Rx Java Retry Api Extension

RxJavaExtension.kt

package com.vk.android.extension

import com.vk.android.utils.Const
import io.reactivex.Observable
import io.reactivex.functions.BiFunction
import retrofit2.HttpException
import java.io.IOException
import java.io.InterruptedIOException
import java.net.SocketTimeoutException
import java.util.concurrent.TimeUnit

fun Observable<Throwable>.retryWhenError(): Observable<Any> {
    return this.flatMap { error ->
        if (error is IOException) {
            return@flatMap Observable.timer(3, TimeUnit.SECONDS)
        } else if (error is HttpException) {
            if (error.code() == Const.HttpErrorCode.HTTP_BAD_GATEWAY) {
                return@flatMap Observable.timer(5, TimeUnit.SECONDS)
            }
        }
        return@flatMap Observable.error<Any>(error)
    }
}

fun Observable<Throwable>.retryWithCountAndDelay(maxRetryCount: Int, delay: Long, unit: TimeUnit): Observable<Long> {
    return this.zipWith(Observable.range(1, maxRetryCount), BiFunction { _: Throwable?, retryCount: Int -> retryCount })
        .flatMap { retryCount -> Observable.timer(Math.pow(delay.toDouble(), retryCount.toDouble()).toLong(), unit) }
}