From 4f99efaaf492b425feb01de727c9648e931bfda9 Mon Sep 17 00:00:00 2001
From: Martynas Pumputis <martynasp@gmail.com>
Date: Thu, 10 May 2018 12:43:33 +0200
Subject: [PATCH] Export tracker.RemoveCommon and tracker.Merge

It's going to be used by NoMasqLocalTracker.
---
 ipam/tracker/awsvpc.go                        | 43 +----------------
 ipam/tracker/helpers.go                       | 46 +++++++++++++++++++
 .../{awsvpc_test.go => helpers_test.go}       |  4 +-
 3 files changed, 49 insertions(+), 44 deletions(-)
 create mode 100644 ipam/tracker/helpers.go
 rename ipam/tracker/{awsvpc_test.go => helpers_test.go} (95%)

diff --git a/ipam/tracker/awsvpc.go b/ipam/tracker/awsvpc.go
index 02489b19..fdd4f313 100644
--- a/ipam/tracker/awsvpc.go
+++ b/ipam/tracker/awsvpc.go
@@ -84,7 +84,7 @@ func NewAWSVPCTracker(bridgeName string) (*AWSVPCTracker, error) {
 func (t *AWSVPCTracker) HandleUpdate(prevRanges, currRanges []address.Range, local bool) error {
 	t.debugf("replacing %q by %q; local(%t)", prevRanges, currRanges, local)
 
-	prev, curr := removeCommon(address.NewCIDRs(merge(prevRanges)), address.NewCIDRs(merge(currRanges)))
+	prev, curr := RemoveCommon(address.NewCIDRs(Merge(prevRanges)), address.NewCIDRs(Merge(currRanges)))
 
 	// It might make sense to do the removal first and then add entries
 	// because of the 50 routes limit. However, in such case a container might
@@ -236,47 +236,6 @@ func (t *AWSVPCTracker) infof(fmt string, args ...interface{}) {
 
 // Helpers
 
-// merge merges adjacent range entries.
-// The given slice has to be sorted in increasing order.
-func merge(r []address.Range) []address.Range {
-	var merged []address.Range
-
-	for i := range r {
-		if prev := len(merged) - 1; prev >= 0 && merged[prev].End == r[i].Start {
-			merged[prev].End = r[i].End
-		} else {
-			merged = append(merged, r[i])
-		}
-	}
-
-	return merged
-}
-
-// removeCommon filters out CIDR ranges which are contained in both a and b slices.
-// Both slices have to be sorted in increasing order.
-func removeCommon(a, b []address.CIDR) (newA, newB []address.CIDR) {
-	i, j := 0, 0
-
-	for i < len(a) && j < len(b) {
-		switch {
-		case a[i].Start() < b[j].Start() || a[i].End() < b[j].End():
-			newA = append(newA, a[i])
-			i++
-		case a[i].Start() > b[j].Start() || a[i].End() > b[j].End():
-			newB = append(newB, b[j])
-			j++
-		default:
-			i++
-			j++
-		}
-
-	}
-	newA = append(newA, a[i:]...)
-	newB = append(newB, b[j:]...)
-
-	return
-}
-
 func parseCIDR(cidr string) (*net.IPNet, error) {
 	ip, ipnet, err := net.ParseCIDR(cidr)
 	if err != nil {
diff --git a/ipam/tracker/helpers.go b/ipam/tracker/helpers.go
new file mode 100644
index 00000000..b8823007
--- /dev/null
+++ b/ipam/tracker/helpers.go
@@ -0,0 +1,46 @@
+package tracker
+
+import (
+	"github.com/weaveworks/weave/net/address"
+)
+
+// Merge merges adjacent range entries.
+// The given slice has to be sorted in increasing order.
+func Merge(r []address.Range) []address.Range {
+	var merged []address.Range
+
+	for i := range r {
+		if prev := len(merged) - 1; prev >= 0 && merged[prev].End == r[i].Start {
+			merged[prev].End = r[i].End
+		} else {
+			merged = append(merged, r[i])
+		}
+	}
+
+	return merged
+}
+
+// RemoveCommon filters out CIDR ranges which are contained in both a and b slices.
+// Both slices have to be sorted in increasing order.
+func RemoveCommon(a, b []address.CIDR) (newA, newB []address.CIDR) {
+	i, j := 0, 0
+
+	for i < len(a) && j < len(b) {
+		switch {
+		case a[i].Start() < b[j].Start() || a[i].End() < b[j].End():
+			newA = append(newA, a[i])
+			i++
+		case a[i].Start() > b[j].Start() || a[i].End() > b[j].End():
+			newB = append(newB, b[j])
+			j++
+		default:
+			i++
+			j++
+		}
+
+	}
+	newA = append(newA, a[i:]...)
+	newB = append(newB, b[j:]...)
+
+	return
+}
diff --git a/ipam/tracker/awsvpc_test.go b/ipam/tracker/helpers_test.go
similarity index 95%
rename from ipam/tracker/awsvpc_test.go
rename to ipam/tracker/helpers_test.go
index b99500a1..dce74eec 100644
--- a/ipam/tracker/awsvpc_test.go
+++ b/ipam/tracker/helpers_test.go
@@ -19,7 +19,7 @@ var (
 func TestRemoveCommon(t *testing.T) {
 	a := []address.CIDR{r0to127, r1dot0to255}
 	b := []address.CIDR{r1dot0to255, r2dot0to255}
-	newA, newB := removeCommon(a, b)
+	newA, newB := RemoveCommon(a, b)
 	require.Equal(t, []address.CIDR{r0to127}, newA)
 	require.Equal(t, []address.CIDR{r2dot0to255}, newB)
 }
@@ -30,7 +30,7 @@ func TestMerge(t *testing.T) {
 		r128to255.Range(),
 		r2dot0to255.Range(),
 	}
-	require.Equal(t, []address.Range{r0to255.Range(), r2dot0to255.Range()}, merge(ranges))
+	require.Equal(t, []address.Range{r0to255.Range(), r2dot0to255.Range()}, Merge(ranges))
 }
 
 // Helper