engine.io-parser - npm Package Compare versions

Comparing version 5.2.0 to 5.2.1

build/cjs/index.js

@@ -39,3 +39,2 @@ "use strict";
 exports.decodePayload = decodePayload;
-const HEADER_LENGTH = 4;
 function createPacketEncoderStream() {
@@ -45,5 +44,21 @@ return new TransformStream({
             (0, encodePacket_js_1.encodePacketToBinary)(packet, encodedPacket => {
-                const header = new Uint8Array(HEADER_LENGTH);
-                // last 31 bits indicate the length of the payload
-                new DataView(header.buffer).setUint32(0, encodedPacket.length);
+                const payloadLength = encodedPacket.length;
+                let header;
+                // inspired by the WebSocket format: https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API/Writing_WebSocket_servers#decoding_payload_length
+                if (payloadLength < 126) {
+                    header = new Uint8Array(1);
+                    new DataView(header.buffer).setUint8(0, payloadLength);
+                }
+                else if (payloadLength < 65536) {
+                    header = new Uint8Array(3);
+                    const view = new DataView(header.buffer);
+                    view.setUint8(0, 126);
+                    view.setUint16(1, payloadLength);
+                }
+                else {
+                    header = new Uint8Array(9);
+                    const view = new DataView(header.buffer);
+                    view.setUint8(0, 127);
+                    view.setBigUint64(1, BigInt(payloadLength));
+                }
                 // first bit indicates whether the payload is plain text (0) or binary (1)
@@ -87,3 +102,4 @@ if (packet.data && typeof packet.data !== "string") {
     const chunks = [];
-    let expectedSize = -1;
+    let state = 0 /* READ_HEADER */;
+    let expectedLength = -1;
     let isBinary = false;
@@ -94,24 +110,54 @@ return new TransformStream({
             while (true) {
-                const expectHeader = expectedSize === -1;
-                if (expectHeader) {
-                    if (totalLength(chunks) < HEADER_LENGTH) {
+                if (state === 0 /* READ_HEADER */) {
+                    if (totalLength(chunks) < 1) {
                         break;
                     }
-                    const headerArray = concatChunks(chunks, HEADER_LENGTH);
-                    const header = new DataView(headerArray.buffer, headerArray.byteOffset, headerArray.length).getUint32(0);
-                    isBinary = header >> 31 === -1;
-                    expectedSize = header & 0x7fffffff;
-                    if (expectedSize === 0 || expectedSize > maxPayload) {
+                    const header = concatChunks(chunks, 1);
+                    isBinary = (header[0] & 0x80) === 0x80;
+                    expectedLength = header[0] & 0x7f;
+                    if (expectedLength < 126) {
+                        state = 3 /* READ_PAYLOAD */;
+                    }
+                    else if (expectedLength === 126) {
+                        state = 1 /* READ_EXTENDED_LENGTH_16 */;
+                    }
+                    else {
+                        state = 2 /* READ_EXTENDED_LENGTH_64 */;
+                    }
+                }
+                else if (state === 1 /* READ_EXTENDED_LENGTH_16 */) {
+                    if (totalLength(chunks) < 2) {
+                        break;
+                    }
+                    const headerArray = concatChunks(chunks, 2);
+                    expectedLength = new DataView(headerArray.buffer, headerArray.byteOffset, headerArray.length).getUint16(0);
+                    state = 3 /* READ_PAYLOAD */;
+                }
+                else if (state === 2 /* READ_EXTENDED_LENGTH_64 */) {
+                    if (totalLength(chunks) < 8) {
+                        break;
+                    }
+                    const headerArray = concatChunks(chunks, 8);
+                    const view = new DataView(headerArray.buffer, headerArray.byteOffset, headerArray.length);
+                    const n = view.getUint32(0);
+                    if (n > Math.pow(2, 53 - 32) - 1) {
+                        // the maximum safe integer in JavaScript is 2^53 - 1
                         controller.enqueue(commons_js_1.ERROR_PACKET);
                         break;
                     }
+                    expectedLength = n * Math.pow(2, 32) + view.getUint32(4);
+                    state = 3 /* READ_PAYLOAD */;
                 }
                 else {
-                    if (totalLength(chunks) < expectedSize) {
+                    if (totalLength(chunks) < expectedLength) {
                         break;
                     }
-                    const data = concatChunks(chunks, expectedSize);
+                    const data = concatChunks(chunks, expectedLength);
                     controller.enqueue((0, decodePacket_js_1.decodePacket)(isBinary ? data : TEXT_DECODER.decode(data), binaryType));
-                    expectedSize = -1;
+                    state = 0 /* READ_HEADER */;
                 }
+                if (expectedLength === 0 || expectedLength > maxPayload) {
+                    controller.enqueue(commons_js_1.ERROR_PACKET);
+                    break;
+                }
             }
@@ -118,0 +164,0 @@ }

build/esm/index.js

@@ -32,3 +32,2 @@ import { encodePacket, encodePacketToBinary } from "./encodePacket.js";
 };
-const HEADER_LENGTH = 4;
 export function createPacketEncoderStream() {
@@ -38,5 +37,21 @@ return new TransformStream({
             encodePacketToBinary(packet, encodedPacket => {
-                const header = new Uint8Array(HEADER_LENGTH);
-                // last 31 bits indicate the length of the payload
-                new DataView(header.buffer).setUint32(0, encodedPacket.length);
+                const payloadLength = encodedPacket.length;
+                let header;
+                // inspired by the WebSocket format: https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API/Writing_WebSocket_servers#decoding_payload_length
+                if (payloadLength < 126) {
+                    header = new Uint8Array(1);
+                    new DataView(header.buffer).setUint8(0, payloadLength);
+                }
+                else if (payloadLength < 65536) {
+                    header = new Uint8Array(3);
+                    const view = new DataView(header.buffer);
+                    view.setUint8(0, 126);
+                    view.setUint16(1, payloadLength);
+                }
+                else {
+                    header = new Uint8Array(9);
+                    const view = new DataView(header.buffer);
+                    view.setUint8(0, 127);
+                    view.setBigUint64(1, BigInt(payloadLength));
+                }
                 // first bit indicates whether the payload is plain text (0) or binary (1)
@@ -79,3 +94,4 @@ if (packet.data && typeof packet.data !== "string") {
     const chunks = [];
-    let expectedSize = -1;
+    let state = 0 /* READ_HEADER */;
+    let expectedLength = -1;
     let isBinary = false;
@@ -86,24 +102,54 @@ return new TransformStream({
             while (true) {
-                const expectHeader = expectedSize === -1;
-                if (expectHeader) {
-                    if (totalLength(chunks) < HEADER_LENGTH) {
+                if (state === 0 /* READ_HEADER */) {
+                    if (totalLength(chunks) < 1) {
                         break;
                     }
-                    const headerArray = concatChunks(chunks, HEADER_LENGTH);
-                    const header = new DataView(headerArray.buffer, headerArray.byteOffset, headerArray.length).getUint32(0);
-                    isBinary = header >> 31 === -1;
-                    expectedSize = header & 0x7fffffff;
-                    if (expectedSize === 0 || expectedSize > maxPayload) {
+                    const header = concatChunks(chunks, 1);
+                    isBinary = (header[0] & 0x80) === 0x80;
+                    expectedLength = header[0] & 0x7f;
+                    if (expectedLength < 126) {
+                        state = 3 /* READ_PAYLOAD */;
+                    }
+                    else if (expectedLength === 126) {
+                        state = 1 /* READ_EXTENDED_LENGTH_16 */;
+                    }
+                    else {
+                        state = 2 /* READ_EXTENDED_LENGTH_64 */;
+                    }
+                }
+                else if (state === 1 /* READ_EXTENDED_LENGTH_16 */) {
+                    if (totalLength(chunks) < 2) {
+                        break;
+                    }
+                    const headerArray = concatChunks(chunks, 2);
+                    expectedLength = new DataView(headerArray.buffer, headerArray.byteOffset, headerArray.length).getUint16(0);
+                    state = 3 /* READ_PAYLOAD */;
+                }
+                else if (state === 2 /* READ_EXTENDED_LENGTH_64 */) {
+                    if (totalLength(chunks) < 8) {
+                        break;
+                    }
+                    const headerArray = concatChunks(chunks, 8);
+                    const view = new DataView(headerArray.buffer, headerArray.byteOffset, headerArray.length);
+                    const n = view.getUint32(0);
+                    if (n > Math.pow(2, 53 - 32) - 1) {
+                        // the maximum safe integer in JavaScript is 2^53 - 1
                         controller.enqueue(ERROR_PACKET);
                         break;
                     }
+                    expectedLength = n * Math.pow(2, 32) + view.getUint32(4);
+                    state = 3 /* READ_PAYLOAD */;
                 }
                 else {
-                    if (totalLength(chunks) < expectedSize) {
+                    if (totalLength(chunks) < expectedLength) {
                         break;
                     }
-                    const data = concatChunks(chunks, expectedSize);
+                    const data = concatChunks(chunks, expectedLength);
                     controller.enqueue(decodePacket(isBinary ? data : TEXT_DECODER.decode(data), binaryType));
-                    expectedSize = -1;
+                    state = 0 /* READ_HEADER */;
                 }
+                if (expectedLength === 0 || expectedLength > maxPayload) {
+                    controller.enqueue(ERROR_PACKET);
+                    break;
+                }
             }
@@ -110,0 +156,0 @@ }

package.json

@@ -5,3 +5,3 @@ {
   "license": "MIT",
-  "version": "5.2.0",
+  "version": "5.2.1",
   "main": "./build/cjs/index.js",
@@ -8,0 +8,0 @@ "module": "./build/esm/index.js",

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Improved metrics

Total package byte prevSize

46274

increased by10.53%

Lines of code

975

increased by10.42%

No dependency changes