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//=============================================================================
/**
* @file Notifier_i.cpp
*
* $Id$
*
* Implementation of the Notifier_i class. This class is the servant
* object for the callback quoter server.
*
*
* @author Kirthika Parameswaran <kirthika@cs.wustl.edu>
*/
//=============================================================================
#include "Notifier_i.h"
Notifier_i::Notifier_i (void)
: notifier_exited_(0)
{
// No-op
}
Notifier_i::~Notifier_i (void)
{
// No-op
}
// Register a distributed callback handler that is invoked when the
// given stock reaches the desired threshold value.
void
Notifier_i::register_callback (const char *stock_name,
CORBA::Long threshold_value,
Callback_Quoter::Consumer_ptr consumer_handler)
{
// Store the client information.
Consumer_Data consumer_data;
// Necessary to make another copy of the consumer_handler using
// <_duplicate> so that we dont lose the consumer object reference
// after the method invocation is done.
consumer_data.consumer_ =
Callback_Quoter::Consumer::_duplicate (consumer_handler);
consumer_data.desired_value_= threshold_value;
CONSUMERS *consumers = 0;
// The consumer_map consists of the stockname and various consumers
// with their threshold values. To register a consumer into this
// map, first the stockname is matched with an existing one (if any)
// and the consumer and the threshold value is attached. Else, a new
// entry is created for the stockname.
if (this->consumer_map_.find (stock_name, consumers) == 0)
{
if ( consumers->insert (consumer_data) == -1)
throw Callback_Quoter::Invalid_Stock (
"Insertion failed! Invalid Stock!\n");
else
ACE_DEBUG ((LM_DEBUG,
"Inserted map entry: stockname %s threshold %d",
stock_name,
threshold_value));
}
else
{
// the unbounded set entry is created.
ACE_NEW_THROW_EX (consumers, CONSUMERS, CORBA::NO_MEMORY ());
// When a new entry is tried to be inserted into the unbounded set and it
// fails an exception is raised.
if (consumers->insert (consumer_data) == -1)
throw Callback_Quoter::Invalid_Stock (
"Insertion failed! Invalid Stock!\n");
// The bond between the stockname <hash_key> and the consumers <hash_value>
// is fused.
if (this->consumer_map_.bind (stock_name, consumers) == -1)
ACE_ERROR ((LM_ERROR,
"register_callback: Bind failed!/n"));
else
ACE_DEBUG ((LM_DEBUG,
"new map entry: stockname %s threshold %d\n",
stock_name,
threshold_value));
}
}
// Obtain a pointer to the orb.
void
Notifier_i::orb (CORBA::ORB_ptr orb)
{
this->orb_ = CORBA::ORB::_duplicate (orb);
}
// Remove the client handler.
void
Notifier_i::unregister_callback (Callback_Quoter::Consumer_ptr consumer)
{
// The consumer_map consists of a map of stocknames with consumers
// and their threshold values attached to it. To unregister a
// consumer it is necessary to remove that entry from the
// map. Hence, the map is iterated till the consumer entry to be
// removed is found and then removed from the map.
// Check to see whether the hash_map still exists. Chances are there
// that the notifier has exited closing the hash map.
if (notifier_exited_ == 1)
return;
for (CONSUMER_MAP::ITERATOR iter = this->consumer_map_.begin ();
iter != this->consumer_map_.end ();
++iter)
{
// The *iter is nothing but the stockname + unbounded set of
// consumers+threshold values, i.e a ACE_Hash_Map_Entry.
Consumer_Data consumer_to_remove;
consumer_to_remove.consumer_ =
Callback_Quoter::Consumer::_duplicate (consumer);
// int_id is a member of the ACE_Hash_Map_Entry. The remove
// method will do a find internally using operator == which
// will check only the consumer pointers. If match found it
// will be removed from the set. If the consumer cannot be
// removed an exception is raised.
if ((*iter).int_id_->remove (consumer_to_remove) == -1)
throw Callback_Quoter::Invalid_Handle (
"Unregistration failed! Invalid Consumer Handle!\n");
else
ACE_DEBUG ((LM_DEBUG,
"unregister_callback:consumer removed\n"));
}
}
// Gets the market status and sends the information to the consumer
// who is interested in it.
void
Notifier_i::market_status (const char *stock_name,
CORBA::Long stock_value)
{
ACE_DEBUG ((LM_DEBUG,
"Notifier_i:: The stockname is %s with price %d\n",
stock_name,
stock_value));
CONSUMERS *consumers = 0;
if (this->consumer_map_.find (stock_name, consumers) == 0)
{
// Go through the list of <Consumer_Data> to find which
// registered client wants to be notified.
for (CONSUMERS::ITERATOR iter = consumers->begin ();
iter != consumers->end ();
++iter)
{
// Check whether the stockname is equal before proceeding
// further.
if (stock_value >= (*iter).desired_value_)
{
Callback_Quoter::Info interested_consumer_data;
interested_consumer_data.stock_name =
CORBA::string_dup (stock_name);
interested_consumer_data.value =
stock_value;
ACE_DEBUG ((LM_DEBUG,
"pushing information to consumer\n"));
// The status desired by the consumer is then passed to
// it.
(*iter).consumer_->push (interested_consumer_data);
}
}
}
else
ACE_DEBUG ((LM_DEBUG,
" Stock Not Present!\n"));
// Raising an exception caused problems as they were caught by the Market daemon
// who exited prematurely.
}
void
Notifier_i::shutdown (void)
{
if ( this->consumer_map_.close () > 0)
ACE_ERROR ((LM_ERROR,
"Consumer_map_close error!\n"));
else
// This marks the exit of the notifier. This should be taken care of
// before the consumer tries to unregister after the notifier quits.
notifier_exited_ = 1;
ACE_DEBUG ((LM_DEBUG,
"The Callback Quoter server is shutting down...\n"));
// Instruct the ORB to shutdown.
this->orb_->shutdown ();
}
bool
Notifier_i::Consumer_Data::operator== (const Consumer_Data &rhs) const
{
// The <_is_equivalent> function checks if the _var and _ptr objects
// are the same. NOTE: this call might not behave well on other
// ORBs since <_is_equivalent> isn't guaranteed to differentiate
// object references.
return this->consumer_->_is_equivalent (rhs.consumer_.in ());
}
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