1. Hash the strings in metric dimensions.
2. Optimize the timestamp encoding in bucket.
Use bucket num for full bucket and millis for
partial bucket.
3. Encode the dimension path per metric and avoid
deduping it across dimensons.
Test: statsd test
Change-Id: I18f69654de85edb21a9c835c73edead756295e05
BUG: b/77813755
The key change is to revamp how we parse/store/match a log event, especially how we match repeated
field and attribution nodes, and how we construct dimensions and compare them.
+ We use a integer to encode the field of a log element. And also encode the FieldMatcher into an
integer and a bit mask. The log matching becomes 2 integer operations.
+ Dimension is stored as encoded field and value pair. Checking if 2 dimensions are equal is then
becoming checking if the underlying integers are equal. The integers are stored contiguously
in memory, so it's much faster than previous tree structure.
Start review from FieldValue.h
Test: statsd_test + new unit tests
Bug: 72659059
Change-Id: Iec8daeacdd3f39ab297c10ab9cd7b710a9c42e86
