Simplify & update ANR logging; report ANR data into the dropbox.

Eliminate the per-process 200ms timeout during ANR thread-dumping.
Dump all the threads at once, then wait for the file to stabilize.
Seems to work great and is much, much, much faster.

Don't dump stack traces to traces.txt on app crashes (it isn't very
useful and mostly just clutters up the file).

Tweak the formatting of the dropbox dumpsys a bit, for readability,
and avoid running out of memory when dumping large log files.

Report build & kernel version with kernel log dropbox entries.

1 files changed, 5 insertions, 3 deletions

diff --git a/core/java/android/os/FileUtils.java b/core/java/android/os/FileUtils.java
index 51dfb5b..4780cf3 100644
--- a/core/java/android/os/FileUtils.java
+++ b/core/java/android/os/FileUtils.java
@@ -153,14 +153,16 @@ public class FileUtils
     public static String readTextFile(File file, int max, String ellipsis) throws IOException {
         InputStream input = new FileInputStream(file);
         try {
-            if (max > 0) {  // "head" mode: read the first N bytes
+            long size = file.length();
+            if (max > 0 || (size > 0 && max == 0)) {  // "head" mode: read the first N bytes
+                if (size > 0 && (max == 0 || size < max)) max = (int) size;
                 byte[] data = new byte[max + 1];
                 int length = input.read(data);
                 if (length <= 0) return "";
                 if (length <= max) return new String(data, 0, length);
                 if (ellipsis == null) return new String(data, 0, max);
                 return new String(data, 0, max) + ellipsis;
-            } else if (max < 0) {  // "tail" mode: read it all, keep the last N
+            } else if (max < 0) {  // "tail" mode: keep the last N
                 int len;
                 boolean rolled = false;
                 byte[] last = null, data = null;
@@ -180,7 +182,7 @@ public class FileUtils
                 }
                 if (ellipsis == null || !rolled) return new String(last);
                 return ellipsis + new String(last);
-            } else {  // "cat" mode: read it all
+            } else {  // "cat" mode: size unknown, read it all in streaming fashion
                 ByteArrayOutputStream contents = new ByteArrayOutputStream();
                 int len;
                 byte[] data = new byte[1024];