Avoid copying fields

5 files changed, 34 insertions, 33 deletions

diff --git a/client/go/internal/vespa/document/dispatcher_test.go b/client/go/internal/vespa/document/dispatcher_test.go
index 7ef2043f9c5..252bd94dff9 100644
--- a/client/go/internal/vespa/document/dispatcher_test.go
+++ b/client/go/internal/vespa/document/dispatcher_test.go
@@ -61,8 +61,8 @@ func TestDispatcher(t *testing.T) {
 	breaker := NewCircuitBreaker(time.Second, 0)
 	dispatcher := NewDispatcher(feeder, throttler, breaker, io.Discard, false)
 	docs := []Document{
-		{Id: mustParseId("id:ns:type::doc1"), Operation: OperationPut, Body: []byte(`{"fields":{"foo": "123"}}`)},
-		{Id: mustParseId("id:ns:type::doc2"), Operation: OperationPut, Body: []byte(`{"fields":{"bar": "456"}}`)},
+		{Id: mustParseId("id:ns:type::doc1"), Operation: OperationPut, Fields: []byte(`{"foo": "123"}`)},
+		{Id: mustParseId("id:ns:type::doc2"), Operation: OperationPut, Fields: []byte(`{"bar": "456"}`)},
 	}
 	for _, d := range docs {
 		dispatcher.Enqueue(d)
@@ -192,7 +192,7 @@ func BenchmarkDocumentDispatching(b *testing.B) {
 	throttler := newThrottler(8, clock.now)
 	breaker := NewCircuitBreaker(time.Second, 0)
 	dispatcher := NewDispatcher(feeder, throttler, breaker, io.Discard, false)
-	doc := Document{Id: mustParseId("id:ns:type::doc1"), Operation: OperationPut, Body: []byte(`{"fields":{"foo": "123"}}`)}
+	doc := Document{Id: mustParseId("id:ns:type::doc1"), Operation: OperationPut, Fields: []byte(`{"foo": "123"}`)}
 	b.ResetTimer() // ignore setup time
 
 	for n := 0; n < b.N; n++ {
diff --git a/client/go/internal/vespa/document/document.go b/client/go/internal/vespa/document/document.go
index 8bc897d49b3..984f3d3741a 100644
--- a/client/go/internal/vespa/document/document.go
+++ b/client/go/internal/vespa/document/document.go
@@ -96,7 +96,7 @@ type Document struct {
 	Operation Operation
 	Condition string
 	Create    bool
-	Body      []byte
+	Fields    []byte
 }
 
 type jsonDocument struct {
@@ -235,20 +235,12 @@ func parseDocument(d *jsonDocument) (Document, error) {
 	if err != nil {
 		return Document{}, err
 	}
-	var body []byte
-	if d.Fields != nil {
-		jsonObject := `{"fields":`
-		body = make([]byte, 0, len(jsonObject)+len(d.Fields)+1)
-		body = append(body, []byte(jsonObject)...)
-		body = append(body, d.Fields...)
-		body = append(body, byte('}'))
-	}
 	return Document{
 		Id:        docId,
 		Operation: op,
 		Condition: d.Condition,
 		Create:    d.Create,
-		Body:      body,
+		Fields:    d.Fields,
 	}, nil
 }
 
diff --git a/client/go/internal/vespa/document/document_test.go b/client/go/internal/vespa/document/document_test.go
index bdf18586753..495f3963322 100644
--- a/client/go/internal/vespa/document/document_test.go
+++ b/client/go/internal/vespa/document/document_test.go
@@ -134,8 +134,8 @@ func testDocumentDecoder(t *testing.T, jsonLike string) {
 	t.Helper()
 	r := NewDecoder(strings.NewReader(jsonLike))
 	want := []Document{
-		{Id: mustParseId("id:ns:type::doc1"), Operation: OperationPut, Body: []byte(`{"fields":{"foo": "123"}}`)},
-		{Id: mustParseId("id:ns:type::doc2"), Operation: OperationPut, Body: []byte(`{"fields":{"bar": "456"}}`)},
+		{Id: mustParseId("id:ns:type::doc1"), Operation: OperationPut, Fields: []byte(`{"foo": "123"}`)},
+		{Id: mustParseId("id:ns:type::doc2"), Operation: OperationPut, Fields: []byte(`{"bar": "456"}`)},
 		{Id: mustParseId("id:ns:type::doc1"), Operation: OperationRemove},
 	}
 	got := []Document{}
diff --git a/client/go/internal/vespa/document/http.go b/client/go/internal/vespa/document/http.go
index 3581a791dbe..6e7c2219e8f 100644
--- a/client/go/internal/vespa/document/http.go
+++ b/client/go/internal/vespa/document/http.go
@@ -25,6 +25,9 @@ const (
 	CompressionAuto Compression = iota
 	CompressionNone
 	CompressionGzip
+
+	fieldsPrefix = `{"fields":`
+	fieldsSuffix = "}"
 )
 
 // Client represents a HTTP client for the /document/v1/ API.
@@ -179,13 +182,18 @@ func (c *Client) buffer() *bytes.Buffer {
 }
 
 func (c *Client) createRequest(method, url string, body []byte) (*http.Request, error) {
-	var r io.Reader
+	// include the outer object expected by /document/v1/ without copying the body
+	r := io.MultiReader(
+		strings.NewReader(fieldsPrefix),
+		bytes.NewReader(body),
+		strings.NewReader(fieldsSuffix),
+	)
 	useGzip := c.options.Compression == CompressionGzip || (c.options.Compression == CompressionAuto && len(body) > 512)
 	if useGzip {
 		var buf bytes.Buffer
 		buf.Grow(1024)
 		w := c.gzipWriter(&buf)
-		if _, err := w.Write(body); err != nil {
+		if _, err := io.Copy(w, r); err != nil {
 			return nil, err
 		}
 		if err := w.Close(); err != nil {
@@ -193,8 +201,6 @@ func (c *Client) createRequest(method, url string, body []byte) (*http.Request,
 		}
 		c.gzippers.Put(w)
 		r = &buf
-	} else {
-		r = bytes.NewReader(body)
 	}
 	req, err := http.NewRequest(method, url, r)
 	if err != nil {
@@ -219,7 +225,7 @@ func (c *Client) Send(document Document) Result {
 	start := c.now()
 	result := Result{Id: document.Id, Stats: Stats{Requests: 1}}
 	method, url := c.methodAndURL(document)
-	req, err := c.createRequest(method, url, document.Body)
+	req, err := c.createRequest(method, url, document.Fields)
 	if err != nil {
 		return resultWithErr(result, err)
 	}
@@ -271,7 +277,7 @@ func (c *Client) resultWithResponse(resp *http.Response, result Result, document
 	}
 	result.Message = body.Message
 	result.Trace = string(body.Trace)
-	result.Stats.BytesSent = int64(len(document.Body))
+	result.Stats.BytesSent = int64(len(document.Fields) + len(fieldsPrefix) + len(fieldsSuffix))
 	result.Stats.BytesRecv = int64(written)
 	if !result.Success() {
 		result.Stats.Errors++
diff --git a/client/go/internal/vespa/document/http_test.go b/client/go/internal/vespa/document/http_test.go
index 489460b3ed7..da7f264e8d8 100644
--- a/client/go/internal/vespa/document/http_test.go
+++ b/client/go/internal/vespa/document/http_test.go
@@ -59,9 +59,9 @@ func assertLeastBusy(t *testing.T, id int, client *Client) {
 
 func TestClientSend(t *testing.T) {
 	docs := []Document{
-		{Create: true, Id: mustParseId("id:ns:type::doc1"), Operation: OperationUpdate, Body: []byte(`{"fields":{"foo": "123"}}`)},
-		{Create: true, Id: mustParseId("id:ns:type::doc2"), Operation: OperationUpdate, Body: []byte(`{"fields":{"foo": "456"}}`)},
-		{Create: true, Id: mustParseId("id:ns:type::doc3"), Operation: OperationUpdate, Body: []byte(`{"fields":{"baz": "789"}}`)},
+		{Create: true, Id: mustParseId("id:ns:type::doc1"), Operation: OperationUpdate, Fields: []byte(`{"foo": "123"}`)},
+		{Create: true, Id: mustParseId("id:ns:type::doc2"), Operation: OperationUpdate, Fields: []byte(`{"foo": "456"}`)},
+		{Create: true, Id: mustParseId("id:ns:type::doc3"), Operation: OperationUpdate, Fields: []byte(`{"baz": "789"}`)},
 	}
 	httpClient := mock.HTTPClient{}
 	client, _ := NewClient(ClientOptions{
@@ -116,9 +116,12 @@ func TestClientSend(t *testing.T) {
 		if err != nil {
 			t.Fatalf("got unexpected error %q", err)
 		}
-		wantBody := doc.Body
-		if !bytes.Equal(body, wantBody) {
-			t.Errorf("got r.Body = %q, want %q", string(body), string(wantBody))
+		var wantBody bytes.Buffer
+		wantBody.WriteString(`{"fields":`)
+		wantBody.Write(doc.Fields)
+		wantBody.WriteString("}")
+		if !bytes.Equal(body, wantBody.Bytes()) {
+			t.Errorf("got r.Body = %q, want %q", string(body), wantBody.String())
 		}
 	}
 	want := Stats{
@@ -148,9 +151,9 @@ func TestClientSendCompressed(t *testing.T) {
 		Timeout: time.Duration(5 * time.Second),
 	}, []util.HTTPClient{&httpClient})
 
-	bigBody := fmt.Sprintf(`{"fields":{"foo": "%s"}}`, strings.Repeat("s", 512+1))
-	bigDoc := Document{Create: true, Id: mustParseId("id:ns:type::doc1"), Operation: OperationUpdate, Body: []byte(bigBody)}
-	smallDoc := Document{Create: true, Id: mustParseId("id:ns:type::doc2"), Operation: OperationUpdate, Body: []byte(`{"fields":{"foo": "s"}}`)}
+	bigBody := fmt.Sprintf(`{"foo": "%s"}`, strings.Repeat("s", 512+1))
+	bigDoc := Document{Create: true, Id: mustParseId("id:ns:type::doc1"), Operation: OperationUpdate, Fields: []byte(bigBody)}
+	smallDoc := Document{Create: true, Id: mustParseId("id:ns:type::doc2"), Operation: OperationUpdate, Fields: []byte(`{"foo": "s"}`)}
 
 	client.options.Compression = CompressionNone
 	_ = client.Send(bigDoc)
@@ -289,12 +292,12 @@ func benchmarkClientSend(b *testing.B, compression Compression, document Documen
 }
 
 func BenchmarkClientSend(b *testing.B) {
-	doc := Document{Create: true, Id: mustParseId("id:ns:type::doc1"), Operation: OperationUpdate, Body: []byte(`{"fields":{"foo": "my document"}}`)}
+	doc := Document{Create: true, Id: mustParseId("id:ns:type::doc1"), Operation: OperationUpdate, Fields: []byte(`{"foo": "my document"}`)}
 	benchmarkClientSend(b, CompressionNone, doc)
 }
 
 func BenchmarkClientSendCompressed(b *testing.B) {
-	body := fmt.Sprintf(`{"fields":{"foo": "%s"}}`, strings.Repeat("my document", 100))
-	doc := Document{Create: true, Id: mustParseId("id:ns:type::doc1"), Operation: OperationUpdate, Body: []byte(body)}
+	body := fmt.Sprintf(`{"foo": "%s"}`, strings.Repeat("my document", 100))
+	doc := Document{Create: true, Id: mustParseId("id:ns:type::doc1"), Operation: OperationUpdate, Fields: []byte(body)}
 	benchmarkClientSend(b, CompressionGzip, doc)
 }