Optimize cell-ewma circuit priority algorithm.

There are two big changes here:
  - We store active circuits in a priority queue for each or_conn,
    rather than doing a linear search over all the active circuits
    before we send each cell.
  - Rather than multiplying every circuit's cell-ewma by a decay
    factor every time we send a cell (thus normalizing the value of a
    current cell to 1.0 and a past cell to alpha^t), we instead
    only scale down the cell-ewma every tick (ten seconds atm),
    normalizing so that a cell sent at the start of the tick has
    value 1.0).

1 files changed, 3 insertions, 0 deletions

diff --git a/src/or/config.c b/src/or/config.c
index fe5fe9f7ee..a22ec4b13d 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -1379,6 +1379,9 @@ options_act(or_options_t *old_options)
   if (accounting_is_enabled(options))
     configure_accounting(time(NULL));
 
+  /* Change the cell EWMA settings */
+  cell_ewma_set_scale_factor(options);
+
   /* Check for transitions that need action. */
   if (old_options) {
     if (options->UseEntryGuards && !old_options->UseEntryGuards) {