cmd/vendor/github.com/google/pprof: refresh from upstream

Updating to commit fffc5831a499a958516664a34cb7ba2b9e228793
from github.com/google/pprof

Fixes #19380

Change-Id: I7a0c64101f42b494c4a469c41628374272eccf95
Reviewed-on: https://go-review.googlesource.com/46155
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

3 files changed, 70 insertions, 22 deletions

diff --git a/src/cmd/vendor/github.com/google/pprof/internal/graph/dotgraph.go b/src/cmd/vendor/github.com/google/pprof/internal/graph/dotgraph.go
index c99e8992de..514156a184 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/graph/dotgraph.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/graph/dotgraph.go
@@ -50,7 +50,9 @@ type DotConfig struct {
 	Total       int64                      // The total weight of the graph, used to compute percentages
 }
 
-// Compose creates and writes a in the DOT format to the writer, using
+const maxNodelets = 4 // Number of nodelets for labels (both numeric and non)
+
+// ComposeDot creates and writes a in the DOT format to the writer, using
 // the configurations given.
 func ComposeDot(w io.Writer, g *Graph, a *DotAttributes, c *DotConfig) {
 	builder := &builder{w, a, c}
@@ -204,13 +206,11 @@ func (b *builder) addNode(node *Node, nodeID int, maxFlat float64) {
 
 // addNodelets generates the DOT boxes for the node tags if they exist.
 func (b *builder) addNodelets(node *Node, nodeID int) bool {
-	const maxNodelets = 4    // Number of nodelets for alphanumeric labels
-	const maxNumNodelets = 4 // Number of nodelets for numeric labels
 	var nodelets string
 
 	// Populate two Tag slices, one for LabelTags and one for NumericTags.
 	var ts []*Tag
-	lnts := make(map[string][]*Tag, 0)
+	lnts := make(map[string][]*Tag)
 	for _, t := range node.LabelTags {
 		ts = append(ts, t)
 	}
@@ -242,12 +242,12 @@ func (b *builder) addNodelets(node *Node, nodeID int) bool {
 		nodelets += fmt.Sprintf(`N%d_%d [label = "%s" fontsize=8 shape=box3d tooltip="%s"]`+"\n", nodeID, i, t.Name, weight)
 		nodelets += fmt.Sprintf(`N%d -> N%d_%d [label=" %s" weight=100 tooltip="%s" labeltooltip="%s"]`+"\n", nodeID, nodeID, i, weight, weight, weight)
 		if nts := lnts[t.Name]; nts != nil {
-			nodelets += b.numericNodelets(nts, maxNumNodelets, flatTags, fmt.Sprintf(`N%d_%d`, nodeID, i))
+			nodelets += b.numericNodelets(nts, maxNodelets, flatTags, fmt.Sprintf(`N%d_%d`, nodeID, i))
 		}
 	}
 
 	if nts := lnts[""]; nts != nil {
-		nodelets += b.numericNodelets(nts, maxNumNodelets, flatTags, fmt.Sprintf(`N%d`, nodeID))
+		nodelets += b.numericNodelets(nts, maxNodelets, flatTags, fmt.Sprintf(`N%d`, nodeID))
 	}
 
 	fmt.Fprint(b, nodelets)
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/graph/dotgraph_test.go b/src/cmd/vendor/github.com/google/pprof/internal/graph/dotgraph_test.go
index 7f51269769..c9d4bca5de 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/graph/dotgraph_test.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/graph/dotgraph_test.go
@@ -209,6 +209,59 @@ func compareGraphs(t *testing.T, got, want []byte) {
 	}
 }
 
+func TestNodeletCountCapping(t *testing.T) {
+	labelTags := make(TagMap)
+	for i := 0; i < 10; i++ {
+		name := fmt.Sprintf("tag-%d", i)
+		labelTags[name] = &Tag{
+			Name: name,
+			Flat: 10,
+			Cum:  10,
+		}
+	}
+	numTags := make(TagMap)
+	for i := 0; i < 10; i++ {
+		name := fmt.Sprintf("num-tag-%d", i)
+		numTags[name] = &Tag{
+			Name:  name,
+			Unit:  "mb",
+			Value: 16,
+			Flat:  10,
+			Cum:   10,
+		}
+	}
+	node1 := &Node{
+		Info:        NodeInfo{Name: "node1-with-tags"},
+		Flat:        10,
+		Cum:         10,
+		NumericTags: map[string]TagMap{"": numTags},
+		LabelTags:   labelTags,
+	}
+	node2 := &Node{
+		Info: NodeInfo{Name: "node2"},
+		Flat: 15,
+		Cum:  15,
+	}
+	node3 := &Node{
+		Info: NodeInfo{Name: "node3"},
+		Flat: 15,
+		Cum:  15,
+	}
+	g := &Graph{
+		Nodes: Nodes{
+			node1,
+			node2,
+			node3,
+		},
+	}
+	for n := 1; n <= 3; n++ {
+		input := maxNodelets + n
+		if got, want := len(g.SelectTopNodes(input, true)), n; got != want {
+			t.Errorf("SelectTopNodes(%d): got %d nodes, want %d", input, got, want)
+		}
+	}
+}
+
 func TestMultilinePrintableName(t *testing.T) {
 	ni := &NodeInfo{
 		Name:    "test1.test2::test3",
@@ -240,19 +293,19 @@ func TestTagCollapse(t *testing.T) {
 	}
 
 	tagWant := [][]*Tag{
-		[]*Tag{
+		{
 			makeTag("1B..2GB", "", 0, 2401, 2401),
 		},
-		[]*Tag{
+		{
 			makeTag("2GB", "", 0, 1000, 1000),
 			makeTag("1B..12MB", "", 0, 1401, 1401),
 		},
-		[]*Tag{
+		{
 			makeTag("2GB", "", 0, 1000, 1000),
 			makeTag("12MB", "", 0, 100, 100),
 			makeTag("1B..1MB", "", 0, 1301, 1301),
 		},
-		[]*Tag{
+		{
 			makeTag("2GB", "", 0, 1000, 1000),
 			makeTag("1MB", "", 0, 1000, 1000),
 			makeTag("2B..1kB", "", 0, 201, 201),
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/graph/graph.go b/src/cmd/vendor/github.com/google/pprof/internal/graph/graph.go
index 428e6257c7..7947e2dd42 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/graph/graph.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/graph/graph.go
@@ -240,6 +240,8 @@ type Edge struct {
 	Inline bool
 }
 
+// WeightValue returns the weight value for this edge, normalizing if a
+// divisor is available.
 func (e *Edge) WeightValue() int64 {
 	if e.WeightDiv == 0 {
 		return e.Weight
@@ -800,7 +802,11 @@ func (g *Graph) selectTopNodes(maxNodes int, visualMode bool) Nodes {
 			// If generating a visual graph, count tags as nodes. Update
 			// maxNodes to account for them.
 			for i, n := range g.Nodes {
-				if count += countTags(n) + 1; count >= maxNodes {
+				tags := countTags(n)
+				if tags > maxNodelets {
+					tags = maxNodelets
+				}
+				if count += tags + 1; count >= maxNodes {
 					maxNodes = i + 1
 					break
 				}
@@ -832,17 +838,6 @@ func countTags(n *Node) int {
 	return count
 }
 
-// countEdges counts the number of edges below the specified cutoff.
-func countEdges(el EdgeMap, cutoff int64) int {
-	count := 0
-	for _, e := range el {
-		if e.Weight > cutoff {
-			count++
-		}
-	}
-	return count
-}
-
 // RemoveRedundantEdges removes residual edges if the destination can
 // be reached through another path. This is done to simplify the graph
 // while preserving connectivity.