On Thu, 2006-09-07 at 21:14 +0200, Philip Van Hoof wrote:
> The *new*/*extra* idea is to create a second index file which contains
> the offsets to the pointers in the camel summary file. Then mmap also
> that file. "Extra" because the idea will build on top of the existing
Ummm, but this won't reduce your working set by very much, will it?
I haven't looked at the details, but can't you just keep an array in
memory with pointers to the *start* of each summary block, and then
compute the other pointers on demand?
Sort of
gpointer *pointers_to_message_summaries;
gpointer base;
base = mmap ("summary");
pointers_to_message_summaries = g_new (gpointer, num_messages);
pointers_to_message_summaries[0] = base;
pointers_to_message_summaries[1] = ...;
and then a set of functions
gpointer
gimme_ptr_to_subject_for_message_number (int n)
{
return pointers_to_message_summaries[n] + SUBJECT_OFFSET;
}
etc. Then, instead of 120 bytes per message, you'd have just
sizeof(pointer) and a little more code to compute the offsets on demand.
Federico
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