Plexamp Lite 1.14.1: read-ahead no longer cut off ("Unexpected end of stream")

Two causes, both fixed:
- Plex keeps one file stream per device and cuts the one in progress when another starts, so the read-ahead
  and the player cut each other off. Whole-file fetches (read-ahead, downloads, download-first) now ask for
  the file as a download (?download=1), which Plex leaves out of that rule; the plain address follows for
  servers that refuse downloads.
- Http.abort closed the socket of a response already read to the end, whose connection was back in the pool
  and could be carrying the read-ahead. abort now leaves finished responses alone (test/PoolAbortTest.java).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

AndroidManifest.xml

@@ -1,10 +1,10 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!-- build.sh makes one APK per Android level from this file: it sets minSdkVersion and targetSdkVersion for each,
-     and versionCode = the one below x 100 + the level (15 -> 1508 for Android 2.2, 1516 for 4.1). -->
+     and versionCode = the one below x 100 + the level (16 -> 1608 for Android 2.2, 1616 for 4.1). -->
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.minamp"
-    android:versionCode="15"
-    android:versionName="1.14"
+    android:versionCode="16"
+    android:versionName="1.14.1"
     android:installLocation="internalOnly">
 
     <uses-sdk android:minSdkVersion="8" android:targetSdkVersion="10" />

README.md

@@ -63,7 +63,10 @@ clock has been reset to before 2024 the certificate date check is skipped rather
   Bluetooth share one radio, and a lighter stream keeps the speaker from stuttering.
 * Seeking in a transcoded track restarts the transcode at the new position.
 * **Read-ahead:** while a track plays, the next two in the queue are fetched whole in the background
-  (one at a time) and then played from the file; without an SD card only the next one is kept. Android 2.x's player keeps only a few seconds of stream buffer, so on weak
+  (one at a time) and then played from the file; without an SD card only the next one is kept. Plex keeps one
+  file stream per device and cuts the one in progress when another starts, so whole-file fetches (read-ahead,
+  downloads, *Download tracks before playing*) ask for the file as a download (`?download=1`), which Plex leaves
+  out of that rule; otherwise the read-ahead and the player cut each other off. Android 2.x's player keeps only a few seconds of stream buffer, so on weak
   Wi-Fi shared with a Bluetooth speaker it used to go silent for seconds at a time.
 * If a stream fails, Plexamp Lite re-picks the connection and resumes; if it fails again it downloads
   the whole track first and plays from the SD card. "Download tracks before playing" forces that
@@ -156,6 +159,8 @@ Tests (desktop JVM, no device):
 * `test/QueueTest.java`: shuffle/unshuffle, repeat modes, play next, remove, move, clear.
 * `test/LyricsTest.java`: LRC (several stamps a line, offsets, word stamps) and plain-text lyrics
   (`javac -d /tmp/lt src/com/minamp/util/Lrc.java test/LyricsTest.java && java -cp /tmp/lt LyricsTest`).
+* `test/PoolAbortTest.java` (`test/run_pool_abort.sh`): aborting a response that's already finished leaves
+  its pooled connection, now carrying another request, alone.
 * `test/PreferHomeTest.java` + `test/identity_server.py`: after being away, the home address wins
   again as soon as it answers.
 * `test/NetTest.java`: the bundled TLS + HTTP client against real servers; `test/HandshakeProfile.java`

spec.md

@@ -48,6 +48,8 @@ over a Bluetooth speaker.
 - This repo's `tools/setup_toolchain.sh`, `make_roots.py` and `signapk.py` prepare the toolchain all the
   Galaxy Mini apps use: changes there affect every app.
 - Installs to internal storage (SD-card installs get killed during USB sharing).
+- Whole-file fetches of a part (read-ahead, downloads) use `Library.downloadUrls` (`?download=1` first): Plex
+  cuts a device's file stream when the same device starts another, except for downloads.
 - `platform/api8` and `platform/api16` keep the same `Platform` methods; shared code calls no API the API 8 jar
   lacks (the api8 compile and Dalvik check catch it). Each build's `versionCode` is the manifest's × 100 + level,
   same key; both APKs are listed in `../tenda-lite/repo/apps.json`.

src/com/minamp/Downloads.java

@@ -341,7 +341,7 @@ public final class Downloads {
         if (!direct) part.delete(); // a transcode can't be resumed
         String session = direct ? null : "minamp-dl-" + Long.toString(System.currentTimeMillis(), 36);
         List<String> urls;
-        if (direct) { urls = new ArrayList<String>(); urls.add(lib.directUrl(t)); }
+        if (direct) urls = lib.downloadUrls(t);
         else urls = lib.transcodeUrls(t, quality > 0 ? quality : 320, 0, session);
         int[] order = direct ? null : Library.variantOrder();
 

src/com/minamp/PlayerService.java

@@ -341,7 +341,8 @@ public class PlayerService extends Service implements Engine.Listener, AudioMana
                     final long startAt = (direct || download) ? 0 : (posMs / 1000) * 1000;
                     final java.util.List<String> urls;
                     final int[] order = direct ? null : Library.variantOrder();
-                    if (direct) { urls = new java.util.ArrayList<String>(); urls.add(lib.directUrl(it)); }
+                    if (direct && download) urls = lib.downloadUrls(it);
+                    else if (direct) { urls = new java.util.ArrayList<String>(); urls.add(lib.directUrl(it)); }
                     else urls = lib.transcodeUrls(it, max, startAt, sess);
                     final String ext = direct ? extFor(it) : "mp3";
                     File file = null;
@@ -422,7 +423,7 @@ public class PlayerService extends Service implements Engine.Listener, AudioMana
                     int max = app.currentMaxKbps();
                     boolean direct = Library.canDirectPlay(next, max);
                     java.util.List<String> urls;
-                    if (direct) { urls = new java.util.ArrayList<String>(); urls.add(lib.directUrl(next)); ext = extFor(next); }
+                    if (direct) { urls = lib.downloadUrls(next); ext = extFor(next); }
                     else urls = lib.transcodeUrls(next, max, 0, "minamp-ahead-" + Long.toString(System.currentTimeMillis(), 36));
                     k = direct ? 0 : (max <= 0 ? 320 : max);
                     for (String u : urls) {

src/com/minamp/net/Http.java

@@ -442,19 +442,25 @@ public final class Http {
     // ------------------------------------------------------------------ body streams
 
     private static final class FixedStream extends InputStream {
-        private final Conn c; private long left; private final boolean keepAlive; private boolean closed;
+        private final Conn c; private long left; private final boolean keepAlive; private volatile boolean closed;
 
         FixedStream(Conn c, long len, boolean keepAlive) {
             this.c = c; this.left = len; this.keepAlive = keepAlive;
             if (len == 0) finish(true);
         }
 
-        private void finish(boolean complete) {
+        private synchronized void finish(boolean complete) {
             if (closed) return;
             closed = true;
             if (complete && keepAlive) release(c); else c.close();
         }
 
+        synchronized void abort() {
+            if (closed) return;   // done: the connection may already be back in the pool, serving someone else
+            closed = true;
+            try { c.socket.close(); } catch (Exception ignored) {}
+        }
+
         @Override public int read() throws IOException {
             byte[] one = new byte[1];
             int n = read(one, 0, 1);
@@ -481,16 +487,22 @@ public final class Http {
 
     private static final class ChunkedStream extends InputStream {
         private final Conn c; private final boolean keepAlive;
-        private long chunkLeft = 0; private boolean eof; private boolean closed;
+        private long chunkLeft = 0; private boolean eof; private volatile boolean closed;
 
         ChunkedStream(Conn c, boolean keepAlive) { this.c = c; this.keepAlive = keepAlive; }
 
-        private void finish(boolean complete) {
+        private synchronized void finish(boolean complete) {
             if (closed) return;
             closed = true;
             if (complete && keepAlive) release(c); else c.close();
         }
 
+        synchronized void abort() {
+            if (closed) return;   // done: the connection may already be back in the pool, serving someone else
+            closed = true;
+            try { c.socket.close(); } catch (Exception ignored) {}
+        }
+
         private boolean nextChunk() throws IOException {
             if (eof) return false;
             String line = readLine(c.in);
@@ -542,7 +554,7 @@ public final class Http {
     }
 
     private static final class EofStream extends InputStream {
-        private final Conn c; private boolean closed;
+        private final Conn c; private volatile boolean closed;
         EofStream(Conn c) { this.c = c; }
 
         @Override public int read() throws IOException {
@@ -559,21 +571,25 @@ public final class Http {
             return n;
         }
 
-        @Override public void close() {
+        @Override public synchronized void close() {
             if (!closed) { closed = true; c.close(); }
         }
-    }
 
-    /** Close one in-flight response's socket from another thread (used to abort streams). */
-    public static void abort(Response r) {
-        if (r == null) return;
-        InputStream b = r.body;
-        Conn c = null;
-        if (b instanceof FixedStream) c = ((FixedStream) b).c;
-        else if (b instanceof ChunkedStream) c = ((ChunkedStream) b).c;
-        else if (b instanceof EofStream) c = ((EofStream) b).c;
-        if (c != null) {
+        synchronized void abort() {
+            if (closed) return;
+            closed = true;
             try { c.socket.close(); } catch (Exception ignored) {}
         }
     }
+
+    /** Close one in-flight response's socket from another thread (used to abort streams). A response that has
+     *  already been read to the end is left alone: its connection went back to the pool and may be carrying
+     *  another request by now (closing it cut read-ahead downloads short: "Unexpected end of stream"). */
+    public static void abort(Response r) {
+        if (r == null) return;
+        InputStream b = r.body;
+        if (b instanceof FixedStream) ((FixedStream) b).abort();
+        else if (b instanceof ChunkedStream) ((ChunkedStream) b).abort();
+        else if (b instanceof EofStream) ((EofStream) b).abort();
+    }
 }

src/com/minamp/plex/Library.java

@@ -202,6 +202,19 @@ public final class Library {
         return server.url(t.partKey);
     }
 
+    /**
+     * For fetching a whole file while something may be playing (read-ahead, downloads). Plex keeps one file stream
+     * per device: a new request for a file cuts the one in progress, so the read-ahead and the player cut each
+     * other off ("Unexpected end of stream"). A request marked as a download is outside that rule. The plain
+     * address follows, for a server that refuses downloads (a shared library can).
+     */
+    public List<String> downloadUrls(Item t) throws IOException {
+        List<String> l = new ArrayList<String>();
+        l.add(server.url(t.partKey + (t.partKey.indexOf('?') >= 0 ? "&" : "?") + "download=1"));
+        l.add(directUrl(t));
+        return l;
+    }
+
     /**
      * Plex only transcodes for a client identity it has a profile for: an unknown platform or
      * device gets a bare 400 ("unable to find a matching profile"). These are request shapes

test/PoolAbortTest.java

@@ -0,0 +1,81 @@
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.net.InetSocketAddress;
+
+import com.minamp.net.Http;
+import com.sun.net.httpserver.HttpExchange;
+import com.sun.net.httpserver.HttpHandler;
+import com.sun.net.httpserver.HttpServer;
+
+/**
+ * Http.abort on a response that was already read to the end must not close its connection: by then it's back in
+ * the pool and may be carrying the next request. (The stream proxy aborts every response it served once done;
+ * that used to cut the read-ahead of the next track short with "Unexpected end of stream".)
+ * Run: test/run_pool_abort.sh
+ */
+public class PoolAbortTest {
+    static int fails;
+
+    static void check(boolean ok, String what) {
+        System.out.println((ok ? "PASS " : "FAIL ") + what);
+        if (!ok) fails++;
+    }
+
+    public static void main(String[] a) throws Exception {
+        HttpServer srv = HttpServer.create(new InetSocketAddress("127.0.0.1", 0), 0);
+        srv.createContext("/", new HttpHandler() {
+            public void handle(HttpExchange x) throws java.io.IOException {
+                int size = x.getRequestURI().getPath().startsWith("/big") ? 2 * 1024 * 1024 : 1000;
+                x.sendResponseHeaders(200, size);
+                OutputStream o = x.getResponseBody();
+                byte[] chunk = new byte[16384];
+                for (int sent = 0; sent < size; sent += chunk.length) {
+                    o.write(chunk, 0, Math.min(chunk.length, size - sent));
+                    o.flush();
+                    if (size > 1000) try { Thread.sleep(2); } catch (InterruptedException ignored) {}
+                }
+                o.close();
+            }
+        });
+        srv.start();
+        String base = "http://127.0.0.1:" + srv.getAddress().getPort();
+
+        // 1. the player's response, read to the end: its connection goes back to the pool
+        Http.Response first = Http.get(base + "/small", null, 5000);
+        check(first.readAll().length == 1000, "first response read whole");
+        // 2. the read-ahead's request takes that pooled connection
+        Http.Response second = Http.get(base + "/big", null, 5000);
+        InputStream in = second.body;
+        byte[] buf = new byte[16384];
+        long got = 0;
+        int n = in.read(buf);
+        got += n;
+        // 3. the proxy cleans up the first response
+        Http.abort(first);
+        String err = "";
+        try {
+            while ((n = in.read(buf)) > 0) got += n;
+        } catch (java.io.IOException e) {
+            err = " (" + e.getMessage() + ")";
+        }
+        check(got == 2 * 1024 * 1024, "aborting a finished response leaves the next request alone: " + got + " bytes" + err);
+
+        // an unfinished response is still cut off
+        Http.Response third = Http.get(base + "/big", null, 5000);
+        third.body.read(buf);
+        Http.abort(third);
+        boolean cut = false;
+        try {
+            long left = 2 * 1024 * 1024;
+            while ((n = third.body.read(buf)) > 0) left -= n;
+            cut = left > 0;
+        } catch (java.io.IOException e) {
+            cut = true;
+        }
+        check(cut, "aborting a response still being read cuts it off");
+
+        srv.stop(0);
+        System.out.println(fails == 0 ? "all passed" : fails + " failed");
+        System.exit(fails == 0 ? 0 : 1);
+    }
+}

test/run_pool_abort.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+# Runs test/PoolAbortTest.java on this computer (JDK 11+; Bouncy Castle from the toolchain, Android's Log stubbed).
+set -euo pipefail
+cd "$(dirname "$0")/.."
+T=${TOOLS:-$HOME/android-toolchain}
+J=${JAVA_HOME:-/opt/homebrew/opt/openjdk@17}/bin
+out=$(mktemp -d)
+trap 'rm -rf "$out"' EXIT
+"$J/javac" -nowarn -d "$out" -sourcepath "src:$T/bcsrc:test/stub" test/PoolAbortTest.java 2>&1 | grep -v '^Note:' || true
+"$J/java" -cp "$out" PoolAbortTest

test/stub/android/util/Log.java

@@ -0,0 +1,9 @@
+package android.util;
+
+/** Desktop stand-in for Android's Log, so the network code runs in tests on the computer. */
+public final class Log {
+    private Log() {}
+    public static int i(String tag, String msg) { return 0; }
+    public static int w(String tag, String msg) { return 0; }
+    public static int e(String tag, String msg) { return 0; }
+}