The type walking is similar to what the find function does, but
refactoring it doesn't seem worth it if these are the only two uses.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
The type hierarchy is closed, so we can give each leaf an enum value.
This will be used to implement a visitor pattern and reduce code
duplication.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
The new collector parameter is a pointer to a
`compaction_garbage_collector` implementation. This collector is passed
all atoms that are expired and would be discarded. The body of
`compact_and_expire()` was changed so that it checks cells' tombstone
coverage before it checks their expiry, so that cells that are both
covered by a tombstone and also expired are not passed to the collector.
The collector param is optional and defaults to nullptr. To accommodate
the collector, which needs to know the column id, a new `column_id`
parameter was added as well.
This is quick fix to the immediate problem of large collections causing
large allocations, triggering stalls or OOM. The proper fix is to
use IMR for storing the cells, but that is a complex change that will
require time, so let's not stall/OOM in the meanwhile.
Currently to_string takes raw bytes. This means that to print a
data_value it has to first be serialized to be passed to to_string,
which will then deserializes it.
This patch adds a virtual to_string_impl that takes a data_value and
implements a now non virtual to_sting on top of it.
I don't expect this to have a performance impact. It mostly documents
how to access a data_value without converting it to bytes.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Message-Id: <20190620183449.64779-3-espindola@scylladb.com>
The to_json_string utility implementation was based on const references
instead of views, which can be a source of unnecessary memory copying.
This patch migrates all to_json_string to use bytes_view and leaves
the const reference version as a thin wrapper.
Message-Id: <2bf9f1951b862f8e8a2211cb4e83852e7ac70c67.1559654014.git.sarna@scylladb.com>
Both cql3_type and abstract_type are normally used inside
shared_ptr. This creates a problem when an abstract_type needs to refer
to a cql3_type as that creates a cycle.
To avoid warnings from asan, we were using a std::unordered_map to
store one of the edges of the cycle. This avoids the warning, but
wastes even more memory.
Even before this patch cql3_type was a fairly light weight
structure. This patch pushes in that direction and now cql3_type is a
struct with a single member variable, a data_type.
This avoids the reference cycle and is easier to understand IMHO.
Tests: unit (dev)
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
