From 6ad7d0bfaba07cf1a4823c4878bb80a3db2aabe2 Mon Sep 17 00:00:00 2001
From: Ben Johnson <benbjohnson@yahoo.com>
Date: Fri, 12 Aug 2016 10:02:57 -0600
Subject: [PATCH] fix count() cache retrieval

---
 cache.go    |  3 ++-
 fragment.go | 10 ++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/cache.go b/cache.go
index 03e02d15f..2ff5f60ce 100644
--- a/cache.go
+++ b/cache.go
@@ -51,7 +51,8 @@ func (c *LRUCache) Add(bitmapID, n uint64) {
 // Get returns a bitmap with a given id.
 func (c *LRUCache) Get(bitmapID uint64) uint64 {
 	n, _ := c.cache.Get(bitmapID)
-	return n.(uint64)
+	nn, _ := n.(uint64)
+	return nn
 }
 
 // Len returns the number of items in the cache.
diff --git a/fragment.go b/fragment.go
index c1ded3c1c..6d32bca9d 100644
--- a/fragment.go
+++ b/fragment.go
@@ -527,6 +527,16 @@ func (f *Fragment) topBitmapPairs(bitmapIDs []uint64) []BitmapPair {
 	// Otherwise retrieve specific bitmaps.
 	pairs := make([]BitmapPair, len(bitmapIDs))
 	for i, bitmapID := range bitmapIDs {
+		// Look up cache first, if available.
+		if n := f.cache.Get(bitmapID); n > 0 {
+			pairs[i] = BitmapPair{
+				ID:    bitmapID,
+				Count: n,
+			}
+			continue
+		}
+
+		// Otherwise load from storage.
 		pairs[i] = BitmapPair{
 			ID:    bitmapID,
 			Count: f.Bitmap(bitmapID).Count(),