tree 942f74b4d39c69404de7bb089c38a0cf5ff861f1
parent bb612a356a7fce97c29558d41f8fce1944313d30
author Mark Salyzyn <salyzyn@google.com> 1481653889 -0800
committer Mark Salyzyn <salyzyn@google.com> 1481848311 -0800

logd: record multiple duplicate messages as chatty

If a series of messages arrive from a single source with identical
message content payload, then suppress them and generate a chatty
report.  The checking is done on a per log id basis.

This alters the assumption that chatty messages are always at the
oldest entries, they now show up in the middle too.  To address this
change in behavior we print the first line, a chatty reference
which internally takes little space, then the last line in the series.

This does not conserve processing time in logd, and certainly has no
impact on the long path of formatting and submitting log messages from
from the source, but it may contribute to memory space and signal to
noise savings under heavy spammy loads.

Test: gTest liblog-unit-tests, logd-unit-tests & logcat-unit-tests
Bug: 33535908
Change-Id: I3160c36d4f4e2f8216f528605a1b3993173f4dec