Make tracking of file size the responsibility of the Reader

The Decompressor class doesn't have to know and doesn't care.

Author: joto

include/osmium/io/compression.hpp

@@ -90,7 +90,6 @@ namespace osmium {
 
         class Decompressor {
 
-            std::atomic<std::size_t> m_file_size{0};
             std::atomic<std::size_t> m_offset{0};
 
             std::atomic_bool m_want_buffered_pages_removed{false};
@@ -119,14 +118,6 @@ namespace osmium {
                 return true;
             }
 
-            std::size_t file_size() const noexcept {
-                return m_file_size;
-            }
-
-            void set_file_size(const std::size_t size) noexcept {
-                m_file_size = size;
-            }
-
             std::size_t offset() const noexcept {
                 return m_offset;
             }
@@ -222,9 +213,7 @@ namespace osmium {
 
             std::unique_ptr<osmium::io::Decompressor> create_decompressor(const osmium::io::file_compression compression, const int fd) const {
                 const auto callbacks = find_callbacks(compression);
-                auto p = std::unique_ptr<osmium::io::Decompressor>(std::get<1>(callbacks)(fd));
-                p->set_file_size(osmium::file_size(fd));
-                return p;
+                return std::unique_ptr<osmium::io::Decompressor>(std::get<1>(callbacks)(fd));
             }
 
             std::unique_ptr<osmium::io::Decompressor> create_decompressor(const osmium::io::file_compression compression, const char* buffer, const std::size_t size) const {

include/osmium/io/reader.hpp

@@ -322,7 +322,7 @@ namespace osmium {
                 m_read_thread_manager(*m_decompressor, m_input_queue),
                 m_osmdata_queue(detail::get_osmdata_queue_size(), "parser_results"),
                 m_osmdata_queue_wrapper(m_osmdata_queue),
-                m_file_size(m_decompressor->is_real() ? m_decompressor->file_size() : osmium::file_size(m_fd)) {
+                m_file_size(m_fd > 2 ? osmium::file_size(m_fd) : 0) {
 
                 (void)std::initializer_list<int>{
                     (set_option(args), 0)...