From 05a9df474958724eb33836e13f6166fb3055ad88 Mon Sep 17 00:00:00 2001
From: Tao Wen <taowen@gmail.com>
Date: Fri, 2 Dec 2016 00:13:13 +0800
Subject: [PATCH] support skip
---
jsoniter.go | 134 +++++++++++++++++++++++++++++++++++-----
jsoniter_skip_test.go | 138 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 258 insertions(+), 14 deletions(-)
create mode 100644 jsoniter_skip_test.go
diff --git a/jsoniter.go b/jsoniter.go
index 27ebc5a..67209bc 100644
--- a/jsoniter.go
+++ b/jsoniter.go
@@ -43,7 +43,7 @@ func ParseString(input string) *Iterator {
func (iter *Iterator) skipWhitespaces() {
c := iter.readByte()
- for c == ' ' {
+ for c == ' ' || c == '\n' {
c = iter.readByte()
}
iter.unreadByte()
@@ -326,7 +326,9 @@ func (iter *Iterator) ReadArray() (ret bool) {
}
}
case ']': return false
- case ',': return true
+ case ',':
+ iter.skipWhitespaces()
+ return true
default:
iter.ReportError("ReadArray", "expect [ or , or ]")
return
@@ -397,18 +399,8 @@ func (iter *Iterator) readObjectField() (ret string) {
func (iter *Iterator) ReadFloat64() (ret float64) {
str := make([]byte, 0, 10)
for c := iter.readByte(); iter.Error == nil; c = iter.readByte() {
- switch {
- case c == '+':
- fallthrough
- case c == '-':
- fallthrough
- case c == '.':
- fallthrough
- case c == 'e':
- fallthrough
- case c == 'E':
- fallthrough
- case c > '0' && c < '9':
+ switch c {
+ case '-', '+', '.', 'e', 'E', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
str = append(str, c)
default:
iter.unreadByte()
@@ -430,3 +422,117 @@ func (iter *Iterator) ReadFloat64() (ret float64) {
}
return
}
+
+func (iter *Iterator) Skip() {
+ c := iter.readByte()
+ if iter.Error != nil {
+ return
+ }
+ switch c {
+ case '"':
+ iter.skipString()
+ case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+ iter.skipNumber()
+ case '[':
+ iter.skipArray()
+ case '{':
+ iter.skipObject()
+ default:
+ iter.ReportError("Skip", fmt.Sprintf("do not know how to skip: %v", c))
+ return
+ }
+}
+
+func (iter *Iterator) skipString() {
+ for c := iter.readByte(); iter.Error == nil; c = iter.readByte() {
+ switch c {
+ case '"':
+ return // end of string found
+ case '\\':
+ iter.readByte() // " after \\ does not count
+ if iter.Error != nil {
+ return
+ }
+ }
+ }
+}
+
+func (iter *Iterator) skipNumber() {
+ for c := iter.readByte(); iter.Error == nil; c = iter.readByte() {
+ switch c {
+ case '-', '+', '.', 'e', 'E', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+ continue
+ default:
+ iter.unreadByte()
+ return
+ }
+ }
+}
+
+func (iter *Iterator) skipArray() {
+ for {
+ iter.skipWhitespaces()
+ c := iter.readByte()
+ if iter.Error != nil {
+ return
+ }
+ if c == ']' {
+ return
+ }
+ iter.unreadByte()
+ iter.Skip()
+ iter.skipWhitespaces()
+ c = iter.readByte()
+ if iter.Error != nil {
+ return
+ }
+ switch c {
+ case ',':
+ iter.skipWhitespaces()
+ continue
+ case ']':
+ return
+ default:
+ iter.ReportError("skipArray", "expects , or ]")
+ return
+ }
+ }
+}
+
+func (iter *Iterator) skipObject() {
+ for {
+ iter.skipWhitespaces()
+ c := iter.readByte()
+ if c != '"' {
+ iter.ReportError("skipObject", `expects "`)
+ return
+ }
+ iter.skipString()
+ iter.skipWhitespaces()
+ c = iter.readByte()
+ if iter.Error != nil {
+ return
+ }
+ if c != ':' {
+ iter.ReportError("skipObject", `expects :`)
+ return
+ }
+ iter.skipWhitespaces()
+ iter.Skip()
+ iter.skipWhitespaces()
+ c = iter.readByte()
+ if iter.Error != nil {
+ return
+ }
+ switch c {
+ case ',':
+ iter.skipWhitespaces()
+ continue
+ case '}':
+ return // end of object
+ default:
+ iter.ReportError("skipObject", "expects , or }")
+ return
+ }
+ }
+}
\ No newline at end of file
diff --git a/jsoniter_skip_test.go b/jsoniter_skip_test.go
new file mode 100644
index 0000000..9b68068
--- /dev/null
+++ b/jsoniter_skip_test.go
@@ -0,0 +1,138 @@
+package jsoniter
+
+import (
+ "testing"
+ "encoding/json"
+)
+
+func Test_skip_string(t *testing.T) {
+ iter := ParseString(`["a", "b"]`)
+ iter.ReadArray()
+ iter.Skip()
+ iter.ReadArray()
+ if iter.ReadString() != "b" {
+ t.FailNow()
+ }
+}
+
+func Test_skip_string_with_escape(t *testing.T) {
+ iter := ParseString(`["a\"", "b"]`)
+ iter.ReadArray()
+ iter.Skip()
+ iter.ReadArray()
+ if iter.ReadString() != "b" {
+ t.FailNow()
+ }
+}
+
+func Test_skip_number(t *testing.T) {
+ iter := ParseString(`[-0.12, "b"]`)
+ iter.ReadArray()
+ iter.Skip()
+ iter.ReadArray()
+ if iter.ReadString() != "b" {
+ t.FailNow()
+ }
+}
+
+func Test_skip_array(t *testing.T) {
+ iter := ParseString(`[[1, [2, [3], 4]], "b"]`)
+ iter.ReadArray()
+ iter.Skip()
+ iter.ReadArray()
+ if iter.ReadString() != "b" {
+ t.FailNow()
+ }
+}
+
+func Test_skip_object(t *testing.T) {
+ iter := ParseString(`[ {"a" : {"b": "c"}, "d": 102 }, "b"]`)
+ iter.ReadArray()
+ iter.Skip()
+ iter.ReadArray()
+ if iter.ReadString() != "b" {
+ t.FailNow()
+ }
+}
+
+func Test_skip_nested(t *testing.T) {
+ iter := ParseString(`[ {"a" : [{"b": "c"}], "d": 102 }, "b"]`)
+ iter.ReadArray()
+ iter.Skip()
+ iter.ReadArray()
+ if iter.ReadString() != "b" {
+ t.FailNow()
+ }
+}
+
+type TestResp struct {
+ Code uint64
+}
+
+func Benchmark_jsoniter_skip(b *testing.B) {
+ for n := 0; n < b.N; n++ {
+ result := TestResp{}
+ iter := ParseString(`
+{
+ "_shards":{
+ "total" : 5,
+ "successful" : 5,
+ "failed" : 0
+ },
+ "code": 200,
+ "hits":{
+ "total" : 1,
+ "hits" : [
+ {
+ "_index" : "twitter",
+ "_type" : "tweet",
+ "_id" : "1",
+ "_source" : {
+ "user" : "kimchy",
+ "postDate" : "2009-11-15T14:12:12",
+ "message" : "trying out Elasticsearch"
+ }
+ }
+ ]
+ }
+}`)
+ for field := iter.ReadObject(); field != ""; field = iter.ReadObject() {
+ switch field {
+ case "code":
+ result.Code = iter.ReadUint64()
+ default:
+ iter.Skip()
+ }
+ }
+ }
+}
+
+func Benchmark_json_skip(b *testing.B) {
+ for n := 0; n < b.N; n++ {
+ result := TestResp{}
+ json.Unmarshal([]byte(`
+{
+ "_shards":{
+ "total" : 5,
+ "successful" : 5,
+ "failed" : 0
+ },
+ "code": 200,
+ "hits":{
+ "total" : 1,
+ "hits" : [
+ {
+ "_index" : "twitter",
+ "_type" : "tweet",
+ "_id" : "1",
+ "_source" : {
+ "user" : "kimchy",
+ "postDate" : "2009-11-15T14:12:12",
+ "message" : "trying out Elasticsearch"
+ }
+ }
+ ]
+ }
+}`), &result)
+ }
+}
\ No newline at end of file