src/odb.h

   1 #ifndef INCLUDE_odb_h__
   2 #define INCLUDE_odb_h__
   3
   4 /** First 4 bytes of a pack-*.idx file header.
   5  *
   6  * Note this header exists only in idx v2 and later.  The idx v1
   7  * file format does not have a magic sequence at the front, and
   8  * must be detected by the first four bytes *not* being this value
   9  * and the first 8 bytes matching the following expression:
  10  *
  11  *   uint32_t *fanout = ... the file data at offset 0 ...
  12  *   ntohl(fanout[0]) < ntohl(fanout[1])
  13  *
  14  * The value chosen here for PACK_TOC is such that the above
  15  * cannot be true for an idx v1 file.
  16  */
  17 #define PACK_TOC 0xff744f63 /* -1tOc */
  18
  19 #endif