0) {
484 return buffer;
485 }
486 }
487 } catch (...) {
488 close();
489 m_status = status::error;
490 throw;
491 }
492 }
493
498 bool eof() const {
499 return m_status == status::eof || m_status == status::closed;
500 }
501
506 std::size_t file_size() const noexcept {
507 return m_file_size;
508 }
509
524 std::size_t offset() const noexcept {
525 return m_offset;
526 }
527
528 }; // class Reader
529
538 template <typename... TArgs>
539 osmium::memory::Buffer read_file(TArgs&&... args) {
540 osmium::memory::Buffer buffer{1024UL * 1024UL, osmium::memory::Buffer::auto_grow::yes};
541
542 Reader reader{std::forward<TArgs>(args)...};
543 while (auto read_buffer = reader.read()) {
544 buffer.add_buffer(read_buffer);
545 buffer.commit();
546 }
547
548 return buffer;
549 }
550
551 } // namespace io
552
553} // namespace osmium
554
555#endif // OSMIUM_IO_READER_HPP
buffer.hpp
osmium::io::CompressionFactory::instance
static CompressionFactory & instance()
Definition compression.hpp:191
osmium::io::DummyDecompressor
Definition compression.hpp:291
osmium::io::File
Definition file.hpp:72
osmium::io::File::buffer_size
size_t buffer_size() const noexcept
Definition file.hpp:147
osmium::io::File::compression
file_compression compression() const noexcept
Definition file.hpp:294
osmium::io::File::format
file_format format() const noexcept
Definition file.hpp:285
osmium::io::File::buffer
const char * buffer() const noexcept
Definition file.hpp:143
osmium::io::Header
Definition header.hpp:68
osmium::io::Reader
Definition reader.hpp:90
osmium::io::Reader::read
osmium::memory::Buffer read()
Definition reader.hpp:444
osmium::io::Reader::m_buffers_kind
osmium::io::buffers_type m_buffers_kind
Definition reader.hpp:134
osmium::io::Reader::m_input_queue
detail::future_string_queue_type m_input_queue
Definition reader.hpp:114
osmium::io::Reader::m_back_buffers
osmium::memory::Buffer m_back_buffers
Definition reader.hpp:95
osmium::io::Reader::parser_thread
static void parser_thread(osmium::thread::Pool &pool, int fd, const detail::ParserFactory::create_parser_type &creator, detail::future_string_queue_type &input_queue, detail::future_buffer_queue_type &osmdata_queue, std::promise< osmium::io::Header > &&header_promise, std::atomic< std::size_t > *offset_ptr, osmium::osm_entity_bits::type read_which_entities, osmium::io::read_meta read_metadata, osmium::io::buffers_type buffers_kind, bool want_buffered_pages_removed)
Definition reader.hpp:158
osmium::io::Reader::operator=
Reader & operator=(Reader &&)=delete
osmium::io::Reader::m_childpid
int m_childpid
Definition reader.hpp:112
osmium::io::Reader::set_option
void set_option(osmium::io::read_meta value) noexcept
Definition reader.hpp:144
osmium::io::Reader::m_osmdata_queue
detail::future_buffer_queue_type m_osmdata_queue
Definition reader.hpp:124
osmium::io::Reader::make_decompressor
static std::unique_ptr< Decompressor > make_decompressor(const osmium::io::File &file, int fd, std::atomic< std::size_t > *offset_ptr)
Definition reader.hpp:260
osmium::io::Reader::m_file_size
std::size_t m_file_size
Definition reader.hpp:118
osmium::io::Reader::set_option
void set_option(osmium::thread::Pool &pool) noexcept
Definition reader.hpp:136
osmium::io::Reader::set_option
void set_option(osmium::io::buffers_type value) noexcept
Definition reader.hpp:153
osmium::io::Reader::operator=
Reader & operator=(const Reader &)=delete
osmium::io::Reader::execute
static int execute(const std::string &command, const std::string &filename, int *childpid)
Definition reader.hpp:196
osmium::io::Reader::m_status
enum osmium::io::Reader::status m_status
osmium::io::Reader::open_input_file_or_url
static int open_input_file_or_url(const std::string &filename, int *childpid)
Definition reader.hpp:241
osmium::io::Reader::m_decompressor
std::unique_ptr< osmium::io::Decompressor > m_decompressor
Definition reader.hpp:120
osmium::io::Reader::status
status
Definition reader.hpp:105
osmium::io::Reader::status::eof
@ eof
Definition reader.hpp:109
osmium::io::Reader::status::closed
@ closed
Definition reader.hpp:108
osmium::io::Reader::status::error
@ error
Definition reader.hpp:107
osmium::io::Reader::status::okay
@ okay
Definition reader.hpp:106
osmium::io::Reader::Reader
Reader(const char *filename, TArgs &&... args)
Definition reader.hpp:358
osmium::io::Reader::m_header
osmium::io::Header m_header
Definition reader.hpp:128
osmium::io::Reader::m_creator
detail::ParserFactory::create_parser_type m_creator
Definition reader.hpp:103
osmium::io::Reader::header
osmium::io::Header header()
Definition reader.hpp:418
osmium::io::Reader::m_osmdata_queue_wrapper
detail::queue_wrapper< osmium::memory::Buffer > m_osmdata_queue_wrapper
Definition reader.hpp:125
osmium::io::Reader::Reader
Reader(const osmium::io::File &file, TArgs &&... args)
Definition reader.hpp:319
osmium::io::Reader::file_size
std::size_t file_size() const noexcept
Definition reader.hpp:506
osmium::io::Reader::Reader
Reader(Reader &&)=delete
osmium::io::Reader::set_option
void set_option(osmium::osm_entity_bits::type value) noexcept
Definition reader.hpp:140
osmium::io::Reader::m_header_future
std::future< osmium::io::Header > m_header_future
Definition reader.hpp:127
osmium::io::Reader::m_read_thread_manager
osmium::io::detail::ReadThreadManager m_read_thread_manager
Definition reader.hpp:122
osmium::io::Reader::eof
bool eof() const
Definition reader.hpp:498
osmium::io::Reader::Reader
Reader(const Reader &)=delete
osmium::io::Reader::offset
std::size_t offset() const noexcept
Definition reader.hpp:524
osmium::io::Reader::m_offset
std::atomic< std::size_t > m_offset
Definition reader.hpp:101
osmium::io::Reader::m_thread
osmium::thread::thread_handler m_thread
Definition reader.hpp:130
osmium::io::Reader::close
void close()
Definition reader.hpp:384
osmium::io::Reader::~Reader
~Reader() noexcept
Definition reader.hpp:368
osmium::io::Reader::m_file
osmium::io::File m_file
Definition reader.hpp:97
osmium::io::Reader::m_read_which_entities
osmium::osm_entity_bits::type m_read_which_entities
Definition reader.hpp:132
osmium::io::Reader::Reader
Reader(const std::string &filename, TArgs &&... args)
Definition reader.hpp:353
osmium::io::Reader::m_read_metadata
osmium::io::read_meta m_read_metadata
Definition reader.hpp:133
osmium::io::Reader::m_fd
int m_fd
Definition reader.hpp:116
osmium::io::Reader::m_pool
osmium::thread::Pool * m_pool
Definition reader.hpp:99
osmium::thread::Pool
Definition pool.hpp:90
osmium::thread::Pool::default_instance
static Pool & default_instance()
Definition pool.hpp:186
osmium::thread::thread_handler
Definition util.hpp:91
compression.hpp
config.hpp
entity_bits.hpp
error.hpp
header.hpp
file.hpp
detail
Definition attr.hpp:342
osmium::config::get_max_queue_size
std::size_t get_max_queue_size(const char *queue_name, const std::size_t default_value) noexcept
Definition config.hpp:83
osmium::config::clean_page_cache_after_read
int8_t clean_page_cache_after_read() noexcept
Definition config.hpp:106
osmium::io
Everything related to input and output of OSM data.
Definition bzip2_compression.hpp:86
osmium::io::file_format::pbf
@ pbf
Definition file_format.hpp:45
osmium::io::read_file
osmium::memory::Buffer read_file(TArgs &&... args)
Definition reader.hpp:539
osmium::io::buffers_type
buffers_type
Definition file_format.hpp:60
osmium::io::buffers_type::any
@ any
Definition file_format.hpp:61
osmium::io::read_meta
read_meta
Definition file_format.hpp:55
osmium::io::read_meta::yes
@ yes
Definition file_format.hpp:57
osmium::osm_entity_bits::type
type
Definition entity_bits.hpp:65
osmium::osm_entity_bits::all
@ all
object or changeset
Definition entity_bits.hpp:87
osmium::osm_entity_bits::nothing
@ nothing
Definition entity_bits.hpp:69
osmium
Namespace for everything in the Osmium library.
Definition assembler.hpp:53
std
Definition location.hpp:654
pool.hpp
osmium::io_error
Definition error.hpp:46
util.hpp