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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
"use strict";
/**
* Packets contain read / write functionality for the different packet types
* supported by the debugging protocol, so that a transport can focus on
* delivery and queue management without worrying too much about the specific
* packet types.
*
* They are intended to be "one use only", so a new packet should be
* instantiated for each incoming or outgoing packet.
*
* A complete Packet type should expose at least the following:
* * read(stream, scriptableStream)
* Called when the input stream has data to read
* * write(stream)
* Called when the output stream is ready to write
* * get done()
* Returns true once the packet is done being read / written
* * destroy()
* Called to clean up at the end of use
*/
const { dumpn, dumpv } = DevToolsUtils;
DevToolsUtils.defineLazyGetter(this, "unicodeConverter", () => {
// eslint-disable-next-line no-shadow
const unicodeConverter = Cc[
"@mozilla.org/intl/scriptableunicodeconverter"
].createInstance(Ci.nsIScriptableUnicodeConverter);
unicodeConverter.charset = "UTF-8";
return unicodeConverter;
});
// The transport's previous check ensured the header length did not exceed 20
// characters. Here, we opt for the somewhat smaller, but still large limit of
// 1 TiB.
const PACKET_LENGTH_MAX = Math.pow(2, 40);
/**
* A generic Packet processing object (extended by two subtypes below).
*/
function Packet(transport) {
this._transport = transport;
this._length = 0;
}
/**
* Attempt to initialize a new Packet based on the incoming packet header we've
* received so far. We try each of the types in succession, trying JSON packets
* first since they are much more common.
* @param header string
* The packet header string to attempt parsing.
* @param transport DebuggerTransport
* The transport instance that will own the packet.
* @return Packet
* The parsed packet of the matching type, or null if no types matched.
*/
Packet.fromHeader = function (header, transport) {
return (
JSONPacket.fromHeader(header, transport) ||
BulkPacket.fromHeader(header, transport)
);
};
Packet.prototype = {
get length() {
return this._length;
},
set length(length) {
if (length > PACKET_LENGTH_MAX) {
throw Error(
"Packet length " +
length +
" exceeds the max length of " +
PACKET_LENGTH_MAX
);
}
this._length = length;
},
destroy() {
this._transport = null;
},
};
exports.Packet = Packet;
/**
* With a JSON packet (the typical packet type sent via the transport), data is
* transferred as a JSON packet serialized into a string, with the string length
* prepended to the packet, followed by a colon ([length]:[packet]). The
* contents of the JSON packet are specified in the Remote Debugging Protocol
* specification.
* @param transport DebuggerTransport
* The transport instance that will own the packet.
*/
function JSONPacket(transport) {
Packet.call(this, transport);
this._data = "";
this._done = false;
}
/**
* Attempt to initialize a new JSONPacket based on the incoming packet header
* we've received so far.
* @param header string
* The packet header string to attempt parsing.
* @param transport DebuggerTransport
* The transport instance that will own the packet.
* @return JSONPacket
* The parsed packet, or null if it's not a match.
*/
JSONPacket.fromHeader = function (header, transport) {
const match = this.HEADER_PATTERN.exec(header);
if (!match) {
return null;
}
dumpv("Header matches JSON packet");
const packet = new JSONPacket(transport);
packet.length = +match[1];
return packet;
};
JSONPacket.HEADER_PATTERN = /^(\d+):$/;
JSONPacket.prototype = Object.create(Packet.prototype);
Object.defineProperty(JSONPacket.prototype, "object", {
/**
* Gets the object (not the serialized string) being read or written.
*/
get() {
return this._object;
},
/**
* Sets the object to be sent when write() is called.
*/
set(object) {
this._object = object;
const data = JSON.stringify(object);
this._data = unicodeConverter.ConvertFromUnicode(data);
this.length = this._data.length;
},
});
JSONPacket.prototype.read = function (stream, scriptableStream) {
dumpv("Reading JSON packet");
// Read in more packet data.
this._readData(stream, scriptableStream);
if (!this.done) {
// Don't have a complete packet yet.
return;
}
let json = this._data;
try {
json = unicodeConverter.ConvertToUnicode(json);
this._object = JSON.parse(json);
} catch (e) {
const msg =
"Error parsing incoming packet: " +
json +
" (" +
e +
" - " +
e.stack +
")";
console.error(msg);
dumpn(msg);
return;
}
this._transport._onJSONObjectReady(this._object);
};
JSONPacket.prototype._readData = function (stream, scriptableStream) {
if (flags.wantVerbose) {
dumpv(
"Reading JSON data: _l: " +
this.length +
" dL: " +
this._data.length +
" sA: " +
stream.available()
);
}
const bytesToRead = Math.min(
this.length - this._data.length,
stream.available()
);
this._data += scriptableStream.readBytes(bytesToRead);
this._done = this._data.length === this.length;
};
JSONPacket.prototype.write = function (stream) {
dumpv("Writing JSON packet");
if (this._outgoing === undefined) {
// Format the serialized packet to a buffer
this._outgoing = this.length + ":" + this._data;
}
const written = stream.write(this._outgoing, this._outgoing.length);
this._outgoing = this._outgoing.slice(written);
this._done = !this._outgoing.length;
};
Object.defineProperty(JSONPacket.prototype, "done", {
get() {
return this._done;
},
});
JSONPacket.prototype.toString = function () {
return JSON.stringify(this._object, null, 2);
};
exports.JSONPacket = JSONPacket;
/**
* With a bulk packet, data is transferred by temporarily handing over the
* transport's input or output stream to the application layer for writing data
* directly. This can be much faster for large data sets, and avoids various
* stages of copies and data duplication inherent in the JSON packet type. The
* bulk packet looks like:
*
* bulk [actor] [type] [length]:[data]
*
* The interpretation of the data portion depends on the kind of actor and the
* packet's type. See the Remote Debugging Protocol Stream Transport spec for
* more details.
* @param transport DebuggerTransport
* The transport instance that will own the packet.
*/
function BulkPacket(transport) {
Packet.call(this, transport);
this._done = false;
let _resolve;
this._readyForWriting = new Promise(resolve => {
_resolve = resolve;
});
this._readyForWriting.resolve = _resolve;
}
/**
* Attempt to initialize a new BulkPacket based on the incoming packet header
* we've received so far.
* @param header string
* The packet header string to attempt parsing.
* @param transport DebuggerTransport
* The transport instance that will own the packet.
* @return BulkPacket
* The parsed packet, or null if it's not a match.
*/
BulkPacket.fromHeader = function (header, transport) {
const match = this.HEADER_PATTERN.exec(header);
if (!match) {
return null;
}
dumpv("Header matches bulk packet");
const packet = new BulkPacket(transport);
packet.header = {
actor: match[1],
type: match[2],
length: +match[3],
};
return packet;
};
BulkPacket.HEADER_PATTERN = /^bulk ([^: ]+) ([^: ]+) (\d+):$/;
BulkPacket.prototype = Object.create(Packet.prototype);
BulkPacket.prototype.read = function (stream) {
dumpv("Reading bulk packet, handing off input stream");
// Temporarily pause monitoring of the input stream
this._transport.pauseIncoming();
new Promise(resolve => {
this._transport._onBulkReadReady({
actor: this.actor,
type: this.type,
length: this.length,
copyTo: output => {
dumpv("CT length: " + this.length);
const copying = StreamUtils.copyStream(stream, output, this.length);
resolve(copying);
return copying;
},
stream,
done: resolve,
});
// Await the result of reading from the stream
}).then(() => {
dumpv("onReadDone called, ending bulk mode");
this._done = true;
this._transport.resumeIncoming();
}, this._transport.close);
// Ensure this is only done once
this.read = () => {
throw new Error("Tried to read() a BulkPacket's stream multiple times.");
};
};
BulkPacket.prototype.write = function (stream) {
dumpv("Writing bulk packet");
if (this._outgoingHeader === undefined) {
dumpv("Serializing bulk packet header");
// Format the serialized packet header to a buffer
this._outgoingHeader =
"bulk " + this.actor + " " + this.type + " " + this.length + ":";
}
// Write the header, or whatever's left of it to write.
if (this._outgoingHeader.length) {
dumpv("Writing bulk packet header");
const written = stream.write(
this._outgoingHeader,
this._outgoingHeader.length
);
this._outgoingHeader = this._outgoingHeader.slice(written);
return;
}
dumpv("Handing off output stream");
// Temporarily pause the monitoring of the output stream
this._transport.pauseOutgoing();
new Promise(resolve => {
this._readyForWriting.resolve({
copyFrom: input => {
dumpv("CF length: " + this.length);
const copying = StreamUtils.copyStream(input, stream, this.length);
resolve(copying);
return copying;
},
stream,
done: resolve,
});
// Await the result of writing to the stream
}).then(() => {
dumpv("onWriteDone called, ending bulk mode");
this._done = true;
this._transport.resumeOutgoing();
}, this._transport.close);
// Ensure this is only done once
this.write = () => {
throw new Error("Tried to write() a BulkPacket's stream multiple times.");
};
};
Object.defineProperty(BulkPacket.prototype, "streamReadyForWriting", {
get() {
return this._readyForWriting;
},
});
Object.defineProperty(BulkPacket.prototype, "header", {
get() {
return {
actor: this.actor,
type: this.type,
length: this.length,
};
},
set(header) {
this.actor = header.actor;
this.type = header.type;
this.length = header.length;
},
});
Object.defineProperty(BulkPacket.prototype, "done", {
get() {
return this._done;
},
});
BulkPacket.prototype.toString = function () {
return "Bulk: " + JSON.stringify(this.header, null, 2);
};
exports.BulkPacket = BulkPacket;
/**
* RawPacket is used to test the transport's error handling of malformed
* packets, by writing data directly onto the stream.
* @param transport DebuggerTransport
* The transport instance that will own the packet.
* @param data string
* The raw string to send out onto the stream.
*/
function RawPacket(transport, data) {
Packet.call(this, transport);
this._data = data;
this.length = data.length;
this._done = false;
}
RawPacket.prototype = Object.create(Packet.prototype);
RawPacket.prototype.read = function () {
// This hasn't yet been needed for testing.
throw Error("Not implmented.");
};
RawPacket.prototype.write = function (stream) {
const written = stream.write(this._data, this._data.length);
this._data = this._data.slice(written);
this._done = !this._data.length;
};
Object.defineProperty(RawPacket.prototype, "done", {
get() {
return this._done;
},
});
exports.RawPacket = RawPacket;