@microsoft/signalr-protocol-msgpack
Version:
MsgPack Protocol support for ASP.NET Core SignalR
63 lines • 2.69 kB
JavaScript
;
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
Object.defineProperty(exports, "__esModule", { value: true });
exports.BinaryMessageFormat = void 0;
// Not exported from index.
/** @private */
class BinaryMessageFormat {
// The length prefix of binary messages is encoded as VarInt. Read the comment in
// the BinaryMessageParser.TryParseMessage for details.
static write(output) {
let size = output.byteLength || output.length;
const lenBuffer = [];
do {
let sizePart = size & 0x7f;
size = size >> 7;
if (size > 0) {
sizePart |= 0x80;
}
lenBuffer.push(sizePart);
} while (size > 0);
size = output.byteLength || output.length;
const buffer = new Uint8Array(lenBuffer.length + size);
buffer.set(lenBuffer, 0);
buffer.set(output, lenBuffer.length);
return buffer.buffer;
}
static parse(input) {
const result = [];
const uint8Array = new Uint8Array(input);
const maxLengthPrefixSize = 5;
const numBitsToShift = [0, 7, 14, 21, 28];
for (let offset = 0; offset < input.byteLength;) {
let numBytes = 0;
let size = 0;
let byteRead;
do {
byteRead = uint8Array[offset + numBytes];
size = size | ((byteRead & 0x7f) << (numBitsToShift[numBytes]));
numBytes++;
} while (numBytes < Math.min(maxLengthPrefixSize, input.byteLength - offset) && (byteRead & 0x80) !== 0);
if ((byteRead & 0x80) !== 0 && numBytes < maxLengthPrefixSize) {
throw new Error("Cannot read message size.");
}
if (numBytes === maxLengthPrefixSize && byteRead > 7) {
throw new Error("Messages bigger than 2GB are not supported.");
}
if (uint8Array.byteLength >= (offset + numBytes + size)) {
// IE does not support .slice() so use subarray
result.push(uint8Array.slice
? uint8Array.slice(offset + numBytes, offset + numBytes + size)
: uint8Array.subarray(offset + numBytes, offset + numBytes + size));
}
else {
throw new Error("Incomplete message.");
}
offset = offset + numBytes + size;
}
return result;
}
}
exports.BinaryMessageFormat = BinaryMessageFormat;
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