commit e13abda470c347f95cb2bc9fc499bf93d1f85a68 Author: Mike Perry mikeperry-git@fscked.org Date: Thu Aug 23 20:27:41 2012 -0700

Bug 6647: Use correct scale constant and prevent rounding error

We were effectively resetting our counts, and the rounding error leads to incorrect log messages. --- src/or/circuitbuild.c | 23 ++++++++++++++--------- 1 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c index 8ad6d17..fc4d4ae 100644 --- a/src/or/circuitbuild.c +++ b/src/or/circuitbuild.c @@ -2601,12 +2601,12 @@ pathbias_get_scale_threshold(const or_options_t *options) static int pathbias_get_scale_factor(const or_options_t *options) { -#define DFLT_PATH_BIAS_SCALE_FACTOR 4 +#define DFLT_PATH_BIAS_SCALE_FACTOR 2 if (options->PathBiasScaleFactor >= 1) return options->PathBiasScaleFactor; else return networkstatus_get_param(NULL, "pb_scalefactor", - DFLT_PATH_BIAS_SCALE_THRESHOLD, 1, INT32_MAX); + DFLT_PATH_BIAS_SCALE_FACTOR, 1, INT32_MAX); }

static const char * @@ -2859,13 +2859,18 @@ entry_guard_inc_first_hop_count(entry_guard_t *guard) /* If we get a ton of circuits, just scale everything down */ if (guard->first_hops > (unsigned)pathbias_get_scale_threshold(options)) { const int scale_factor = pathbias_get_scale_factor(options); - log_info(LD_PROTOCOL, - "Scaling pathbias counts to (%u/%u)/%d for guard %s=%s", - guard->circuit_successes, guard->first_hops, - scale_factor, guard->nickname, hex_str(guard->identity, - DIGEST_LEN)); - guard->first_hops /= scale_factor; - guard->circuit_successes /= scale_factor; + /* For now, only scale if there will be no rounding error... + * XXX024: We want to switch to a real moving average for 0.2.4. */ + if ((guard->first_hops % scale_factor) == 0 && + (guard->circuit_successes % scale_factor) == 0) { + log_info(LD_PROTOCOL, + "Scaling pathbias counts to (%u/%u)/%d for guard %s=%s", + guard->circuit_successes, guard->first_hops, + scale_factor, guard->nickname, hex_str(guard->identity, + DIGEST_LEN)); + guard->first_hops /= scale_factor; + guard->circuit_successes /= scale_factor; + } } guard->first_hops++; log_info(LD_PROTOCOL, "Got success count %u/%u for guard %s=%s",