bson: add BenchmarkCode{Marshal,Unmarshal} benchmarks from encoding/json

These benchmarks do a good job of identifying bottlenecks in the bson
encoding/decoding logic.

bson/benchmark_test.go

@@ -7,12 +7,15 @@
 package bson
 
 import (
+ "bytes"
  "compress/gzip"
  "encoding/json"
  "fmt"
+ "io"
  "io/ioutil"
  "os"
  "path"
+ "sync"
  "testing"
 )
 
@@ -129,10 +132,20 @@ var nestedInstance = nestedtest1{
 
 const extendedBSONDir = "../testdata/extended_bson"
 
+var (
+ extJSONFiles map[string]map[string]interface{}
+ extJSONFilesMu sync.Mutex
+)
+
 // readExtJSONFile reads the GZIP-compressed extended JSON document from the given filename in the
 // "extended BSON" test data directory (../testdata/extended_bson) and returns it as a
 // map[string]interface{}. It panics on any errors.
 func readExtJSONFile(filename string) map[string]interface{} {
+ extJSONFilesMu.Lock()
+ defer extJSONFilesMu.Unlock()
+ if v, ok := extJSONFiles[filename]; ok {
+ return v
+ }
  filePath := path.Join(extendedBSONDir, filename)
  file, err := os.Open(filePath)
  if err != nil {
@@ -161,6 +174,10 @@ func readExtJSONFile(filename string) map[string]interface{} {
  panic(fmt.Sprintf("error unmarshalling extended JSON: %s", err))
  }
 
+ if extJSONFiles == nil {
+ extJSONFiles = make(map[string]map[string]interface{})
+ }
+ extJSONFiles[filename] = v
  return v
 }
 
@@ -305,3 +322,128 @@ func BenchmarkUnmarshal(b *testing.B) {
  })
  }
 }
+
+// The following benchmarks are copied from the Go standard library's
+// encoding/json package.
+
+type codeResponse struct {
+ Tree *codeNode `json:"tree"`
+ Username string `json:"username"`
+}
+
+type codeNode struct {
+ Name string `json:"name"`
+ Kids []*codeNode `json:"kids"`
+ CLWeight float64 `json:"cl_weight"`
+ Touches int `json:"touches"`
+ MinT int64 `json:"min_t"`
+ MaxT int64 `json:"max_t"`
+ MeanT int64 `json:"mean_t"`
+}
+
+var codeJSON []byte
+var codeBSON []byte
+var codeStruct codeResponse
+
+func codeInit() {
+ f, err := os.Open("testdata/code.json.gz")
+ if err != nil {
+ panic(err)
+ }
+ defer f.Close()
+ gz, err := gzip.NewReader(f)
+ if err != nil {
+ panic(err)
+ }
+ data, err := io.ReadAll(gz)
+ if err != nil {
+ panic(err)
+ }
+
+ codeJSON = data
+
+ if err := json.Unmarshal(codeJSON, &codeStruct); err != nil {
+ panic("json.Unmarshal code.json: " + err.Error())
+ }
+
+ if data, err = json.Marshal(&codeStruct); err != nil {
+ panic("json.Marshal code.json: " + err.Error())
+ }
+
+ if codeBSON, err = Marshal(&codeStruct); err != nil {
+ panic("Marshal code.json: " + err.Error())
+ }
+
+ if !bytes.Equal(data, codeJSON) {
+ println("different lengths", len(data), len(codeJSON))
+ for i := 0; i < len(data) && i < len(codeJSON); i++ {
+ if data[i] != codeJSON[i] {
+ println("re-marshal: changed at byte", i)
+ println("orig: ", string(codeJSON[i-10:i+10]))
+ println("new: ", string(data[i-10:i+10]))
+ break
+ }
+ }
+ panic("re-marshal code.json: different result")
+ }
+}
+
+func BenchmarkCodeUnmarshal(b *testing.B) {
+ b.ReportAllocs()
+ if codeJSON == nil {
+ b.StopTimer()
+ codeInit()
+ b.StartTimer()
+ }
+ b.Run("BSON", func(b *testing.B) {
+ b.RunParallel(func(pb *testing.PB) {
+ for pb.Next() {
+ var r codeResponse
+ if err := Unmarshal(codeBSON, &r); err != nil {
+ b.Fatal("Unmarshal:", err)
+ }
+ }
+ })
+ b.SetBytes(int64(len(codeJSON)))
+ })
+ b.Run("JSON", func(b *testing.B) {
+ b.RunParallel(func(pb *testing.PB) {
+ for pb.Next() {
+ var r codeResponse
+ if err := json.Unmarshal(codeJSON, &r); err != nil {
+ b.Fatal("json.Unmarshal:", err)
+ }
+ }
+ })
+ b.SetBytes(int64(len(codeJSON)))
+ })
+}
+
+func BenchmarkCodeMarshal(b *testing.B) {
+ b.ReportAllocs()
+ if codeJSON == nil {
+ b.StopTimer()
+ codeInit()
+ b.StartTimer()
+ }
+ b.Run("BSON", func(b *testing.B) {
+ b.RunParallel(func(pb *testing.PB) {
+ for pb.Next() {
+ if _, err := Marshal(&codeStruct); err != nil {
+ b.Fatal("Marshal:", err)
+ }
+ }
+ })
+ b.SetBytes(int64(len(codeJSON)))
+ })
+ b.Run("JSON", func(b *testing.B) {
+ b.RunParallel(func(pb *testing.PB) {
+ for pb.Next() {
+ if _, err := json.Marshal(&codeStruct); err != nil {
+ b.Fatal("json.Marshal:", err)
+ }
+ }
+ })
+ b.SetBytes(int64(len(codeJSON)))
+ })
+}