/*
* tinc app, an Android binding and user interface for the tinc mesh VPN daemon
* Copyright (C) 2018 Pacien TRAN-GIRARD
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see .
*/
package org.pacien.tincapp.commands
import android.os.AsyncTask
import java8.util.concurrent.CompletableFuture
import java8.util.function.Supplier
import java.io.BufferedReader
import java.io.IOException
import java.io.InputStream
import java.io.InputStreamReader
/**
* @author pacien
*/
internal object Executor {
private const val FAILED = -1
private const val SUCCESS = 0
class CommandExecutionException(msg: String) : Exception(msg)
init {
System.loadLibrary("exec")
}
/**
* @return FAILED (-1) on error, forked child PID otherwise
*/
private external fun forkExec(argcv: Array): Int
/**
* @return FAILED (-1) on error, the exit status of the process otherwise
*/
private external fun wait(pid: Int): Int
private fun read(stream: InputStream) = BufferedReader(InputStreamReader(stream)).readLines()
fun forkExec(cmd: Command): CompletableFuture {
val pid = forkExec(cmd.asArray()).also {
if (it == FAILED) throw CommandExecutionException("Could not fork child process.")
}
return runAsyncTask {
when (wait(pid)) {
SUCCESS -> Unit
FAILED -> throw CommandExecutionException("Process terminated abnormally.")
else -> throw CommandExecutionException("Non-zero exit status code.")
}
}
}
fun run(cmd: Command): Process = try {
ProcessBuilder(cmd.asList()).start()
} catch (e: IOException) {
throw CommandExecutionException(e.message ?: "Could not start process.")
}
fun call(cmd: Command): CompletableFuture> = run(cmd).let { process ->
supplyAsyncTask> {
if (process.waitFor() == 0) read(process.inputStream)
else throw CommandExecutionException(read(process.errorStream).lastOrNull() ?: "Non-zero exit status.")
}
}
fun runAsyncTask(r: () -> Unit) = CompletableFuture.supplyAsync(Supplier(r), AsyncTask.THREAD_POOL_EXECUTOR)!!
fun supplyAsyncTask(s: () -> U) = CompletableFuture.supplyAsync(Supplier(s), AsyncTask.THREAD_POOL_EXECUTOR)!!
}