1 files changed, 316 insertions, 0 deletions
diff --git a/webclients/novnc/core/websock.js b/webclients/novnc/core/websock.js
new file mode 100644
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--- /dev/null
+++ b/webclients/novnc/core/websock.js
@@ -0,0 +1,316 @@
+/*
+ * Websock: high-performance binary WebSockets
+ * Copyright (C) 2012 Joel Martin
+ * Licensed under MPL 2.0 (see LICENSE.txt)
+ *
+ * Websock is similar to the standard WebSocket object but with extra
+ * buffer handling.
+ *
+ * Websock has built-in receive queue buffering; the message event
+ * does not contain actual data but is simply a notification that
+ * there is new data available. Several rQ* methods are available to
+ * read binary data off of the receive queue.
+ */
+
+import * as Log from './util/logging.js';
+
+export default function Websock() {
+    "use strict";
+
+    this._websocket = null;  // WebSocket object
+
+    this._rQi = 0;           // Receive queue index
+    this._rQlen = 0;         // Next write position in the receive queue
+    this._rQbufferSize = 1024 * 1024 * 4; // Receive queue buffer size (4 MiB)
+    this._rQmax = this._rQbufferSize / 8;
+    // called in init: this._rQ = new Uint8Array(this._rQbufferSize);
+    this._rQ = null; // Receive queue
+
+    this._sQbufferSize = 1024 * 10;  // 10 KiB
+    // called in init: this._sQ = new Uint8Array(this._sQbufferSize);
+    this._sQlen = 0;
+    this._sQ = null;  // Send queue
+
+    this._eventHandlers = {
+        'message': function () {},
+        'open': function () {},
+        'close': function () {},
+        'error': function () {}
+    };
+};
+
+// this has performance issues in some versions Chromium, and
+// doesn't gain a tremendous amount of performance increase in Firefox
+// at the moment.  It may be valuable to turn it on in the future.
+var ENABLE_COPYWITHIN = false;
+
+var MAX_RQ_GROW_SIZE = 40 * 1024 * 1024;  // 40 MiB
+
+var typedArrayToString = (function () {
+    // This is only for PhantomJS, which doesn't like apply-ing
+    // with Typed Arrays
+    try {
+        var arr = new Uint8Array([1, 2, 3]);
+        String.fromCharCode.apply(null, arr);
+        return function (a) { return String.fromCharCode.apply(null, a); };
+    } catch (ex) {
+        return function (a) {
+            return String.fromCharCode.apply(
+                null, Array.prototype.slice.call(a));
+        };
+    }
+})();
+
+Websock.prototype = {
+    // Getters and Setters
+    get_sQ: function () {
+        return this._sQ;
+    },
+
+    get_rQ: function () {
+        return this._rQ;
+    },
+
+    get_rQi: function () {
+        return this._rQi;
+    },
+
+    set_rQi: function (val) {
+        this._rQi = val;
+    },
+
+    // Receive Queue
+    rQlen: function () {
+        return this._rQlen - this._rQi;
+    },
+
+    rQpeek8: function () {
+        return this._rQ[this._rQi];
+    },
+
+    rQshift8: function () {
+        return this._rQ[this._rQi++];
+    },
+
+    rQskip8: function () {
+        this._rQi++;
+    },
+
+    rQskipBytes: function (num) {
+        this._rQi += num;
+    },
+
+    // TODO(directxman12): test performance with these vs a DataView
+    rQshift16: function () {
+        return (this._rQ[this._rQi++] << 8) +
+               this._rQ[this._rQi++];
+    },
+
+    rQshift32: function () {
+        return (this._rQ[this._rQi++] << 24) +
+               (this._rQ[this._rQi++] << 16) +
+               (this._rQ[this._rQi++] << 8) +
+               this._rQ[this._rQi++];
+    },
+
+    rQshiftStr: function (len) {
+        if (typeof(len) === 'undefined') { len = this.rQlen(); }
+        var arr = new Uint8Array(this._rQ.buffer, this._rQi, len);
+        this._rQi += len;
+        return typedArrayToString(arr);
+    },
+
+    rQshiftBytes: function (len) {
+        if (typeof(len) === 'undefined') { len = this.rQlen(); }
+        this._rQi += len;
+        return new Uint8Array(this._rQ.buffer, this._rQi - len, len);
+    },
+
+    rQshiftTo: function (target, len) {
+        if (len === undefined) { len = this.rQlen(); }
+        // TODO: make this just use set with views when using a ArrayBuffer to store the rQ
+        target.set(new Uint8Array(this._rQ.buffer, this._rQi, len));
+        this._rQi += len;
+    },
+
+    rQwhole: function () {
+        return new Uint8Array(this._rQ.buffer, 0, this._rQlen);
+    },
+
+    rQslice: function (start, end) {
+        if (end) {
+            return new Uint8Array(this._rQ.buffer, this._rQi + start, end - start);
+        } else {
+            return new Uint8Array(this._rQ.buffer, this._rQi + start, this._rQlen - this._rQi - start);
+        }
+    },
+
+    // Check to see if we must wait for 'num' bytes (default to FBU.bytes)
+    // to be available in the receive queue. Return true if we need to
+    // wait (and possibly print a debug message), otherwise false.
+    rQwait: function (msg, num, goback) {
+        var rQlen = this._rQlen - this._rQi; // Skip rQlen() function call
+        if (rQlen < num) {
+            if (goback) {
+                if (this._rQi < goback) {
+                    throw new Error("rQwait cannot backup " + goback + " bytes");
+                }
+                this._rQi -= goback;
+            }
+            return true; // true means need more data
+        }
+        return false;
+    },
+
+    // Send Queue
+
+    flush: function () {
+        if (this._sQlen > 0 && this._websocket.readyState === WebSocket.OPEN) {
+            this._websocket.send(this._encode_message());
+            this._sQlen = 0;
+        }
+    },
+
+    send: function (arr) {
+        this._sQ.set(arr, this._sQlen);
+        this._sQlen += arr.length;
+        this.flush();
+    },
+
+    send_string: function (str) {
+        this.send(str.split('').map(function (chr) {
+            return chr.charCodeAt(0);
+        }));
+    },
+
+    // Event Handlers
+    off: function (evt) {
+        this._eventHandlers[evt] = function () {};
+    },
+
+    on: function (evt, handler) {
+        this._eventHandlers[evt] = handler;
+    },
+
+    _allocate_buffers: function () {
+        this._rQ = new Uint8Array(this._rQbufferSize);
+        this._sQ = new Uint8Array(this._sQbufferSize);
+    },
+
+    init: function () {
+        this._allocate_buffers();
+        this._rQi = 0;
+        this._websocket = null;
+    },
+
+    open: function (uri, protocols) {
+        var ws_schema = uri.match(/^([a-z]+):\/\//)[1];
+        this.init();
+
+        this._websocket = new WebSocket(uri, protocols);
+        this._websocket.binaryType = 'arraybuffer';
+
+        this._websocket.onmessage = this._recv_message.bind(this);
+        this._websocket.onopen = (function () {
+            Log.Debug('>> WebSock.onopen');
+            if (this._websocket.protocol) {
+                Log.Info("Server choose sub-protocol: " + this._websocket.protocol);
+            }
+
+            this._eventHandlers.open();
+            Log.Debug("<< WebSock.onopen");
+        }).bind(this);
+        this._websocket.onclose = (function (e) {
+            Log.Debug(">> WebSock.onclose");
+            this._eventHandlers.close(e);
+            Log.Debug("<< WebSock.onclose");
+        }).bind(this);
+        this._websocket.onerror = (function (e) {
+            Log.Debug(">> WebSock.onerror: " + e);
+            this._eventHandlers.error(e);
+            Log.Debug("<< WebSock.onerror: " + e);
+        }).bind(this);
+    },
+
+    close: function () {
+        if (this._websocket) {
+            if ((this._websocket.readyState === WebSocket.OPEN) ||
+                    (this._websocket.readyState === WebSocket.CONNECTING)) {
+                Log.Info("Closing WebSocket connection");
+                this._websocket.close();
+            }
+
+            this._websocket.onmessage = function (e) { return; };
+        }
+    },
+
+    // private methods
+    _encode_message: function () {
+        // Put in a binary arraybuffer
+        // according to the spec, you can send ArrayBufferViews with the send method
+        return new Uint8Array(this._sQ.buffer, 0, this._sQlen);
+    },
+
+    _expand_compact_rQ: function (min_fit) {
+        var resizeNeeded = min_fit || this._rQlen - this._rQi > this._rQbufferSize / 2;
+        if (resizeNeeded) {
+            if (!min_fit) {
+                // just double the size if we need to do compaction
+                this._rQbufferSize *= 2;
+            } else {
+                // otherwise, make sure we satisy rQlen - rQi + min_fit < rQbufferSize / 8
+                this._rQbufferSize = (this._rQlen - this._rQi + min_fit) * 8;
+            }
+        }
+
+        // we don't want to grow unboundedly
+        if (this._rQbufferSize > MAX_RQ_GROW_SIZE) {
+            this._rQbufferSize = MAX_RQ_GROW_SIZE;
+            if (this._rQbufferSize - this._rQlen - this._rQi < min_fit) {
+                throw new Exception("Receive Queue buffer exceeded " + MAX_RQ_GROW_SIZE + " bytes, and the new message could not fit");
+            }
+        }
+
+        if (resizeNeeded) {
+            var old_rQbuffer = this._rQ.buffer;
+            this._rQmax = this._rQbufferSize / 8;
+            this._rQ = new Uint8Array(this._rQbufferSize);
+            this._rQ.set(new Uint8Array(old_rQbuffer, this._rQi));
+        } else {
+            if (ENABLE_COPYWITHIN) {
+                this._rQ.copyWithin(0, this._rQi);
+            } else {
+                this._rQ.set(new Uint8Array(this._rQ.buffer, this._rQi));
+            }
+        }
+
+        this._rQlen = this._rQlen - this._rQi;
+        this._rQi = 0;
+    },
+
+    _decode_message: function (data) {
+        // push arraybuffer values onto the end
+        var u8 = new Uint8Array(data);
+        if (u8.length > this._rQbufferSize - this._rQlen) {
+            this._expand_compact_rQ(u8.length);
+        }
+        this._rQ.set(u8, this._rQlen);
+        this._rQlen += u8.length;
+    },
+
+    _recv_message: function (e) {
+        this._decode_message(e.data);
+        if (this.rQlen() > 0) {
+            this._eventHandlers.message();
+            // Compact the receive queue
+            if (this._rQlen == this._rQi) {
+                this._rQlen = 0;
+                this._rQi = 0;
+            } else if (this._rQlen > this._rQmax) {
+                this._expand_compact_rQ();
+            }
+        } else {
+            Log.Debug("Ignoring empty message");
+        }
+    }
+};