From 52db5c2539413aded9a7fb855030c6a3a7a25798 Mon Sep 17 00:00:00 2001 From: Nick Mathewson Date: Tue, 21 Sep 2010 14:59:43 -0400 Subject: Even more accurate handling for shifting accounting intervals Roger correctly pointed out that my code was broken for accounting periods that shifted forwards, since start_of_accounting_period_containing(interval_start_time) would not be equal to interval_start_time, but potentially much earlier. --- src/or/hibernate.c | 29 ++++++++++++++++++----------- 1 file changed, 18 insertions(+), 11 deletions(-) (limited to 'src/or/hibernate.c') diff --git a/src/or/hibernate.c b/src/or/hibernate.c index 994b7ea932..eb9c1cf6d6 100644 --- a/src/or/hibernate.c +++ b/src/or/hibernate.c @@ -354,31 +354,38 @@ length_of_accounting_period_containing(time_t now) void configure_accounting(time_t now) { + time_t s_now; /* Try to remember our recorded usage. */ if (!interval_start_time) read_bandwidth_usage(); /* If we fail, we'll leave values at zero, and * reset below.*/ - if (!interval_start_time || - start_of_accounting_period_after(interval_start_time) <= now) { - /* We didn't have recorded usage, or we don't have recorded usage - * for this interval. Start a new interval. */ + + s_now = start_of_accounting_period_containing(now); + + if (!interval_start_time) { + /* We didn't have recorded usage; Start a new interval. */ log_info(LD_ACCT, "Starting new accounting interval."); reset_accounting(now); - } else if (interval_start_time == - start_of_accounting_period_containing(interval_start_time)) { + } else if (s_now == interval_start_time) { log_info(LD_ACCT, "Continuing accounting interval."); /* We are in the interval we thought we were in. Do nothing.*/ interval_end_time = start_of_accounting_period_after(interval_start_time); } else { - time_t s_now = start_of_accounting_period_containing(interval_start_time); - long duration = length_of_accounting_period_containing(interval_start_time); + long duration = length_of_accounting_period_containing(now); double delta = ((double)(s_now - interval_start_time)) / duration; if (-0.50 <= delta && delta <= 0.50) { - /* The start of the period is now a little later than we remembered. - * That's fine; we might lose a little time, but that's ok. */ + /* The start of the period is now a little later or earlier than we + * remembered. That's fine; we might lose some bytes we could otherwise + * have written, but better to err on the side of obeying people's + * accounting settings. */ log_info(LD_ACCT, "Accounting interval moved by %.02f%%; " "that's fine.", delta*100); - interval_end_time = start_of_accounting_period_after(interval_start_time); + interval_end_time = start_of_accounting_period_after(now); + } else if (delta >= 0.99) { + /* This is the regular time-moved-forward case; don't be too noisy + * about it or people will complain */ + log_info(LD_ACCT, "Accounting interval elapsed; starting a new one"); + reset_accounting(now); } else { log_warn(LD_ACCT, "Mismatched accounting interval: moved by %.02f%%. " -- cgit v1.2.3-54-g00ecf