[VOL-2235] Mocks and interfaces for rw-core

This update consists of mocks that are used by the rw-core
during unit testing.  It also includes interfaces used for unit
tests.

Change-Id: I20ca1455c358113c3aa897acc6355e0ddbc614b7
diff --git a/vendor/github.com/prometheus/procfs/buddyinfo.go b/vendor/github.com/prometheus/procfs/buddyinfo.go
new file mode 100644
index 0000000..63d4229
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/buddyinfo.go
@@ -0,0 +1,85 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package procfs
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// A BuddyInfo is the details parsed from /proc/buddyinfo.
+// The data is comprised of an array of free fragments of each size.
+// The sizes are 2^n*PAGE_SIZE, where n is the array index.
+type BuddyInfo struct {
+	Node  string
+	Zone  string
+	Sizes []float64
+}
+
+// NewBuddyInfo reads the buddyinfo statistics from the specified `proc` filesystem.
+func (fs FS) BuddyInfo() ([]BuddyInfo, error) {
+	file, err := os.Open(fs.proc.Path("buddyinfo"))
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	return parseBuddyInfo(file)
+}
+
+func parseBuddyInfo(r io.Reader) ([]BuddyInfo, error) {
+	var (
+		buddyInfo   = []BuddyInfo{}
+		scanner     = bufio.NewScanner(r)
+		bucketCount = -1
+	)
+
+	for scanner.Scan() {
+		var err error
+		line := scanner.Text()
+		parts := strings.Fields(line)
+
+		if len(parts) < 4 {
+			return nil, fmt.Errorf("invalid number of fields when parsing buddyinfo")
+		}
+
+		node := strings.TrimRight(parts[1], ",")
+		zone := strings.TrimRight(parts[3], ",")
+		arraySize := len(parts[4:])
+
+		if bucketCount == -1 {
+			bucketCount = arraySize
+		} else {
+			if bucketCount != arraySize {
+				return nil, fmt.Errorf("mismatch in number of buddyinfo buckets, previous count %d, new count %d", bucketCount, arraySize)
+			}
+		}
+
+		sizes := make([]float64, arraySize)
+		for i := 0; i < arraySize; i++ {
+			sizes[i], err = strconv.ParseFloat(parts[i+4], 64)
+			if err != nil {
+				return nil, fmt.Errorf("invalid value in buddyinfo: %s", err)
+			}
+		}
+
+		buddyInfo = append(buddyInfo, BuddyInfo{node, zone, sizes})
+	}
+
+	return buddyInfo, scanner.Err()
+}