jsrrdgraph: Simplify matching logic

Instead of using a flag for determining whether a value is set or not,
set values that will never match and test for the validity of the
results instead of checking the flags.

1 files changed, 8 insertions, 10 deletions

diff --git a/js/RrdDataFile.js b/js/RrdDataFile.js
index 4f96234..46f7811 100644
--- a/js/RrdDataFile.js
+++ b/js/RrdDataFile.js
@@ -40,11 +40,10 @@ RrdDataFile.prototype = {
         build: function(gdp, ft_step, rrd)
         {
                 var cal_start, cal_end;
-                var best_full_rra = 0, best_part_rra = 0, chosen_rra = 0;
-                var best_full_step_diff = 0, best_part_step_diff = 0, tmp_step_diff = 0, tmp_match = 0, best_match = 0;
+                var best_full_rra = -1, best_part_rra = -1, chosen_rra = 0;
+                var best_full_step_diff = Infinity, best_part_step_diff = Infinity;
+                var tmp_step_diff = 0, tmp_match = 0, best_match = -1;
                 var full_match;
-                var first_full = 1;
-                var first_part = 1;
                 var data_ptr;
                 var rows;
                 var rra;
@@ -80,16 +79,15 @@ RrdDataFile.prototype = {
 
                                 tmp_step_diff = Math.abs(ft_step - range_secs);
                                 if (cal_start <= gdp.start) {
-                                        if (first_full || (tmp_step_diff < best_full_step_diff)) {
-                                                first_full = 0;
+                                        if (tmp_step_diff < best_full_step_diff) {
                                                 best_full_step_diff = tmp_step_diff;
                                                 best_full_rra = i;
                                         }
                                 } else {
                                         tmp_match = full_match;
                                         if (cal_start > gdp.start) tmp_match -= (cal_start - gdp.start);
-                                        if (first_part || (best_match < tmp_match) || (best_match === tmp_match && tmp_step_diff < best_part_step_diff)) {
-                                                first_part = 0;
+                                        if (best_match < tmp_match || (best_match === tmp_match &&
+                                                                tmp_step_diff < best_part_step_diff)) {
                                                 best_match = tmp_match;
                                                 best_part_step_diff = tmp_step_diff;
                                                 best_part_rra = i;
@@ -98,8 +96,8 @@ RrdDataFile.prototype = {
                         }
                 }
 
-                if (first_full === 0) chosen_rra = best_full_rra;
-                else if (first_part === 0) chosen_rra = best_part_rra;
+                if (best_full_rra >= 0) chosen_rra = best_full_rra;
+                else if (best_part_rra >= 0) chosen_rra = best_part_rra;
                 else throw "the RRD does not contain an RRA matching the chosen CF";
 
                 var rra_info = rrd.getRRAInfo(chosen_rra);