Files
scylladb/frozen_mutation.cc
Tomasz Grabiec 4ab66de0ae db: Introduce frozen_mutation
The immediate motivation for introducing frozen_mutation is inability
to deserialize current "mutation" object, which needs schema reference
at the time it's constructed. It needs schema to initialize its
internal maps with proper key comparators, which depend on schema.

frozen_mutation is an immutable, compact form of a mutation. It
doesn't use complex in-memory strucutres, data is stored in a linear
buffer. In case of frozen_mutation schema needs to be supplied only at
the time mutation partition is visited. Therefore it can be trivially
deserialized without schema.
2015-05-08 09:19:01 +02:00

76 lines
1.9 KiB
C++

/*
* Copyright (C) 2015 Cloudius Systems, Ltd.
*/
#include "db/serializer.hh"
#include "frozen_mutation.hh"
#include "partition_builder.hh"
#include "mutation_partition_serializer.hh"
#include "utils/UUID.hh"
#include "utils/data_input.hh"
//
// Representation layout:
//
// <mutation> ::= <column-family-id> <partition-key> <partition>
//
using namespace db;
utils::UUID
frozen_mutation::column_family_id() const {
data_input in(_bytes);
return uuid_serializer::read(in);
}
partition_key_view
frozen_mutation::key(const schema& s) const {
data_input in(_bytes);
uuid_serializer::skip(in);
return partition_key_view_serializer::read(in);
}
static size_t
serialized_size(const mutation& m) {
return uuid_serializer(m.schema()->id()).size()
+ partition_key_view_serializer(m.key()).size()
+ mutation_partition_serializer::size(*m.schema(), m.partition());
}
frozen_mutation::frozen_mutation(bytes&& b)
: _bytes(std::move(b))
{ }
frozen_mutation
frozen_mutation::from_bytes(bytes b) {
return { std::move(b) };
}
frozen_mutation::frozen_mutation(const mutation& m)
: _bytes(bytes::initialized_later(), serialized_size(m))
{
data_output out(_bytes);
uuid_serializer::write(out, m.schema()->id());
partition_key_view_serializer::write(out, m.key());
mutation_partition_serializer::write(out, *m.schema(), m.partition());
}
mutation
frozen_mutation::unfreeze(schema_ptr schema) const {
mutation m(key(*schema), schema);
partition_builder b(*schema, m.partition());
partition().accept(*schema, b);
return m;
}
frozen_mutation freeze(const mutation& m) {
return { m };
}
mutation_partition_view frozen_mutation::partition() const {
data_input in(_bytes);
uuid_serializer::skip(in);
partition_key_view_serializer::skip(in);
return mutation_partition_view::from_bytes(in.read_view(in.avail()));
}