summaryrefslogtreecommitdiffstats
path: root/devtools/shared/transport/packets.js
diff options
context:
space:
mode:
Diffstat (limited to 'devtools/shared/transport/packets.js')
-rw-r--r--devtools/shared/transport/packets.js414
1 files changed, 414 insertions, 0 deletions
diff --git a/devtools/shared/transport/packets.js b/devtools/shared/transport/packets.js
new file mode 100644
index 000000000..3ebcd8f13
--- /dev/null
+++ b/devtools/shared/transport/packets.js
@@ -0,0 +1,414 @@
+/* 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
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"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 { Cc, Ci, Cu } = require("chrome");
+const DevToolsUtils = require("devtools/shared/DevToolsUtils");
+const { dumpn, dumpv } = DevToolsUtils;
+const flags = require("devtools/shared/flags");
+const StreamUtils = require("devtools/shared/transport/stream-utils");
+const promise = require("promise");
+const defer = require("devtools/shared/defer");
+
+DevToolsUtils.defineLazyGetter(this, "unicodeConverter", () => {
+ 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: function () {
+ 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) {
+ let match = this.HEADER_PATTERN.exec(header);
+
+ if (!match) {
+ return null;
+ }
+
+ dumpv("Header matches JSON packet");
+ let 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: function () { return this._object; },
+
+ /**
+ * Sets the object to be sent when write() is called.
+ */
+ set: function (object) {
+ this._object = object;
+ let 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) {
+ let 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());
+ }
+ let 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;
+ }
+
+ let 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: function () { 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;
+ this._readyForWriting = defer();
+}
+
+/**
+ * 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) {
+ let match = this.HEADER_PATTERN.exec(header);
+
+ if (!match) {
+ return null;
+ }
+
+ dumpv("Header matches bulk packet");
+ let 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();
+
+ let deferred = defer();
+
+ this._transport._onBulkReadReady({
+ actor: this.actor,
+ type: this.type,
+ length: this.length,
+ copyTo: (output) => {
+ dumpv("CT length: " + this.length);
+ let copying = StreamUtils.copyStream(stream, output, this.length);
+ deferred.resolve(copying);
+ return copying;
+ },
+ stream: stream,
+ done: deferred
+ });
+
+ // Await the result of reading from the stream
+ deferred.promise.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");
+ let 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();
+
+ let deferred = defer();
+
+ this._readyForWriting.resolve({
+ copyFrom: (input) => {
+ dumpv("CF length: " + this.length);
+ let copying = StreamUtils.copyStream(input, stream, this.length);
+ deferred.resolve(copying);
+ return copying;
+ },
+ stream: stream,
+ done: deferred
+ });
+
+ // Await the result of writing to the stream
+ deferred.promise.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: function () {
+ return this._readyForWriting.promise;
+ }
+});
+
+Object.defineProperty(BulkPacket.prototype, "header", {
+ get: function () {
+ return {
+ actor: this.actor,
+ type: this.type,
+ length: this.length
+ };
+ },
+
+ set: function (header) {
+ this.actor = header.actor;
+ this.type = header.type;
+ this.length = header.length;
+ },
+});
+
+Object.defineProperty(BulkPacket.prototype, "done", {
+ get: function () { 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 (stream) {
+ // This hasn't yet been needed for testing.
+ throw Error("Not implmented.");
+};
+
+RawPacket.prototype.write = function (stream) {
+ let 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: function () { return this._done; }
+});
+
+exports.RawPacket = RawPacket;