bench_test.go

     1  // Copyright 2011 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // Large data benchmark.
     6  // The JSON data is a summary of agl's changes in the
     7  // go, webkit, and chromium open source projects.
     8  // We benchmark converting between the JSON form
     9  // and in-memory data structures.
    10  
    11  package json
    12  
    13  import (
    14  	"bytes"
    15  	"compress/gzip"
    16  	"fmt"
    17  	"internal/testenv"
    18  	"io"
    19  	"os"
    20  	"reflect"
    21  	"regexp"
    22  	"runtime"
    23  	"strings"
    24  	"sync"
    25  	"testing"
    26  )
    27  
    28  type codeResponse struct {
    29  	Tree     *codeNode `json:"tree"`
    30  	Username string    `json:"username"`
    31  }
    32  
    33  type codeNode struct {
    34  	Name     string      `json:"name"`
    35  	Kids     []*codeNode `json:"kids"`
    36  	CLWeight float64     `json:"cl_weight"`
    37  	Touches  int         `json:"touches"`
    38  	MinT     int64       `json:"min_t"`
    39  	MaxT     int64       `json:"max_t"`
    40  	MeanT    int64       `json:"mean_t"`
    41  }
    42  
    43  var codeJSON []byte
    44  var codeStruct codeResponse
    45  
    46  func codeInit() {
    47  	f, err := os.Open("testdata/code.json.gz")
    48  	if err != nil {
    49  		panic(err)
    50  	}
    51  	defer f.Close()
    52  	gz, err := gzip.NewReader(f)
    53  	if err != nil {
    54  		panic(err)
    55  	}
    56  	data, err := io.ReadAll(gz)
    57  	if err != nil {
    58  		panic(err)
    59  	}
    60  
    61  	codeJSON = data
    62  
    63  	if err := Unmarshal(codeJSON, &codeStruct); err != nil {
    64  		panic("unmarshal code.json: " + err.Error())
    65  	}
    66  
    67  	if data, err = Marshal(&codeStruct); err != nil {
    68  		panic("marshal code.json: " + err.Error())
    69  	}
    70  
    71  	if !bytes.Equal(data, codeJSON) {
    72  		println("different lengths", len(data), len(codeJSON))
    73  		for i := 0; i < len(data) && i < len(codeJSON); i++ {
    74  			if data[i] != codeJSON[i] {
    75  				println("re-marshal: changed at byte", i)
    76  				println("orig: ", string(codeJSON[i-10:i+10]))
    77  				println("new: ", string(data[i-10:i+10]))
    78  				break
    79  			}
    80  		}
    81  		panic("re-marshal code.json: different result")
    82  	}
    83  }
    84  
    85  func BenchmarkCodeEncoder(b *testing.B) {
    86  	b.ReportAllocs()
    87  	if codeJSON == nil {
    88  		b.StopTimer()
    89  		codeInit()
    90  		b.StartTimer()
    91  	}
    92  	b.RunParallel(func(pb *testing.PB) {
    93  		enc := NewEncoder(io.Discard)
    94  		for pb.Next() {
    95  			if err := enc.Encode(&codeStruct); err != nil {
    96  				b.Fatal("Encode:", err)
    97  			}
    98  		}
    99  	})
   100  	b.SetBytes(int64(len(codeJSON)))
   101  }
   102  
   103  func BenchmarkCodeEncoderError(b *testing.B) {
   104  	b.ReportAllocs()
   105  	if codeJSON == nil {
   106  		b.StopTimer()
   107  		codeInit()
   108  		b.StartTimer()
   109  	}
   110  
   111  	// Trigger an error in Marshal with cyclic data.
   112  	type Dummy struct {
   113  		Name string
   114  		Next *Dummy
   115  	}
   116  	dummy := Dummy{Name: "Dummy"}
   117  	dummy.Next = &dummy
   118  
   119  	b.RunParallel(func(pb *testing.PB) {
   120  		enc := NewEncoder(io.Discard)
   121  		for pb.Next() {
   122  			if err := enc.Encode(&codeStruct); err != nil {
   123  				b.Fatal("Encode:", err)
   124  			}
   125  			if _, err := Marshal(dummy); err == nil {
   126  				b.Fatal("expect an error here")
   127  			}
   128  		}
   129  	})
   130  	b.SetBytes(int64(len(codeJSON)))
   131  }
   132  
   133  func BenchmarkCodeMarshal(b *testing.B) {
   134  	b.ReportAllocs()
   135  	if codeJSON == nil {
   136  		b.StopTimer()
   137  		codeInit()
   138  		b.StartTimer()
   139  	}
   140  	b.RunParallel(func(pb *testing.PB) {
   141  		for pb.Next() {
   142  			if _, err := Marshal(&codeStruct); err != nil {
   143  				b.Fatal("Marshal:", err)
   144  			}
   145  		}
   146  	})
   147  	b.SetBytes(int64(len(codeJSON)))
   148  }
   149  
   150  func BenchmarkCodeMarshalError(b *testing.B) {
   151  	b.ReportAllocs()
   152  	if codeJSON == nil {
   153  		b.StopTimer()
   154  		codeInit()
   155  		b.StartTimer()
   156  	}
   157  
   158  	// Trigger an error in Marshal with cyclic data.
   159  	type Dummy struct {
   160  		Name string
   161  		Next *Dummy
   162  	}
   163  	dummy := Dummy{Name: "Dummy"}
   164  	dummy.Next = &dummy
   165  
   166  	b.RunParallel(func(pb *testing.PB) {
   167  		for pb.Next() {
   168  			if _, err := Marshal(&codeStruct); err != nil {
   169  				b.Fatal("Marshal:", err)
   170  			}
   171  			if _, err := Marshal(dummy); err == nil {
   172  				b.Fatal("expect an error here")
   173  			}
   174  		}
   175  	})
   176  	b.SetBytes(int64(len(codeJSON)))
   177  }
   178  
   179  func benchMarshalBytes(n int) func(*testing.B) {
   180  	sample := []byte("hello world")
   181  	// Use a struct pointer, to avoid an allocation when passing it as an
   182  	// interface parameter to Marshal.
   183  	v := &struct {
   184  		Bytes []byte
   185  	}{
   186  		bytes.Repeat(sample, (n/len(sample))+1)[:n],
   187  	}
   188  	return func(b *testing.B) {
   189  		for i := 0; i < b.N; i++ {
   190  			if _, err := Marshal(v); err != nil {
   191  				b.Fatal("Marshal:", err)
   192  			}
   193  		}
   194  	}
   195  }
   196  
   197  func benchMarshalBytesError(n int) func(*testing.B) {
   198  	sample := []byte("hello world")
   199  	// Use a struct pointer, to avoid an allocation when passing it as an
   200  	// interface parameter to Marshal.
   201  	v := &struct {
   202  		Bytes []byte
   203  	}{
   204  		bytes.Repeat(sample, (n/len(sample))+1)[:n],
   205  	}
   206  
   207  	// Trigger an error in Marshal with cyclic data.
   208  	type Dummy struct {
   209  		Name string
   210  		Next *Dummy
   211  	}
   212  	dummy := Dummy{Name: "Dummy"}
   213  	dummy.Next = &dummy
   214  
   215  	return func(b *testing.B) {
   216  		for i := 0; i < b.N; i++ {
   217  			if _, err := Marshal(v); err != nil {
   218  				b.Fatal("Marshal:", err)
   219  			}
   220  			if _, err := Marshal(dummy); err == nil {
   221  				b.Fatal("expect an error here")
   222  			}
   223  		}
   224  	}
   225  }
   226  
   227  func BenchmarkMarshalBytes(b *testing.B) {
   228  	b.ReportAllocs()
   229  	// 32 fits within encodeState.scratch.
   230  	b.Run("32", benchMarshalBytes(32))
   231  	// 256 doesn't fit in encodeState.scratch, but is small enough to
   232  	// allocate and avoid the slower base64.NewEncoder.
   233  	b.Run("256", benchMarshalBytes(256))
   234  	// 4096 is large enough that we want to avoid allocating for it.
   235  	b.Run("4096", benchMarshalBytes(4096))
   236  }
   237  
   238  func BenchmarkMarshalBytesError(b *testing.B) {
   239  	b.ReportAllocs()
   240  	// 32 fits within encodeState.scratch.
   241  	b.Run("32", benchMarshalBytesError(32))
   242  	// 256 doesn't fit in encodeState.scratch, but is small enough to
   243  	// allocate and avoid the slower base64.NewEncoder.
   244  	b.Run("256", benchMarshalBytesError(256))
   245  	// 4096 is large enough that we want to avoid allocating for it.
   246  	b.Run("4096", benchMarshalBytesError(4096))
   247  }
   248  
   249  func BenchmarkCodeDecoder(b *testing.B) {
   250  	b.ReportAllocs()
   251  	if codeJSON == nil {
   252  		b.StopTimer()
   253  		codeInit()
   254  		b.StartTimer()
   255  	}
   256  	b.RunParallel(func(pb *testing.PB) {
   257  		var buf bytes.Buffer
   258  		dec := NewDecoder(&buf)
   259  		var r codeResponse
   260  		for pb.Next() {
   261  			buf.Write(codeJSON)
   262  			// hide EOF
   263  			buf.WriteByte('\n')
   264  			buf.WriteByte('\n')
   265  			buf.WriteByte('\n')
   266  			if err := dec.Decode(&r); err != nil {
   267  				b.Fatal("Decode:", err)
   268  			}
   269  		}
   270  	})
   271  	b.SetBytes(int64(len(codeJSON)))
   272  }
   273  
   274  func BenchmarkUnicodeDecoder(b *testing.B) {
   275  	b.ReportAllocs()
   276  	j := []byte(`"\uD83D\uDE01"`)
   277  	b.SetBytes(int64(len(j)))
   278  	r := bytes.NewReader(j)
   279  	dec := NewDecoder(r)
   280  	var out string
   281  	b.ResetTimer()
   282  	for i := 0; i < b.N; i++ {
   283  		if err := dec.Decode(&out); err != nil {
   284  			b.Fatal("Decode:", err)
   285  		}
   286  		r.Seek(0, 0)
   287  	}
   288  }
   289  
   290  func BenchmarkDecoderStream(b *testing.B) {
   291  	b.ReportAllocs()
   292  	b.StopTimer()
   293  	var buf bytes.Buffer
   294  	dec := NewDecoder(&buf)
   295  	buf.WriteString(`"` + strings.Repeat("x", 1000000) + `"` + "\n\n\n")
   296  	var x any
   297  	if err := dec.Decode(&x); err != nil {
   298  		b.Fatal("Decode:", err)
   299  	}
   300  	ones := strings.Repeat(" 1\n", 300000) + "\n\n\n"
   301  	b.StartTimer()
   302  	for i := 0; i < b.N; i++ {
   303  		if i%300000 == 0 {
   304  			buf.WriteString(ones)
   305  		}
   306  		x = nil
   307  		if err := dec.Decode(&x); err != nil || x != 1.0 {
   308  			b.Fatalf("Decode: %v after %d", err, i)
   309  		}
   310  	}
   311  }
   312  
   313  func BenchmarkCodeUnmarshal(b *testing.B) {
   314  	b.ReportAllocs()
   315  	if codeJSON == nil {
   316  		b.StopTimer()
   317  		codeInit()
   318  		b.StartTimer()
   319  	}
   320  	b.RunParallel(func(pb *testing.PB) {
   321  		for pb.Next() {
   322  			var r codeResponse
   323  			if err := Unmarshal(codeJSON, &r); err != nil {
   324  				b.Fatal("Unmarshal:", err)
   325  			}
   326  		}
   327  	})
   328  	b.SetBytes(int64(len(codeJSON)))
   329  }
   330  
   331  func BenchmarkCodeUnmarshalReuse(b *testing.B) {
   332  	b.ReportAllocs()
   333  	if codeJSON == nil {
   334  		b.StopTimer()
   335  		codeInit()
   336  		b.StartTimer()
   337  	}
   338  	b.RunParallel(func(pb *testing.PB) {
   339  		var r codeResponse
   340  		for pb.Next() {
   341  			if err := Unmarshal(codeJSON, &r); err != nil {
   342  				b.Fatal("Unmarshal:", err)
   343  			}
   344  		}
   345  	})
   346  	b.SetBytes(int64(len(codeJSON)))
   347  }
   348  
   349  func BenchmarkUnmarshalString(b *testing.B) {
   350  	b.ReportAllocs()
   351  	data := []byte(`"hello, world"`)
   352  	b.RunParallel(func(pb *testing.PB) {
   353  		var s string
   354  		for pb.Next() {
   355  			if err := Unmarshal(data, &s); err != nil {
   356  				b.Fatal("Unmarshal:", err)
   357  			}
   358  		}
   359  	})
   360  }
   361  
   362  func BenchmarkUnmarshalFloat64(b *testing.B) {
   363  	b.ReportAllocs()
   364  	data := []byte(`3.14`)
   365  	b.RunParallel(func(pb *testing.PB) {
   366  		var f float64
   367  		for pb.Next() {
   368  			if err := Unmarshal(data, &f); err != nil {
   369  				b.Fatal("Unmarshal:", err)
   370  			}
   371  		}
   372  	})
   373  }
   374  
   375  func BenchmarkUnmarshalInt64(b *testing.B) {
   376  	b.ReportAllocs()
   377  	data := []byte(`3`)
   378  	b.RunParallel(func(pb *testing.PB) {
   379  		var x int64
   380  		for pb.Next() {
   381  			if err := Unmarshal(data, &x); err != nil {
   382  				b.Fatal("Unmarshal:", err)
   383  			}
   384  		}
   385  	})
   386  }
   387  
   388  func BenchmarkIssue10335(b *testing.B) {
   389  	b.ReportAllocs()
   390  	j := []byte(`{"a":{ }}`)
   391  	b.RunParallel(func(pb *testing.PB) {
   392  		var s struct{}
   393  		for pb.Next() {
   394  			if err := Unmarshal(j, &s); err != nil {
   395  				b.Fatal(err)
   396  			}
   397  		}
   398  	})
   399  }
   400  
   401  func BenchmarkIssue34127(b *testing.B) {
   402  	b.ReportAllocs()
   403  	j := struct {
   404  		Bar string `json:"bar,string"`
   405  	}{
   406  		Bar: `foobar`,
   407  	}
   408  	b.RunParallel(func(pb *testing.PB) {
   409  		for pb.Next() {
   410  			if _, err := Marshal(&j); err != nil {
   411  				b.Fatal(err)
   412  			}
   413  		}
   414  	})
   415  }
   416  
   417  func BenchmarkUnmapped(b *testing.B) {
   418  	b.ReportAllocs()
   419  	j := []byte(`{"s": "hello", "y": 2, "o": {"x": 0}, "a": [1, 99, {"x": 1}]}`)
   420  	b.RunParallel(func(pb *testing.PB) {
   421  		var s struct{}
   422  		for pb.Next() {
   423  			if err := Unmarshal(j, &s); err != nil {
   424  				b.Fatal(err)
   425  			}
   426  		}
   427  	})
   428  }
   429  
   430  func BenchmarkTypeFieldsCache(b *testing.B) {
   431  	b.ReportAllocs()
   432  	var maxTypes int = 1e6
   433  	if testenv.Builder() != "" {
   434  		maxTypes = 1e3 // restrict cache sizes on builders
   435  	}
   436  
   437  	// Dynamically generate many new types.
   438  	types := make([]reflect.Type, maxTypes)
   439  	fs := []reflect.StructField{{
   440  		Type:  reflect.TypeOf(""),
   441  		Index: []int{0},
   442  	}}
   443  	for i := range types {
   444  		fs[0].Name = fmt.Sprintf("TypeFieldsCache%d", i)
   445  		types[i] = reflect.StructOf(fs)
   446  	}
   447  
   448  	// clearClear clears the cache. Other JSON operations, must not be running.
   449  	clearCache := func() {
   450  		fieldCache = sync.Map{}
   451  	}
   452  
   453  	// MissTypes tests the performance of repeated cache misses.
   454  	// This measures the time to rebuild a cache of size nt.
   455  	for nt := 1; nt <= maxTypes; nt *= 10 {
   456  		ts := types[:nt]
   457  		b.Run(fmt.Sprintf("MissTypes%d", nt), func(b *testing.B) {
   458  			nc := runtime.GOMAXPROCS(0)
   459  			for i := 0; i < b.N; i++ {
   460  				clearCache()
   461  				var wg sync.WaitGroup
   462  				for j := 0; j < nc; j++ {
   463  					wg.Add(1)
   464  					go func(j int) {
   465  						for _, t := range ts[(j*len(ts))/nc : ((j+1)*len(ts))/nc] {
   466  							cachedTypeFields(t)
   467  						}
   468  						wg.Done()
   469  					}(j)
   470  				}
   471  				wg.Wait()
   472  			}
   473  		})
   474  	}
   475  
   476  	// HitTypes tests the performance of repeated cache hits.
   477  	// This measures the average time of each cache lookup.
   478  	for nt := 1; nt <= maxTypes; nt *= 10 {
   479  		// Pre-warm a cache of size nt.
   480  		clearCache()
   481  		for _, t := range types[:nt] {
   482  			cachedTypeFields(t)
   483  		}
   484  		b.Run(fmt.Sprintf("HitTypes%d", nt), func(b *testing.B) {
   485  			b.RunParallel(func(pb *testing.PB) {
   486  				for pb.Next() {
   487  					cachedTypeFields(types[0])
   488  				}
   489  			})
   490  		})
   491  	}
   492  }
   493  
   494  func BenchmarkEncodeMarshaler(b *testing.B) {
   495  	b.ReportAllocs()
   496  
   497  	m := struct {
   498  		A int
   499  		B RawMessage
   500  	}{}
   501  
   502  	b.RunParallel(func(pb *testing.PB) {
   503  		enc := NewEncoder(io.Discard)
   504  
   505  		for pb.Next() {
   506  			if err := enc.Encode(&m); err != nil {
   507  				b.Fatal("Encode:", err)
   508  			}
   509  		}
   510  	})
   511  }
   512  
   513  func BenchmarkEncoderEncode(b *testing.B) {
   514  	b.ReportAllocs()
   515  	type T struct {
   516  		X, Y string
   517  	}
   518  	v := &T{"foo", "bar"}
   519  	b.RunParallel(func(pb *testing.PB) {
   520  		for pb.Next() {
   521  			if err := NewEncoder(io.Discard).Encode(v); err != nil {
   522  				b.Fatal(err)
   523  			}
   524  		}
   525  	})
   526  }
   527  
   528  func BenchmarkNumberIsValid(b *testing.B) {
   529  	s := "-61657.61667E+61673"
   530  	for i := 0; i < b.N; i++ {
   531  		isValidNumber(s)
   532  	}
   533  }
   534  
   535  func BenchmarkNumberIsValidRegexp(b *testing.B) {
   536  	var jsonNumberRegexp = regexp.MustCompile(`^-?(?:0|[1-9]\d*)(?:\.\d+)?(?:[eE][+-]?\d+)?$`)
   537  	s := "-61657.61667E+61673"
   538  	for i := 0; i < b.N; i++ {
   539  		jsonNumberRegexp.MatchString(s)
   540  	}
   541  }
   542
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