root/examples/mqueue-cpp/mqueue.cpp

DEFINITIONS

1. MQueue_eq
2. popMessage
3. pushMessage
4. registerSelf
5. unregisterSelf
6. findByName

   1 //
   2 // mqueue.c
   3 //
   4 //   The mqueue-cpp extension module to show how to embed external C++
   5 //   library in Gauche.
   6 //   This file is a source of a supposed external C++ library, knowing
   7 //   nothing about Gauche.  In typical case, such external library is
   8 //   provided by the third party.
   9 //
  11 #include "mqueue.h"
  12 #include <functional>
  14 class MQueue_eq : public unary_function<MQueue*, bool> {
string name;
  16   public:
  17     explicit MQueue_eq(const string& name_) : name(name_) {}
  18     bool operator() (const MQueue* q) const { return q->getName() == name; }
  19 };
set<MQueue*> MQueue::knownQueues;
string MQueue::popMessage() throw (MQueueException)
  24 {
  25     if (q.empty()) {
  26         throw MQueueException("attempt to pop from an empty queue");
  27     }
Message m = q.top();
q.pop();
  30     return m.getBody();
  31 }
size_t MQueue::pushMessage(string body, int urgency)
  34 {
Message *m = new Message(body, urgency);
q.push(*m);
  37     return q.size();
  38 }
  40 void MQueue::registerSelf()
  41 {
knownQueues.insert(this);
  43 }
  45 void MQueue::unregisterSelf()
  46 {
knownQueues.erase(this);
  48 }
MQueue *MQueue::findByName(string name)
  51 {
set<MQueue*>::iterator z = find_if(knownQueues.begin(),
knownQueues.end(),
MQueue_eq(name));
  55     if (z == knownQueues.end()) return NULL;
  56     return *z;
  57 }