+
+SegmentWriter::SegmentWriter(OutputStream &output, struct uuid u)
+ : out(output),
+ id(u),
+ object_stream(NULL)
+{
+ /* Write out the segment header first. */
+ static const char signature[] = "LBSSEG0\n";
+ out.write(signature, strlen(signature));
+ out.write(id.bytes, sizeof(struct uuid));
+}
+
+SegmentWriter::~SegmentWriter()
+{
+ if (object_stream)
+ finish_object();
+
+ // Write out the object table which gives the sizes and locations of all
+ // objects, and then add the trailing signature, which indicates the end of
+ // the segment and gives the offset of the object table.
+ int64_t index_offset = out.get_pos();
+
+ for (object_table::const_iterator i = objects.begin();
+ i != objects.end(); ++i) {
+ out.write_s64(i->first);
+ out.write_s64(i->second);
+ }
+
+ static const char signature2[] = "LBSEND";
+ out.write(signature2, strlen(signature2));
+ out.write_s64(index_offset);
+ out.write_u32(objects.size());
+}
+
+OutputStream *SegmentWriter::new_object()
+{
+ if (object_stream)
+ finish_object();
+
+ object_start_offset = out.get_pos();
+ object_stream = new WrapperOutputStream(out);
+
+ return object_stream;
+}
+
+void SegmentWriter::finish_object()
+{
+ assert(object_stream != NULL);
+
+ // store (start, length) information for locating this object
+ objects.push_back(std::make_pair(object_start_offset,
+ object_stream->get_pos()));
+
+ delete object_stream;
+ object_stream = NULL;
+}
+
+struct uuid SegmentWriter::generate_uuid()
+{
+ struct uuid u;
+
+ uuid_generate(u.bytes);
+
+ return u;
+}
+
+string SegmentWriter::format_uuid(const struct uuid u)
+{
+ // A UUID only takes 36 bytes, plus the trailing '\0', so this is safe.
+ char buf[40];
+
+ uuid_unparse_lower(u.bytes, buf);
+
+ return string(buf);
+}