commit 42c4418bed2cdad029404cca39fc60f7d7235aab Author: Nick Mathewson <nickm@torproject.org> Date: Fri Jan 18 12:24:54 2013 -0500 Split smartlist_choose_node_by_bandwidth_weights This is a minimal refactoring to expose the weighted bandwidth calculations for each node so I can use them to see what fraction of nodes, weighted by bandwidth, we have descriptors for. --- src/or/routerlist.c | 50 +++++++++++++++++++++++++++++++++++++------------- 1 files changed, 37 insertions(+), 13 deletions(-) diff --git a/src/or/routerlist.c b/src/or/routerlist.c index b294bfa..33c0839 100644 --- a/src/or/routerlist.c +++ b/src/or/routerlist.c @@ -42,6 +42,9 @@ /****************************************************************************/ /* static function prototypes */ +static int compute_weighted_bandwidths(const smartlist_t *sl, + bandwidth_weight_rule_t rule, + u64_dbl_t **bandwidths_out); static const routerstatus_t *router_pick_directory_server_impl( dirinfo_type_t auth, int flags); static const routerstatus_t *router_pick_trusteddirserver_impl( @@ -1681,9 +1684,35 @@ kb_to_bytes(uint32_t bw) * guards proportionally less. */ static const node_t * -smartlist_choose_node_by_bandwidth_weights(smartlist_t *sl, +smartlist_choose_node_by_bandwidth_weights(const smartlist_t *sl, bandwidth_weight_rule_t rule) { + u64_dbl_t *bandwidths=NULL; + + if (compute_weighted_bandwidths(sl, rule, &bandwidths) < 0) + return NULL; + + scale_array_elements_to_u64(bandwidths, smartlist_len(sl), + &sl_last_total_weighted_bw); + + { + int idx = choose_array_element_by_weight(bandwidths, + smartlist_len(sl)); + tor_free(bandwidths); + return idx < 0 ? NULL : smartlist_get(sl, idx); + } +} + +/** Given a list of routers and a weighting rule as in + * smartlist_choose_node_by_bandwidth_weights, compute weighted bandwidth + * values for each node and store them in a freshly allocated + * *<b>bandwidths_out</b> of the same length as <b>sl</b>. Return 0 on + * success, -1 on failure. */ +static int +compute_weighted_bandwidths(const smartlist_t *sl, + bandwidth_weight_rule_t rule, + u64_dbl_t **bandwidths_out) +{ int64_t weight_scale; double Wg = -1, Wm = -1, We = -1, Wd = -1; double Wgb = -1, Wmb = -1, Web = -1, Wdb = -1; @@ -1702,7 +1731,7 @@ smartlist_choose_node_by_bandwidth_weights(smartlist_t *sl, "Empty routerlist passed in to consensus weight node " "selection for rule %s", bandwidth_weight_rule_to_string(rule)); - return NULL; + return -1; } weight_scale = circuit_build_times_get_bw_scale(NULL); @@ -1756,7 +1785,7 @@ smartlist_choose_node_by_bandwidth_weights(smartlist_t *sl, log_debug(LD_CIRC, "Got negative bandwidth weights. Defaulting to old selection" " algorithm."); - return NULL; // Use old algorithm. + return -1; // Use old algorithm. } Wg /= weight_scale; @@ -1786,7 +1815,7 @@ smartlist_choose_node_by_bandwidth_weights(smartlist_t *sl, log_warn(LD_BUG, "Consensus is not listing bandwidths. Defaulting back to " "old router selection algorithm."); - return NULL; + return -1; } this_bw = kb_to_bytes(node->rs->bandwidth); } else if (node->ri) { @@ -1819,20 +1848,15 @@ smartlist_choose_node_by_bandwidth_weights(smartlist_t *sl, sl_last_weighted_bw_of_me = (uint64_t) bandwidths[node_sl_idx].dbl; } SMARTLIST_FOREACH_END(node); - log_debug(LD_CIRC, "Choosing node for rule %s based on weights " + log_debug(LD_CIRC, "Generated weighted bandwidths for rule %s based " + "on weights " "Wg=%f Wm=%f We=%f Wd=%f with total bw "U64_FORMAT, bandwidth_weight_rule_to_string(rule), Wg, Wm, We, Wd, U64_PRINTF_ARG(weighted_bw)); - scale_array_elements_to_u64(bandwidths, smartlist_len(sl), - &sl_last_total_weighted_bw); + *bandwidths_out = bandwidths; - { - int idx = choose_array_element_by_weight(bandwidths, - smartlist_len(sl)); - tor_free(bandwidths); - return idx < 0 ? NULL : smartlist_get(sl, idx); - } + return 0; } /** Helper function: