[9fans] I hate to insist... (Was: Venti for Fossil)

[9fans] I hate to insist... (Was: Venti for Fossil)

[Lucio De Re]

I appreciate that some of my previous questions may have been a little
uninformed, but now I really would like a simple answer:

  In /sys/src/cmd/venti/fmtindex.c, the last section starts

	addr = IndexBase;
	n = 0;
	...

  and seemingly proceeeds to compute arena maps (amap[n]) based on the
  arena size

	amap[n].start = addr;
	addr += ap->arenas[j]->size;
	amap[n].stop = addr;

  with, later:

	ix->amap = amap;

  Why is the start address "IndexBase" and not "ArenaBase"?  And, in
  my opinion, "addr" should be incremented by

	ap->arenas[j]->size + 2 * ap->arenas[j]->blockSize

  because ap->arenas[j]->size is generated (in arena.c:/initArena) by

	arena->size = size - 2 * blockSize;

Please someone tell me where I'm going wrong!

++L