This fixes#1214
The basic idea is that ProtocolVersion is now its own type. This
alone is an improvement as it makes many things more typesafe. For
each version, we can now add breaking features (for example Fearless).
After that, there's no need to test against actual (confusing) version
numbers. Instead a developer can simply test
`protocolVersion->hasFearless()` and this will return true iff the
protocolVersion is newer than the newest version that didn't support
fearless.
In Tlogs, disable pop is done whlie taking snapshots. Earlier, tlogs
were ignoring the pops if it got pop requests when pops were
disabled. In this change, instead of ignoring the pop - it remembers
the list of pops in-memory and plays them once the popping is
enabled.
- exec operation to go to all the TLogs
- minor bug fix in tlog
- restore implementation for the simulator
- restore snap UID to be stored in restartInfo.ini
- test cases added
- indentation and trace file fixes
If a peek is entirely fulfilled from spilled data, then it's likely that
the next peek will be also. It is thus wasteful for each of these peeks
to call peekMessagesFromMemory, which memcpy's excessively, and then
throw all that data away without using it.
Now, TLogs will give a hint back to peek cursors about if the provided
reply was served entirely from the spilled data, which peek curors then
feed back as the hint into their next request.
At some point, a cursor will send a request for only spilled data, get
an incomplete response, and then be told to send its next request as one
that peeks from memory as well, and then it will fully catch up.
This changes the logic of pop operations from log routers (LG):
- LG pops tagLocalityLogRouterMapped from TLogs;
- TLog converts tagLocalityLogRouterMapped back to tagLocalityLogRouter before
popping.
Later when we add more psuedo localities, the same pattern can be used.
* log_version in the database (`/conf/log_version`) is now a hint that gets
rounded to the nearest supported version.
* fdbcli and FDB enforce that only a valid log_version can be configured to
* TLogVersion is persisted in CoreTLogSet (and LogSet and TLogSet)
* Some comments here and there
* Add an assert on filename length to make sure KV-pairs in filename
don't exceed a maximum length.
Evan Tschannen