Trivial style tuning on last change.

decode.go

@@ -319,10 +319,14 @@ func (d *decoder) prepare(n *node, out reflect.Value) (newout reflect.Value, unm
 }
 
 const (
-	// 400,000 decode operations is ~500kb of dense object declarations, or ~5kb of dense object declarations with 10000% alias expansion
+	// 400,000 decode operations is ~500kb of dense object declarations, or
+	// ~5kb of dense object declarations with 10000% alias expansion
 	alias_ratio_range_low = 400000
-	// 4,000,000 decode operations is ~5MB of dense object declarations, or ~4.5MB of dense object declarations with 10% alias expansion
+
+	// 4,000,000 decode operations is ~5MB of dense object declarations, or
+	// ~4.5MB of dense object declarations with 10% alias expansion
 	alias_ratio_range_high = 4000000
+
 	// alias_ratio_range is the range over which we scale allowed alias ratios
 	alias_ratio_range = float64(alias_ratio_range_high - alias_ratio_range_low)
 )

limit_test.go

@@ -0,0 +1,113 @@
+package yaml_test
+
+import (
+	"strings"
+	"testing"
+
+	. "gopkg.in/check.v1"
+	"gopkg.in/yaml.v2"
+)
+
+var limitTests = []struct {
+	name  string
+	data  []byte
+	error string
+}{
+	{
+		name:  "1000kb of maps with 100 aliases",
+		data:  []byte(`{a: &a [{a}` + strings.Repeat(`,{a}`, 1000*1024/4-100) + `], b: &b [*a` + strings.Repeat(`,*a`, 99) + `]}`),
+		error: "yaml: document contains excessive aliasing",
+	}, {
+		name:  "1000kb of deeply nested slices",
+		data:  []byte(strings.Repeat(`[`, 1000*1024)),
+		error: "yaml: exceeded max depth of 10000",
+	}, {
+		name:  "1000kb of deeply nested maps",
+		data:  []byte("x: " + strings.Repeat(`{`, 1000*1024)),
+		error: "yaml: exceeded max depth of 10000",
+	}, {
+		name:  "1000kb of deeply nested indents",
+		data:  []byte(strings.Repeat(`- `, 1000*1024)),
+		error: "yaml: exceeded max depth of 10000",
+	}, {
+		name: "1000kb of 1000-indent lines",
+		data: []byte(strings.Repeat(strings.Repeat(`- `, 1000)+"\n", 1024/2)),
+	},
+	{name: "1kb of maps", data: []byte(`a: &a [{a}` + strings.Repeat(`,{a}`, 1*1024/4-1) + `]`)},
+	{name: "10kb of maps", data: []byte(`a: &a [{a}` + strings.Repeat(`,{a}`, 10*1024/4-1) + `]`)},
+	{name: "100kb of maps", data: []byte(`a: &a [{a}` + strings.Repeat(`,{a}`, 100*1024/4-1) + `]`)},
+	{name: "1000kb of maps", data: []byte(`a: &a [{a}` + strings.Repeat(`,{a}`, 1000*1024/4-1) + `]`)},
+}
+
+func (s *S) TestLimits(c *C) {
+	if testing.Short() {
+		return
+	}
+	for _, tc := range limitTests {
+		var v interface{}
+		err := yaml.Unmarshal(tc.data, &v)
+		if len(tc.error) > 0 {
+			c.Assert(err, ErrorMatches, tc.error, Commentf("testcase: %s", tc.name))
+		} else {
+			c.Assert(err, IsNil, Commentf("testcase: %s", tc.name))
+		}
+	}
+}
+
+func Benchmark1000KB100Aliases(b *testing.B) {
+	benchmark(b, "1000kb of maps with 100 aliases")
+}
+func Benchmark1000KBDeeplyNestedSlices(b *testing.B) {
+	benchmark(b, "1000kb of deeply nested slices")
+}
+func Benchmark1000KBDeeplyNestedMaps(b *testing.B) {
+	benchmark(b, "1000kb of deeply nested maps")
+}
+func Benchmark1000KBDeeplyNestedIndents(b *testing.B) {
+	benchmark(b, "1000kb of deeply nested indents")
+}
+func Benchmark1000KB1000IndentLines(b *testing.B) {
+	benchmark(b, "1000kb of 1000-indent lines")
+}
+func Benchmark1KBMaps(b *testing.B) {
+	benchmark(b, "1kb of maps")
+}
+func Benchmark10KBMaps(b *testing.B) {
+	benchmark(b, "10kb of maps")
+}
+func Benchmark100KBMaps(b *testing.B) {
+	benchmark(b, "100kb of maps")
+}
+func Benchmark1000KBMaps(b *testing.B) {
+	benchmark(b, "1000kb of maps")
+}
+
+func benchmark(b *testing.B, name string) {
+	for _, t := range limitTests {
+		if t.name != name {
+			continue
+		}
+
+		b.ResetTimer()
+
+		for i := 0; i < b.N; i++ {
+			var v interface{}
+			err := yaml.Unmarshal(t.data, &v)
+			if len(t.error) > 0 {
+				if err == nil {
+					b.Errorf("expected error, got none")
+				} else if err.Error() != t.error {
+					b.Errorf("expected error '%s', got '%s'", t.error, err.Error())
+				}
+			} else {
+				if err != nil {
+					b.Errorf("unexpected error: %v", err)
+				}
+			}
+		}
+
+		return
+	}
+
+	b.Errorf("testcase %q not found", name)
+}