Add metadata buffer class

lib/src/MetadataBuffer.cpp

@@ -0,0 +1,37 @@
+#include "MetadataBuffer.hpp"
+
+using namespace std;
+
+MetadataBuffer::MetadataBuffer(uint64_t n_images, shared_ptr<unordered_map<string, HeaderDataType>> header_values_type) :
+    n_images(n_images), header_values_type(header_values_type)
+{
+    if (header_values_type) {
+        for (const auto& header_type : *header_values_type) {
+	    auto& name = header_type.first;
+            auto& header_data_type = header_type.second;
+
+	    size_t bytes_size_per_frame = header_data_type.value_shape * header_data_type.value_bytes_size;
+	    size_t buffer_size_bytes = n_images * bytes_size_per_frame;
+
+	    shared_ptr<char> buffer(new char[buffer_size_bytes], std::default_delete<char[]>());
+	    metadata_buffer.insert({name, buffer});
+	    metadata_length_bytes.insert({name, bytes_size_per_frame});
+	}
+    }
+}
+
+void MetadataBuffer::add_metadata_to_buffer(string name, uint64_t frame_index, const char* data)
+{
+    size_t bytes_size_per_frame = metadata_length_bytes.at(name);
+    size_t buffer_offset = frame_index * bytes_size_per_frame;
+
+    char* buffer = (metadata_buffer.at(name)).get();
+    buffer += buffer_offset;
+
+    memcpy(buffer, data, bytes_size_per_frame); 
+}
+
+shared_ptr<char> MetadataBuffer::get_metadata_values(string name)
+{
+    return metadata_buffer.at(name);
+}