ServiceMessage.cpp

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/* Copyright (c) 2005-2009 Rexx Language Association. All rights reserved.    */
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#include "ServiceMessage.hpp"
#include "ServiceException.hpp"
#include "SysAPIManager.hpp"
 
 
ServiceMessage::ServiceMessage()
{
    messageTarget = APIManager;
    operation = CONNECTION_ACTIVE;
    session = 0;
    parameter1 = 0;
    parameter2 = 0;
    parameter3 = 0;
    parameter4 = 0;
    parameter5 = 0;
    result = MESSAGE_OK;
    errorCode = NO_ERROR_CODE;
    messageData = NULL;
    messageDataLength = 0;
    retainMessageData = false;
    nameArg[0] = '\0';
    userid[0] = '\0';
}
 
/**
 * Read a message from the server-side stream.
 *
 * @param server The server stream that has already received a connection message.
 */
void ServiceMessage::readMessage(SysServerConnection *connection)
{
    size_t actual = 0;
    size_t required = sizeof(ServiceMessage);
    size_t offset = 0;
    while (required > 0)
    {
        if (!connection->read(((char *)this) + offset, required, &actual) || actual == 0)
        {
            throw new ServiceException(SERVER_FAILURE, "ServiceMessage::readMessage() Failure reading service message");
        }
        required -= actual;
        offset += actual;
    }
 
    // does this message have extra data associated with it?
    if (messageDataLength != 0)
    {
        // allocate a data buffer for the extra information and read it in.
        messageData = allocateResultMemory(messageDataLength);
        if (messageData == NULL)
        {
            // this will close this connection and raise an error back in the caller
            throw new ServiceException(SERVER_FAILURE, "ServiceMessage::readMessage() Failure allocating message buffer");
        }
        required = messageDataLength;
        offset = 0;
        while (required > 0)
        {
            if (!connection->read(((char *)messageData) + offset, required, &actual) || actual == 0)
            {
                releaseResultMemory(messageData);
                // make sure these are cleared out
                messageData = NULL;
                messageDataLength = 0;
                throw new ServiceException(SERVER_FAILURE, "ServiceMessage::readMessage() Failure reading service message");
            }
            // add in the count
            required -= actual;
            offset += actual;
        }
        // this is a releasable value
        retainMessageData = false;
    }
}
 
 
/**
 * Write a server side message result back to the client.
 *
 * @param server The server message stream used to receive the original message.
 */
void ServiceMessage::writeResult(SysServerConnection *connection)
{
    size_t expected = sizeof(ServiceMessage) + messageDataLength;
    size_t actual = 0;
    if (!connection->write((void *)this, sizeof(ServiceMessage), messageData, messageDataLength, &actual) || actual != expected)
    {
        freeMessageData();
        throw new ServiceException(SERVER_FAILURE, "ServiceMessage::writeResult() Failure writing service message result");
    }
    // we might be sending a copy of data that's still resident in the connection->  If
    // we are, then don't delete the message data after doing the send.
    // free the message data after the send.
    freeMessageData();
}
 
 
/**
 * Write a message over to the connection->
 *
 * @param pipe   The pipe we've opened to write the message.
 */
void ServiceMessage::writeMessage(SysClientStream &pipe)
{
    size_t actual = 0;
    size_t expected = sizeof(ServiceMessage) + messageDataLength;
    if (!pipe.write((void *)this, sizeof(ServiceMessage), messageData, messageDataLength, &actual) || actual != expected)
    {
        freeMessageData();
        throw new ServiceException(SERVER_FAILURE, "ServiceMessage::writeResult() Failure writing service message result");
    }
    // make sure we free and release any attached data before proceeding
    freeMessageData();
}
 
 
/**
 * Read a message result back from a server message.
 *
 * @param pipe   The connection used to send the original message.
 */
void ServiceMessage::readResult(SysClientStream &pipe)
{
    size_t actual = 0;
    size_t required = sizeof(ServiceMessage);
    size_t offset = 0;
    while (required > 0)
    {
        if (!pipe.read(((char *)this) + offset, required, &actual) || actual == 0)
        {
            throw new ServiceException(SERVER_FAILURE, "ServiceMessage::readResult() Failure reading service message");
        }
        required -= actual;
        offset += actual;
    }
    // the server sets this value to what is required required on its end.  We allocated this memory
    // when we read it in on this end, so mark it for freeing initially.  If it should not
    // be freed, the sender of the message needs to take ownership.
    retainMessageData = false;
 
    // handle any errors that the server side might have raised.
    raiseServerError();
 
    // does this message have extra data associated with it?
    if (messageDataLength != 0)
    {
        // allocate a data buffer for the extra information and read it in.
        // we add a courtesy null terminator on this message, so we read one extra bit
        messageData = allocateResultMemory(messageDataLength + 1);
        if (messageData == NULL)
        {
            // this will close this connection and raise an error back in the caller
            throw new ServiceException(SERVER_FAILURE, "ServiceMessage::readResult() Failure allocating message buffer");
        }
        ((char *)messageData)[messageDataLength] = '\0';
        required = messageDataLength;
        offset = 0;
        while (required > 0)
        {
            if (!pipe.read(((char *)messageData) + offset, required, &actual) || actual == 0)
            {
                releaseResultMemory(messageData);
                throw new ServiceException(SERVER_FAILURE, "ServiceMessage::readResult() Failure reading service message");
            }
            // remove the amount read
            required -= actual;
            offset += actual;
        }
    }
    else
    {
        // make sure this is nulled out
        messageData = NULL;
    }
}
 
 
/**
 * Allocate a buffer for result information returned by a service
 * message.  This is allocated using the Rexx API allocation
 * routine so that the memory can be handed out and deallocated
 * by an API caller.
 *
 * @param length The length to allocate.
 *
 * @return A data pointer with the result memory.
 */
void *ServiceMessage::allocateResultMemory(size_t length)
{
    void *data = SysAPIManager::allocateMemory(length);
    if (data == NULL)
    {
        throw new ServiceException(MEMORY_ERROR, "ServiceMessage::allocateResultMemory() Failure allocating result memory");
    }
    return data;
}
 
/**
 * Free result memory in the case of a read failure.
 *
 * @param data   The data to be released.
 */
void ServiceMessage::releaseResultMemory(void *data)
{
    SysAPIManager::releaseMemory(data);
}