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Diffstat (limited to 'cpp/src/qpid/broker/MessageDistributor.h')
-rw-r--r-- | cpp/src/qpid/broker/MessageDistributor.h | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/cpp/src/qpid/broker/MessageDistributor.h b/cpp/src/qpid/broker/MessageDistributor.h new file mode 100644 index 0000000000..090393c160 --- /dev/null +++ b/cpp/src/qpid/broker/MessageDistributor.h @@ -0,0 +1,76 @@ +#ifndef _broker_MessageDistributor_h +#define _broker_MessageDistributor_h + +/* + * + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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. + * + */ + +/** Abstraction used by Queue to determine the next "most desirable" message to provide to + * a particular consuming client + */ + + +#include "qpid/broker/Consumer.h" + +namespace qpid { +namespace broker { + +struct QueuedMessage; + +class MessageDistributor +{ + public: + virtual ~MessageDistributor() {}; + + /** Locking Note: all methods assume the caller is holding the Queue::messageLock + * during the method call. + */ + + /** Determine the next message available for consumption by the consumer + * @param consumer the consumer that needs a message to consume + * @param next set to the next message that the consumer may consume. + * @return true if message is available and next is set + */ + virtual bool nextConsumableMessage( Consumer::shared_ptr& consumer, + QueuedMessage& next ) = 0; + + /** Allow the comsumer to take ownership of the given message. + * @param consumer the name of the consumer that is attempting to acquire the message + * @param qm the message to be acquired, previously returned from nextConsumableMessage() + * @return true if ownership is permitted, false if ownership cannot be assigned. + */ + virtual bool allocate( const std::string& consumer, + const QueuedMessage& target) = 0; + + /** Determine the next message available for browsing by the consumer + * @param consumer the consumer that is browsing the queue + * @param next set to the next message that the consumer may browse. + * @return true if a message is available and next is returned + */ + virtual bool nextBrowsableMessage( Consumer::shared_ptr& consumer, + QueuedMessage& next ) = 0; + + /** hook to add any interesting management state to the status map */ + virtual void query(qpid::types::Variant::Map&) const = 0; +}; + +}} + +#endif |