Not used yet, this patch does all the churn of propagating a permit
to each impl.
In the next patch we will use it to track to track the memory
consumption of `_buffer`.
Now that the most prevalent users (range scan and single partition
reads) all pass valid permits we require all users to do so and
propagate the permit down towards `make_sstable_reader()`. The plan is
to use this permit for restricting the sstable readers, instead of the
semaphore the table is configured with. The various
`make_streaming_*reader()` overloads keep using the internal semaphores
as but they also create the permit before the read starts and pass it to
`make_sstable_reader()`.
The header sits in many other headers, but there's a handy
schema_fwd.hh that's tiny and contains needed declarations
for other headers. So replace shema.hh with schema_fwd.hh
in most of the headers (and remove completely from some).
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Message-Id: <20200303102050.18462-1-xemul@scylladb.com>
The former was never really more than a reader_permit with one
additional method. Currently using it doesn't even save one from any
includes. Now that readers will be using reader_permit we would have to
pass down both to mutation_source. Instead get rid of
reader_resource_tracker and just use reader_permit. Instead of making it
a last and optional parameter that is easy to ignore, make it a
first class parameter, right after schema, to signify that permits are
now a prominent part of the reader API.
This -- mostly mechanical -- patch essentially refactors mutation_source
to ask for the reader_permit instead of reader_resource_tracking and
updates all usage sites.
Many headers don't really need to include database.hh, the include can
be replaced by forward declarations and/or including the actually needed
headers directly. Some headers don't need this include at all.
Each header was verified to be compilable on its own after the change,
by including it into an empty `.cc` file and compiling it. `.cc` files
that used to get `database.hh` through headers that no longer include it
were changed to include it themselves.
The IndexInfo table tracks the secondary indexes that have already
been populated. Since our secondary index implementation is backed by
materialized views, we can virtualize that table so queries are
actually answered by built_views.
Fixes#3483
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
