From 830653a4496b30dd535a14c6c9ec93c856f49ead Mon Sep 17 00:00:00 2001
From: Dave Hoover <dhoover@threerings.net>
Date: Mon, 20 Oct 2008 22:41:59 +0000
Subject: [PATCH] Don't let us create a percentiler with an insane range, and
 carp if we expand to one. I'm half tempted to also try and cap the range to
 something less broken, but the bug I had that caused insanity involved
 recording a value of infinity, and there's not a hell of a lot I can do to
 sanely recover in that case (other than throw it away, I suppose). So let's
 yell a little bit and keep from hosing us quite as much as I was when I wound
 up with crazy stuff persisted to my ratings table.

git-svn-id: svn+ssh://src.earth.threerings.net/vilya/trunk@761 c613c5cb-e716-0410-b11b-feb51c14d237
---
 .../parlor/rating/util/Percentiler.java       | 26 ++++++++++++++++---
 1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/src/java/com/threerings/parlor/rating/util/Percentiler.java b/src/java/com/threerings/parlor/rating/util/Percentiler.java
index 87e6a8a9..832dd370 100644
--- a/src/java/com/threerings/parlor/rating/util/Percentiler.java
+++ b/src/java/com/threerings/parlor/rating/util/Percentiler.java
@@ -79,6 +79,14 @@ public class Percentiler
             _min = in.asIntBuffer().get();
         }
 
+        // Un-break percentilers that have been stored with bogus data
+        if (_max < _min) {
+            log.warning("Percentiler initialized with bogus range. Coping.",
+                "min", _min, "max", _max);
+
+            _max = _min + 1;
+        }
+
         // compute our percentiles
         recomputePercentiles();
     }
@@ -107,17 +115,27 @@ public class Percentiler
         // if this value is outside our bounds, we need to redistribute our buckets
         if (value < _min || value > _max) {
             if (_fixedRange) {
-                log.warning("Recording value outside of initially fixed range", "min", _min,
-                    "max", _max, "value", value);
+                log.warning("Recording value outside of initially fixed range",
+                    "min", _min, "max", _max, "value", value);
                 _fixedRange = false;
             }
+
             // expand by 20% in the direction of either our new minimum or new maximum
             int newmin = (value < _min) ? (_max - (int)Math.ceil((_max - value) * 1.2f)) : _min;
             int newmax = (value > _max) ? (_min + (int)Math.ceil((value - _min) * 1.2f)) : _max;
 
+            if (newmin > _min || newmax < _max) {
+                log.warning("Grew our range in crazy ways?!",
+                    "value", value, "total", _total,
+                    "new", ("" + newmin + ":" + newmax),
+                    "old", ("" + _min + ":" + _max));
+            }
+
             if (logNewMax) {
-                log.info("Resizing [total=" + _total + ", new=" + newmin + ":" + newmax +
-                         ", old=" + _min + ":" + _max + "].");
+                log.info("Resizing",
+                    "value", value, "total", _total,
+                    "new", ("" + newmin + ":" + newmax),
+                    "old", ("" + _min + ":" + _max));
             }
 
             // create a new counts array and map the old array to the new