NapCatQQ source snapshot

packages/napcat-core/packet/highway/frame.ts

@@ -0,0 +1,23 @@
+import assert from 'node:assert';
+
+export class Frame {
+  static pack (head: Buffer, body: Buffer): Buffer {
+    const totalLength = 9 + head.length + body.length + 1;
+    const buffer = Buffer.allocUnsafe(totalLength);
+    buffer[0] = 0x28;
+    buffer.writeUInt32BE(head.length, 1);
+    buffer.writeUInt32BE(body.length, 5);
+    head.copy(buffer, 9);
+    body.copy(buffer, 9 + head.length);
+    buffer[totalLength - 1] = 0x29;
+    return buffer;
+  }
+
+  static unpack (frame: Buffer): [Buffer, Buffer] {
+    assert(frame[0] === 0x28 && frame[frame.length - 1] === 0x29, 'Invalid frame!');
+    const headLen = frame.readUInt32BE(1);
+    const bodyLen = frame.readUInt32BE(5);
+    // assert(frame.length === 9 + headLen + bodyLen + 1, `Frame ${frame.toString('hex')} length does not match head and body lengths!`);
+    return [frame.subarray(9, 9 + headLen), frame.subarray(9 + headLen, 9 + headLen + bodyLen)];
+  }
+}