encoding/json: make use of Buffer.AvailableBuffer

Use the explicit API for acquiring an empty available buffer,
rather than the hack that's implemented in terms of Bytes and Len.

Change-Id: If286ed42693acd61ffe28dc849ed4b76c3ae4434
Reviewed-on: https://go-review.googlesource.com/c/go/+/476337
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Auto-Submit: Joseph Tsai <joetsai@digital-static.net>
Run-TryBot: Joseph Tsai <joetsai@digital-static.net>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>

diff --git a/src/encoding/json/encode.go b/src/encoding/json/encode.go
index f3c824d13e0d2dc52918b67aeb6cf69807b8adbf..79a82cfe757b43f9eb82abdbcc7d45b5b6ac8bc4 100644 (file)
--- a/src/encoding/json/encode.go
+++ b/src/encoding/json/encode.go
@@ -259,10 +259,6 @@ type encodeState struct {
        ptrSeen  map[any]struct{}
 }
 
-func (e *encodeState) AvailableBuffer() []byte {
-       return availableBuffer(&e.Buffer)
-}
-
 const startDetectingCyclesAfter = 1000
 
 var encodeStatePool sync.Pool
@@ -445,7 +441,7 @@ func marshalerEncoder(e *encodeState, v reflect.Value, opts encOpts) {
        b, err := m.MarshalJSON()
        if err == nil {
                e.Grow(len(b))
-               out := availableBuffer(&e.Buffer)
+               out := e.AvailableBuffer()
                out, err = appendCompact(out, b, opts.escapeHTML)
                e.Buffer.Write(out)
        }
@@ -464,7 +460,7 @@ func addrMarshalerEncoder(e *encodeState, v reflect.Value, opts encOpts) {
        b, err := m.MarshalJSON()
        if err == nil {
                e.Grow(len(b))
-               out := availableBuffer(&e.Buffer)
+               out := e.AvailableBuffer()
                out, err = appendCompact(out, b, opts.escapeHTML)
                e.Buffer.Write(out)
        }

diff --git a/src/encoding/json/indent.go b/src/encoding/json/indent.go
index 99951208a0514f2b914e4dff5e9dc24548ad38fb..26bb5d2e470023d8c7c0eaa72d5faab8a846f48f 100644 (file)
--- a/src/encoding/json/indent.go
+++ b/src/encoding/json/indent.go
@@ -6,11 +6,6 @@ package json
 
 import "bytes"
 
-// TODO(https://go.dev/issue/53685): Use bytes.Buffer.AvailableBuffer instead.
-func availableBuffer(b *bytes.Buffer) []byte {
-       return b.Bytes()[b.Len():]
-}
-
 // HTMLEscape appends to dst the JSON-encoded src with <, >, &, U+2028 and U+2029
 // characters inside string literals changed to \u003c, \u003e, \u0026, \u2028, \u2029
 // so that the JSON will be safe to embed inside HTML <script> tags.
@@ -18,7 +13,7 @@ func availableBuffer(b *bytes.Buffer) []byte {
 // escaping within <script> tags, so an alternative JSON encoding must be used.
 func HTMLEscape(dst *bytes.Buffer, src []byte) {
        dst.Grow(len(src))
-       dst.Write(appendHTMLEscape(availableBuffer(dst), src))
+       dst.Write(appendHTMLEscape(dst.AvailableBuffer(), src))
 }
 
 func appendHTMLEscape(dst, src []byte) []byte {
@@ -45,7 +40,7 @@ func appendHTMLEscape(dst, src []byte) []byte {
 // insignificant space characters elided.
 func Compact(dst *bytes.Buffer, src []byte) error {
        dst.Grow(len(src))
-       b := availableBuffer(dst)
+       b := dst.AvailableBuffer()
        b, err := appendCompact(b, src, false)
        dst.Write(b)
        return err
@@ -114,7 +109,7 @@ const indentGrowthFactor = 2
 // if src ends in a trailing newline, so will dst.
 func Indent(dst *bytes.Buffer, src []byte, prefix, indent string) error {
        dst.Grow(indentGrowthFactor * len(src))
-       b := availableBuffer(dst)
+       b := dst.AvailableBuffer()
        b, err := appendIndent(b, src, prefix, indent)
        dst.Write(b)
        return err