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Transport

export interface AdbTransport {
  readonly serial: string;

  readonly maxPayloadSize: number;

  readonly banner: AdbBanner;

  readonly disconnected: Promise<void>;

  connect(service: string): AdbSocket | Promise<AdbSocket>;

  addReverseTunnel(
    handler: AdbIncomingSocketHandler,
    address?: string,
  ): string | Promise<string>;

  removeReverseTunnel(address: string): void | Promise<void>;

  clearReverseTunnels(): void | Promise<void>;

  close(): void | Promise<void>;
}

As mentioned before, the main function of AdbTransport is the connect method, which creates an ADB socket for a service (request).

Other fields:

  • serial: The serial number of the device. It's not used by Tango, but it helps you to identify the device.
  • maxPayloadSize: The maximum payload size of the device. AdbSync#write will split data into multiple packets if it's larger than this value. If you don't know this value, 4KB (4096) is compatible with all versions of ADB Daemons, but the performance will be affected.
  • banner: ADB banner returned from the device. It contains the list of ADB features the device supports, which is important for many command to choose the correct behavior.
  • disconnected: A promise that resolves when the transport is disconnected.
  • close: Close the transport. It should close all sockets created by connect method, and resolve disconnected promise.

Reverse tunnel​

addReverseTunnel, removeReverseTunnel, clearReverseTunnels methods manage reverse tunnels.

When AdbReverseCommand#add is called, Tango not only sends a command to ADB Daemon to create the socket listener on device, but also calls addReverseTunnel method with add's arguments.

The transport should register the reverse tunnel, so when ADB Daemon creates a socket to the address, the corresponding handler method can be retrieved and invoked. How does the transport receives the incoming socket is also up to the implementation.

If you never use reverse tunnel with your transport, you can throw an error in these methods.

Example​

This is a mock transport that uses the MockSocket from the previous example to respond to the getprop shell command:

import { AdbBanner, AdbIncomingSocketHandler, AdbSocket, AdbTransport } from "@yume-chan/adb";
import { PromiseResolver } from "@yume-chan/async";
import { Consumable, ReadableStream, WritableStream } from "@yume-chan/stream-extra";
import { ValueOrPromise, encodeUtf8 } from "@yume-chan/struct";

class MockTransport implements AdbTransport {
  get serial(): string {
    return "12345678";
  }

  get maxPayloadSize(): number {
    return 4 * 1024;
  }

  get banner(): AdbBanner {
    return new AdbBanner("mock", "mock", "mock", []);
  }

  #disconnected = new PromiseResolver<void>();
  get disconnected(): Promise<void> {
    return this.#disconnected.promise;
  }

  connect(service: string): AdbSocket {
    if (service.startsWith("shell:getprop")) {
      const key = service.split(" ")[1];
      switch (key) {
        case "ro.product.model":
          return new MockSocket(service, encodeUtf8("Pixel 3a"));
      }
    }

    throw new Error(`Unknown service: ${service}`);
  }

  addReverseTunnel(
    handler: AdbIncomingSocketHandler,
    address?: string | undefined,
  ): ValueOrPromise<string> {
    throw new Error("Method not implemented.");
  }

  removeReverseTunnel(address: string): ValueOrPromise<void> {
    throw new Error("Method not implemented.");
  }

  clearReverseTunnels(): ValueOrPromise<void> {
    throw new Error("Method not implemented.");
  }

  close(): ValueOrPromise<void> {
    this.#disconnected.resolve();
  }
}