Add "finally" continuation overload for functions returning future type that
awaits finishing the continuation in question before continuing the "present"
one. I.e. a wrapper around "then_wrapped" to remove the need to deal with the
original return value.
Signed-off-by: Calle Wilund <calle@cloudius-systems.com>
Basic explanation of the reclaimer algorithm:
- Each slab page has a descriptor containing information about it, such as
refcnt, vector of free objects, link into LRU, etc.
- The LRU list will only contain slab pages which items are unused, so as
to make the reclaiming process faster and easier. Maintaining the LRU of slab
pages has a performance penalty of ~1.3%. Shlomi suggested an approach where
LRU would no longer exist and timestamp would be used instead to keep track of
recency. Reclaimer would then iterate through all slab pages checking for an
unused slab page with the lowest timestamp.
- Reclaimer will get the least-recently-used slab page from the LRU list,
do all the management stuff required, and iterate through the page erasing any
of the items there contained. Once reclaimer was called, it's likely that slab
memory usage is calibrated, thus slab pages shouldn't be allocated anymore.
- Reclaimer is enabled by default but can be disabled by specifying the slab
size using the application parameter --max-slab-size.
Signed-off-by: Raphael S. Carvalho <raphaelsc@cloudius-systems.com>
input_stream's constructor had an unused buf_size parameter. Such a
parameter is not needed - whenever the input_stream needs more
data it calls the underlying data_source's get(), and thus only the
data_source gets to decide the buffer size. Moreover, in some
implementations, this read buffer size will be different each time -
e.g., in a chunk-compressed file, the uncompressed chunk's size will
be different each time.
Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
We use bytes for many different things, and it is easy to get confused as
to what format the data is actually in.
Fix that for atomic_cell by proving wrappers. atomic_cell::one corresponds
to a bytes object holding exactly one atomic cell, and atomic_cell::view is
a bytes_view to an atomic_cell. The static functions of atomic_cell itself
are privatized to prevent the unwashed masses from using them on the wrong
objects.
Since a row entry can hold either a an atomic cell, or a collection,
depending on the schema, also introduce a variant type
atomic_cell_or_collection and allow the user to pick the type explicitly.
Internally both are stored as bytes object.
Implement "double" and "float" cql types.
This implementation doesn't touch serialization.hh (which should be
eventually removed) and rather follows the other examples in types.cc.
It is relatively ugly, because of all the cleverness of our "general"
byte swapping implementation actually works only for integer types, and
we need to get it to work for float/double as well.
Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Left some of the stuff I got tired of converting in #if 0. Most likely
I'll need them later, and convert them then.
Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
The schema_altering_statement class must implement
cql_statement::uses_function() to be instantiable.
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
Add a comment string to a schema, which may be set but is currently
not further used.
The originals Cassandra code has a comment for each of the builtin
schemas, and it's a shame not to remember them.
Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Convert the schemas from LegacySchemaTables.java to C++.
Some FIXMEs still left because of types we don't yet support, or
schema features we don't yet support - this will be fixed later.
Note that I put legacy_schema_tables in the "db" namespace, not in the
"schema" namespace where Origin had it. This was the *only* class in
the "schema" package in Origin, and unfortunately in Urchin we can't use
the name "schema" as a namespace, as we already have it as a class.
Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Do not store the tcp header in unacked queue. When partial ack of a
segment happens, trim off the acked part of a segment. When retransmits,
recalculate the tcp header and retransmit only the unacked part.
Tomek points out that:
Origin calls org.apache.cassandra.utils.Hex#hexToBytes here, which is
not what to_bytes() does. BytesType.getSerializer().toString() calls
ByteBufferUtil.bytesToHex(value), so you should call to_hex() here.
Fix that up.
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
We neglected to set offload_info::needs_csum on reset packets, resuling in
them being ignored by the recipient. Symptoms include connection attempts
to closed ports (seastar = passive end) hanging instead the active end
understanding the port is closed.
Allocate exactly the available fragment size in order to catch buffer
overflows.
We get similar behaviour in dpdk, since without huge pages, it must copy
the packet into a newly allocated buffer.
Two bugs:
1. get_header<type>(offset) was used with size given as the offset
2. opt_end failed to account for the mandatory tcp header, and thus was
20 bytes to large, resulting in overflow.
SFINAE only works for substituted template parameters, not any complication
error (or it would be called CEINAE); therefore hash<T> for enums will fail
to compile, given a non-enum, rather than being ignored.
It's not possible to specialize hash<> for enums, since the primary template
does not have en extra Enable template argument for use with enable_if. We
therefore rename it to enum_hash<> and require users to explicitly define
hash<MyEnum> as inheriting from it.
We currently only signal eof for consume() users. If one is calling
read_exactly, eof will never be signalled.
This might make some sense in continuous streams, but specially when
dealing with files, eof is a natural part of line that can and will
happen all the time. Every "read-until-finish" file-loop will at some
point rely on eof.
Signed-off-by: Glauber Costa <glommer@cloudius-systems.com>
