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#ifndef CPG_H
#define CPG_H
/*
*
* Copyright (c) 2006 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
#include <stdexcept>
#include <cassert>
#ifdef CLUSTER
extern "C" {
#include <openais/cpg.h>
}
#endif
namespace qpid {
namespace cluster {
/**
* Lightweight C++ interface to cpg.h operations.
* Manages a single CPG handle, initialized in ctor, finialzed in destructor.
* On error all functions throw Cpg::Exception
*/
class Cpg {
public:
// FIXME aconway 2007-06-01: qpid::Exception
struct Exception : public std::runtime_error {
Exception(const std::string& msg) : runtime_error(msg) {}
};
struct Name : public cpg_name {
Name(const char* s) { copy(s, strlen(s)); }
Name(const char* s, size_t n) { copy(s,n); }
Name(const std::string& s) { copy(s.data(), s.size()); }
void copy(const char* s, size_t n) {
assert(n < CPG_MAX_NAME_LENGTH);
memcpy(value, s, n);
length=n;
}
std::string str() const { return std::string(value, length); }
};
static inline std::string str(const cpg_name& n) {
return std::string(n.value, n.length);
}
// TODO aconway 2007-06-01: when cpg handle supports a context pointer
// use callback objects (boost::function) instead of free functions.
//
/** Open a CPG handle.
*@param deliver - free function called when a message is delivered.
*@param reconfig - free function called when CPG configuration changes.
*/
Cpg(cpg_deliver_fn_t deliver, cpg_confchg_fn_t reconfig) {
cpg_callbacks_t callbacks = { deliver, reconfig };
check(cpg_initialize(&handle, &callbacks), "Cannot initialize CPG");
}
/** Disconnect */
~Cpg() {
check(cpg_finalize(handle), "Cannot finalize CPG");
}
/** Dispatch CPG events.
*@param type one of
* - CPG_DISPATCH_ONE - dispatch exactly one event.
* - CPG_DISPATCH_ALL - dispatch all available events, don't wait.
* - CPG_DISPATCH_BLOCKING - blocking dispatch loop.
*/
void dispatch(cpg_dispatch_t type) {
check(cpg_dispatch(handle,type), "Error in CPG dispatch");
}
void join(const Name& group) {
check(cpg_join(handle, const_cast<Name*>(&group)),cantJoinMsg(group));
};
void leave(const Name& group) {
check(cpg_leave(handle,const_cast<Name*>(&group)),cantLeaveMsg(group));
}
void mcast(const Name& group, const iovec* iov, int iovLen) {
check(cpg_mcast_joined(
handle, CPG_TYPE_AGREED, const_cast<iovec*>(iov), iovLen),
cantMcastMsg(group));
}
private:
static std::string errorStr(cpg_error_t err, const std::string& msg);
static std::string cantJoinMsg(const Name&);
static std::string cantLeaveMsg(const Name&);
static std::string cantMcastMsg(const Name&);
static void check(cpg_error_t result, const std::string& msg) {
// TODO aconway 2007-06-01: Logging and exceptions.
if (result != CPG_OK)
throw Exception(errorStr(result, msg));
}
cpg_handle_t handle;
};
}} // namespace qpid::cluster
#endif /*!CPG_H*/
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