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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
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const DevToolsUtils = require("resource://devtools/shared/DevToolsUtils.js");
+const { dumpn, dumpv } = DevToolsUtils;
+const flags = require("resource://devtools/shared/flags.js");
+const StreamUtils = require("resource://devtools/shared/transport/stream-utils.js");
+const {
+ Packet,
+ JSONPacket,
+ BulkPacket,
+} = require("resource://devtools/shared/transport/packets.js");
+
+loader.lazyGetter(this, "ScriptableInputStream", () => {
+ return Components.Constructor(
+ "@mozilla.org/scriptableinputstream;1",
+ "nsIScriptableInputStream",
+ "init"
+ );
+});
+
+const PACKET_HEADER_MAX = 200;
+
+/**
+ * An adapter that handles data transfers between the devtools client and
+ * server. It can work with both nsIPipe and nsIServerSocket transports so
+ * long as the properly created input and output streams are specified.
+ * (However, for intra-process connections, LocalDebuggerTransport, below,
+ * is more efficient than using an nsIPipe pair with DebuggerTransport.)
+ *
+ * @param input nsIAsyncInputStream
+ * The input stream.
+ * @param output nsIAsyncOutputStream
+ * The output stream.
+ *
+ * Given a DebuggerTransport instance dt:
+ * 1) Set dt.hooks to a packet handler object (described below).
+ * 2) Call dt.ready() to begin watching for input packets.
+ * 3) Call dt.send() / dt.startBulkSend() to send packets.
+ * 4) Call dt.close() to close the connection, and disengage from the event
+ * loop.
+ *
+ * A packet handler is an object with the following methods:
+ *
+ * - onPacket(packet) - called when we have received a complete packet.
+ * |packet| is the parsed form of the packet --- a JavaScript value, not
+ * a JSON-syntax string.
+ *
+ * - onBulkPacket(packet) - called when we have switched to bulk packet
+ * receiving mode. |packet| is an object containing:
+ * * actor: Name of actor that will receive the packet
+ * * type: Name of actor's method that should be called on receipt
+ * * length: Size of the data to be read
+ * * stream: This input stream should only be used directly if you can ensure
+ * that you will read exactly |length| bytes and will not close the
+ * stream when reading is complete
+ * * done: If you use the stream directly (instead of |copyTo| below), you
+ * must signal completion by resolving / rejecting this deferred.
+ * If it's rejected, the transport will be closed. If an Error is
+ * supplied as a rejection value, it will be logged via |dumpn|.
+ * If you do use |copyTo|, resolving is taken care of for you when
+ * copying completes.
+ * * copyTo: A helper function for getting your data out of the stream that
+ * meets the stream handling requirements above, and has the
+ * following signature:
+ * @param output nsIAsyncOutputStream
+ * The stream to copy to.
+ * @return Promise
+ * The promise is resolved when copying completes or rejected if any
+ * (unexpected) errors occur.
+ * This object also emits "progress" events for each chunk that is
+ * copied. See stream-utils.js.
+ *
+ * - onTransportClosed(reason) - called when the connection is closed. |reason| is
+ * an optional nsresult or object, typically passed when the transport is
+ * closed due to some error in a underlying stream.
+ *
+ * See ./packets.js and the Remote Debugging Protocol specification for more
+ * details on the format of these packets.
+ */
+function DebuggerTransport(input, output) {
+ this._input = input;
+ this._scriptableInput = new ScriptableInputStream(input);
+ this._output = output;
+
+ // The current incoming (possibly partial) header, which will determine which
+ // type of Packet |_incoming| below will become.
+ this._incomingHeader = "";
+ // The current incoming Packet object
+ this._incoming = null;
+ // A queue of outgoing Packet objects
+ this._outgoing = [];
+
+ this.hooks = null;
+ this.active = false;
+
+ this._incomingEnabled = true;
+ this._outgoingEnabled = true;
+
+ this.close = this.close.bind(this);
+}
+
+DebuggerTransport.prototype = {
+ /**
+ * Transmit an object as a JSON packet.
+ *
+ * This method returns immediately, without waiting for the entire
+ * packet to be transmitted, registering event handlers as needed to
+ * transmit the entire packet. Packets are transmitted in the order
+ * they are passed to this method.
+ */
+ send(object) {
+ const packet = new JSONPacket(this);
+ packet.object = object;
+ this._outgoing.push(packet);
+ this._flushOutgoing();
+ },
+
+ /**
+ * Transmit streaming data via a bulk packet.
+ *
+ * This method initiates the bulk send process by queuing up the header data.
+ * The caller receives eventual access to a stream for writing.
+ *
+ * N.B.: Do *not* attempt to close the stream handed to you, as it will
+ * continue to be used by this transport afterwards. Most users should
+ * instead use the provided |copyFrom| function instead.
+ *
+ * @param header Object
+ * This is modeled after the format of JSON packets above, but does not
+ * actually contain the data, but is instead just a routing header:
+ * * actor: Name of actor that will receive the packet
+ * * type: Name of actor's method that should be called on receipt
+ * * length: Size of the data to be sent
+ * @return Promise
+ * The promise will be resolved when you are allowed to write to the
+ * stream with an object containing:
+ * * stream: This output stream should only be used directly if
+ * you can ensure that you will write exactly |length|
+ * bytes and will not close the stream when writing is
+ * complete
+ * * done: If you use the stream directly (instead of |copyFrom|
+ * below), you must signal completion by resolving /
+ * rejecting this deferred. If it's rejected, the
+ * transport will be closed. If an Error is supplied as
+ * a rejection value, it will be logged via |dumpn|. If
+ * you do use |copyFrom|, resolving is taken care of for
+ * you when copying completes.
+ * * copyFrom: A helper function for getting your data onto the
+ * stream that meets the stream handling requirements
+ * above, and has the following signature:
+ * @param input nsIAsyncInputStream
+ * The stream to copy from.
+ * @return Promise
+ * The promise is resolved when copying completes or
+ * rejected if any (unexpected) errors occur.
+ * This object also emits "progress" events for each chunk
+ * that is copied. See stream-utils.js.
+ */
+ startBulkSend(header) {
+ const packet = new BulkPacket(this);
+ packet.header = header;
+ this._outgoing.push(packet);
+ this._flushOutgoing();
+ return packet.streamReadyForWriting;
+ },
+
+ /**
+ * Close the transport.
+ * @param reason nsresult / object (optional)
+ * The status code or error message that corresponds to the reason for
+ * closing the transport (likely because a stream closed or failed).
+ */
+ close(reason) {
+ this.active = false;
+ this._input.close();
+ this._scriptableInput.close();
+ this._output.close();
+ this._destroyIncoming();
+ this._destroyAllOutgoing();
+ if (this.hooks) {
+ this.hooks.onTransportClosed(reason);
+ this.hooks = null;
+ }
+ if (reason) {
+ dumpn("Transport closed: " + DevToolsUtils.safeErrorString(reason));
+ } else {
+ dumpn("Transport closed.");
+ }
+ },
+
+ /**
+ * The currently outgoing packet (at the top of the queue).
+ */
+ get _currentOutgoing() {
+ return this._outgoing[0];
+ },
+
+ /**
+ * Flush data to the outgoing stream. Waits until the output stream notifies
+ * us that it is ready to be written to (via onOutputStreamReady).
+ */
+ _flushOutgoing() {
+ if (!this._outgoingEnabled || this._outgoing.length === 0) {
+ return;
+ }
+
+ // If the top of the packet queue has nothing more to send, remove it.
+ if (this._currentOutgoing.done) {
+ this._finishCurrentOutgoing();
+ }
+
+ if (this._outgoing.length) {
+ const threadManager = Cc["@mozilla.org/thread-manager;1"].getService();
+ this._output.asyncWait(this, 0, 0, threadManager.currentThread);
+ }
+ },
+
+ /**
+ * Pause this transport's attempts to write to the output stream. This is
+ * used when we've temporarily handed off our output stream for writing bulk
+ * data.
+ */
+ pauseOutgoing() {
+ this._outgoingEnabled = false;
+ },
+
+ /**
+ * Resume this transport's attempts to write to the output stream.
+ */
+ resumeOutgoing() {
+ this._outgoingEnabled = true;
+ this._flushOutgoing();
+ },
+
+ // nsIOutputStreamCallback
+ /**
+ * This is called when the output stream is ready for more data to be written.
+ * The current outgoing packet will attempt to write some amount of data, but
+ * may not complete.
+ */
+ onOutputStreamReady: DevToolsUtils.makeInfallible(function (stream) {
+ if (!this._outgoingEnabled || this._outgoing.length === 0) {
+ return;
+ }
+
+ try {
+ this._currentOutgoing.write(stream);
+ } catch (e) {
+ if (e.result != Cr.NS_BASE_STREAM_WOULD_BLOCK) {
+ this.close(e.result);
+ return;
+ }
+ throw e;
+ }
+
+ this._flushOutgoing();
+ }, "DebuggerTransport.prototype.onOutputStreamReady"),
+
+ /**
+ * Remove the current outgoing packet from the queue upon completion.
+ */
+ _finishCurrentOutgoing() {
+ if (this._currentOutgoing) {
+ this._currentOutgoing.destroy();
+ this._outgoing.shift();
+ }
+ },
+
+ /**
+ * Clear the entire outgoing queue.
+ */
+ _destroyAllOutgoing() {
+ for (const packet of this._outgoing) {
+ packet.destroy();
+ }
+ this._outgoing = [];
+ },
+
+ /**
+ * Initialize the input stream for reading. Once this method has been called,
+ * we watch for packets on the input stream, and pass them to the appropriate
+ * handlers via this.hooks.
+ */
+ ready() {
+ this.active = true;
+ this._waitForIncoming();
+ },
+
+ /**
+ * Asks the input stream to notify us (via onInputStreamReady) when it is
+ * ready for reading.
+ */
+ _waitForIncoming() {
+ if (this._incomingEnabled) {
+ const threadManager = Cc["@mozilla.org/thread-manager;1"].getService();
+ this._input.asyncWait(this, 0, 0, threadManager.currentThread);
+ }
+ },
+
+ /**
+ * Pause this transport's attempts to read from the input stream. This is
+ * used when we've temporarily handed off our input stream for reading bulk
+ * data.
+ */
+ pauseIncoming() {
+ this._incomingEnabled = false;
+ },
+
+ /**
+ * Resume this transport's attempts to read from the input stream.
+ */
+ resumeIncoming() {
+ this._incomingEnabled = true;
+ this._flushIncoming();
+ this._waitForIncoming();
+ },
+
+ // nsIInputStreamCallback
+ /**
+ * Called when the stream is either readable or closed.
+ */
+ onInputStreamReady: DevToolsUtils.makeInfallible(function (stream) {
+ try {
+ while (
+ stream.available() &&
+ this._incomingEnabled &&
+ this._processIncoming(stream, stream.available())
+ ) {
+ // Loop until there is nothing more to process
+ }
+ this._waitForIncoming();
+ } catch (e) {
+ if (e.result != Cr.NS_BASE_STREAM_WOULD_BLOCK) {
+ this.close(e.result);
+ } else {
+ throw e;
+ }
+ }
+ }, "DebuggerTransport.prototype.onInputStreamReady"),
+
+ /**
+ * Process the incoming data. Will create a new currently incoming Packet if
+ * needed. Tells the incoming Packet to read as much data as it can, but
+ * reading may not complete. The Packet signals that its data is ready for
+ * delivery by calling one of this transport's _on*Ready methods (see
+ * ./packets.js and the _on*Ready methods below).
+ * @return boolean
+ * Whether incoming stream processing should continue for any
+ * remaining data.
+ */
+ _processIncoming(stream, count) {
+ dumpv("Data available: " + count);
+
+ if (!count) {
+ dumpv("Nothing to read, skipping");
+ return false;
+ }
+
+ try {
+ if (!this._incoming) {
+ dumpv("Creating a new packet from incoming");
+
+ if (!this._readHeader(stream)) {
+ // Not enough data to read packet type
+ return false;
+ }
+
+ // Attempt to create a new Packet by trying to parse each possible
+ // header pattern.
+ this._incoming = Packet.fromHeader(this._incomingHeader, this);
+ if (!this._incoming) {
+ throw new Error(
+ "No packet types for header: " + this._incomingHeader
+ );
+ }
+ }
+
+ if (!this._incoming.done) {
+ // We have an incomplete packet, keep reading it.
+ dumpv("Existing packet incomplete, keep reading");
+ this._incoming.read(stream, this._scriptableInput);
+ }
+ } catch (e) {
+ const msg =
+ "Error reading incoming packet: (" + e + " - " + e.stack + ")";
+ dumpn(msg);
+
+ // Now in an invalid state, shut down the transport.
+ this.close();
+ return false;
+ }
+
+ if (!this._incoming.done) {
+ // Still not complete, we'll wait for more data.
+ dumpv("Packet not done, wait for more");
+ return true;
+ }
+
+ // Ready for next packet
+ this._flushIncoming();
+ return true;
+ },
+
+ /**
+ * Read as far as we can into the incoming data, attempting to build up a
+ * complete packet header (which terminates with ":"). We'll only read up to
+ * PACKET_HEADER_MAX characters.
+ * @return boolean
+ * True if we now have a complete header.
+ */
+ _readHeader() {
+ const amountToRead = PACKET_HEADER_MAX - this._incomingHeader.length;
+ this._incomingHeader += StreamUtils.delimitedRead(
+ this._scriptableInput,
+ ":",
+ amountToRead
+ );
+ if (flags.wantVerbose) {
+ dumpv("Header read: " + this._incomingHeader);
+ }
+
+ if (this._incomingHeader.endsWith(":")) {
+ if (flags.wantVerbose) {
+ dumpv("Found packet header successfully: " + this._incomingHeader);
+ }
+ return true;
+ }
+
+ if (this._incomingHeader.length >= PACKET_HEADER_MAX) {
+ throw new Error("Failed to parse packet header!");
+ }
+
+ // Not enough data yet.
+ return false;
+ },
+
+ /**
+ * If the incoming packet is done, log it as needed and clear the buffer.
+ */
+ _flushIncoming() {
+ if (!this._incoming.done) {
+ return;
+ }
+ if (flags.wantLogging) {
+ dumpn("Got: " + this._incoming);
+ }
+ this._destroyIncoming();
+ },
+
+ /**
+ * Handler triggered by an incoming JSONPacket completing it's |read| method.
+ * Delivers the packet to this.hooks.onPacket.
+ */
+ _onJSONObjectReady(object) {
+ DevToolsUtils.executeSoon(
+ DevToolsUtils.makeInfallible(() => {
+ // Ensure the transport is still alive by the time this runs.
+ if (this.active) {
+ this.hooks.onPacket(object);
+ }
+ }, "DebuggerTransport instance's this.hooks.onPacket")
+ );
+ },
+
+ /**
+ * Handler triggered by an incoming BulkPacket entering the |read| phase for
+ * the stream portion of the packet. Delivers info about the incoming
+ * streaming data to this.hooks.onBulkPacket. See the main comment on the
+ * transport at the top of this file for more details.
+ */
+ _onBulkReadReady(...args) {
+ DevToolsUtils.executeSoon(
+ DevToolsUtils.makeInfallible(() => {
+ // Ensure the transport is still alive by the time this runs.
+ if (this.active) {
+ this.hooks.onBulkPacket(...args);
+ }
+ }, "DebuggerTransport instance's this.hooks.onBulkPacket")
+ );
+ },
+
+ /**
+ * Remove all handlers and references related to the current incoming packet,
+ * either because it is now complete or because the transport is closing.
+ */
+ _destroyIncoming() {
+ if (this._incoming) {
+ this._incoming.destroy();
+ }
+ this._incomingHeader = "";
+ this._incoming = null;
+ },
+};
+
+exports.DebuggerTransport = DebuggerTransport;
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