Refactored loading code for .hsgr file

2016-10-18 01:32:52 +02:00
parent ae157d0b4f
commit b7ee38eca7
5 changed files with 102 additions and 103 deletions
@@ -0,0 +1,68 @@
+#ifndef OSRM_STORAGE_IO_HPP_
+#define OSRM_STORAGE_IO_HPP_
+
+#include "util/fingerprint.hpp"
+#include "util/simple_logger.hpp"
+
+#include <boost/filesystem/fstream.hpp>
+
+#include <tuple>
+
+namespace osrm
+{
+namespace storage
+{
+namespace io
+{
+
+#pragma pack(push, 1)
+struct HSGRHeader
+{
+    std::uint32_t checksum;
+    std::uint32_t number_of_nodes;
+    std::uint32_t number_of_edges;
+};
+#pragma pack(pop)
+static_assert(sizeof(HSGRHeader) == 12, "HSGRHeader is not packed");
+
+// Returns the checksum and the number of nodes and number of edges
+inline HSGRHeader readHSGRHeader(boost::filesystem::ifstream &input_stream)
+{
+    const util::FingerPrint fingerprint_valid = util::FingerPrint::GetValid();
+    util::FingerPrint fingerprint_loaded;
+    input_stream.read(reinterpret_cast<char *>(&fingerprint_loaded), sizeof(util::FingerPrint));
+    if (!fingerprint_loaded.TestGraphUtil(fingerprint_valid))
+    {
+        util::SimpleLogger().Write(logWARNING) << ".hsgr was prepared with different build.\n"
+                                                  "Reprocess to get rid of this warning.";
+    }
+
+    HSGRHeader header;
+    input_stream.read(reinterpret_cast<char *>(&header.checksum), sizeof(header.checksum));
+    input_stream.read(reinterpret_cast<char *>(&header.number_of_nodes), sizeof(header.number_of_nodes));
+    input_stream.read(reinterpret_cast<char *>(&header.number_of_edges), sizeof(header.number_of_edges));
+
+    BOOST_ASSERT_MSG(0 != header.number_of_nodes, "number of nodes is zero");
+    // number of edges can be zero, this is the case in a few test fixtures
+
+    return header;
+}
+
+// Needs to be called after getHSGRSize() to get the correct offset in the stream
+// 
+template <typename NodeT, typename EdgeT>
+void readHSGR(boost::filesystem::ifstream &input_stream,
+              NodeT *node_buffer,
+              std::uint32_t number_of_nodes,
+              EdgeT *edge_buffer,
+              std::uint32_t number_of_edges)
+{
+    input_stream.read(reinterpret_cast<char *>(node_buffer), number_of_nodes * sizeof(NodeT));
+    input_stream.read(reinterpret_cast<char *>(edge_buffer), number_of_edges * sizeof(EdgeT));
+}
+
+}
+}
+}
+
+#endif