blob: ff5d31a08e5fef423d1a2f2230377bbdf8b8d8ec [file] [log] [blame]
// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
define("mojo/public/js/codec", [
"mojo/public/js/buffer",
"mojo/public/js/interface_types",
"mojo/public/js/unicode",
], function(buffer, types, unicode) {
var kErrorUnsigned = "Passing negative value to unsigned";
var kErrorArray = "Passing non Array for array type";
var kErrorString = "Passing non String for string type";
var kErrorMap = "Passing non Map for map type";
// Memory -------------------------------------------------------------------
var kAlignment = 8;
function align(size) {
return size + (kAlignment - (size % kAlignment)) % kAlignment;
}
function isAligned(offset) {
return offset >= 0 && (offset % kAlignment) === 0;
}
// Constants ----------------------------------------------------------------
var kArrayHeaderSize = 8;
var kStructHeaderSize = 8;
var kMessageHeaderSize = 24;
var kMessageWithRequestIDHeaderSize = 32;
var kMapStructPayloadSize = 16;
var kStructHeaderNumBytesOffset = 0;
var kStructHeaderVersionOffset = 4;
var kEncodedInvalidHandleValue = 0xFFFFFFFF;
// Decoder ------------------------------------------------------------------
function Decoder(buffer, handles, base) {
this.buffer = buffer;
this.handles = handles;
this.base = base;
this.next = base;
}
Decoder.prototype.align = function() {
this.next = align(this.next);
};
Decoder.prototype.skip = function(offset) {
this.next += offset;
};
Decoder.prototype.readInt8 = function() {
var result = this.buffer.getInt8(this.next);
this.next += 1;
return result;
};
Decoder.prototype.readUint8 = function() {
var result = this.buffer.getUint8(this.next);
this.next += 1;
return result;
};
Decoder.prototype.readInt16 = function() {
var result = this.buffer.getInt16(this.next);
this.next += 2;
return result;
};
Decoder.prototype.readUint16 = function() {
var result = this.buffer.getUint16(this.next);
this.next += 2;
return result;
};
Decoder.prototype.readInt32 = function() {
var result = this.buffer.getInt32(this.next);
this.next += 4;
return result;
};
Decoder.prototype.readUint32 = function() {
var result = this.buffer.getUint32(this.next);
this.next += 4;
return result;
};
Decoder.prototype.readInt64 = function() {
var result = this.buffer.getInt64(this.next);
this.next += 8;
return result;
};
Decoder.prototype.readUint64 = function() {
var result = this.buffer.getUint64(this.next);
this.next += 8;
return result;
};
Decoder.prototype.readFloat = function() {
var result = this.buffer.getFloat32(this.next);
this.next += 4;
return result;
};
Decoder.prototype.readDouble = function() {
var result = this.buffer.getFloat64(this.next);
this.next += 8;
return result;
};
Decoder.prototype.decodePointer = function() {
// TODO(abarth): To correctly decode a pointer, we need to know the real
// base address of the array buffer.
var offsetPointer = this.next;
var offset = this.readUint64();
if (!offset)
return 0;
return offsetPointer + offset;
};
Decoder.prototype.decodeAndCreateDecoder = function(pointer) {
return new Decoder(this.buffer, this.handles, pointer);
};
Decoder.prototype.decodeHandle = function() {
return this.handles[this.readUint32()] || null;
};
Decoder.prototype.decodeString = function() {
var numberOfBytes = this.readUint32();
var numberOfElements = this.readUint32();
var base = this.next;
this.next += numberOfElements;
return unicode.decodeUtf8String(
new Uint8Array(this.buffer.arrayBuffer, base, numberOfElements));
};
Decoder.prototype.decodeArray = function(cls) {
var numberOfBytes = this.readUint32();
var numberOfElements = this.readUint32();
var val = new Array(numberOfElements);
if (cls === PackedBool) {
var byte;
for (var i = 0; i < numberOfElements; ++i) {
if (i % 8 === 0)
byte = this.readUint8();
val[i] = (byte & (1 << i % 8)) ? true : false;
}
} else {
for (var i = 0; i < numberOfElements; ++i) {
val[i] = cls.decode(this);
}
}
return val;
};
Decoder.prototype.decodeStruct = function(cls) {
return cls.decode(this);
};
Decoder.prototype.decodeStructPointer = function(cls) {
var pointer = this.decodePointer();
if (!pointer) {
return null;
}
return cls.decode(this.decodeAndCreateDecoder(pointer));
};
Decoder.prototype.decodeArrayPointer = function(cls) {
var pointer = this.decodePointer();
if (!pointer) {
return null;
}
return this.decodeAndCreateDecoder(pointer).decodeArray(cls);
};
Decoder.prototype.decodeStringPointer = function() {
var pointer = this.decodePointer();
if (!pointer) {
return null;
}
return this.decodeAndCreateDecoder(pointer).decodeString();
};
Decoder.prototype.decodeMap = function(keyClass, valueClass) {
this.skip(4); // numberOfBytes
this.skip(4); // version
var keys = this.decodeArrayPointer(keyClass);
var values = this.decodeArrayPointer(valueClass);
var val = new Map();
for (var i = 0; i < keys.length; i++)
val.set(keys[i], values[i]);
return val;
};
Decoder.prototype.decodeMapPointer = function(keyClass, valueClass) {
var pointer = this.decodePointer();
if (!pointer) {
return null;
}
var decoder = this.decodeAndCreateDecoder(pointer);
return decoder.decodeMap(keyClass, valueClass);
};
// Encoder ------------------------------------------------------------------
function Encoder(buffer, handles, base) {
this.buffer = buffer;
this.handles = handles;
this.base = base;
this.next = base;
}
Encoder.prototype.align = function() {
this.next = align(this.next);
};
Encoder.prototype.skip = function(offset) {
this.next += offset;
};
Encoder.prototype.writeInt8 = function(val) {
this.buffer.setInt8(this.next, val);
this.next += 1;
};
Encoder.prototype.writeUint8 = function(val) {
if (val < 0) {
throw new Error(kErrorUnsigned);
}
this.buffer.setUint8(this.next, val);
this.next += 1;
};
Encoder.prototype.writeInt16 = function(val) {
this.buffer.setInt16(this.next, val);
this.next += 2;
};
Encoder.prototype.writeUint16 = function(val) {
if (val < 0) {
throw new Error(kErrorUnsigned);
}
this.buffer.setUint16(this.next, val);
this.next += 2;
};
Encoder.prototype.writeInt32 = function(val) {
this.buffer.setInt32(this.next, val);
this.next += 4;
};
Encoder.prototype.writeUint32 = function(val) {
if (val < 0) {
throw new Error(kErrorUnsigned);
}
this.buffer.setUint32(this.next, val);
this.next += 4;
};
Encoder.prototype.writeInt64 = function(val) {
this.buffer.setInt64(this.next, val);
this.next += 8;
};
Encoder.prototype.writeUint64 = function(val) {
if (val < 0) {
throw new Error(kErrorUnsigned);
}
this.buffer.setUint64(this.next, val);
this.next += 8;
};
Encoder.prototype.writeFloat = function(val) {
this.buffer.setFloat32(this.next, val);
this.next += 4;
};
Encoder.prototype.writeDouble = function(val) {
this.buffer.setFloat64(this.next, val);
this.next += 8;
};
Encoder.prototype.encodePointer = function(pointer) {
if (!pointer)
return this.writeUint64(0);
// TODO(abarth): To correctly encode a pointer, we need to know the real
// base address of the array buffer.
var offset = pointer - this.next;
this.writeUint64(offset);
};
Encoder.prototype.createAndEncodeEncoder = function(size) {
var pointer = this.buffer.alloc(align(size));
this.encodePointer(pointer);
return new Encoder(this.buffer, this.handles, pointer);
};
Encoder.prototype.encodeHandle = function(handle) {
if (handle) {
this.handles.push(handle);
this.writeUint32(this.handles.length - 1);
} else {
this.writeUint32(kEncodedInvalidHandleValue);
}
};
Encoder.prototype.encodeString = function(val) {
var base = this.next + kArrayHeaderSize;
var numberOfElements = unicode.encodeUtf8String(
val, new Uint8Array(this.buffer.arrayBuffer, base));
var numberOfBytes = kArrayHeaderSize + numberOfElements;
this.writeUint32(numberOfBytes);
this.writeUint32(numberOfElements);
this.next += numberOfElements;
};
Encoder.prototype.encodeArray =
function(cls, val, numberOfElements, encodedSize) {
if (numberOfElements === undefined)
numberOfElements = val.length;
if (encodedSize === undefined)
encodedSize = kArrayHeaderSize + cls.encodedSize * numberOfElements;
this.writeUint32(encodedSize);
this.writeUint32(numberOfElements);
if (cls === PackedBool) {
var byte = 0;
for (i = 0; i < numberOfElements; ++i) {
if (val[i])
byte |= (1 << i % 8);
if (i % 8 === 7 || i == numberOfElements - 1) {
Uint8.encode(this, byte);
byte = 0;
}
}
} else {
for (var i = 0; i < numberOfElements; ++i)
cls.encode(this, val[i]);
}
};
Encoder.prototype.encodeStruct = function(cls, val) {
return cls.encode(this, val);
};
Encoder.prototype.encodeStructPointer = function(cls, val) {
if (val == null) {
// Also handles undefined, since undefined == null.
this.encodePointer(val);
return;
}
var encoder = this.createAndEncodeEncoder(cls.encodedSize);
cls.encode(encoder, val);
};
Encoder.prototype.encodeArrayPointer = function(cls, val) {
if (val == null) {
// Also handles undefined, since undefined == null.
this.encodePointer(val);
return;
}
var numberOfElements = val.length;
if (!Number.isSafeInteger(numberOfElements) || numberOfElements < 0)
throw new Error(kErrorArray);
var encodedSize = kArrayHeaderSize + ((cls === PackedBool) ?
Math.ceil(numberOfElements / 8) : cls.encodedSize * numberOfElements);
var encoder = this.createAndEncodeEncoder(encodedSize);
encoder.encodeArray(cls, val, numberOfElements, encodedSize);
};
Encoder.prototype.encodeStringPointer = function(val) {
if (val == null) {
// Also handles undefined, since undefined == null.
this.encodePointer(val);
return;
}
// Only accepts string primivites, not String Objects like new String("foo")
if (typeof(val) !== "string") {
throw new Error(kErrorString);
}
var encodedSize = kArrayHeaderSize + unicode.utf8Length(val);
var encoder = this.createAndEncodeEncoder(encodedSize);
encoder.encodeString(val);
};
Encoder.prototype.encodeMap = function(keyClass, valueClass, val) {
var keys = new Array(val.size);
var values = new Array(val.size);
var i = 0;
val.forEach(function(value, key) {
values[i] = value;
keys[i++] = key;
});
this.writeUint32(kStructHeaderSize + kMapStructPayloadSize);
this.writeUint32(0); // version
this.encodeArrayPointer(keyClass, keys);
this.encodeArrayPointer(valueClass, values);
}
Encoder.prototype.encodeMapPointer = function(keyClass, valueClass, val) {
if (val == null) {
// Also handles undefined, since undefined == null.
this.encodePointer(val);
return;
}
if (!(val instanceof Map)) {
throw new Error(kErrorMap);
}
var encodedSize = kStructHeaderSize + kMapStructPayloadSize;
var encoder = this.createAndEncodeEncoder(encodedSize);
encoder.encodeMap(keyClass, valueClass, val);
};
// Message ------------------------------------------------------------------
var kMessageInterfaceIdOffset = kStructHeaderSize;
var kMessageNameOffset = kMessageInterfaceIdOffset + 4;
var kMessageFlagsOffset = kMessageNameOffset + 4;
var kMessageRequestIDOffset = kMessageFlagsOffset + 8;
var kMessageExpectsResponse = 1 << 0;
var kMessageIsResponse = 1 << 1;
function Message(buffer, handles) {
this.buffer = buffer;
this.handles = handles;
}
Message.prototype.getHeaderNumBytes = function() {
return this.buffer.getUint32(kStructHeaderNumBytesOffset);
};
Message.prototype.getHeaderVersion = function() {
return this.buffer.getUint32(kStructHeaderVersionOffset);
};
Message.prototype.getName = function() {
return this.buffer.getUint32(kMessageNameOffset);
};
Message.prototype.getFlags = function() {
return this.buffer.getUint32(kMessageFlagsOffset);
};
Message.prototype.isResponse = function() {
return (this.getFlags() & kMessageIsResponse) != 0;
};
Message.prototype.expectsResponse = function() {
return (this.getFlags() & kMessageExpectsResponse) != 0;
};
Message.prototype.setRequestID = function(requestID) {
// TODO(darin): Verify that space was reserved for this field!
this.buffer.setUint64(kMessageRequestIDOffset, requestID);
};
// MessageBuilder -----------------------------------------------------------
function MessageBuilder(messageName, payloadSize) {
// Currently, we don't compute the payload size correctly ahead of time.
// Instead, we resize the buffer at the end.
var numberOfBytes = kMessageHeaderSize + payloadSize;
this.buffer = new buffer.Buffer(numberOfBytes);
this.handles = [];
var encoder = this.createEncoder(kMessageHeaderSize);
encoder.writeUint32(kMessageHeaderSize);
encoder.writeUint32(0); // version.
encoder.writeUint32(0); // interface ID.
encoder.writeUint32(messageName);
encoder.writeUint32(0); // flags.
encoder.writeUint32(0); // padding.
}
MessageBuilder.prototype.createEncoder = function(size) {
var pointer = this.buffer.alloc(size);
return new Encoder(this.buffer, this.handles, pointer);
};
MessageBuilder.prototype.encodeStruct = function(cls, val) {
cls.encode(this.createEncoder(cls.encodedSize), val);
};
MessageBuilder.prototype.finish = function() {
// TODO(abarth): Rather than resizing the buffer at the end, we could
// compute the size we need ahead of time, like we do in C++.
this.buffer.trim();
var message = new Message(this.buffer, this.handles);
this.buffer = null;
this.handles = null;
this.encoder = null;
return message;
};
// MessageWithRequestIDBuilder -----------------------------------------------
function MessageWithRequestIDBuilder(messageName, payloadSize, flags,
requestID) {
// Currently, we don't compute the payload size correctly ahead of time.
// Instead, we resize the buffer at the end.
var numberOfBytes = kMessageWithRequestIDHeaderSize + payloadSize;
this.buffer = new buffer.Buffer(numberOfBytes);
this.handles = [];
var encoder = this.createEncoder(kMessageWithRequestIDHeaderSize);
encoder.writeUint32(kMessageWithRequestIDHeaderSize);
encoder.writeUint32(1); // version.
encoder.writeUint32(0); // interface ID.
encoder.writeUint32(messageName);
encoder.writeUint32(flags);
encoder.writeUint32(0); // padding.
encoder.writeUint64(requestID);
}
MessageWithRequestIDBuilder.prototype =
Object.create(MessageBuilder.prototype);
MessageWithRequestIDBuilder.prototype.constructor =
MessageWithRequestIDBuilder;
// MessageReader ------------------------------------------------------------
function MessageReader(message) {
this.decoder = new Decoder(message.buffer, message.handles, 0);
var messageHeaderSize = this.decoder.readUint32();
this.payloadSize = message.buffer.byteLength - messageHeaderSize;
var version = this.decoder.readUint32();
var interface_id = this.decoder.readUint32();
if (interface_id != 0) {
throw new Error("Receiving non-zero interface ID. Associated interfaces " +
"are not yet supported.");
}
this.messageName = this.decoder.readUint32();
this.flags = this.decoder.readUint32();
// Skip the padding.
this.decoder.skip(4);
if (version >= 1)
this.requestID = this.decoder.readUint64();
this.decoder.skip(messageHeaderSize - this.decoder.next);
}
MessageReader.prototype.decodeStruct = function(cls) {
return cls.decode(this.decoder);
};
// Built-in types -----------------------------------------------------------
// This type is only used with ArrayOf(PackedBool).
function PackedBool() {
}
function Int8() {
}
Int8.encodedSize = 1;
Int8.decode = function(decoder) {
return decoder.readInt8();
};
Int8.encode = function(encoder, val) {
encoder.writeInt8(val);
};
Uint8.encode = function(encoder, val) {
encoder.writeUint8(val);
};
function Uint8() {
}
Uint8.encodedSize = 1;
Uint8.decode = function(decoder) {
return decoder.readUint8();
};
Uint8.encode = function(encoder, val) {
encoder.writeUint8(val);
};
function Int16() {
}
Int16.encodedSize = 2;
Int16.decode = function(decoder) {
return decoder.readInt16();
};
Int16.encode = function(encoder, val) {
encoder.writeInt16(val);
};
function Uint16() {
}
Uint16.encodedSize = 2;
Uint16.decode = function(decoder) {
return decoder.readUint16();
};
Uint16.encode = function(encoder, val) {
encoder.writeUint16(val);
};
function Int32() {
}
Int32.encodedSize = 4;
Int32.decode = function(decoder) {
return decoder.readInt32();
};
Int32.encode = function(encoder, val) {
encoder.writeInt32(val);
};
function Uint32() {
}
Uint32.encodedSize = 4;
Uint32.decode = function(decoder) {
return decoder.readUint32();
};
Uint32.encode = function(encoder, val) {
encoder.writeUint32(val);
};
function Int64() {
}
Int64.encodedSize = 8;
Int64.decode = function(decoder) {
return decoder.readInt64();
};
Int64.encode = function(encoder, val) {
encoder.writeInt64(val);
};
function Uint64() {
}
Uint64.encodedSize = 8;
Uint64.decode = function(decoder) {
return decoder.readUint64();
};
Uint64.encode = function(encoder, val) {
encoder.writeUint64(val);
};
function String() {
};
String.encodedSize = 8;
String.decode = function(decoder) {
return decoder.decodeStringPointer();
};
String.encode = function(encoder, val) {
encoder.encodeStringPointer(val);
};
function NullableString() {
}
NullableString.encodedSize = String.encodedSize;
NullableString.decode = String.decode;
NullableString.encode = String.encode;
function Float() {
}
Float.encodedSize = 4;
Float.decode = function(decoder) {
return decoder.readFloat();
};
Float.encode = function(encoder, val) {
encoder.writeFloat(val);
};
function Double() {
}
Double.encodedSize = 8;
Double.decode = function(decoder) {
return decoder.readDouble();
};
Double.encode = function(encoder, val) {
encoder.writeDouble(val);
};
function Enum(cls) {
this.cls = cls;
}
Enum.prototype.encodedSize = 4;
Enum.prototype.decode = function(decoder) {
return decoder.readInt32();
};
Enum.prototype.encode = function(encoder, val) {
encoder.writeInt32(val);
};
function PointerTo(cls) {
this.cls = cls;
}
PointerTo.prototype.encodedSize = 8;
PointerTo.prototype.decode = function(decoder) {
var pointer = decoder.decodePointer();
if (!pointer) {
return null;
}
return this.cls.decode(decoder.decodeAndCreateDecoder(pointer));
};
PointerTo.prototype.encode = function(encoder, val) {
if (!val) {
encoder.encodePointer(val);
return;
}
var objectEncoder = encoder.createAndEncodeEncoder(this.cls.encodedSize);
this.cls.encode(objectEncoder, val);
};
function NullablePointerTo(cls) {
PointerTo.call(this, cls);
}
NullablePointerTo.prototype = Object.create(PointerTo.prototype);
function ArrayOf(cls, length) {
this.cls = cls;
this.length = length || 0;
}
ArrayOf.prototype.encodedSize = 8;
ArrayOf.prototype.dimensions = function() {
return [this.length].concat(
(this.cls instanceof ArrayOf) ? this.cls.dimensions() : []);
}
ArrayOf.prototype.decode = function(decoder) {
return decoder.decodeArrayPointer(this.cls);
};
ArrayOf.prototype.encode = function(encoder, val) {
encoder.encodeArrayPointer(this.cls, val);
};
function NullableArrayOf(cls) {
ArrayOf.call(this, cls);
}
NullableArrayOf.prototype = Object.create(ArrayOf.prototype);
function Handle() {
}
Handle.encodedSize = 4;
Handle.decode = function(decoder) {
return decoder.decodeHandle();
};
Handle.encode = function(encoder, val) {
encoder.encodeHandle(val);
};
function NullableHandle() {
}
NullableHandle.encodedSize = Handle.encodedSize;
NullableHandle.decode = Handle.decode;
NullableHandle.encode = Handle.encode;
function Interface(cls) {
this.cls = cls;
}
Interface.prototype.encodedSize = 8;
Interface.prototype.decode = function(decoder) {
var interfacePtrInfo = new types.InterfacePtrInfo(
decoder.decodeHandle(), decoder.readUint32());
var interfacePtr = new this.cls();
interfacePtr.ptr.bind(interfacePtrInfo);
return interfacePtr;
};
Interface.prototype.encode = function(encoder, val) {
var interfacePtrInfo =
val ? val.ptr.passInterface() : new types.InterfacePtrInfo(null, 0);
encoder.encodeHandle(interfacePtrInfo.handle);
encoder.writeUint32(interfacePtrInfo.version);
};
function NullableInterface(cls) {
Interface.call(this, cls);
}
NullableInterface.prototype = Object.create(Interface.prototype);
function InterfaceRequest() {
}
InterfaceRequest.encodedSize = 4;
InterfaceRequest.decode = function(decoder) {
return new types.InterfaceRequest(decoder.decodeHandle());
};
InterfaceRequest.encode = function(encoder, val) {
encoder.encodeHandle(val ? val.handle : null);
};
function NullableInterfaceRequest() {
}
NullableInterfaceRequest.encodedSize = InterfaceRequest.encodedSize;
NullableInterfaceRequest.decode = InterfaceRequest.decode;
NullableInterfaceRequest.encode = InterfaceRequest.encode;
function MapOf(keyClass, valueClass) {
this.keyClass = keyClass;
this.valueClass = valueClass;
}
MapOf.prototype.encodedSize = 8;
MapOf.prototype.decode = function(decoder) {
return decoder.decodeMapPointer(this.keyClass, this.valueClass);
};
MapOf.prototype.encode = function(encoder, val) {
encoder.encodeMapPointer(this.keyClass, this.valueClass, val);
};
function NullableMapOf(keyClass, valueClass) {
MapOf.call(this, keyClass, valueClass);
}
NullableMapOf.prototype = Object.create(MapOf.prototype);
var exports = {};
exports.align = align;
exports.isAligned = isAligned;
exports.Message = Message;
exports.MessageBuilder = MessageBuilder;
exports.MessageWithRequestIDBuilder = MessageWithRequestIDBuilder;
exports.MessageReader = MessageReader;
exports.kArrayHeaderSize = kArrayHeaderSize;
exports.kMapStructPayloadSize = kMapStructPayloadSize;
exports.kStructHeaderSize = kStructHeaderSize;
exports.kEncodedInvalidHandleValue = kEncodedInvalidHandleValue;
exports.kMessageHeaderSize = kMessageHeaderSize;
exports.kMessageWithRequestIDHeaderSize = kMessageWithRequestIDHeaderSize;
exports.kMessageExpectsResponse = kMessageExpectsResponse;
exports.kMessageIsResponse = kMessageIsResponse;
exports.Int8 = Int8;
exports.Uint8 = Uint8;
exports.Int16 = Int16;
exports.Uint16 = Uint16;
exports.Int32 = Int32;
exports.Uint32 = Uint32;
exports.Int64 = Int64;
exports.Uint64 = Uint64;
exports.Float = Float;
exports.Double = Double;
exports.String = String;
exports.Enum = Enum;
exports.NullableString = NullableString;
exports.PointerTo = PointerTo;
exports.NullablePointerTo = NullablePointerTo;
exports.ArrayOf = ArrayOf;
exports.NullableArrayOf = NullableArrayOf;
exports.PackedBool = PackedBool;
exports.Handle = Handle;
exports.NullableHandle = NullableHandle;
exports.Interface = Interface;
exports.NullableInterface = NullableInterface;
exports.InterfaceRequest = InterfaceRequest;
exports.NullableInterfaceRequest = NullableInterfaceRequest;
exports.MapOf = MapOf;
exports.NullableMapOf = NullableMapOf;
return exports;
});