/*
* Websock: high-performance binary WebSockets
- * Copyright (C) 2018 The noVNC Authors
+ * Copyright (C) 2019 The noVNC Authors
* Licensed under MPL 2.0 (see LICENSE.txt)
*
* Websock is similar to the standard WebSocket object but with extra
// 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.
+// Also copyWithin() for TypedArrays is not supported in IE 11 or
+// Safari 13 (at the moment we want to support Safari 11).
const ENABLE_COPYWITHIN = false;
const MAX_RQ_GROW_SIZE = 40 * 1024 * 1024; // 40 MiB
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
}
// Getters and Setters
- get_sQ() {
+ get sQ() {
return this._sQ;
}
- get_rQ() {
+ get rQ() {
return this._rQ;
}
- get_rQi() {
+ get rQi() {
return this._rQi;
}
- set_rQi(val) {
+ set rQi(val) {
this._rQi = val;
}
// Receive Queue
- rQlen() {
+ get rQlen() {
return this._rQlen - this._rQi;
}
return this._rQ[this._rQi];
}
- rQshift8() {
- return this._rQ[this._rQi++];
- }
-
- rQskip8() {
- this._rQi++;
+ rQskipBytes(bytes) {
+ this._rQi += bytes;
}
- rQskipBytes(num) {
- this._rQi += num;
+ rQshift8() {
+ return this._rQshift(1);
}
- // TODO(directxman12): test performance with these vs a DataView
rQshift16() {
- return (this._rQ[this._rQi++] << 8) +
- this._rQ[this._rQi++];
+ return this._rQshift(2);
}
rQshift32() {
- return (this._rQ[this._rQi++] << 24) +
- (this._rQ[this._rQi++] << 16) +
- (this._rQ[this._rQi++] << 8) +
- this._rQ[this._rQi++];
+ return this._rQshift(4);
+ }
+
+ // TODO(directxman12): test performance with these vs a DataView
+ _rQshift(bytes) {
+ let res = 0;
+ for (let byte = bytes - 1; byte >= 0; byte--) {
+ res += this._rQ[this._rQi++] << (byte * 8);
+ }
+ return res;
}
rQshiftStr(len) {
- if (typeof(len) === 'undefined') { len = this.rQlen(); }
+ if (typeof(len) === 'undefined') { len = this.rQlen; }
let str = "";
// Handle large arrays in steps to avoid long strings on the stack
for (let i = 0; i < len; i += 4096) {
}
rQshiftBytes(len) {
- if (typeof(len) === 'undefined') { len = this.rQlen(); }
+ if (typeof(len) === 'undefined') { len = this.rQlen; }
this._rQi += len;
return new Uint8Array(this._rQ.buffer, this._rQi - len, len);
}
rQshiftTo(target, len) {
- if (len === undefined) { len = this.rQlen(); }
+ 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() {
- return new Uint8Array(this._rQ.buffer, 0, this._rQlen);
- }
-
- rQslice(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);
- }
+ rQslice(start, end = this.rQlen) {
+ return new Uint8Array(this._rQ.buffer, this._rQi + start, end - 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(msg, num, goback) {
- const rQlen = this._rQlen - this._rQi; // Skip rQlen() function call
- if (rQlen < num) {
+ if (this.rQlen < num) {
if (goback) {
if (this._rQi < goback) {
throw new Error("rQwait cannot backup " + goback + " bytes");
return new Uint8Array(this._sQ.buffer, 0, this._sQlen);
}
+ // We want to move all the unread data to the start of the queue,
+ // e.g. compacting.
+ // The function also expands the receive que if needed, and for
+ // performance reasons we combine these two actions to avoid
+ // unneccessary copying.
_expand_compact_rQ(min_fit) {
- const resizeNeeded = min_fit || this._rQlen - this._rQi > this._rQbufferSize / 2;
+ // if we're using less than 1/8th of the buffer even with the incoming bytes, compact in place
+ // instead of resizing
+ const required_buffer_size = (this._rQlen - this._rQi + min_fit) * 8;
+ const resizeNeeded = this._rQbufferSize < required_buffer_size;
+
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;
- }
+ // Make sure we always *at least* double the buffer size, and have at least space for 8x
+ // the current amount of data
+ this._rQbufferSize = Math.max(this._rQbufferSize * 2, required_buffer_size);
}
// 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) {
+ if (this._rQbufferSize - this.rQlen < min_fit) {
throw new Error("Receive Queue buffer exceeded " + MAX_RQ_GROW_SIZE + " bytes, and the new message could not fit");
}
}
if (resizeNeeded) {
const 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));
+ this._rQ.set(new Uint8Array(old_rQbuffer, this._rQi, this._rQlen - this._rQi));
} else {
if (ENABLE_COPYWITHIN) {
- this._rQ.copyWithin(0, this._rQi);
+ this._rQ.copyWithin(0, this._rQi, this._rQlen);
} else {
- this._rQ.set(new Uint8Array(this._rQ.buffer, this._rQi));
+ this._rQ.set(new Uint8Array(this._rQ.buffer, this._rQi, this._rQlen - this._rQi));
}
}
this._rQi = 0;
}
+ // push arraybuffer values onto the end of the receive que
_decode_message(data) {
- // push arraybuffer values onto the end
const u8 = new Uint8Array(data);
if (u8.length > this._rQbufferSize - this._rQlen) {
this._expand_compact_rQ(u8.length);
_recv_message(e) {
this._decode_message(e.data);
- if (this.rQlen() > 0) {
+ if (this.rQlen > 0) {
this._eventHandlers.message();
- // Compact the receive queue
if (this._rQlen == this._rQi) {
+ // All data has now been processed, this means we
+ // can reset the receive queue.
this._rQlen = 0;
this._rQi = 0;
- } else if (this._rQlen > this._rQmax) {
- this._expand_compact_rQ();
}
} else {
Log.Debug("Ignoring empty message");
projects / mirror_novnc.git / blobdiff