From a4609fcec7ffb3213a617bf4d0510542efb3deab Mon Sep 17 00:00:00 2001
From: Victor Marmol <vmarmol@google.com>
Date: Mon, 20 Apr 2015 19:17:31 -0700
Subject: [PATCH] Remove unused FirstN() from StatsBuffer

---
 storage/memory/stats_buffer.go      | 24 ------------------------
 storage/memory/stats_buffer_test.go | 20 ++++++++++++--------
 2 files changed, 12 insertions(+), 32 deletions(-)

diff --git a/storage/memory/stats_buffer.go b/storage/memory/stats_buffer.go
index b71bfe2a..9089e30c 100644
--- a/storage/memory/stats_buffer.go
+++ b/storage/memory/stats_buffer.go
@@ -113,30 +113,6 @@ func (self *StatsBuffer) InTimeRange(start, end time.Time, maxResults int) []*in
 	return result
 }
 
-// TODO(vmarmol): Remove this function as it will no longer be neededt.
-// Returns the first N elements in the buffer. If N > size of buffer, size of buffer elements are returned.
-// Returns the elements in ascending timestamp order.
-func (self *StatsBuffer) FirstN(n int) []*info.ContainerStats {
-	// Cap n at the number of elements we have.
-	if n > self.size {
-		n = self.size
-	}
-
-	// index points to the latest element, get n before that one (keeping in mind we may have gone through 0).
-	start := self.index - (n - 1)
-	if start < 0 {
-		start += len(self.buffer)
-	}
-
-	// Copy the elements.
-	res := make([]*info.ContainerStats, n)
-	for i := 0; i < n; i++ {
-		index := (start + i) % len(self.buffer)
-		res[i] = self.buffer[index]
-	}
-	return res
-}
-
 // Gets the element at the specified index. Note that elements are stored in LIFO order.
 func (self *StatsBuffer) Get(index int) *info.ContainerStats {
 	calculatedIndex := self.index - index
diff --git a/storage/memory/stats_buffer_test.go b/storage/memory/stats_buffer_test.go
index f142e931..b466540d 100644
--- a/storage/memory/stats_buffer_test.go
+++ b/storage/memory/stats_buffer_test.go
@@ -44,8 +44,13 @@ func expectSize(t *testing.T, sb *StatsBuffer, expectedSize int) {
 	}
 }
 
-func expectFirstN(t *testing.T, sb *StatsBuffer, expected []int32) {
-	expectElements(t, sb.FirstN(sb.Size()), expected)
+func expectAllElements(t *testing.T, sb *StatsBuffer, expected []int32) {
+	size := sb.Size()
+	els := make([]*info.ContainerStats, size)
+	for i := 0; i < size; i++ {
+		els[i] = sb.Get(size - i - 1)
+	}
+	expectElements(t, els, expected)
 }
 
 func expectElements(t *testing.T, actual []*info.ContainerStats, expected []int32) {
@@ -71,13 +76,13 @@ func expectElement(t *testing.T, stat *info.ContainerStats, expected int32) {
 	}
 }
 
-func TestAddAndFirstN(t *testing.T) {
+func TestAdd(t *testing.T) {
 	sb := NewStatsBuffer(5)
 
 	// Add 1.
 	sb.Add(createStats(1))
 	expectSize(t, sb, 1)
-	expectFirstN(t, sb, []int32{1})
+	expectAllElements(t, sb, []int32{1})
 
 	// Fill the buffer.
 	for i := 1; i <= 5; i++ {
@@ -85,19 +90,19 @@ func TestAddAndFirstN(t *testing.T) {
 		sb.Add(createStats(int32(i)))
 	}
 	expectSize(t, sb, 5)
-	expectFirstN(t, sb, []int32{1, 2, 3, 4, 5})
+	expectAllElements(t, sb, []int32{1, 2, 3, 4, 5})
 
 	// Add more than is available in the buffer
 	sb.Add(createStats(6))
 	expectSize(t, sb, 5)
-	expectFirstN(t, sb, []int32{2, 3, 4, 5, 6})
+	expectAllElements(t, sb, []int32{2, 3, 4, 5, 6})
 
 	// Replace all elements.
 	for i := 7; i <= 10; i++ {
 		sb.Add(createStats(int32(i)))
 	}
 	expectSize(t, sb, 5)
-	expectFirstN(t, sb, []int32{6, 7, 8, 9, 10})
+	expectAllElements(t, sb, []int32{6, 7, 8, 9, 10})
 }
 
 func TestGet(t *testing.T) {
@@ -106,7 +111,6 @@ func TestGet(t *testing.T) {
 	sb.Add(createStats(2))
 	sb.Add(createStats(3))
 	expectSize(t, sb, 3)
-	expectFirstN(t, sb, []int32{1, 2, 3})
 
 	expectElement(t, sb.Get(0), 3)
 	expectElement(t, sb.Get(1), 2)