-/* swaroop chain file format:
- *
- * 0 [int16_t] IV length
- * 2 [int16_t] cert #1 length, or 0 for none
- * 4 [int16_t] cert #2 length, or 0 for none
- * 6 [int16_t] cert #3 length, or 0 for none
- * 8 [int16_t] cert #4 length, or 0 for none
- * 10 [int16_t] cert #5 length, or 0 for none
- * 12 [int16_t] cert #6 length, or 0 for none
- * 14 [int16_t] cert #7 length, or 0 for none
- * 16 [int16_t] cert #8 length, or 0 for none
- * 16 [int16_t] private key length
- * 20 IV
- * cert #1
- * cert #2
- * cert #3
- * cert #4
- * cert #5
- * cert #6
- * cert #7
- * cert #8
- * private key
- */
+ /* on the order of a second's worth of copying */
+ boost::uintmax_t const chunk = 20 * 1024 * 1024;
+
+ uint8_t* buffer = static_cast<uint8_t*> (malloc(chunk));
+ if (!buffer) {
+ throw std::bad_alloc ();
+ }
+
+ boost::uintmax_t const total = boost::filesystem::file_size (from);
+ boost::uintmax_t remaining = total;
+
+ while (remaining) {
+ boost::uintmax_t this_time = min (chunk, remaining);
+ size_t N = fread (buffer, 1, chunk, f);
+ if (N < this_time) {
+ fclose (f);
+ fclose (t);
+ free (buffer);
+ throw ReadFileError (from, errno);
+ }
+
+ N = fwrite (buffer, 1, this_time, t);
+ if (N < this_time) {
+ fclose (f);
+ fclose (t);
+ free (buffer);
+ throw WriteFileError (to, errno);
+ }
+
+ progress (1 - float(remaining) / total);
+ remaining -= this_time;
+ }