Simplify usage (#54)

* Simplify usage
* Add root foreach callback.
* Simplify path specification for FindElement
* Add buger/jsonparser benchmark. Crazy fast.

benchmarks_test.go

@@ -20,6 +20,7 @@ import (
 	"encoding/json"
 	"testing"
 
+	"github.com/buger/jsonparser"
 	jsoniter "github.com/json-iterator/go"
 )
 
@@ -166,31 +167,31 @@ func BenchmarkJsonParserLarge(b *testing.B) {
 				b.Fatal(err)
 			}
 			iter := pj.Iter()
-			elem, err = iter.FindElement("users", elem)
+			elem, err = iter.FindElement(elem, "users")
 			if checkErrs && err != nil {
 				b.Fatal(err)
 			}
 			ar, err = elem.Iter.Array(ar)
 			if checkErrs && err != nil {
 				b.Fatal(err)
 			}
-			ar.ForEach(func(t Type, i Iter) {
-				elem, err = i.FindElement("username", elem)
+			ar.ForEach(func(i Iter) {
+				elem, err = i.FindElement(elem, "username")
 				if checkErrs && err != nil {
 					b.Fatal(err)
 				}
 				_, _ = elem.Iter.StringBytes()
 			})
 
-			elem, err = iter.FindElement("topics/topics", elem)
+			elem, err = iter.FindElement(elem, "topics", "topics")
 			if checkErrs && err != nil {
 				b.Fatal(err)
 			}
 			ar, err = elem.Iter.Array(ar)
 			if checkErrs && err != nil {
 				b.Fatal(err)
 			}
-			ar.ForEach(func(t Type, i Iter) {
+			ar.ForEach(func(i Iter) {
 				if true {
 					// Use foreach...
 					obj, err = i.Object(obj)
@@ -213,13 +214,13 @@ func BenchmarkJsonParserLarge(b *testing.B) {
 
 					}, onlyKeys)
 				} else {
-					elem, err = i.FindElement("id", elem)
+					elem, err = i.FindElement(elem, "id")
 					if checkErrs && err != nil {
 						b.Fatal(err)
 					}
 					_, _ = elem.Iter.Int()
 					//b.Log(elem.Iter.Int())
-					elem, err = i.FindElement("slug", elem)
+					elem, err = i.FindElement(elem, "slug")
 					if checkErrs && err != nil {
 						b.Fatal(err)
 					}
@@ -230,3 +231,37 @@ func BenchmarkJsonParserLarge(b *testing.B) {
 		}
 	})
 }
+
+func BenchmarkBugerJsonParserLarge(b *testing.B) {
+	largeFixture := loadCompressed(b, "payload-large")
+	const logVals = false
+	b.SetBytes(int64(len(largeFixture)))
+	b.ReportAllocs()
+	b.ResetTimer()
+	var dump int
+	for i := 0; i < b.N; i++ {
+		jsonparser.ArrayEach(largeFixture, func(value []byte, dataType jsonparser.ValueType, offset int, err error) {
+			sval, _, _, _ := jsonparser.Get(value, "username")
+			if logVals && i == 0 {
+				b.Log(string(sval))
+			}
+			dump += len(sval)
+		}, "users")
+
+		jsonparser.ArrayEach(largeFixture, func(value []byte, dataType jsonparser.ValueType, offset int, err error) {
+			ival, _ := jsonparser.GetInt(value, "id")
+			if logVals && i == 0 {
+				b.Log(ival)
+			}
+			dump += int(ival)
+			sval, _, _, _ := jsonparser.Get(value, "slug")
+			if logVals && i == 0 {
+				b.Log(string(sval))
+			}
+			dump += len(sval)
+		}, "topics", "topics")
+	}
+	if dump == 0 {
+		b.Log("")
+	}
+}

examples/simdjson_example.go

@@ -1,42 +1,30 @@
 package main
 
 import (
+	"encoding/json"
 	"fmt"
 	"io/ioutil"
 	"log"
 
 	"github.com/minio/simdjson-go"
 )
 
-func printKey(iter simdjson.Iter, key string) (err error) {
-
-	obj, tmp, elem := &simdjson.Object{}, &simdjson.Iter{}, simdjson.Element{}
-
-	for {
-		typ := iter.Advance()
-
-		switch typ {
-		case simdjson.TypeRoot:
-			if typ, tmp, err = iter.Root(tmp); err != nil {
-				return
-			}
-
-			if typ == simdjson.TypeObject {
-				if obj, err = tmp.Object(obj); err != nil {
-					return
-				}
-
-				e := obj.FindKey(key, &elem)
-				if e != nil && elem.Type == simdjson.TypeString {
-					v, _ := elem.Iter.StringBytes()
-					fmt.Println(string(v))
-				}
-			}
-
-		default:
-			return
+func printKeyHistogram(pj *simdjson.ParsedJson, key string) (err error) {
+	var elem *simdjson.Element
+	count := make(map[string]int)
+	err = pj.ForEach(func(i simdjson.Iter) error {
+		if elem, err = i.FindElement(elem, key); err != nil {
+			return nil
 		}
-	}
+		if elem.Type == simdjson.TypeString {
+			s, _ := elem.Iter.String()
+			count[s]++
+		}
+		return nil
+	})
+	res, _ := json.Marshal(count)
+	fmt.Println(key, ":", string(res)+"\n")
+	return err
 }
 
 func main() {
@@ -53,5 +41,7 @@ func main() {
 		log.Fatalf("Failed to parse JSON: %v", err)
 	}
 
-	printKey(parsed.Iter(), "Make")
+	printKeyHistogram(parsed, "Make")
+	printKeyHistogram(parsed, "MeterId")
+	printKeyHistogram(parsed, "ViolationCode")
 }

go.mod

@@ -1,9 +1,10 @@
 module github.com/minio/simdjson-go
 
-go 1.13
+go 1.15
 
 require (
+	github.com/buger/jsonparser v1.1.1
 	github.com/json-iterator/go v1.1.9
 	github.com/klauspost/compress v1.13.6
-	github.com/klauspost/cpuid/v2 v2.0.6
+	github.com/klauspost/cpuid/v2 v2.0.9
 )

go.sum

@@ -1,3 +1,5 @@
+github.com/buger/jsonparser v1.1.1 h1:2PnMjfWD7wBILjqQbt530v576A/cAbQvEW9gGIpYMUs=
+github.com/buger/jsonparser v1.1.1/go.mod h1:6RYKKt7H4d4+iWqouImQ9R2FZql3VbhNgx27UK13J/0=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -6,8 +8,8 @@ github.com/json-iterator/go v1.1.9 h1:9yzud/Ht36ygwatGx56VwCZtlI/2AD15T1X2sjSuGn
 github.com/json-iterator/go v1.1.9/go.mod h1:KdQUCv79m/52Kvf8AW2vK1V8akMuk1QjK/uOdHXbAo4=
 github.com/klauspost/compress v1.13.6 h1:P76CopJELS0TiO2mebmnzgWaajssP/EszplttgQxcgc=
 github.com/klauspost/compress v1.13.6/go.mod h1:/3/Vjq9QcHkK5uEr5lBEmyoZ1iFhe47etQ6QUkpK6sk=
-github.com/klauspost/cpuid/v2 v2.0.6 h1:dQ5ueTiftKxp0gyjKSx5+8BtPWkyQbd95m8Gys/RarI=
-github.com/klauspost/cpuid/v2 v2.0.6/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa0213Md/qVLRg=
+github.com/klauspost/cpuid/v2 v2.0.9 h1:lgaqFMSdTdQYdZ04uHyN2d/eKdOMyi2YLSvlQIBFYa4=
+github.com/klauspost/cpuid/v2 v2.0.9/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa0213Md/qVLRg=
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421 h1:ZqeYNhU3OHLH3mGKHDcjJRFFRrJa6eAM5H+CtDdOsPc=
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742 h1:Esafd1046DLDQ0W1YjYsBW+p8U2u7vzgW2SQVmlNazg=

ndjson_test.go

@@ -259,14 +259,60 @@ func TestNdjsonCountWhere(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	ser := NewSerializer()
-	ser.CompressMode(CompressBest)
-	b := ser.Serialize(nil, *pj)
-	t.Log(len(b))
+
 	const want = 116
-	if result := countWhere("Make", "HOND", *pj); result != want {
-		t.Errorf("TestNdjsonCountWhere: got: %d want: %d", result, want)
-	}
+	t.Run("countWhere", func(t *testing.T) {
+		if result := countWhere("Make", "HOND", *pj); result != want {
+			t.Errorf("TestNdjsonCountWhere: got: %d want: %d", result, want)
+		}
+	})
+	t.Run("foreach", func(t *testing.T) {
+		var result int
+		var elem *Element
+		var obj *Object
+		err := pj.ForEach(func(i Iter) error {
+			var err error
+			obj, err = i.Object(obj)
+			if err == nil {
+				elem = obj.FindKey("Make", elem)
+				if elem != nil {
+					bts, _ := elem.Iter.StringBytes()
+					if string(bts) == "HOND" {
+						result++
+					}
+				}
+			}
+			return nil
+		})
+		if err != nil {
+			t.Fatal(err)
+		}
+		if result != want {
+			t.Errorf("TestNdjsonCountWhere: got: %d want: %d", result, want)
+		}
+	})
+	t.Run("foreach-findelement", func(t *testing.T) {
+		var result int
+		var elem *Element
+		err := pj.ForEach(func(i Iter) error {
+			var err error
+			elem, err = i.FindElement(elem, "Make")
+			if err != nil {
+				return nil
+			}
+			bts, _ := elem.Iter.StringBytes()
+			if string(bts) == "HOND" {
+				result++
+			}
+			return nil
+		})
+		if err != nil {
+			t.Fatal(err)
+		}
+		if result != want {
+			t.Errorf("TestNdjsonCountWhere: got: %d want: %d", result, want)
+		}
+	})
 }
 
 func TestNdjsonCountWhere2(t *testing.T) {
@@ -287,9 +333,34 @@ func TestNdjsonCountWhere2(t *testing.T) {
 		t.Fatal(err)
 	}
 	const want = 170315
-	if result := countWhere("subreddit", "reddit.com", *pj); result != want {
-		t.Errorf("TestNdjsonCountWhere: got: %d want: %d", result, want)
-	}
+	t.Run("countWhere", func(t *testing.T) {
+		if result := countWhere("subreddit", "reddit.com", *pj); result != want {
+			t.Errorf("TestNdjsonCountWhere: got: %d want: %d", result, want)
+		}
+
+	})
+	t.Run("foreach-findelement", func(t *testing.T) {
+		var result int
+		var elem *Element
+		err := pj.ForEach(func(i Iter) error {
+			var err error
+			elem, err = i.FindElement(elem, "subreddit")
+			if err != nil {
+				return nil
+			}
+			bts, _ := elem.Iter.StringBytes()
+			if string(bts) == "reddit.com" {
+				result++
+			}
+			return nil
+		})
+		if err != nil {
+			t.Fatal(err)
+		}
+		if result != want {
+			t.Errorf("TestNdjsonCountWhere: got: %d want: %d", result, want)
+		}
+	})
 }
 
 func loadFile(filename string) []byte {

parsed_array.go

@@ -43,14 +43,14 @@ func (a *Array) Iter() Iter {
 }
 
 // ForEach calls the provided function for every element.
-func (a *Array) ForEach(fn func(t Type, i Iter)) {
+func (a *Array) ForEach(fn func(i Iter)) {
 	i := a.Iter()
 	for {
 		t := i.Advance()
 		if t == TypeNone {
 			break
 		}
-		fn(t, i)
+		fn(i)
 	}
 	return
 }

parsed_json.go

@@ -119,6 +119,24 @@ func (pj *ParsedJson) stringByteAt(offset, length uint64) ([]byte, error) {
 	return pj.Strings.B[offset : offset+length], nil
 }
 
+// ForEach returns each line in NDJSON, or the top element in non-ndjson.
+// This will usually be an object or an array.
+// If the callback returns a non-nil error parsing stops and the errors is returned.
+func (pj *ParsedJson) ForEach(fn func(i Iter) error) error {
+	i := Iter{tape: *pj}
+	var elem Iter
+	for {
+		t, err := i.AdvanceIter(&elem)
+		if err != nil || t != TypeRoot {
+			return err
+		}
+		elem.AdvanceInto()
+		if err = fn(elem); err != nil {
+			return err
+		}
+	}
+}
+
 // Clone returns a deep clone of the ParsedJson.
 // If a nil destination is sent a new will be created.
 func (pj *ParsedJson) Clone(dst *ParsedJson) *ParsedJson {
@@ -751,13 +769,15 @@ func (i *Iter) Root(dst *Iter) (Type, *Iter, error) {
 
 // FindElement allows searching for fields and objects by path from the iter and forward,
 // moving into root and objects, but not arrays.
-// Separate each object name by /.
-// For example `Image/Url` will search the current root/object for an "Image"
+// For example "Image", "Url" will search the current root/object for an "Image"
 // object and return the value of the "Url" element.
 // ErrPathNotFound is returned if any part of the path cannot be found.
 // If the tape contains an error it will be returned.
 // The iter will *not* be advanced.
-func (i *Iter) FindElement(path string, dst *Element) (*Element, error) {
+func (i *Iter) FindElement(dst *Element, path ...string) (*Element, error) {
+	if len(path) == 0 {
+		return dst, ErrPathNotFound
+	}
 	// Local copy.
 	cp := *i
 	for {
@@ -768,7 +788,7 @@ func (i *Iter) FindElement(path string, dst *Element) (*Element, error) {
 			if err != nil {
 				return dst, err
 			}
-			return obj.FindPath(path, dst)
+			return obj.FindPath(dst, path...)
 		case TagRoot:
 			_, _, err := cp.Root(&cp)
 			if err != nil {