+ struct segment_info *segment;
+
+ // Find the segment into which the object should be written, looking up by
+ // group. If no segment exists yet, create one.
+ if (segments.find(group) == segments.end()) {
+ segment = new segment_info;
+
+ segment->name = generate_uuid();
+
+ string filename = path + "/" + segment->name + ".tar";
+ segment->file = new Tarfile(filename, segment->name);
+
+ segment->count = 0;
+
+ segments[group] = segment;
+ } else {
+ segment = segments[group];
+ }
+
+ int id = segment->count;
+ char id_buf[64];
+ sprintf(id_buf, "%08x", id);
+
+ segment->file->write_object(id, data, len);
+ segment->count++;
+
+ ObjectReference ref(segment->name, id_buf);
+
+ // If this segment meets or exceeds the size target, close it so that
+ // future objects will go into a new segment.
+ if (segment->file->size_estimate() >= SEGMENT_SIZE)
+ close_segment(group);
+
+ return ref;