stats: Add a histogram statistic type

1 files changed, 83 insertions, 0 deletions

diff --git a/src/base/statistics.cc b/src/base/statistics.cc
index 1e108298a..95402a221 100644
--- a/src/base/statistics.cc
+++ b/src/base/statistics.cc
@@ -236,6 +236,89 @@ Vector2dInfo::enable()
         y_subnames.resize(y);
 }
 
+void
+HistStor::grow_out()
+{
+    int size = cvec.size();
+    int zero = size / 2; // round down!
+    int top_half = zero + (size - zero + 1) / 2; // round up!
+    int bottom_half = (size - zero) / 2; // round down!
+
+    // grow down
+    int low_pair = zero - 1;
+    for (int i = zero - 1; i >= bottom_half; i--) {
+        cvec[i] = cvec[low_pair];
+        if (low_pair - 1 >= 0)
+            cvec[i] += cvec[low_pair - 1];
+        low_pair -= 2;
+    }
+    assert(low_pair == 0 || low_pair == -1 || low_pair == -2);
+
+    for (int i = bottom_half - 1; i >= 0; i--)
+        cvec[i] = Counter();
+
+    // grow up
+    int high_pair = zero;
+    for (int i = zero; i < top_half; i++) {
+        cvec[i] = cvec[high_pair];
+        if (high_pair + 1 < size)
+            cvec[i] += cvec[high_pair + 1];
+        high_pair += 2;
+    }
+    assert(high_pair == size || high_pair == size + 1);
+
+    for (int i = top_half; i < size; i++)
+        cvec[i] = Counter();
+
+    max_bucket *= 2;
+    min_bucket *= 2;
+    bucket_size *= 2;
+}
+
+void
+HistStor::grow_convert()
+{
+    int size = cvec.size();
+    int half = (size + 1) / 2; // round up!
+    //bool even = (size & 1) == 0;
+
+    int pair = size - 1;
+    for (int i = size - 1; i >= half; --i) {
+        cvec[i] = cvec[pair];
+        if (pair - 1 >= 0)
+            cvec[i] += cvec[pair - 1];
+        pair -= 2;
+    }
+
+    for (int i = half - 1; i >= 0; i--)
+        cvec[i] = Counter();
+
+    min_bucket = -max_bucket;// - (even ? bucket_size : 0);
+    bucket_size *= 2;
+}
+
+void
+HistStor::grow_up()
+{
+    int size = cvec.size();
+    int half = (size + 1) / 2; // round up!
+
+    int pair = 0;
+    for (int i = 0; i < half; i++) {
+        cvec[i] = cvec[pair];
+        if (pair + 1 < size)
+            cvec[i] += cvec[pair + 1];
+        pair += 2;
+    }
+    assert(pair == size || pair == size + 1);
+
+    for (int i = half; i < size; i++)
+        cvec[i] = Counter();
+
+    max_bucket *= 2;
+    bucket_size *= 2;
+}
+
 Formula::Formula()
 {
 }