Commit Graph

10 Commits

Author SHA1 Message Date
Tom Cherry 1a796bca57 logd: add a SerializedLogBuffer suitable for compression
Initial commit for a SerializedLogBuffer.  The intention here is for
the serialized data to be compressed (currently using zlib) to allow
for substantially longer logs in the same memory footprint.

Test: unit tests
Change-Id: I2528e4e1ff1cf3bc91130173a107f371f04d911a
2020-06-12 14:35:30 -07:00
Tom Cherry b3e163399a logd: move leading_dropped logic into FlushTo()
This logic isn't generic, so it should not be in the generic
LogReaderThread.

Moreover, it's currently broken in essentially every case except when
filtering by UID, because it runs as in the filter functions before
the actual filtering by pid/etc takes place.  For example, when
filtering by pid, it's possible to get leading chatty messages.  The
newly added test was failing previously but is fixed by this change.

It's fundamentally broken in the tail case.  Take this example:
1: Normal message
2: Chatty message
3: Normal message
4: Normal message

If you read that log buffer with a tail value of 3, there are three
possible outcomes:
1) Messages #2-4, however this would include a leading chatty message,
   which is not allowed.
2) Messages #3-4, however this is only 2, not 3 messages.
3) Messages #1-4, however this is 4, more than the 3 requested
   messages.

This code chooses 2) as the correct solution, in this case, we don't
need to account for leading chatty messages when counting the total
logs in the buffer.  A test is added for this case as well.

Test: new unit test
Change-Id: Id02eb81a8e77390aba4f85aac659c6cab498dbcd
2020-06-02 13:26:48 -07:00
Tom Cherry 855c7c87a3 logd: create FlushToState class
ChattyLogBuffer::FlushTo() needs an array of pid_t's to differentiate
between deduplication and spam removal chatty messages, but that won't
be useful to other log buffers, so it doesn't deserve its own entry in
the abstruct LogBuffer::FlushTo() function.

Other log buffers may need their own data stored for each reader, so
we create an interface that the reader itself owns and passes to the
log buffer.  It uses a unique_ptr, such that the when the reader is
destroyed, so will this state.

FlushToState will additionally contain the start point, that it will
increment itself and the log mask, which LogBuffers can use to
efficiently keep track of the next elements that will be read during a
call to FlushTo().

Side benefit: this allows ChattyLogBufferTests to correctly report
'identical' instead of 'expired' lines the deduplication tests.

Side benefit #2: This updates LogReaderThread::start() more
aggressively, which should result in readers being disconnected less
often, particularly readers who read only a certain UID.

Test: logging unit tests
Change-Id: I969565eb2996afb1431f20e7ccaaa906fcb8f6d1
2020-06-01 14:45:02 -07:00
Tom Cherry 70fadea36f logd: remove LogBufferElement dependency of LogReaderThread
In the future, not all log buffers will be implemented in terms of
LogBufferElement.

Test: build
Change-Id: I5cf0d01414857b1bfa08c92a4f8035b43ef2aad7
2020-05-27 15:13:52 -07:00
Tom Cherry 3e61a1368a logd: rename FlushToResult to FilterResult
This was a typo; the enum corresponds to the result of the 'Filter'
function, not the 'FlushTo' function.

Test: build
Change-Id: Ib46f0646570b6dbaac17ae9fc95c990128cdbe72
2020-05-27 15:09:34 -07:00
Tom Cherry 283c9a1c00 logd: remove SocketClient from LogBuffer and LogBufferElement
In the future, we'll want to be able to write to outputs that are not
necessarily a libsysutils SocketClient, for example host tests of
LogBuffer.  Therefore, we add a LogWriter class to be used instead of
SocketClient.

Test: logging unit tests
Change-Id: I4385be65e14e83a635691a7ba79e9bf060e49484
2020-05-14 19:53:45 -07:00
Tom Cherry d5b3838dbc logd: make LogBuffer an interface
We may use different implementations of LogBuffer in the future, so we
make it interface and create a concrete ChattyLogBuffer class that
implements it.

Test: logging unit tests
Change-Id: I5731d6404640664c9acc26b7c677dff3110c6a11
2020-05-12 15:39:19 -07:00
Tom Cherry 68630a0dbe logd: refactor LastLogTimes a bit
There's still plenty of work that can be done here, particularly
re-doing the locking so each LogReaderThread does not mutually exclude
the others, but that's out of the scope here.

This change primarily removes the public 'mTimes' from LogBuffer and
creates a new LogReaderList class instead.  It would have merged this
into LogReader, but that creates a circular dependency.

This change also removes the need to reference LogReader or
LogReaderList from LogAudit, LogKLog, and LogListener, instead relying
on LogBuffer()::log() to call LogReaderList::NotifyNewLog().

Test: logging unit tests
Change-Id: Ia874b57a9ec1254af1295bfa6f7af2f92a75755b
2020-05-12 15:39:11 -07:00
Tom Cherry cef47bb38c logd: start cleaning up LogReaderThread
1) We can use real member functions with std::thread and
   std::function, so use those instead of the 'me' pointer.
2) Don't expose member variables directly.
3) Rename and document member variables, since all of their references
   are being touched anyway.

Test: logging unit tests
Change-Id: I9a357a3ea8691433d58687c95356b984b83e9c36
2020-05-04 17:44:52 -07:00
Tom Cherry 6ec71e9253 logd: rename LogTimes -> LogReaderThread
LogTimes has evolved from being simply a store of the last timestamp
that each reader has read to being a class representing an individual
reader thread, including the thread function, so name it
appropriately.

Test: logging unit tests
Change-Id: I6914824376a6ff1f7509e657fa4dc044ead62954
2020-05-04 17:37:08 -07:00