Line data    Source code

       1             : #include "../../burp.h"
       2             : #include "../backup_phase1.h"
       3             : #include "blocklen.h"
       4             : 
       5             : #include <math.h>
       6             : 
       7             : // Use the same MAX_BLOCK_SIZE as rsync.
       8             : #define MAX_BLOCK_SIZE ((uint32_t)1 << 17)
       9             : 
      10             : /* Need to base librsync block length on the size of the old file, otherwise
      11             :    the risk of librsync collisions and silent corruption increases as the
      12             :    size of the new file gets bigger. */
      13          16 : size_t get_librsync_block_len(const char *endfile)
      14             : {
      15          16 :         size_t ret=0;
      16          16 :         uint64_t oldlen=0;
      17          16 :         oldlen=strtoull(endfile, NULL, 10);
      18             :         // round to a multiple of 16.
      19          16 :         ret=(size_t)(ceil((sqrt((double)oldlen))/16)*16);
      20          16 :         if(ret<64) return 64; // minimum of 64 bytes.
      21          13 :         if(ret>MAX_BLOCK_SIZE) return MAX_BLOCK_SIZE;
      22           9 :         return ret;
      23             : }