[generator:preprocess] Fix read ahead the o5m file for asynchronously mode.

generator/CMakeLists.txt

@@ -152,7 +152,7 @@ set(
   world_map_generator.hpp
 )
 
-find_package(Boost REQUIRED COMPONENTS iostreams)
+find_package(Boost REQUIRED COMPONENTS iostreams filesystem)
 
 geocore_add_library(${PROJECT_NAME} ${SRC})
 geocore_link_libraries(${PROJECT_NAME}

generator/intermediate_data.cpp

@@ -3,10 +3,10 @@
 #include "platform/platform.hpp"
 
 #include <atomic>
-#include <future>
 #include <new>
 #include <set>
 #include <string>
+#include <thread>
 
 #include <boost/filesystem.hpp>
 #include <boost/iostreams/device/mapped_file.hpp>
@@ -378,6 +378,7 @@ OSMElementCacheReader::OSMElementCacheReader(string const & name)
   if (!m_fileMap.is_open())
     MYTHROW(Writer::OpenException, ("Failed to open", name));
 
+  // Try aggressively (MADV_WILLNEED) and asynchronously read ahead.
   auto readaheadTask = std::thread([data = m_fileMap.data(), size = m_fileMap.size()] {
     ::madvise(const_cast<char*>(data), size, MADV_WILLNEED);
   });
@@ -514,10 +515,5 @@ shared_ptr<IntermediateDataReader> const & IntermediateData::GetCache() const
 {
   return m_reader;
 }
-
-shared_ptr<IntermediateData const> IntermediateData::Clone() const
-{
-  return shared_from_this();
-}
 }  // namespace cache
 }  // namespace generator

generator/intermediate_data.hpp

@@ -366,12 +366,11 @@ CreatePointStorageReader(feature::GenerateInfo::NodeStorageType type, std::strin
 std::unique_ptr<PointStorageWriterInterface>
 CreatePointStorageWriter(feature::GenerateInfo::NodeStorageType type, std::string const & name);
 
-class IntermediateData : public std::enable_shared_from_this<IntermediateData>
+class IntermediateData
 {
 public:
   explicit IntermediateData(feature::GenerateInfo const & info);
   std::shared_ptr<IntermediateDataReader> const & GetCache() const;
-  std::shared_ptr<IntermediateData const> Clone() const;
 
 private:
   feature::GenerateInfo const & m_info;

generator/osm_source.cpp

@@ -15,7 +15,6 @@
 #include "base/file_name_utils.hpp"
 
 #include <fstream>
-#include <future>
 #include <memory>
 #include <set>
 #include <thread>
@@ -254,11 +253,11 @@ void BuildIntermediateDataFromO5M(
   auto sourceMap = boost::iostreams::mapped_file_source{filename};
   if (!sourceMap.is_open())
     MYTHROW(Writer::OpenException, ("Failed to open", filename));
-  // Try aggressively (MADV_WILLNEED) and asynchronously (std::launch::async) read ahead
-  // the o5m-file.
-  std::async(std::launch::async, [data = sourceMap.data(), size = sourceMap.size()] {
+  // Try aggressively (MADV_WILLNEED) and asynchronously read ahead the o5m-file.
+  auto readaheadTask = std::thread([data = sourceMap.data(), size = sourceMap.size()] {
     ::madvise(const_cast<char*>(data), size, MADV_WILLNEED);
   });
+  readaheadTask.detach();
 
   constexpr size_t chunkSize = 10'000;
   std::vector<std::thread> threads;

generator/raw_generator.cpp

@@ -223,11 +223,11 @@ boost::iostreams::mapped_file_source RawGenerator::MakeFileMap(std::string const
   if (!fileMap.is_open())
     MYTHROW(Writer::OpenException, ("Failed to open", filename));
 
-  // Try aggressively (MADV_WILLNEED) and asynchronously (std::launch::async) read ahead
-  // the o5m-file.
-  std::async(std::launch::async, [data = fileMap.data(), size = fileMap.size()] {
+  // Try aggressively (MADV_WILLNEED) and asynchronously read ahead the o5m-file.
+  auto readaheadTask = std::thread([data = fileMap.data(), size = fileMap.size()] {
     ::madvise(const_cast<char*>(data), size, MADV_WILLNEED);
   });
+  readaheadTask.detach();
 
   return fileMap;
 }

generator/translator.hpp

@@ -47,7 +47,7 @@ protected:
   template <typename T>
   decltype(auto) CloneBase() const
   {
-    auto cache = m_cache->Clone();
+    auto cache = m_cache;
     auto processor = m_processor->Clone();
     auto featureMaker = m_featureMaker->Clone();
     auto filter = m_filter->Clone();