WIP: strings in reflection tables

Working on cctbx/dxtbx#465

This could never have worked. Now trying to make something which does work.
This does not work. This is at least some stubs / breadcrumbs on how it
could work

array_family/reflection_table_msgpack_adapter.h

@@ -175,6 +175,64 @@ MSGPACK_API_VERSION_NAMESPACE(MSGPACK_DEFAULT_API_NS) {
       }
     };
 
+    /**
+     * Overload of above for type std::string
+     */
+    template <>
+    struct pack<scitbx::af::const_ref<std::string> > {
+      template <typename Stream>
+      msgpack::packer<Stream>& operator()(
+        msgpack::packer<Stream>& o,
+        const scitbx::af::const_ref<std::string>& v) const {
+        typedef typename scitbx::af::const_ref<std::string>::const_iterator iterator;
+        std::stringstream buffer;
+        for (iterator it = v.begin(); it != v.end(); ++it) {
+          // N.B. + 1 because NULL terminated
+          uint32_t s = it->size();
+          buffer.write((const char*)&s, sizeof(uint32_t));
+          buffer.write(it->c_str(), (uint32_t)s);
+          std::cout << "Writing string of length " << s << std::endl;
+        }
+        std::string buffer_string = buffer.str();
+        std::cout << "Total size " << buffer_string.size() << std::endl;
+        o.pack_bin(buffer_string.size());
+        o.pack_bin_body(buffer_string.c_str(), buffer_string.size());
+        return o;
+      }
+    };
+
+    /**
+     * Unpacking thereof...
+     */
+
+    scitbx::af::shared<std::string> extract_strings(msgpack::object const& o) {
+      // packed strings are different as the sizes are not uniform ->
+      // we need to pick out the strings one at a time and then push
+      // them onto the back of an array - N.B. these are packed as a
+      // uint32_t size followed by the bytes...
+
+      scitbx::af::shared<std::string> result;
+
+      size_t s;
+
+      std::size_t binary_size = o.via.bin.size;
+
+      std::cout << "Object size is " << binary_size << std::endl;
+      char* ptr = (char*)o.via.bin.ptr;
+
+      while (binary_size > 0) {
+        s = (size_t) * ((uint32_t*)ptr);
+        std::cout << "Reading string of length " << s << std::endl;
+        ptr += sizeof(uint32_t);
+        binary_size -= sizeof(uint32_t);
+        result.push_back(std::string((const char*)ptr, s));
+        ptr += s + 1;
+        binary_size -= s + 1;
+      }
+
+      return result;
+    }
+
     /**
      * Pack a shared<Shoebox<>> into a msgpack array.
      *
@@ -663,7 +721,7 @@ MSGPACK_API_VERSION_NAMESPACE(MSGPACK_DEFAULT_API_NS) {
         } else if (name == "double") {
           v = extract<double>(o.via.array.ptr[1]);
         } else if (name == "std::string") {
-          v = extract<std::string>(o.via.array.ptr[1]);
+          v = extract_strings(o.via.array.ptr[1]);
         } else if (name == "vec2<double>") {
           v = extract<scitbx::vec2<double> >(o.via.array.ptr[1]);
         } else if (name == "vec3<double>") {