An app's devlog poll forwards at most 500 lines at a time

A ring holds thousands, and two things routinely hand this the whole of
it at once: the first poll after the tab opens, and every restart of the
app being read, since an in-memory ring starts again at zero. Unbounded
that is one request, one append and one redraw of the whole log per
second -- measured on the emulator as an ANR in this app while the app it
was reading crash-looped. The cursor advances by what was sent, so a
backlog drains over a few polls and nothing is lost.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

app/androidApp/src/main/kotlin/com/example/devupdater/DevLog.kt

@@ -193,7 +193,7 @@ fun forwardDevLog(
     val status = devLogStatus(resolver, authority) ?: return DevLogForward(null, 0)
     val stored = devLogCursor(context, key, component)
     val since = if (status.newestSeq >= 0 && status.newestSeq + 1 < stored) 0 else stored
-    val lines = devLogLines(resolver, authority, since)
+    val lines = devLogLines(resolver, authority, since).take(MAX_LINES_PER_POLL)
     if (lines.isEmpty()) {
         // Still worth writing back, so a reset is not re-decided every
         // second while an app that restarted says nothing.
@@ -215,6 +215,18 @@ fun forwardDevLog(
     return DevLogForward(status, lines.size)
 }
 
+/**
+ * How much one poll will forward, leaving the rest for the next one.
+ *
+ * An app's ring can hold thousands of lines, and two things routinely hand this the whole of it at
+ * once: the first poll after the tab opens, and every restart of the app being read, since an
+ * in-memory ring starts again at zero. Unbounded, that is one request, one append and one redraw of
+ * the whole log per second — measured on the emulator as an ANR in this app while the app it was
+ * reading crash-looped. The cursor advances by what was actually sent, so nothing is lost; a
+ * backlog simply drains over a few polls.
+ */
+private const val MAX_LINES_PER_POLL = 500
+
 /** What one poll found: the ring as a whole, and how many lines it forwarded. */
 data class DevLogForward(val status: DevLogStatus?, val sent: Int)