From 781a4a66b096dcb1b8f9186deb0efec0c4310205 Mon Sep 17 00:00:00 2001 From: dece Date: Mon, 13 Dec 2021 23:35:12 +0100 Subject: [PATCH] MainActivity: proper alerts for each error type Also moved the PageViewModel into its own file? What's the norm? --- .../dev/lowrespalmtree/comet/MainActivity.kt | 167 ++-------------- .../dev/lowrespalmtree/comet/PageViewModel.kt | 183 ++++++++++++++++++ .../java/dev/lowrespalmtree/comet/Response.kt | 10 +- 3 files changed, 203 insertions(+), 157 deletions(-) create mode 100644 app/src/main/java/dev/lowrespalmtree/comet/PageViewModel.kt diff --git a/app/src/main/java/dev/lowrespalmtree/comet/MainActivity.kt b/app/src/main/java/dev/lowrespalmtree/comet/MainActivity.kt index b192f37..ba29cff 100644 --- a/app/src/main/java/dev/lowrespalmtree/comet/MainActivity.kt +++ b/app/src/main/java/dev/lowrespalmtree/comet/MainActivity.kt @@ -11,18 +11,10 @@ import android.view.inputmethod.EditorInfo import android.view.inputmethod.InputMethodManager import androidx.appcompat.app.AlertDialog import androidx.appcompat.app.AppCompatActivity -import androidx.lifecycle.MutableLiveData -import androidx.lifecycle.ViewModel import androidx.lifecycle.ViewModelProvider -import androidx.lifecycle.viewModelScope import androidx.recyclerview.widget.LinearLayoutManager import dev.lowrespalmtree.comet.databinding.ActivityMainBinding -import kotlinx.coroutines.* -import kotlinx.coroutines.channels.onSuccess -import java.net.ConnectException -import java.net.SocketTimeoutException -import java.net.UnknownHostException -import java.nio.charset.Charset +import kotlinx.coroutines.ExperimentalCoroutinesApi @ExperimentalCoroutinesApi class MainActivity : AppCompatActivity(), ContentAdapter.ContentAdapterListen { @@ -129,16 +121,23 @@ class MainActivity : AppCompatActivity(), ContentAdapter.ContentAdapterListen { currentUrl = event.uri visitedUrls.add(event.uri) } - is PageViewModel.RedirectEvent -> openUrl(event.uri, redirections = event.redirects) - is PageViewModel.FailureEvent -> alert(event.message) + is PageViewModel.RedirectEvent -> { + openUrl(event.uri, base = currentUrl, redirections = event.redirects) + } + is PageViewModel.FailureEvent -> { + var message = event.details + if (!event.serverDetails.isNullOrEmpty()) + message += "\n\n" + "Server details: ${event.serverDetails}" + alert(message, title = event.short) + } } event.handled = true } } - private fun alert(message: String) { + private fun alert(message: String, title: String? = null) { AlertDialog.Builder(this) - .setTitle(R.string.error_alert_title) + .setTitle(title ?: getString(R.string.error_alert_title)) .setMessage(message) .create() .show() @@ -152,148 +151,6 @@ class MainActivity : AppCompatActivity(), ContentAdapter.ContentAdapterListen { } } - class PageViewModel : ViewModel() { - private var requestJob: Job? = null - val state: MutableLiveData by lazy { MutableLiveData(State.IDLE) } - private var linesList = ArrayList() - val lines: MutableLiveData> by lazy { MutableLiveData>() } - val event: MutableLiveData by lazy { MutableLiveData() } - - enum class State { - IDLE, CONNECTING, RECEIVING - } - - abstract class Event(var handled: Boolean = false) - data class SuccessEvent(val uri: String) : Event() - data class RedirectEvent(val uri: String, val redirects: Int) : Event() - data class FailureEvent(val message: String) : Event() - - /** - * Perform a request against this URI. - * - * The URI must be valid, absolute and with a gemini scheme. - */ - fun sendGeminiRequest(uri: Uri, redirects: Int = 0) { - Log.d(TAG, "sendRequest: URI \"$uri\"") - state.postValue(State.CONNECTING) - requestJob?.apply { if (isActive) cancel() } - requestJob = viewModelScope.launch(Dispatchers.IO) { - val response = try { - val request = Request(uri) - val socket = request.connect() - val channel = request.proceed(socket, this) - Response.from(channel, viewModelScope) - } catch (e: Exception) { - Log.e(TAG, "sendGeminiRequest coroutine: ${e.stackTraceToString()}") - // If we got cancelled, die silently. - if (!isActive) - return@launch - signalError( - when (e) { - is UnknownHostException -> "Unknown host \"${uri.authority}\"." - is ConnectException -> "Can't connect to this server: ${e.localizedMessage}." - is SocketTimeoutException -> "Connection timed out." - is CancellationException -> "Connection cancelled: ${e.message}." - else -> "Oops, something failed!" - } - ) - return@launch - } - if (!isActive) - return@launch - if (response == null) { - signalError("Can't parse server response.") - return@launch - } - - Log.i(TAG, "sendRequest: got ${response.code} with meta \"${response.meta}\"") - when (response.code.getCategory()) { - Response.Code.Category.SUCCESS -> handleRequestSuccess(response, uri) - Response.Code.Category.REDIRECT -> handleRedirect( - response, - redirects = redirects + 1 - ) - Response.Code.Category.SERVER_ERROR -> handleError(response) - else -> signalError("Can't handle code ${response.code}.") - } - } - } - - private fun signalError(message: String) { - event.postValue(FailureEvent(message)) - state.postValue(State.IDLE) - } - - private suspend fun handleRequestSuccess(response: Response, uri: Uri) { - state.postValue(State.RECEIVING) - - linesList.clear() - lines.postValue(linesList) - val charset = Charset.defaultCharset() - var mainTitle: String? = null - var lastUpdate = System.currentTimeMillis() - var lastNumLines = 0 - Log.d(TAG, "handleRequestSuccess: start parsing line data") - try { - val lineChannel = parseData(response.data, charset, viewModelScope) - while (!lineChannel.isClosedForReceive) { - val lineChannelResult = withTimeout(100) { lineChannel.tryReceive() } - lineChannelResult.onSuccess { line -> - linesList.add(line) - if (mainTitle == null && line is TitleLine && line.level == 1) - mainTitle = line.text - } - - // Throttle the recycler view updates to 100ms and new content only. - if (linesList.size > lastNumLines) { - val time = System.currentTimeMillis() - if (time - lastUpdate >= 100) { - lines.postValue(linesList) - lastUpdate = time - lastNumLines = linesList.size - } - } - } - } catch (e: CancellationException) { - Log.e(TAG, "handleRequestSuccess: coroutine cancelled: ${e.message}") - state.postValue(State.IDLE) - return - } - Log.d(TAG, "handleRequestSuccess: done parsing line data") - lines.postValue(linesList) - - // We record the history entry here: it's nice because we have the main title available - // and we're already in a coroutine for database access. - History.record(uri.toString(), mainTitle) - event.postValue(SuccessEvent(uri.toString())) - state.postValue(State.IDLE) - } - - private fun handleRedirect(response: Response, redirects: Int) { - event.postValue(RedirectEvent(response.meta, redirects)) - } - - private fun handleError(response: Response) { - event.postValue( - FailureEvent( - when (response.code) { - Response.Code.TEMPORARY_FAILURE -> "40: the server encountered a temporary failure." - Response.Code.SERVER_UNAVAILABLE -> "41: the server is currently unavailable." - Response.Code.CGI_ERROR -> "42: a CGI script encountered an error." - Response.Code.PROXY_ERROR -> "43: the server failed to proxy the request." - Response.Code.SLOW_DOWN -> "44: slow down!" - Response.Code.PERMANENT_FAILURE -> "50: this request failed and similar requests will likely fail as well." - Response.Code.NOT_FOUND -> "51: this page can't be found." - Response.Code.GONE -> "52: this page is gone." - Response.Code.PROXY_REQUEST_REFUSED -> "53: the server refused to proxy the request." - Response.Code.BAD_REQUEST -> "59: bad request." - else -> "${response.code}: unknown error code." - } - ) - ) - } - } - companion object { const val TAG = "MainActivity" } diff --git a/app/src/main/java/dev/lowrespalmtree/comet/PageViewModel.kt b/app/src/main/java/dev/lowrespalmtree/comet/PageViewModel.kt new file mode 100644 index 0000000..a5df0f5 --- /dev/null +++ b/app/src/main/java/dev/lowrespalmtree/comet/PageViewModel.kt @@ -0,0 +1,183 @@ +package dev.lowrespalmtree.comet + +import android.net.Uri +import android.util.Log +import androidx.lifecycle.MutableLiveData +import androidx.lifecycle.ViewModel +import androidx.lifecycle.viewModelScope +import kotlinx.coroutines.* +import kotlinx.coroutines.channels.onSuccess +import java.net.ConnectException +import java.net.SocketTimeoutException +import java.net.UnknownHostException +import java.nio.charset.Charset + +@ExperimentalCoroutinesApi +class PageViewModel : ViewModel() { + private var requestJob: Job? = null + val state: MutableLiveData by lazy { MutableLiveData(State.IDLE) } + private var linesList = ArrayList() + val lines: MutableLiveData> by lazy { MutableLiveData>() } + val event: MutableLiveData by lazy { MutableLiveData() } + + enum class State { + IDLE, CONNECTING, RECEIVING + } + + abstract class Event(var handled: Boolean = false) + data class SuccessEvent(val uri: String) : Event() + data class RedirectEvent(val uri: String, val redirects: Int) : Event() + data class FailureEvent( + val short: String, + val details: String, + val serverDetails: String? = null + ) : Event() + + /** + * Perform a request against this URI. + * + * The URI must be valid, absolute and with a gemini scheme. + */ + fun sendGeminiRequest(uri: Uri, redirects: Int = 0) { + Log.d(TAG, "sendRequest: URI \"$uri\"") + state.postValue(State.CONNECTING) + requestJob?.apply { if (isActive) cancel() } + requestJob = viewModelScope.launch(Dispatchers.IO) { + val response = try { + val request = Request(uri) + val socket = request.connect() + val channel = request.proceed(socket, this) + Response.from(channel, viewModelScope) + } catch (e: Exception) { + Log.e(TAG, "sendGeminiRequest coroutine: ${e.stackTraceToString()}") + // If we got cancelled, die silently. + if (!isActive) + return@launch + signalError( + when (e) { + is UnknownHostException -> "Unknown host \"${uri.authority}\"." + is ConnectException -> "Can't connect to this server: ${e.localizedMessage}." + is SocketTimeoutException -> "Connection timed out." + is CancellationException -> "Connection cancelled: ${e.message}." + else -> "Oops, something failed!" + } + ) + return@launch + } + if (!isActive) + return@launch + if (response == null) { + signalError("Can't parse server response.") + return@launch + } + + Log.i(TAG, "sendRequest: got ${response.code} with meta \"${response.meta}\"") + when (response.code.getCategory()) { + Response.Code.Category.SUCCESS -> + handleRequestSuccess(response, uri) + Response.Code.Category.REDIRECT -> + handleRedirect(response, redirects = redirects + 1) + Response.Code.Category.SERVER_ERROR, Response.Code.Category.CLIENT_ERROR -> + handleError(response) + else -> + signalError("Can't handle code ${response.code}.") + } + } + } + + private fun signalError(message: String) { + event.postValue(FailureEvent("Error", message)) + state.postValue(State.IDLE) + } + + private suspend fun handleRequestSuccess(response: Response, uri: Uri) { + state.postValue(State.RECEIVING) + + linesList.clear() + lines.postValue(linesList) + val charset = Charset.defaultCharset() + var mainTitle: String? = null + var lastUpdate = System.currentTimeMillis() + var lastNumLines = 0 + Log.d(TAG, "handleRequestSuccess: start parsing line data") + try { + val lineChannel = parseData(response.data, charset, viewModelScope) + while (!lineChannel.isClosedForReceive) { + val lineChannelResult = withTimeout(100) { lineChannel.tryReceive() } + lineChannelResult.onSuccess { line -> + linesList.add(line) + if (mainTitle == null && line is TitleLine && line.level == 1) + mainTitle = line.text + } + + // Throttle the recycler view updates to 100ms and new content only. + if (linesList.size > lastNumLines) { + val time = System.currentTimeMillis() + if (time - lastUpdate >= 100) { + lines.postValue(linesList) + lastUpdate = time + lastNumLines = linesList.size + } + } + } + } catch (e: CancellationException) { + Log.e(TAG, "handleRequestSuccess: coroutine cancelled: ${e.message}") + state.postValue(State.IDLE) + return + } + Log.d(TAG, "handleRequestSuccess: done parsing line data") + lines.postValue(linesList) + + // We record the history entry here: it's nice because we have the main title available + // and we're already in a coroutine for database access. + History.record(uri.toString(), mainTitle) + event.postValue(SuccessEvent(uri.toString())) + state.postValue(State.IDLE) + } + + private fun handleRedirect(response: Response, redirects: Int) { + event.postValue(RedirectEvent(response.meta, redirects)) + } + + private fun handleError(response: Response) { + val briefMessage = when (response.code) { + Response.Code.TEMPORARY_FAILURE -> "40 Temporary failure" + Response.Code.SERVER_UNAVAILABLE -> "41 Server unavailable" + Response.Code.CGI_ERROR -> "42 CGI error" + Response.Code.PROXY_ERROR -> "43 Proxy error" + Response.Code.SLOW_DOWN -> "44 Slow down" + Response.Code.PERMANENT_FAILURE -> "50 Permanent failure" + Response.Code.NOT_FOUND -> "51 Not found" + Response.Code.GONE -> "52 Gone" + Response.Code.PROXY_REQUEST_REFUSED -> "53 Proxy request refused" + Response.Code.BAD_REQUEST -> "59 Bad request" + else -> "${response.code} (unknown)" + } + val longMessage: String + var serverMessage: String? = null + if (response.code == Response.Code.SLOW_DOWN) { + longMessage = + "You should wait ${response.meta.toIntOrNull() ?: "a few"} seconds before retrying." + } else { + longMessage = when (response.code) { + Response.Code.TEMPORARY_FAILURE -> "The server encountered a temporary failure." + Response.Code.SERVER_UNAVAILABLE -> "The server is currently unavailable." + Response.Code.CGI_ERROR -> "A CGI script encountered an error." + Response.Code.PROXY_ERROR -> "The server failed to proxy the request." + Response.Code.PERMANENT_FAILURE -> "This request failed and similar requests will likely fail as well." + Response.Code.NOT_FOUND -> "This page can't be found." + Response.Code.GONE -> "This page is gone." + Response.Code.PROXY_REQUEST_REFUSED -> "The server refused to proxy the request." + Response.Code.BAD_REQUEST -> "Bad request." + else -> "Unknown error code." + } + if (response.meta.isNotEmpty()) + serverMessage = response.meta + } + event.postValue(FailureEvent(briefMessage, longMessage, serverMessage)) + } + + companion object { + const val TAG = "PageViewModel" + } +} \ No newline at end of file diff --git a/app/src/main/java/dev/lowrespalmtree/comet/Response.kt b/app/src/main/java/dev/lowrespalmtree/comet/Response.kt index 47f5c24..c51e8d3 100644 --- a/app/src/main/java/dev/lowrespalmtree/comet/Response.kt +++ b/app/src/main/java/dev/lowrespalmtree/comet/Response.kt @@ -51,6 +51,8 @@ class Response(val code: Code, val meta: String, val data: Channel) { companion object { private const val TAG = "Response" + private const val MAX_META_LEN = 1024 + private const val MAX_HEADER_LEN = 2 + 1 + MAX_META_LEN + 2 /** Return a response object from the incoming server data, served through the channel. */ suspend fun from(channel: Channel, scope: CoroutineScope): Response? { @@ -62,7 +64,11 @@ class Response(val code: Code, val meta: String, val data: Channel) { val data = try { channel.receive() } catch (e: ClosedReceiveChannelException) { - Log.d(TAG, "companion from: channel closed during initial receive") + Log.i(TAG, "companion from: channel closed during initial receive") + return null + } + if (received + data.size > MAX_HEADER_LEN) { + Log.i(TAG, "companion from: received too much data for a valid header") return null } // Push some data into our buffer. @@ -80,7 +86,7 @@ class Response(val code: Code, val meta: String, val data: Channel) { val bytes = headerBuffer.array() val headerData = bytes.sliceArray(0 until lfIndex) val (code, meta) = parseHeader(headerData) - ?: return null.also { Log.e(TAG, "companion from: can't parse header") } + ?: return null .also { Log.i(TAG, "companion from: can't parse header") } val response = Response(code, meta, Channel()) scope.launch { // If we got too much data from the channel: push the trailing data first.