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wsrep-lib/include/wsrep/buffer.hpp
Daniele Sciascia 965642eded Support for detaching prepared XA transactions
Add support for detaching XA transactions. This is useful for handling
the case where the DBMS client has a transaction in prepared state and
disconnects. Before disconnect, the DBMS calls the newly introduced
client_state::xa_detach(), to cleanup the local transaction and
convert it to a high priority transaction. The DBMS may later attempt
to terminate the transaction through client_state::commit_by_xid() or
client_state::rollback_by_xid().

Also in this patch:

- Fix client_state::close() so that it does not rollback transactions
  in prepared state
- Changed class wsrep::xid representation to hold enough information
  so that DBMS can convert to its native representation
- Fix potential infinite loop in
  server_state::find_streaming_applier(wsrep:xid&)
- Append SR keys on prepare fragment and make it pa_unsafe
- Handle one phase commit (simply fall back to two phase)
- Do not rollback prepared streaming clients in
  server_state::close_orphaned_transactions()
2020-10-26 14:20:21 +01:00

129 lines
3.4 KiB
C++

/*
* Copyright (C) 2018-2019 Codership Oy <info@codership.com>
*
* This file is part of wsrep-lib.
*
* Wsrep-lib is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* Wsrep-lib is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with wsrep-lib. If not, see <https://www.gnu.org/licenses/>.
*/
#ifndef WSREP_BUFFER_HPP
#define WSREP_BUFFER_HPP
#include <cstddef>
#include <vector>
namespace wsrep
{
class const_buffer
{
public:
const_buffer()
: ptr_()
, size_()
{ }
const_buffer(const void* ptr, size_t size)
: ptr_(ptr)
, size_(size)
{ }
const_buffer(const const_buffer& b)
: ptr_(b.ptr())
, size_(b.size())
{ }
const void* ptr() const { return ptr_; }
const char* data() const { return static_cast<const char*>(ptr_); }
size_t size() const { return size_; }
const_buffer& operator=(const const_buffer& b)
{
ptr_ = b.ptr();
size_ = b.size();
return *this;
}
private:
const void* ptr_;
size_t size_;
};
class mutable_buffer
{
public:
mutable_buffer()
: buffer_()
{ }
mutable_buffer(const mutable_buffer& b)
: buffer_(b.buffer_)
{ }
void resize(size_t s) { buffer_.resize(s); }
void clear()
{
// using swap to ensure deallocation
std::vector<char>().swap(buffer_);
}
void push_back(const char* begin, const char* end)
{
buffer_.insert(buffer_.end(), begin, end);
}
template <class C> void push_back(const C& c)
{
std::copy(c.begin(), c.end(), std::back_inserter(buffer_));
}
size_t size() const { return buffer_.size(); }
/**
* Return pointer to underlying data array. The returned pointer
* may or may not be null in case of empty buffer, it is up to
* user to check the size of the array before dereferencing the
* pointer.
*
* @return Pointer to underlying data array.
*/
char* data() { return buffer_.data(); }
/**
* Return const pointer to underlying data array. The returned pointer
* may or may not be null in case of empty buffer, it is up to
* user to check the size of the array before dereferencing the
* pointer.
*
* @return Const pointer to underlying data array.
*/
const char* data() const { return buffer_.data(); }
mutable_buffer& operator= (const mutable_buffer& other)
{
buffer_ = other.buffer_;
return *this;
}
bool operator==(const mutable_buffer& other) const
{
return buffer_ == other.buffer_;
}
private:
std::vector<char> buffer_;
};
}
#endif // WSREP_BUFFER_HPP