jspb: Support full 64bit integer ranges

The jspb wrapper makes use of the google-protobuf javascript
library to encode and decode the protobuf wire format. This
commit adds support for encoding and decoding the full
64bit integer ranges to and from the GopherJS types.

jspb/.gitignore

@@ -1 +1,2 @@
 node_modules
+package-lock.json

jspb/Makefile

@@ -1,10 +1,10 @@
 all: checkout build
 
 checkout:
-	npm install google-protobuf webpack
+	npm install google-protobuf webpack-cli webpack
 
 build:
-	./node_modules/.bin/webpack
+	./node_modules/.bin/webpack-cli
 
 clean:
 	rm jspb.inc.js

jspb/reader.go

@@ -48,22 +48,83 @@ type Reader interface {
 	ReadMessage(func())
 }
 
+type decoder struct {
+	*js.Object
+}
+
+// ReadInt64 reads a signed 64 bit varint
+func (d decoder) ReadInt64() int64 {
+	d.Call("readSplitVarint64_")
+	high := d.Get("tempHigh_").Uint64()
+	low := d.Get("tempLow_").Uint64()
+	return d.mergeSignedInteger(low, high)
+}
+
+// ReadZigzag64 reads a signed 64 bit Zigzag encoded varint
+func (d decoder) ReadZigzag64() int64 {
+	v := d.ReadUint64()
+	// https://github.com/gogo/protobuf/blob/1ef32a8b9fc3f8ec940126907cedb5998f6318e4/proto/decode.go#L254
+	return int64((v >> 1) ^ uint64((int64(v&1)<<63)>>63))
+}
+
+// ReadUint64 reads a unsigned 64 bit varint
+func (d decoder) ReadUint64() uint64 {
+	d.Call("readSplitVarint64_")
+	high := d.Get("tempHigh_").Uint64()
+	low := d.Get("tempLow_").Uint64()
+	return high<<32 | low
+}
+
+// ReadFixed64 reads a 64 bit unsigned integer
+func (d decoder) ReadFixed64() uint64 {
+	low := d.Call("readUint32").Uint64()
+	high := d.Call("readUint32").Uint64()
+	return high<<32 | low
+}
+
+// ReadSignedFixed64 reads a 64 bit signed integer
+func (d decoder) ReadSignedFixed64() int64 {
+	low := d.Call("readUint32").Uint64()
+	high := d.Call("readUint32").Uint64()
+	return d.mergeSignedInteger(low, high)
+}
+
+func (d decoder) mergeSignedInteger(low, high uint64) int64 {
+	// Adapted from google-protobuf
+	// https://github.com/google/protobuf/blob/25625b956a2f0d432582009c16553a9fd21c3cea/js/binary/utils.js#L521
+	negative := (high&0x8 == 1)
+	if negative {
+		low = (^low + 1)
+		var carry uint64
+		if low == 0 {
+			carry = 1
+		}
+		high = (^high + carry)
+	}
+	return int64(high<<32 | low)
+}
+
 // NewReader returns a new Reader ready for writing
 func NewReader(data []byte) Reader {
-	return &reader{
+	r := &reader{
 		Object: js.Global.Get("BinaryReader").New(data),
 	}
+	r.decoder = &decoder{
+		Object: r.Get("decoder_"),
+	}
+	return r
 }
 
 // reader implements the Reader interface
 type reader struct {
 	*js.Object
-	err error
+	decoder *decoder
+	err     error
 }
 
 // Reads the next field header in the stream if there is one, returns true if
 // we saw a valid field header or false if we've read the whole stream.
-// Sets err if we encountered a deprecated START_GROUP/END_GROUP field.
+// Sets err if we encountered a deprecated START_GROUP/END_GROUP fielr.decoder.
 func (r *reader) Next() bool {
 	defer catchException(&r.err)
 	return r.err == nil && r.Call("nextField").Bool() && !r.Call("isEndGroup").Bool()
@@ -76,7 +137,7 @@ func (r reader) Err() error {
 }
 
 // The field number of the next field in the buffer, or
-// -1 if there is no next field.
+// -1 if there is no next fielr.decoder.
 func (r reader) GetFieldNumber() int {
 	return r.Call("getFieldNumber").Int()
 }
@@ -99,7 +160,7 @@ func (r *reader) ReadInt32() int32 {
 // stream is not of the correct wire type.
 func (r *reader) ReadInt64() int64 {
 	defer catchException(&r.err)
-	return int64(r.Call("readInt64").Int())
+	return r.decoder.ReadInt64()
 }
 
 // ReadUint32 reads an unsigned 32-bit integer field from the binary
@@ -115,7 +176,7 @@ func (r *reader) ReadUint32() uint32 {
 // stream is not of the correct wire type.
 func (r *reader) ReadUint64() uint64 {
 	defer catchException(&r.err)
-	return uint64(r.Call("readUint64").Int())
+	return r.decoder.ReadUint64()
 }
 
 // ReadSint32 reads a signed 32-bit integer field from the binary
@@ -131,7 +192,7 @@ func (r *reader) ReadSint32() int32 {
 // stream is not of the correct wire type.
 func (r *reader) ReadSint64() int64 {
 	defer catchException(&r.err)
-	return int64(r.Call("readSint64").Int())
+	return r.decoder.ReadZigzag64()
 }
 
 // ReadFixed32 reads an unsigned 32-bit integer field from the binary
@@ -147,7 +208,7 @@ func (r *reader) ReadFixed32() uint32 {
 // stream is not of the correct wire type.
 func (r *reader) ReadFixed64() uint64 {
 	defer catchException(&r.err)
-	return uint64(r.Call("readFixed64").Int())
+	return r.decoder.ReadFixed64()
 }
 
 // ReadSfixed32 reads a signed 32-bit integer field from the binary
@@ -163,7 +224,7 @@ func (r *reader) ReadSfixed32() int32 {
 // stream is not of the correct wire type.
 func (r *reader) ReadSfixed64() int64 {
 	defer catchException(&r.err)
-	return int64(r.Call("readSfixed64").Int())
+	return r.decoder.ReadSignedFixed64()
 }
 
 // ReadFloat32 reads a 32-bit floating point field from the binary
@@ -236,10 +297,11 @@ func (r *reader) ReadInt32Slice() (ret []int32) {
 // stream is not of the correct wire type.
 func (r *reader) ReadInt64Slice() (ret []int64) {
 	defer catchException(&r.err)
-	values := r.Call("readPackedInt64").Interface().([]interface{})
-	for _, value := range values {
-		ret = append(ret, int64(value.(float64)))
-	}
+	cb := js.MakeFunc(func(*js.Object, []*js.Object) interface{} {
+		ret = append(ret, r.decoder.ReadInt64())
+		return js.Undefined
+	})
+	r.Call("readPackedField_", cb)
 
 	return ret
 }
@@ -262,10 +324,11 @@ func (r *reader) ReadUint32Slice() (ret []uint32) {
 // stream is not of the correct wire type.
 func (r *reader) ReadUint64Slice() (ret []uint64) {
 	defer catchException(&r.err)
-	values := r.Call("readPackedUint64").Interface().([]interface{})
-	for _, value := range values {
-		ret = append(ret, uint64(value.(float64)))
-	}
+	cb := js.MakeFunc(func(*js.Object, []*js.Object) interface{} {
+		ret = append(ret, r.decoder.ReadUint64())
+		return js.Undefined
+	})
+	r.Call("readPackedField_", cb)
 
 	return ret
 }
@@ -288,10 +351,11 @@ func (r *reader) ReadSint32Slice() (ret []int32) {
 // stream is not of the correct wire type.
 func (r *reader) ReadSint64Slice() (ret []int64) {
 	defer catchException(&r.err)
-	values := r.Call("readPackedSint64").Interface().([]interface{})
-	for _, value := range values {
-		ret = append(ret, int64(value.(float64)))
-	}
+	cb := js.MakeFunc(func(*js.Object, []*js.Object) interface{} {
+		ret = append(ret, r.decoder.ReadZigzag64())
+		return js.Undefined
+	})
+	r.Call("readPackedField_", cb)
 
 	return ret
 }
@@ -314,10 +378,11 @@ func (r *reader) ReadFixed32Slice() (ret []uint32) {
 // stream is not of the correct wire type.
 func (r *reader) ReadFixed64Slice() (ret []uint64) {
 	defer catchException(&r.err)
-	values := r.Call("readPackedFixed64").Interface().([]interface{})
-	for _, value := range values {
-		ret = append(ret, uint64(value.(float64)))
-	}
+	cb := js.MakeFunc(func(*js.Object, []*js.Object) interface{} {
+		ret = append(ret, r.decoder.ReadFixed64())
+		return js.Undefined
+	})
+	r.Call("readPackedField_", cb)
 
 	return ret
 }
@@ -340,10 +405,11 @@ func (r *reader) ReadSfixed32Slice() (ret []int32) {
 // stream is not of the correct wire type.
 func (r *reader) ReadSfixed64Slice() (ret []int64) {
 	defer catchException(&r.err)
-	values := r.Call("readPackedSfixed64").Interface().([]interface{})
-	for _, value := range values {
-		ret = append(ret, int64(value.(float64)))
-	}
+	cb := js.MakeFunc(func(*js.Object, []*js.Object) interface{} {
+		ret = append(ret, r.decoder.ReadSignedFixed64())
+		return js.Undefined
+	})
+	r.Call("readPackedField_", cb)
 
 	return ret
 }

jspb/webpack.config.js

@@ -1,12 +1,14 @@
 const webpack = require("webpack");
 
 module.exports = {
-  entry: "./node_modules/google-protobuf/google-protobuf.js",
-  output: {
-    filename: "jspb.inc.js",
-    libraryTarget: "this",
-  },
-  plugins: [
-    new webpack.optimize.UglifyJsPlugin()
-  ]
+    entry: "./node_modules/google-protobuf/google-protobuf.js",
+    output: {
+        filename: "jspb.inc.js",
+        libraryTarget: "this",
+        path: __dirname,
+    },
+    optimization: {
+        minimize: true
+    },
+    mode: "production",
 };