path: root/src/gtm/client/fe-protocol.c

/*-------------------------------------------------------------------------
 *
 * fe-protocol3.c
 *	  functions that are specific to frontend/backend protocol version 3
 *
 * Portions Copyright (c) 2012-2014, TransLattice, Inc.
 * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 * Portions Copyright (c) 2010-2012 Postgres-XC Development Group
 *
 *
 * IDENTIFICATION
 *	  $PostgreSQL$
 *
 *-------------------------------------------------------------------------
 */
#include "gtm/gtm_c.h"

#include <ctype.h>
#include <fcntl.h>

#include "gtm/libpq-fe.h"
#include "gtm/libpq-int.h"
#include "gtm/gtm_seq.h"
#include "gtm/gtm_client.h"
#include "gtm/gtm_serialize.h"
#include "gtm/register.h"

#include <unistd.h>
#include <netinet/in.h>


/*
 * This macro lists the backend message types that could be "long" (more
 * than a couple of kilobytes).
 */
#define VALID_LONG_MESSAGE_TYPE(id) \
	((id) == 'S' || (id) == 'E')

static void handleSyncLoss(GTM_Conn *conn, char id, int msgLength);
static GTM_Result *pqParseInput(GTM_Conn *conn);
static int gtmpqParseSuccess(GTM_Conn *conn, GTM_Result *result);
static int gtmpqReadSeqKey(GTM_SequenceKey seqkey, GTM_Conn *conn);

/*
 * parseInput: if appropriate, parse input data from backend
 * until input is exhausted or a stopping state is reached.
 * Note that this function will NOT attempt to read more data from the backend.
 */
static GTM_Result *
pqParseInput(GTM_Conn *conn)
{
	char		id;
	int			msgLength;
	int			avail;
	GTM_Result	*result = NULL;

	if (conn->result == NULL)
	{
		conn->result = (GTM_Result *) malloc(sizeof (GTM_Result));
		memset(conn->result, 0, sizeof (GTM_Result));
	}
	else
		gtmpqFreeResultData(conn->result, conn->remote_type);

	result = conn->result;

	/*
	 * Try to read a message.  First get the type code and length. Return
	 * if not enough data.
	 */
	conn->inCursor = conn->inStart;
	if (gtmpqGetc(&id, conn))
		return NULL;
	if (gtmpqGetInt(&msgLength, 4, conn))
		return NULL;

	/*
	 * Try to validate message type/length here.  A length less than 4 is
	 * definitely broken.  Large lengths should only be believed for a few
	 * message types.
	 */
	if (msgLength < 4)
	{
		handleSyncLoss(conn, id, msgLength);
		return NULL;
	}
	if (msgLength > 30000 && !VALID_LONG_MESSAGE_TYPE(id))
	{
		handleSyncLoss(conn, id, msgLength);
		return NULL;
	}

	/*
	 * Can't process if message body isn't all here yet.
	 */
	conn->result->gr_msglen = msgLength -= 4;
	avail = conn->inEnd - conn->inCursor;
	if (avail < msgLength)
	{
		/*
		 * Before returning, enlarge the input buffer if needed to hold
		 * the whole message.  This is better than leaving it to
		 * gtmpqReadData because we can avoid multiple cycles of realloc()
		 * when the message is large; also, we can implement a reasonable
		 * recovery strategy if we are unable to make the buffer big
		 * enough.
		 */
		if (gtmpqCheckInBufferSpace(conn->inCursor + (size_t) msgLength,
								 conn))
		{
			/*
			 * XXX add some better recovery code... plan is to skip over
			 * the message using its length, then report an error. For the
			 * moment, just treat this like loss of sync (which indeed it
			 * might be!)
			 */
			handleSyncLoss(conn, id, msgLength);
		}
		return NULL;
	}

	switch (id)
	{
		case 'S':		/* command complete */
			if (gtmpqParseSuccess(conn, result))
				return NULL;
			break;

		case 'E':		/* error return */
			if (gtmpqGetError(conn, result))
				return NULL;
			result->gr_status = GTM_RESULT_ERROR;
			break;
		default:
			printfGTMPQExpBuffer(&conn->errorMessage,
							  "unexpected response from server; first received character was \"%c\"\n",
							  id);
			conn->inCursor += msgLength;
			break;
	}					/* switch on protocol character */
	/* Successfully consumed this message */
	if (conn->inCursor == conn->inStart + 5 + msgLength)
	{
		/* Normal case: parsing agrees with specified length */
		conn->inStart = conn->inCursor;
	}
	else
	{
		/* Trouble --- report it */
		printfGTMPQExpBuffer(&conn->errorMessage,
						  "message contents do not agree with length in message type \"%c\"\n",
						  id);
		/* trust the specified message length as what to skip */
		conn->inStart += 5 + msgLength;
	}

	return result;
}

/*
 * handleSyncLoss: clean up after loss of message-boundary sync
 *
 * There isn't really a lot we can do here except abandon the connection.
 */
static void
handleSyncLoss(GTM_Conn *conn, char id, int msgLength)
{
	printfGTMPQExpBuffer(&conn->errorMessage,
	"lost synchronization with server: got message type \"%c\", length %d\n",
					  id, msgLength);
	close(conn->sock);
	conn->sock = -1;
	conn->status = CONNECTION_BAD;		/* No more connection to backend */
}

/*
 * Attempt to read an Error or Notice response message.
 * This is possible in several places, so we break it out as a subroutine.
 * Entry: 'E' message type and length have already been consumed.
 * Exit: returns 0 if successfully consumed message.
 *		 returns EOF if not enough data.
 */
int
gtmpqGetError(GTM_Conn *conn, GTM_Result *result)
{
	char		id;

	/*
	 * If we are a GTM proxy, expect an additional proxy header in the incoming
	 * message.
	 */
	if (conn->remote_type == GTM_NODE_GTM_PROXY)
	{
		if (gtmpqGetnchar((char *)&result->gr_proxyhdr,
					sizeof (GTM_ProxyMsgHeader), conn))
			return 1;
		result->gr_msglen -= sizeof (GTM_ProxyMsgHeader);

		/*
		 * If the allocated buffer is not large enough to hold the proxied
		 * data, realloc the buffer.
		 *
		 * Since the client side code is shared between the proxy and the
		 * backend, we don't want any memory context management etc here. So
		 * just use plain realloc. Anyways, we don't indent to free the memory.
		 */
		if (result->gr_proxy_datalen < result->gr_msglen)
		{
			result->gr_proxy_data = (char *)realloc(
					result->gr_proxy_data, result->gr_msglen);
			result->gr_proxy_datalen = result->gr_msglen;
		}

		if (gtmpqGetnchar((char *)result->gr_proxy_data,
					result->gr_msglen, conn))
		{
			result->gr_status = GTM_RESULT_UNKNOWN;
			return 1;
		}

		return 0;
	}
	else
		result->gr_proxyhdr.ph_conid = InvalidGTMProxyConnID;

	/*
	 * Read the fields and save into res.
	 */
	for (;;)
	{
		if (gtmpqGetc(&id, conn))
			goto fail;
		if (id == '\0')
			break;
		if (gtmpqGets(&conn->errorMessage, conn))
			goto fail;
	}
	return 0;

fail:
	return EOF;
}

/*
 * GTMPQgetResult
 *	  Get the next GTM_Result produced.  Returns NULL if no
 *	  query work remains or an error has occurred (e.g. out of
 *	  memory).
 */

GTM_Result *
GTMPQgetResult(GTM_Conn *conn)
{
	GTM_Result *res;

	if (!conn)
		return NULL;

	/* Parse any available data, if our state permits. */
	while ((res = pqParseInput(conn)) == NULL)
	{
		int			flushResult;

		/*
		 * If data remains unsent, send it.  Else we might be waiting for the
		 * result of a command the backend hasn't even got yet.
		 */
		while ((flushResult = gtmpqFlush(conn)) > 0)
		{
			if (gtmpqWait(false, true, conn))
			{
				flushResult = -1;
				break;
			}
		}

		/* Wait for some more data, and load it. */
		if (flushResult ||
			gtmpqWait(true, false, conn) ||
			gtmpqReadData(conn) < 0)
		{
			/*
			 * conn->errorMessage has been set by gtmpqWait or gtmpqReadData.
			 */
			return NULL;
		}
	}

	return res;
}

/*
 * return 0 if parsing command is totally completed.
 * return 1 if it needs to be read continuously.
 */
static int
gtmpqParseSuccess(GTM_Conn *conn, GTM_Result *result)
{
	int xcnt, xsize;
	int i;
	GlobalTransactionId *xip = NULL;

	result->gr_status = GTM_RESULT_OK;

	if (gtmpqGetInt((int *)&result->gr_type, 4, conn))
		return 1;
	result->gr_msglen -= 4;

	if (conn->remote_type == GTM_NODE_GTM_PROXY)
	{
		if (gtmpqGetnchar((char *)&result->gr_proxyhdr,
					sizeof (GTM_ProxyMsgHeader), conn))
			return 1;
		result->gr_msglen -= sizeof (GTM_ProxyMsgHeader);
	}
	else
		result->gr_proxyhdr.ph_conid = InvalidGTMProxyConnID;

	/*
	 * If we are dealing with a proxied message, just read the remaining binary
	 * data which can then be forwarded to the right backend.
	 */
	if (result->gr_proxyhdr.ph_conid != InvalidGTMProxyConnID)
	{
		/*
		 * If the allocated buffer is not large enough to hold the proxied
		 * data, realloc the buffer.
		 *
		 * Since the client side code is shared between the proxy and the
		 * backend, we don't want any memory context management etc here. So
		 * just use plain realloc. Anyways, we don't indent to free the memory.
		 */
		if (result->gr_proxy_datalen < result->gr_msglen)
		{
			result->gr_proxy_data = (char *)realloc(
					result->gr_proxy_data, result->gr_msglen);
			result->gr_proxy_datalen = result->gr_msglen;
		}

		if (gtmpqGetnchar((char *)result->gr_proxy_data,
					result->gr_msglen, conn))
		{
			result->gr_status = GTM_RESULT_UNKNOWN;
			return 1;
		}

		return result->gr_status;
	}

	result->gr_status = GTM_RESULT_OK;

	switch (result->gr_type)
	{
		case SYNC_STANDBY_RESULT:
			break;

		case NODE_BEGIN_REPLICATION_INIT_RESULT:
			break;

		case NODE_END_REPLICATION_INIT_RESULT:
			break;

		case BEGIN_BACKUP_RESULT:
			break;

		case END_BACKUP_RESULT:
			break;

#ifdef XCP
		case REGISTER_SESSION_RESULT:
			break;
#endif

		case TXN_BEGIN_RESULT:
			if (gtmpqGetnchar((char *)&result->gr_resdata.grd_txnhandle,
						   sizeof (GTM_TransactionHandle), conn))
				result->gr_status = GTM_RESULT_ERROR;
			break;

		case TXN_BEGIN_GETGXID_RESULT:
			if (gtmpqGetnchar((char *)&result->gr_resdata.grd_gxid_tp.gxid,
							  sizeof (GlobalTransactionId), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}
			if (gtmpqGetnchar((char *)&result->gr_resdata.grd_gxid_tp.timestamp,
							  sizeof (GTM_Timestamp), conn))
				result->gr_status = GTM_RESULT_ERROR;
			break;
		case TXN_BEGIN_GETGXID_AUTOVACUUM_RESULT:
		case TXN_PREPARE_RESULT:
		case TXN_START_PREPARED_RESULT:
		case TXN_ROLLBACK_RESULT:
			if (gtmpqGetnchar((char *)&result->gr_resdata.grd_gxid,
						   sizeof (GlobalTransactionId), conn))
				result->gr_status = GTM_RESULT_ERROR;
			break;

		case TXN_COMMIT_RESULT:
		case TXN_COMMIT_PREPARED_RESULT:
			if (gtmpqGetnchar((char *)&result->gr_resdata.grd_eof_txn.gxid,
						   sizeof (GlobalTransactionId), conn))
				result->gr_status = GTM_RESULT_ERROR;
			if (gtmpqGetnchar((char *)&result->gr_resdata.grd_eof_txn.status,
						   sizeof (int), conn))
				result->gr_status = GTM_RESULT_ERROR;
			break;

		case TXN_GET_GXID_RESULT:
			if (gtmpqGetnchar((char *)&result->gr_resdata.grd_txn.txnhandle,
						   sizeof (GTM_TransactionHandle), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}

			if (gtmpqGetnchar((char *)&result->gr_resdata.grd_txn.gxid,
						   sizeof (GlobalTransactionId), conn))
				result->gr_status = GTM_RESULT_ERROR;
			break;

		case TXN_GET_NEXT_GXID_RESULT:
			if (gtmpqGetInt((int *)&result->gr_resdata.grd_next_gxid,
					sizeof (int32), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}
			break;

		case TXN_BEGIN_GETGXID_MULTI_RESULT:
			if (gtmpqGetnchar((char *)&result->gr_resdata.grd_txn_get_multi.txn_count,
						   sizeof (int), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}
			if (gtmpqGetnchar((char *)result->gr_resdata.grd_txn_get_multi.txn_gxid,
						   sizeof (GlobalTransactionId) * result->gr_resdata.grd_txn_get_multi.txn_count,
						   conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}
			if (gtmpqGetnchar((char *)&result->gr_resdata.grd_txn_get_multi.timestamp,
						   sizeof (GTM_Timestamp), conn))
				result->gr_status = GTM_RESULT_ERROR;
			break;

		case TXN_COMMIT_MULTI_RESULT:
		case TXN_ROLLBACK_MULTI_RESULT:
			if (gtmpqGetnchar((char *)&result->gr_resdata.grd_txn_rc_multi.txn_count,
						   sizeof (int), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}
			if (gtmpqGetnchar((char *)result->gr_resdata.grd_txn_rc_multi.status,
						   sizeof (int) * result->gr_resdata.grd_txn_rc_multi.txn_count, conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}
			break;

		case SNAPSHOT_GXID_GET_RESULT:
			if (gtmpqGetnchar((char *)&result->gr_resdata.grd_txn_snap_multi.txnhandle,
						   sizeof (GTM_TransactionHandle), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}
			/* Fall through */
		case SNAPSHOT_GET_RESULT:
			if (gtmpqGetnchar((char *)&result->gr_resdata.grd_txn_snap_multi.gxid,
						   sizeof (GlobalTransactionId), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}
			/* Fall through */
		case SNAPSHOT_GET_MULTI_RESULT:
			if (gtmpqGetnchar((char *)&result->gr_resdata.grd_txn_snap_multi.txn_count,
						   sizeof (int), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}
			if (gtmpqGetnchar((char *)result->gr_resdata.grd_txn_snap_multi.status,
						   sizeof (int) * result->gr_resdata.grd_txn_snap_multi.txn_count, conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}

			if (gtmpqGetnchar((char *)&result->gr_snapshot.sn_xmin,
						   sizeof (GlobalTransactionId), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}

			if (gtmpqGetnchar((char *)&result->gr_snapshot.sn_xmax,
						   sizeof (GlobalTransactionId), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}

			if (gtmpqGetInt((int *)&result->gr_snapshot.sn_xcnt,
						   sizeof (int32), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}

			xsize = result->gr_xip_size;
			xcnt = result->gr_snapshot.sn_xcnt;
			xip = result->gr_snapshot.sn_xip;

			if (!xip || xcnt > xsize)
			{
				if (!xip)
					xip = (GlobalTransactionId *) malloc(sizeof(GlobalTransactionId) *
														 GTM_MAX_GLOBAL_TRANSACTIONS);
				else
					xip = (GlobalTransactionId *) realloc(xip,
									  sizeof(GlobalTransactionId) * xcnt);

				result->gr_snapshot.sn_xip = xip;
				result->gr_xip_size = xcnt;
			}

			if (gtmpqGetnchar((char *)xip, sizeof(GlobalTransactionId) * xcnt, conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}

			break;

		case SEQUENCE_INIT_RESULT:
		case SEQUENCE_RESET_RESULT:
		case SEQUENCE_CLOSE_RESULT:
		case SEQUENCE_RENAME_RESULT:
		case SEQUENCE_ALTER_RESULT:
		case SEQUENCE_SET_VAL_RESULT:
			if (gtmpqReadSeqKey(&result->gr_resdata.grd_seqkey, conn))
				result->gr_status = GTM_RESULT_ERROR;
			break;

		case SEQUENCE_GET_CURRENT_RESULT:
		case SEQUENCE_GET_NEXT_RESULT:
		case SEQUENCE_GET_LAST_RESULT:
			if (gtmpqReadSeqKey(&result->gr_resdata.grd_seq.seqkey, conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}
			if (gtmpqGetnchar((char *)&result->gr_resdata.grd_seq.seqval,
						   sizeof (GTM_Sequence), conn))
				result->gr_status = GTM_RESULT_ERROR;
#ifdef XCP
			if (result->gr_type == SEQUENCE_GET_NEXT_RESULT &&
				 gtmpqGetnchar((char *)&result->gr_resdata.grd_seq.rangemax,
						   sizeof (GTM_Sequence), conn))
				result->gr_status = GTM_RESULT_ERROR;
#endif
			break;

		case SEQUENCE_LIST_RESULT:
			if (gtmpqGetInt(&result->gr_resdata.grd_seq_list.seq_count,
					sizeof (int32), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}

			result->gr_resdata.grd_seq_list.seq =
						(GTM_SeqInfo *)malloc(sizeof(GTM_SeqInfo) *
											   result->gr_resdata.grd_seq_list.seq_count);

			for (i = 0 ; i < result->gr_resdata.grd_seq_list.seq_count; i++)
			{
				int buflen;
				char *buf;

				/* a length of the next serialized sequence */
				if (gtmpqGetInt(&buflen, sizeof (int32), conn))
				{
					result->gr_status = GTM_RESULT_ERROR;
					break;
				}

				/* a data body of the serialized sequence */
				buf = (char *)malloc(buflen);
				if (gtmpqGetnchar(buf, buflen, conn))
				{
					result->gr_status = GTM_RESULT_ERROR;
					break;
				}

				gtm_deserialize_sequence(result->gr_resdata.grd_seq_list.seq+i,
										 buf, buflen);

				free(buf);
			}
			break;

		case TXN_GET_STATUS_RESULT:
			break;

		case TXN_GET_ALL_PREPARED_RESULT:
			break;

		case TXN_GET_GID_DATA_RESULT:
			if (gtmpqGetnchar((char *)&result->gr_resdata.grd_txn_get_gid_data.gxid,
							  sizeof (GlobalTransactionId), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}
			if (gtmpqGetnchar((char *)&result->gr_resdata.grd_txn_get_gid_data.prepared_gxid,
							  sizeof (GlobalTransactionId), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}
			if (gtmpqGetInt(&result->gr_resdata.grd_txn_get_gid_data.nodelen,
					sizeof (int32), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}
			if (result->gr_resdata.grd_txn_get_gid_data.nodelen != 0)
			{
				/* Do necessary allocation */
				result->gr_resdata.grd_txn_get_gid_data.nodestring =
					(char *)malloc(sizeof(char *) * result->gr_resdata.grd_txn_get_gid_data.nodelen + 1);
				if (result->gr_resdata.grd_txn_get_gid_data.nodestring == NULL)
				{
					result->gr_status = GTM_RESULT_ERROR;
					break;
				}

				/* get the string itself */
				if (gtmpqGetnchar(result->gr_resdata.grd_txn_get_gid_data.nodestring,
					result->gr_resdata.grd_txn_get_gid_data.nodelen, conn))
				{
					result->gr_status = GTM_RESULT_ERROR;
					break;
				}

				/* null terminate the name*/
				result->gr_resdata.grd_txn_get_gid_data.nodestring[result->gr_resdata.grd_txn_get_gid_data.nodelen] = '\0';
			}
			else
				result->gr_resdata.grd_txn_get_gid_data.nodestring = NULL;

			break;

		case TXN_GXID_LIST_RESULT:
			result->gr_resdata.grd_txn_gid_list.len = 0;
			result->gr_resdata.grd_txn_gid_list.ptr = NULL;

			if (gtmpqGetInt((int *)&result->gr_resdata.grd_txn_gid_list.len,
					sizeof(int32), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}

			/*
			 * I don't understand why malloc() here?  Should be palloc()?
			 */
			result->gr_resdata.grd_txn_gid_list.ptr =
					(char *)malloc(result->gr_resdata.grd_txn_gid_list.len);

			if (result->gr_resdata.grd_txn_gid_list.ptr==NULL)
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}

			if (gtmpqGetnchar(result->gr_resdata.grd_txn_gid_list.ptr,
					  result->gr_resdata.grd_txn_gid_list.len,
					  conn))  /* serialized GTM_Transactions */
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}
			break;

		case NODE_UNREGISTER_RESULT:
		case NODE_REGISTER_RESULT:
			result->gr_resdata.grd_node.len = 0;
			result->gr_resdata.grd_node.node_name = NULL;

			if (gtmpqGetnchar((char *)&result->gr_resdata.grd_node.type,
						sizeof (GTM_PGXCNodeType), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}
			if (gtmpqGetInt((int *)&result->gr_resdata.grd_node.len,
					sizeof(int32), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}

			result->gr_resdata.grd_node.node_name =
					(char *)malloc(result->gr_resdata.grd_node.len+1);

			if (result->gr_resdata.grd_node.node_name==NULL)
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}

			if (gtmpqGetnchar(result->gr_resdata.grd_node.node_name,
					  result->gr_resdata.grd_node.len,
					  conn))  /* serialized GTM_Transactions */
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}
			result->gr_resdata.grd_node.node_name[result->gr_resdata.grd_node.len] = '\0';

			break;

		case NODE_LIST_RESULT:
		{
			int i;

			if (gtmpqGetInt(&result->gr_resdata.grd_node_list.num_node, sizeof(int32), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}

			for (i = 0 ; i < result->gr_resdata.grd_node_list.num_node; i++)
			{
				int size;
				char *buf;
				GTM_PGXCNodeInfo *data = (GTM_PGXCNodeInfo *)malloc(sizeof(GTM_PGXCNodeInfo));

				if (data == NULL)
				{
					result->gr_status = GTM_RESULT_ERROR;
					printfGTMPQExpBuffer(&conn->errorMessage, "Out of memory");
					break;
				}

				if (gtmpqGetInt(&size, sizeof(int32), conn))
				{
					result->gr_status = GTM_RESULT_ERROR;
					free(data);
					break;
				}

				buf = (char *) malloc(size);
				if (buf == NULL)
				{
					result->gr_status = GTM_RESULT_ERROR;
					printfGTMPQExpBuffer(&conn->errorMessage, "Out of memory");
					free(data);
					break;
				}

				if (gtmpqGetnchar(buf, size, conn))
				{
					result->gr_status = GTM_RESULT_ERROR;
					free(buf);
					free(data);
					break;
				}
				if (!gtm_deserialize_pgxcnodeinfo(data, buf, size, &conn->errorMessage))
				{
					result->gr_status = GTM_RESULT_ERROR;
					free(buf);
					free(data);
					break;
				} 
				else 
				{
					result->gr_resdata.grd_node_list.nodeinfo[i] = data;
					free(buf);
				} 
			}

			break;
		}
		case BARRIER_RESULT:
			break;

		case REPORT_XMIN_RESULT:
			if (gtmpqGetnchar((char *)&result->gr_resdata.grd_report_xmin.latest_completed_xid,
							  sizeof (GlobalTransactionId), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}
			if (gtmpqGetnchar((char *)&result->gr_resdata.grd_report_xmin.global_xmin,
							  sizeof (GlobalTransactionId), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}
			if (gtmpqGetnchar((char *)&result->gr_resdata.grd_report_xmin.errcode,
							  sizeof (int), conn))
			{
				result->gr_status = GTM_RESULT_ERROR;
				break;
			}
			break;

		default:
			printfGTMPQExpBuffer(&conn->errorMessage,
							  "unexpected result type from server; result typr was \"%d\"\n",
							  result->gr_type);
			result->gr_status = GTM_RESULT_ERROR;
			break;
	}

	return (result->gr_status);
}

static int
gtmpqReadSeqKey(GTM_SequenceKey seqkey, GTM_Conn *conn)
{
	/*
	 * Read keylength
	 */
	if (gtmpqGetInt((int *)&seqkey->gsk_keylen, 4, conn))
		return EINVAL;

	/*
	 * Do some sanity checks on the keylength
	 */
	if (seqkey->gsk_keylen <= 0 || seqkey->gsk_keylen > GTM_MAX_SEQKEY_LENGTH)
		return EINVAL;

	if ((seqkey->gsk_key = (char *) malloc(seqkey->gsk_keylen))	== NULL)
		return ENOMEM;

	if (gtmpqGetnchar(seqkey->gsk_key, seqkey->gsk_keylen, conn))
		return EINVAL;

	return 0;
}

void
gtmpqFreeResultData(GTM_Result *result, GTM_PGXCNodeType remote_type)
{
	/*
	 * If we are running as a GTM proxy, we don't have anything to do. This may
	 * change though as we add more message types below and some of them may
	 * need cleanup even at the proxy level
	 */
	if (remote_type == GTM_NODE_GTM_PROXY)
		return;

	switch (result->gr_type)
	{
		case SEQUENCE_INIT_RESULT:
		case SEQUENCE_RESET_RESULT:
		case SEQUENCE_CLOSE_RESULT:
		case SEQUENCE_RENAME_RESULT:
		case SEQUENCE_ALTER_RESULT:
		case SEQUENCE_SET_VAL_RESULT:
			if (result->gr_resdata.grd_seqkey.gsk_key != NULL)
				free(result->gr_resdata.grd_seqkey.gsk_key);
			result->gr_resdata.grd_seqkey.gsk_key = NULL;
			break;

		case SEQUENCE_GET_CURRENT_RESULT:
		case SEQUENCE_GET_NEXT_RESULT:
		case SEQUENCE_GET_LAST_RESULT:
			if (result->gr_resdata.grd_seq.seqkey.gsk_key != NULL)
				free(result->gr_resdata.grd_seq.seqkey.gsk_key);
			result->gr_resdata.grd_seqkey.gsk_key = NULL;
			break;

		case TXN_GET_STATUS_RESULT:
			break;

		case TXN_GET_ALL_PREPARED_RESULT:
			break;

		case BARRIER_RESULT:
			break;

		case SNAPSHOT_GET_RESULT:
		case SNAPSHOT_GXID_GET_RESULT:
			/*
			 * Lets not free the xip array in the snapshot since we may need it
			 * again shortly
			 */
			break;

		default:
			break;
	}
}