openapi3: optimize Unmarshal for maplike structs (#882)

.github/docs/openapi3.txt

@@ -148,7 +148,7 @@ func NewCallback(opts ...NewCallbackOption) *Callback
     NewCallback builds a Callback object with path items in insertion order.
 
 func NewCallbackWithCapacity(cap int) *Callback
-    NewCallbackWithCapacity builds a Callback object of the given capacity.
+    NewCallbackWithCapacity builds a callback object of the given capacity.
 
 func (callback Callback) JSONLookup(token string) (interface{}, error)
     JSONLookup implements
@@ -157,10 +157,10 @@ func (callback Callback) JSONLookup(token string) (interface{}, error)
 func (callback *Callback) Len() int
     Len returns the amount of keys in callback excluding callback.Extensions.
 
-func (callback *Callback) Map() map[string]*PathItem
+func (callback *Callback) Map() (m map[string]*PathItem)
     Map returns callback as a 'map'. Note: iteration on Go maps is not ordered.
 
-func (callback Callback) MarshalJSON() ([]byte, error)
+func (callback *Callback) MarshalJSON() ([]byte, error)
     MarshalJSON returns the JSON encoding of Callback.
 
 func (callback *Callback) Set(key string, value *PathItem)
@@ -944,10 +944,10 @@ func (paths Paths) JSONLookup(token string) (interface{}, error)
 func (paths *Paths) Len() int
     Len returns the amount of keys in paths excluding paths.Extensions.
 
-func (paths *Paths) Map() map[string]*PathItem
+func (paths *Paths) Map() (m map[string]*PathItem)
     Map returns paths as a 'map'. Note: iteration on Go maps is not ordered.
 
-func (paths Paths) MarshalJSON() ([]byte, error)
+func (paths *Paths) MarshalJSON() ([]byte, error)
     MarshalJSON returns the JSON encoding of Paths.
 
 func (paths *Paths) Set(key string, value *PathItem)
@@ -1152,10 +1152,10 @@ func (responses Responses) JSONLookup(token string) (interface{}, error)
 func (responses *Responses) Len() int
     Len returns the amount of keys in responses excluding responses.Extensions.
 
-func (responses *Responses) Map() map[string]*ResponseRef
+func (responses *Responses) Map() (m map[string]*ResponseRef)
     Map returns responses as a 'map'. Note: iteration on Go maps is not ordered.
 
-func (responses Responses) MarshalJSON() ([]byte, error)
+func (responses *Responses) MarshalJSON() ([]byte, error)
     MarshalJSON returns the JSON encoding of Responses.
 
 func (responses *Responses) Set(key string, value *ResponseRef)

.github/workflows/go.yml

@@ -116,11 +116,6 @@ jobs:
       run: |
         [[ "$(git grep -F yaml. -- openapi3/ | grep -v _test.go | wc -l)" = 1 ]]
 
-    - if: runner.os == 'Linux'
-      name: Ensure non-pointer MarshalJSON
-      run: |
-        ! git grep -InE 'func[^{}]+[*][^{}]+[)].MarshalJSON[(][)]'
-
     - if: runner.os == 'Linux'
       name: Use `loader := NewLoader(); loader.Load ...`
       run: |

maps.sh

@@ -29,7 +29,9 @@ names+=('paths')
 [[ "${#types[@]}" = "${#names[@]}" ]]
 [[ "${#types[@]}" = "$(git grep -InF ' m map[string]*' -- openapi3/loader.go | wc -l)" ]]
 
-cat <<EOF >"$maplike"
+
+maplike_header() {
+	cat <<EOF >"$maplike"
 package openapi3
 
 import (
@@ -39,10 +41,13 @@ import (
 
 	"github.com/go-openapi/jsonpointer"
 )
+
 EOF
+}
 
 
-cat <<EOF >"$maplike_test"
+test_header() {
+	cat <<EOF >"$maplike_test"
 package openapi3
 
 import (
@@ -53,16 +58,32 @@ import (
 
 func TestMaplikeMethods(t *testing.T) {
 	t.Parallel()
+
 EOF
+}
 
-for i in "${!types[@]}"; do
-	type=${types[$i]}
-	value_type=${value_types[$i]}
-	deref_v=${deref_vs[$i]}
-	name=${names[$i]}
 
+test_footer() {
+	echo "}" >>"$maplike_test"
+}
+
+
+maplike_NewWithCapa() {
 	cat <<EOF >>"$maplike"
+// New${type#'*'}WithCapacity builds a ${name} object of the given capacity.
+func New${type#'*'}WithCapacity(cap int) ${type} {
+	if cap == 0 {
+		return &${type#'*'}{m: make(map[string]${value_type})}
+	}
+	return &${type#'*'}{m: make(map[string]${value_type}, cap)}
+}
+
+EOF
+}
 
+
+maplike_ValueSetLen() {
+	cat <<EOF >>"$maplike"
 // Value returns the ${name} for key or nil
 func (${name} ${type}) Value(key string) ${value_type} {
 	if ${name}.Len() == 0 {
@@ -82,21 +103,31 @@ func (${name} ${type}) Set(key string, value ${value_type}) {
 
 // Len returns the amount of keys in ${name} excluding ${name}.Extensions.
 func (${name} ${type}) Len() int {
-	if ${name} == nil {
+	if ${name} == nil || ${name}.m == nil {
 		return 0
 	}
 	return len(${name}.m)
 }
 
 // Map returns ${name} as a 'map'.
 // Note: iteration on Go maps is not ordered.
-func (${name} ${type}) Map() map[string]${value_type} {
-	if ${name}.Len() == 0 {
-		return nil
+func (${name} ${type}) Map() (m map[string]${value_type}) {
+	if ${name} == nil || len(${name}.m) == 0 {
+		return make(map[string]${value_type})
+	}
+	m = make(map[string]${value_type}, len(${name}.m))
+	for k, v := range ${name}.m {
+		m[k] = v
 	}
-	return ${name}.m
+	return
+}
+
+EOF
 }
 
+
+maplike_Pointable() {
+	cat <<EOF >>"$maplike"
 var _ jsonpointer.JSONPointable = (${type})(nil)
 
 // JSONLookup implements https://github.com/go-openapi/jsonpointer#JSONPointable
@@ -112,8 +143,14 @@ func (${name} ${type#'*'}) JSONLookup(token string) (interface{}, error) {
 	}
 }
 
+EOF
+}
+
+
+maplike_UnMarsh() {
+	cat <<EOF >>"$maplike"
 // MarshalJSON returns the JSON encoding of ${type#'*'}.
-func (${name} ${type#'*'}) MarshalJSON() ([]byte, error) {
+func (${name} ${type}) MarshalJSON() ([]byte, error) {
 	m := make(map[string]interface{}, ${name}.Len()+len(${name}.Extensions))
 	for k, v := range ${name}.Extensions {
 		m[k] = v
@@ -163,33 +200,55 @@ func (${name} ${type}) UnmarshalJSON(data []byte) (err error) {
 	return
 }
 EOF
+}
 
-	cat <<EOF >>"$maplike_test"
 
+test_body() {
+	cat <<EOF >>"$maplike_test"
 	t.Run("${type}", func(t *testing.T) {
 		t.Parallel()
 		t.Run("nil", func(t *testing.T) {
 			x := (${type})(nil)
 			require.Equal(t, 0, x.Len())
-			require.Equal(t, (map[string]${value_type})(nil), x.Map())
+			require.Equal(t, map[string]${value_type}{}, x.Map())
 			require.Equal(t, (${value_type})(nil), x.Value("key"))
 			require.Panics(t, func() { x.Set("key", &${value_type#'*'}{}) })
 		})
 		t.Run("nonnil", func(t *testing.T) {
 			x := &${type#'*'}{}
 			require.Equal(t, 0, x.Len())
-			require.Equal(t, (map[string]${value_type})(nil), x.Map())
+			require.Equal(t, map[string]${value_type}{}, x.Map())
 			require.Equal(t, (${value_type})(nil), x.Value("key"))
 			x.Set("key", &${value_type#'*'}{})
 			require.Equal(t, 1, x.Len())
 			require.Equal(t, map[string]${value_type}{"key": {}}, x.Map())
 			require.Equal(t, &${value_type#'*'}{}, x.Value("key"))
 		})
 	})
+
 EOF
+}
+
+
+
+maplike_header
+test_header
+
+for i in "${!types[@]}"; do
+	type=${types[$i]}
+	value_type=${value_types[$i]}
+	deref_v=${deref_vs[$i]}
+	name=${names[$i]}
+
+	type="$type" name="$name" value_type="$value_type" maplike_NewWithCapa
+	type="$type" name="$name" value_type="$value_type" maplike_ValueSetLen
+	type="$type" name="$name"    deref_v="$deref_v"    maplike_Pointable
+	type="$type" name="$name" value_type="$value_type" maplike_UnMarsh
+	[[ $((i+1)) != "${#types[@]}" ]] && echo >>"$maplike"
+
+	type="$type" value_type="$value_type" test_body
+
 
 done
 
-	cat <<EOF >>"$maplike_test"
-}
-EOF
+test_footer

openapi3/callback.go

@@ -13,11 +13,6 @@ type Callback struct {
 	m map[string]*PathItem
 }
 
-// NewCallbackWithCapacity builds a Callback object of the given capacity.
-func NewCallbackWithCapacity(cap int) *Callback {
-	return &Callback{m: make(map[string]*PathItem, cap)}
-}
-
 // NewCallback builds a Callback object with path items in insertion order.
 func NewCallback(opts ...NewCallbackOption) *Callback {
 	Callback := NewCallbackWithCapacity(len(opts))

openapi3/internalize_refs.go

@@ -428,6 +428,7 @@ func (doc *T) InternalizeRefs(ctx context.Context, refNameResolver func(ref stri
 		}
 		doc.derefExamples(components.Examples, refNameResolver, false)
 		doc.derefLinks(components.Links, refNameResolver, false)
+
 		for _, cb := range components.Callbacks {
 			isExternal := doc.addCallbackToSpec(cb, refNameResolver, false)
 			if cb != nil && cb.Value != nil {