logd: filters remove leading expire messages and rate

(cherry pick from commit 047cc0729fd837a03b99db901941c1421ef15f96)

- Cleanup resulting from experience and feedback
- When filtering inside logd, drop any leading expire messages, they
  are cluttering up leading edge of tombstones (which filter by pid)
- Increase and introduce EXPIRE_RATELIMIT from 1 to 10 seconds
- Increase EXPIRE_THRESHOLD from 4 to 10 count
- Improve the expire messages from:
   logd : uid=1000(system) too chatty comm=com.google.android.phone,
                                                   expire 2800 lines
  change tag to be more descriptive, and reduce accusatory tone to:
   chatty : uid=1000(system) com.google.android.phone expire 2800
                                                               lines
- if the UID name forms a prefix for comm name, then drop UID name

Change-Id: Ied7cc04c0ab3ae02167649a0b97378e44ef7b588

1 files changed, 2 insertions, 1 deletions

diff --git a/logd/LogBuffer.cpp b/logd/LogBuffer.cpp
index 80fc9f5..4373e2a 100644
--- a/logd/LogBuffer.cpp
+++ b/logd/LogBuffer.cpp
@@ -281,7 +281,8 @@ public:
     }
 
     void clear(LogBufferElement *e) {
-        uint64_t current = e->getRealTime().nsec() - NS_PER_SEC;
+        uint64_t current = e->getRealTime().nsec()
+                         - (EXPIRE_RATELIMIT * NS_PER_SEC);
         for(LogBufferElementMap::iterator it = map.begin(); it != map.end();) {
             LogBufferElement *l = it->second;
             if ((l->getDropped() >= EXPIRE_THRESHOLD)