app: harden mirroring lifecycle and state

1 files changed, 27 insertions, 2 deletions

diff --git a/app/src/main/java/invalid/lena/scrcpy/Crashlog.java b/app/src/main/java/invalid/lena/scrcpy/Crashlog.java
index 00bd3d8..705d191 100644
--- a/app/src/main/java/invalid/lena/scrcpy/Crashlog.java
+++ b/app/src/main/java/invalid/lena/scrcpy/Crashlog.java
@@ -4,8 +4,11 @@ import android.content.Context;
 
 import java.io.File;
 import java.io.FileWriter;
+import java.io.IOException;
 import java.io.PrintWriter;
+import java.nio.file.Files;
 import java.text.SimpleDateFormat;
+import java.util.Arrays;
 import java.util.Date;
 import java.util.Locale;
 
@@ -16,6 +19,8 @@ import java.util.Locale;
 // fishing for it in adb logcat.
 public final class Crashlog {
 
+    private static final int MAX_LOGS = 5;
+
     private Crashlog() {}
 
     public static void install(Context ctx) {
@@ -24,19 +29,25 @@ public final class Crashlog {
             Log.w("crashlog: no external storage, skipping install");
             return;
         }
+        try {
+            prune(dir, MAX_LOGS);
+        } catch (IOException e) {
+            Log.w("crashlog: prune failed: %s", e);
+        }
         Thread.UncaughtExceptionHandler prev =
                 Thread.getDefaultUncaughtExceptionHandler();
         Thread.setDefaultUncaughtExceptionHandler((t, e) -> {
             try {
-                String ts = new SimpleDateFormat("yyyyMMdd-HHmmss",
+                String ts = new SimpleDateFormat("yyyyMMdd-HHmmss-SSS",
                         Locale.ROOT).format(new Date());
-                File out = new File(dir, "crash-" + ts + ".log");
+                File out = File.createTempFile("crash-" + ts + "-", ".log", dir);
                 try (PrintWriter pw = new PrintWriter(new FileWriter(out))) {
                     pw.println("# " + new Date());
                     pw.println("# thread=" + t.getName());
                     pw.println();
                     e.printStackTrace(pw);
                 }
+                prune(dir, MAX_LOGS);
                 Log.e(e, "crashlog: wrote %s", out.getAbsolutePath());
             } catch (Throwable ignored) {
                 // best effort - do not mask the original crash
@@ -45,4 +56,18 @@ public final class Crashlog {
         });
         Log.i("crashlog: installed -> %s", dir.getAbsolutePath());
     }
+
+    static void prune(File dir, int keep) throws IOException {
+        if (keep < 0) throw new IllegalArgumentException("negative retention");
+        File[] logs = dir.listFiles((parent, name) ->
+                name.startsWith("crash-") && name.endsWith(".log"));
+        if (logs == null) throw new IOException("cannot list crashlog directory: " + dir);
+        Arrays.sort(logs, (left, right) -> {
+            int modified = Long.compare(right.lastModified(), left.lastModified());
+            return modified != 0 ? modified : right.getName().compareTo(left.getName());
+        });
+        for (int i = keep; i < logs.length; i++) {
+            Files.deleteIfExists(logs[i].toPath());
+        }
+    }
 }