Merge pull request #190 from goccy/feature/improve-indent-compact

Optimize json.Compact and json.Indent

encode.go

@@ -2,7 +2,6 @@ package json
 
 import (
 	"io"
-	"sync"
 	"unsafe"
 
 	"github.com/goccy/go-json/internal/encoder"
@@ -22,10 +21,6 @@ type Encoder struct {
 	indentStr         string
 }
 
-const (
-	bufSize = 1024
-)
-
 type EncodeOption int
 
 const (
@@ -35,26 +30,6 @@ const (
 	EncodeOptionDebug
 )
 
-var (
-	encRuntimeContextPool = sync.Pool{
-		New: func() interface{} {
-			return &encoder.RuntimeContext{
-				Buf:      make([]byte, 0, bufSize),
-				Ptrs:     make([]uintptr, 128),
-				KeepRefs: make([]unsafe.Pointer, 0, 8),
-			}
-		},
-	}
-)
-
-func takeEncodeRuntimeContext() *encoder.RuntimeContext {
-	return encRuntimeContextPool.Get().(*encoder.RuntimeContext)
-}
-
-func releaseEncodeRuntimeContext(ctx *encoder.RuntimeContext) {
-	encRuntimeContextPool.Put(ctx)
-}
-
 // NewEncoder returns a new encoder that writes to w.
 func NewEncoder(w io.Writer) *Encoder {
 	return &Encoder{w: w, enabledHTMLEscape: true}
@@ -69,11 +44,11 @@ func (e *Encoder) Encode(v interface{}) error {
 
 // EncodeWithOption call Encode with EncodeOption.
 func (e *Encoder) EncodeWithOption(v interface{}, optFuncs ...EncodeOptionFunc) error {
-	ctx := takeEncodeRuntimeContext()
+	ctx := encoder.TakeRuntimeContext()
 
 	err := e.encodeWithOption(ctx, v, optFuncs...)
 
-	releaseEncodeRuntimeContext(ctx)
+	encoder.ReleaseRuntimeContext(ctx)
 	return err
 }
 
@@ -130,11 +105,11 @@ func (e *Encoder) SetIndent(prefix, indent string) {
 }
 
 func marshal(v interface{}, opt EncodeOption) ([]byte, error) {
-	ctx := takeEncodeRuntimeContext()
+	ctx := encoder.TakeRuntimeContext()
 
 	buf, err := encode(ctx, v, opt|EncodeOptionHTMLEscape)
 	if err != nil {
-		releaseEncodeRuntimeContext(ctx)
+		encoder.ReleaseRuntimeContext(ctx)
 		return nil, err
 	}
 
@@ -146,16 +121,16 @@ func marshal(v interface{}, opt EncodeOption) ([]byte, error) {
 	copied := make([]byte, len(buf))
 	copy(copied, buf)
 
-	releaseEncodeRuntimeContext(ctx)
+	encoder.ReleaseRuntimeContext(ctx)
 	return copied, nil
 }
 
 func marshalNoEscape(v interface{}, opt EncodeOption) ([]byte, error) {
-	ctx := takeEncodeRuntimeContext()
+	ctx := encoder.TakeRuntimeContext()
 
 	buf, err := encodeNoEscape(ctx, v, opt|EncodeOptionHTMLEscape)
 	if err != nil {
-		releaseEncodeRuntimeContext(ctx)
+		encoder.ReleaseRuntimeContext(ctx)
 		return nil, err
 	}
 
@@ -167,16 +142,16 @@ func marshalNoEscape(v interface{}, opt EncodeOption) ([]byte, error) {
 	copied := make([]byte, len(buf))
 	copy(copied, buf)
 
-	releaseEncodeRuntimeContext(ctx)
+	encoder.ReleaseRuntimeContext(ctx)
 	return copied, nil
 }
 
 func marshalIndent(v interface{}, prefix, indent string, opt EncodeOption) ([]byte, error) {
-	ctx := takeEncodeRuntimeContext()
+	ctx := encoder.TakeRuntimeContext()
 
 	buf, err := encodeIndent(ctx, v, prefix, indent, opt|EncodeOptionHTMLEscape)
 	if err != nil {
-		releaseEncodeRuntimeContext(ctx)
+		encoder.ReleaseRuntimeContext(ctx)
 		return nil, err
 	}
 
@@ -184,7 +159,7 @@ func marshalIndent(v interface{}, prefix, indent string, opt EncodeOption) ([]by
 	copied := make([]byte, len(buf))
 	copy(copied, buf)
 
-	releaseEncodeRuntimeContext(ctx)
+	encoder.ReleaseRuntimeContext(ctx)
 	return copied, nil
 }
 

internal/encoder/compact.go

@@ -30,9 +30,22 @@ func Compact(buf *bytes.Buffer, src []byte, escape bool) error {
 	}
 	buf.Grow(len(src))
 	dst := buf.Bytes()
-	newSrc := make([]byte, len(src)+1) // append nul byte to the end
+
-	copy(newSrc, src)
+	ctx := TakeRuntimeContext()
-	dst, err := compact(dst, newSrc, escape)
+	ctxBuf := ctx.Buf[:0]
+	ctxBuf = append(append(ctxBuf, src...), nul)
+	ctx.Buf = ctxBuf
+
+	if err := compactAndWrite(buf, dst, ctxBuf, escape); err != nil {
+		ReleaseRuntimeContext(ctx)
+		return err
+	}
+	ReleaseRuntimeContext(ctx)
+	return nil
+}
+
+func compactAndWrite(buf *bytes.Buffer, dst []byte, src []byte, escape bool) error {
+	dst, err := compact(dst, src, escape)
 	if err != nil {
 		return err
 	}

internal/encoder/context.go

@@ -1,6 +1,9 @@
 package encoder
 
 import (
+	"sync"
+	"unsafe"
+
 	"github.com/goccy/go-json/internal/runtime"
 )
 
@@ -80,3 +83,53 @@ func (c *compileContext) decPtrIndex() {
 		c.parent.decPtrIndex()
 	}
 }
+
+const (
+	bufSize = 1024
+)
+
+var (
+	runtimeContextPool = sync.Pool{
+		New: func() interface{} {
+			return &RuntimeContext{
+				Buf:      make([]byte, 0, bufSize),
+				Ptrs:     make([]uintptr, 128),
+				KeepRefs: make([]unsafe.Pointer, 0, 8),
+			}
+		},
+	}
+)
+
+type RuntimeContext struct {
+	Buf        []byte
+	MarshalBuf []byte
+	Ptrs       []uintptr
+	KeepRefs   []unsafe.Pointer
+	SeenPtr    []uintptr
+	BaseIndent int
+	Prefix     []byte
+	IndentStr  []byte
+}
+
+func (c *RuntimeContext) Init(p uintptr, codelen int) {
+	if len(c.Ptrs) < codelen {
+		c.Ptrs = make([]uintptr, codelen)
+	}
+	c.Ptrs[0] = p
+	c.KeepRefs = c.KeepRefs[:0]
+	c.SeenPtr = c.SeenPtr[:0]
+	c.BaseIndent = 0
+}
+
+func (c *RuntimeContext) Ptr() uintptr {
+	header := (*runtime.SliceHeader)(unsafe.Pointer(&c.Ptrs))
+	return uintptr(header.Data)
+}
+
+func TakeRuntimeContext() *RuntimeContext {
+	return runtimeContextPool.Get().(*RuntimeContext)
+}
+
+func ReleaseRuntimeContext(ctx *RuntimeContext) {
+	runtimeContextPool.Put(ctx)
+}

internal/encoder/encoder.go

@@ -304,32 +304,6 @@ func MapIterNext(it unsafe.Pointer)
 //go:noescape
 func MapLen(m unsafe.Pointer) int
 
-type RuntimeContext struct {
-	Buf        []byte
-	MarshalBuf []byte
-	Ptrs       []uintptr
-	KeepRefs   []unsafe.Pointer
-	SeenPtr    []uintptr
-	BaseIndent int
-	Prefix     []byte
-	IndentStr  []byte
-}
-
-func (c *RuntimeContext) Init(p uintptr, codelen int) {
-	if len(c.Ptrs) < codelen {
-		c.Ptrs = make([]uintptr, codelen)
-	}
-	c.Ptrs[0] = p
-	c.KeepRefs = c.KeepRefs[:0]
-	c.SeenPtr = c.SeenPtr[:0]
-	c.BaseIndent = 0
-}
-
-func (c *RuntimeContext) Ptr() uintptr {
-	header := (*runtime.SliceHeader)(unsafe.Pointer(&c.Ptrs))
-	return uintptr(header.Data)
-}
-
 func AppendByteSlice(b []byte, src []byte) []byte {
 	if src == nil {
 		return append(b, `null`...)
@@ -551,13 +525,20 @@ func AppendStructEnd(b []byte) []byte {
 func AppendStructEndIndent(ctx *RuntimeContext, b []byte, indent int) []byte {
 	b = append(b, '\n')
 	b = append(b, ctx.Prefix...)
-	b = append(b, bytes.Repeat(ctx.IndentStr, ctx.BaseIndent+indent)...)
+	indentNum := ctx.BaseIndent + indent
+	for i := 0; i < indentNum; i++ {
+		b = append(b, ctx.IndentStr...)
+	}
 	return append(b, '}', ',', '\n')
 }
 
 func AppendIndent(ctx *RuntimeContext, b []byte, indent int) []byte {
 	b = append(b, ctx.Prefix...)
-	return append(b, bytes.Repeat(ctx.IndentStr, ctx.BaseIndent+indent)...)
+	indentNum := ctx.BaseIndent + indent
+	for i := 0; i < indentNum; i++ {
+		b = append(b, ctx.IndentStr...)
+	}
+	return b
 }
 
 func IsNilForMarshaler(v interface{}) bool {

internal/encoder/indent.go

@@ -7,22 +7,44 @@ import (
 	"github.com/goccy/go-json/internal/errors"
 )
 
+func takeIndentSrcRuntimeContext(src []byte) (*RuntimeContext, []byte) {
+	ctx := TakeRuntimeContext()
+	buf := ctx.Buf[:0]
+	buf = append(append(buf, src...), nul)
+	ctx.Buf = buf
+	return ctx, buf
+}
+
 func Indent(buf *bytes.Buffer, src []byte, prefix, indentStr string) error {
 	if len(src) == 0 {
 		return errors.ErrUnexpectedEndOfJSON("", 0)
 	}
-	buf.Grow(len(src))
+
-	dst := buf.Bytes()
+	srcCtx, srcBuf := takeIndentSrcRuntimeContext(src)
-	newSrc := make([]byte, len(src)+1) // append nul byte to the end
+	dstCtx := TakeRuntimeContext()
-	copy(newSrc, src)
+	dst := dstCtx.Buf[:0]
-	dst, err := doIndent(dst, newSrc, prefix, indentStr, false)
+
+	dst, err := indentAndWrite(buf, dst, srcBuf, prefix, indentStr)
 	if err != nil {
+		ReleaseRuntimeContext(srcCtx)
+		ReleaseRuntimeContext(dstCtx)
 		return err
 	}
+	dstCtx.Buf = dst
+	ReleaseRuntimeContext(srcCtx)
+	ReleaseRuntimeContext(dstCtx)
+	return nil
+}
+
+func indentAndWrite(buf *bytes.Buffer, dst []byte, src []byte, prefix, indentStr string) ([]byte, error) {
+	dst, err := doIndent(dst, src, prefix, indentStr, false)
+	if err != nil {
+		return nil, err
+	}
 	if _, err := buf.Write(dst); err != nil {
-		return err
+		return nil, err
 	}
-	return nil
+	return dst, nil
 }
 
 func doIndent(dst, src []byte, prefix, indentStr string, escape bool) ([]byte, error) {
@@ -94,7 +116,10 @@ func indentObject(
 	indentNum++
 	var err error
 	for {
-		dst = append(append(append(dst, '\n'), prefix...), bytes.Repeat(indentBytes, indentNum)...)
+		dst = append(append(dst, '\n'), prefix...)
+		for i := 0; i < indentNum; i++ {
+			dst = append(dst, indentBytes...)
+		}
 		cursor = skipWhiteSpace(src, cursor)
 		dst, cursor, err = compactString(dst, src, cursor, escape)
 		if err != nil {
@@ -115,7 +140,10 @@ func indentObject(
 		cursor = skipWhiteSpace(src, cursor)
 		switch src[cursor] {
 		case '}':
-			dst = append(append(append(dst, '\n'), prefix...), bytes.Repeat(indentBytes, indentNum-1)...)
+			dst = append(append(dst, '\n'), prefix...)
+			for i := 0; i < indentNum-1; i++ {
+				dst = append(dst, indentBytes...)
+			}
 			dst = append(dst, '}')
 			cursor++
 			return dst, cursor, nil
@@ -152,7 +180,10 @@ func indentArray(
 	indentNum++
 	var err error
 	for {
-		dst = append(append(append(dst, '\n'), prefix...), bytes.Repeat(indentBytes, indentNum)...)
+		dst = append(append(dst, '\n'), prefix...)
+		for i := 0; i < indentNum; i++ {
+			dst = append(dst, indentBytes...)
+		}
 		dst, cursor, err = indentValue(dst, src, indentNum, cursor, prefix, indentBytes, escape)
 		if err != nil {
 			return nil, 0, err
@@ -160,7 +191,10 @@ func indentArray(
 		cursor = skipWhiteSpace(src, cursor)
 		switch src[cursor] {
 		case ']':
-			dst = append(append(append(dst, '\n'), prefix...), bytes.Repeat(indentBytes, indentNum-1)...)
+			dst = append(append(dst, '\n'), prefix...)
+			for i := 0; i < indentNum-1; i++ {
+				dst = append(dst, indentBytes...)
+			}
 			dst = append(dst, ']')
 			cursor++
 			return dst, cursor, nil

internal/encoder/vm_escaped_indent/util.go

@@ -1,7 +1,6 @@
 package vm_escaped_indent
 
 import (
-	"bytes"
 	"encoding/json"
 	"unsafe"
 
@@ -76,15 +75,3 @@ func appendNull(b []byte) []byte {
 func appendComma(b []byte) []byte {
 	return append(b, ',', '\n')
 }
-
-func appendStructEnd(ctx *encoder.RuntimeContext, b []byte, indent int) []byte {
-	b = append(b, '\n')
-	b = append(b, ctx.Prefix...)
-	b = append(b, bytes.Repeat(ctx.IndentStr, ctx.BaseIndent+indent)...)
-	return append(b, '}', ',', '\n')
-}
-
-func appendIndent(ctx *encoder.RuntimeContext, b []byte, indent int) []byte {
-	b = append(b, ctx.Prefix...)
-	return append(b, bytes.Repeat(ctx.IndentStr, ctx.BaseIndent+indent)...)
-}

internal/encoder/vm_escaped_indent/vm.go

@@ -1,7 +1,6 @@
 package vm_escaped_indent
 
 import (
-	"bytes"
 	"fmt"
 	"math"
 	"sort"
@@ -29,6 +28,8 @@ var (
 	appendNumber        = encoder.AppendNumber
 	appendMarshalJSON   = encoder.AppendMarshalJSONIndent
 	appendMarshalText   = encoder.AppendMarshalTextIndent
+	appendStructEnd     = encoder.AppendStructEndIndent
+	appendIndent        = encoder.AppendIndent
 	errUnsupportedValue = encoder.ErrUnsupportedValue
 	errUnsupportedFloat = encoder.ErrUnsupportedFloat
 	mapiterinit         = encoder.MapIterInit
@@ -518,8 +519,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet, opt
 			sort.Sort(mapCtx.Slice)
 			buf := mapCtx.Buf
 			for _, item := range mapCtx.Slice.Items {
-				buf = append(buf, ctx.Prefix...)
+				buf = appendIndent(ctx, buf, code.Indent+1)
-				buf = append(buf, bytes.Repeat(ctx.IndentStr, ctx.BaseIndent+code.Indent+1)...)
 				buf = append(buf, item.Key...)
 				buf[len(buf)-2] = ':'
 				buf[len(buf)-1] = ' '
@@ -527,8 +527,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet, opt
 			}
 			buf = buf[:len(buf)-2]
 			buf = append(buf, '\n')
-			buf = append(buf, ctx.Prefix...)
+			buf = appendIndent(ctx, buf, code.Indent)
-			buf = append(buf, bytes.Repeat(ctx.IndentStr, ctx.BaseIndent+code.Indent)...)
 			buf = append(buf, '}', ',', '\n')
 
 			b = b[:pos[0]]

internal/encoder/vm_indent/util.go

@@ -1,7 +1,6 @@
 package vm_indent
 
 import (
-	"bytes"
 	"encoding/json"
 	"unsafe"
 
@@ -76,15 +75,3 @@ func appendNull(b []byte) []byte {
 func appendComma(b []byte) []byte {
 	return append(b, ',', '\n')
 }
-
-func appendStructEnd(ctx *encoder.RuntimeContext, b []byte, indent int) []byte {
-	b = append(b, '\n')
-	b = append(b, ctx.Prefix...)
-	b = append(b, bytes.Repeat(ctx.IndentStr, ctx.BaseIndent+indent)...)
-	return append(b, '}', ',', '\n')
-}
-
-func appendIndent(ctx *encoder.RuntimeContext, b []byte, indent int) []byte {
-	b = append(b, ctx.Prefix...)
-	return append(b, bytes.Repeat(ctx.IndentStr, ctx.BaseIndent+indent)...)
-}

internal/encoder/vm_indent/vm.go

@@ -1,7 +1,6 @@
 package vm_indent
 
 import (
-	"bytes"
 	"fmt"
 	"math"
 	"sort"
@@ -29,6 +28,8 @@ var (
 	appendNumber        = encoder.AppendNumber
 	appendMarshalJSON   = encoder.AppendMarshalJSONIndent
 	appendMarshalText   = encoder.AppendMarshalTextIndent
+	appendStructEnd     = encoder.AppendStructEndIndent
+	appendIndent        = encoder.AppendIndent
 	errUnsupportedValue = encoder.ErrUnsupportedValue
 	errUnsupportedFloat = encoder.ErrUnsupportedFloat
 	mapiterinit         = encoder.MapIterInit
@@ -518,8 +519,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet, opt
 			sort.Sort(mapCtx.Slice)
 			buf := mapCtx.Buf
 			for _, item := range mapCtx.Slice.Items {
-				buf = append(buf, ctx.Prefix...)
+				buf = appendIndent(ctx, buf, code.Indent+1)
-				buf = append(buf, bytes.Repeat(ctx.IndentStr, ctx.BaseIndent+code.Indent+1)...)
 				buf = append(buf, item.Key...)
 				buf[len(buf)-2] = ':'
 				buf[len(buf)-1] = ' '
@@ -527,8 +527,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet, opt
 			}
 			buf = buf[:len(buf)-2]
 			buf = append(buf, '\n')
-			buf = append(buf, ctx.Prefix...)
+			buf = appendIndent(ctx, buf, code.Indent)
-			buf = append(buf, bytes.Repeat(ctx.IndentStr, ctx.BaseIndent+code.Indent)...)
 			buf = append(buf, '}', ',', '\n')
 
 			b = b[:pos[0]]