bmqa_messageeventbuilder.h

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// Copyright 2014-2023 Bloomberg Finance L.P.
// SPDX-License-Identifier: Apache-2.0
//
// 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.
 
// bmqa_messageeventbuilder.h                                         -*-C++-*-
#ifndef INCLUDED_BMQA_MESSAGEEVENTBUILDER
#define INCLUDED_BMQA_MESSAGEEVENTBUILDER
 
// Clang-format warns about an overlong line in this comment, which gives a
// Markdown anchor to a header.  Unfortunately, by Markdown syntax rules, this
// has to on the same line as the header, meaning we cannot introduce a
// line-break here.
 
// clang-format off
 
 
// clang-format on
 
// BMQ
 
#include <bmqa_message.h>
#include <bmqa_messageevent.h>
#include <bmqt_resultcode.h>
 
// BDE
#include <bsl_memory.h>
 
namespace BloombergLP {
 
// FORWARD DECLARATION
namespace bmqa {
class QueueId;
}
namespace bmqp {
class MessageGUIDGenerator;
}
 
namespace bmqa {
 
// ==============================
// struct MessageEventBuilderImpl
// ==============================
 
struct MessageEventBuilderImpl {
    // PUBLIC DATA
 
    MessageEvent d_msgEvent;
 
    Message d_msg;
 
    // GUID generator object.
    bsl::shared_ptr<bmqp::MessageGUIDGenerator> d_guidGenerator_sp;
 
    // The final number of messages in the current 'd_msgEvent' cached on
    // switching this MessageEvent from WRITE to READ mode.
    // This cached value exists because we are not able to access the
    // underlying PutEventBuilder once downgraded to READ.
    // CONTRACT: the stored value is correct every moment when in READ mode,
    // and the value is not guaranteed to be correct when in WRITE mode.
    int d_messageCountFinal;
 
    // The final message event size of the current 'd_msgEvent' cached on
    // switching this MessageEvent from WRITE to READ mode.
    // This cached value exists because we are not able to access the
    // underlying PutEventBuilder once downgraded to READ.
    // CONTRACT: the stored value is correct every moment when in READ mode,
    // and the value is not guaranteed to be correct when in WRITE mode.
    int d_messageEventSizeFinal;
};
 
// =========================
// class MessageEventBuilder
// =========================
 
class MessageEventBuilder {
  private:
    // DATA
    MessageEventBuilderImpl d_impl;  // Impl
 
  public:
    // CREATORS
 
    MessageEventBuilder();
 
    // MANIPULATORS
 
    Message& startMessage();
 
    bmqt::EventBuilderResult::Enum packMessage(const bmqa::QueueId& queueId);
 
    void reset();
 
    const MessageEvent& messageEvent();
 
    Message& currentMessage();
 
    // ACCESSORS
 
    int messageCount() const;
 
    int messageEventSize() const;
};
 
}  // close package namespace
}  // close enterprise namespace
 
#endif