Consolidate file reading through the new FileReader class/interface. (#3321)

include/extractor/raster_source.hpp

@@ -10,6 +10,7 @@
 #include <boost/filesystem/fstream.hpp>
 #include <boost/spirit/include/qi.hpp>
 #include <boost/spirit/include/qi_int.hpp>
+#include <storage/io.hpp>
 
 #include <iterator>
 #include <unordered_map>
@@ -43,20 +44,14 @@ class RasterGrid
         ydim = _ydim;
         _data.reserve(ydim * xdim);
 
-        boost::filesystem::ifstream stream(filepath, std::ios::binary);
-        if (!stream)
-        {
-            throw util::exception("Unable to open raster file.");
-        }
+        storage::io::FileReader file_reader(filepath, storage::io::FileReader::HasNoFingerprint);
 
-        stream.seekg(0, std::ios_base::end);
         std::string buffer;
-        buffer.resize(static_cast<std::size_t>(stream.tellg()));
-
-        stream.seekg(0, std::ios_base::beg);
+        buffer.resize(file_reader.Size());
 
         BOOST_ASSERT(buffer.size() > 1);
-        stream.read(&buffer[0], static_cast<std::streamsize>(buffer.size()));
+
+        file_reader.ReadInto(&buffer[0], buffer.size());
 
         boost::algorithm::trim(buffer);