/*
 *                         OpenSplice DDS
 *
 *   This software and documentation are Copyright 2006 to TO_YEAR PrismTech
 *   Limited, its affiliated companies and licensors. All rights reserved.
 *
 *   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.
 *
 */
/**
 * @file api/cm/xml/include/cmx_writerSnapshot.h
 * 
 * Represents a snapshot of the history of a writer in XML format.
 */
#ifndef CMX_WRITERSNAPSHOT_H
#define CMX_WRITERSNAPSHOT_H

#include "c_typebase.h"

#if defined (__cplusplus)
extern "C" {
#endif
#include "os_if.h"

#ifdef OSPL_BUILD_CMXML
#define OS_API OS_API_EXPORT
#else
#define OS_API OS_API_IMPORT
#endif
/* !!!!!!!!NOTE From here no more includes are allowed!!!!!!! */

/**
 * Makes a snapshot of the history of the supplied writer by serializing the
 * complete history to XML format and storing it in heap memory.
 * 
 * An XML writer snapshot looks like:
   @verbatim
   <writerSnapshot>
        <id>...</id>
   </writerSnapshot>
   @endverbatim
 * The id represents the heap address of the snapshot.
 * 
 * @param writer The XML representation of the writer, which history needs to 
 *               be serialized.
 * @return The XML representation of the writer snapshot.
 */
OS_API c_char* cmx_writerSnapshotNew       (const c_char* writer);

/**
 * Frees the supplied snapshot.
 * 
 * @param snapshot The snapshot to free.
 */
OS_API void    cmx_writerSnapshotFree      (c_char* snapshot);

/**
 * Reads one sample from the supplied snapshot. The result format depends on the
 * data type of the samples in the snapshot.
 * 
 * @param snapshot The snapshot to read a sample from.
 * @return The XML representation of the read sample or NULL if no sample was
 *         available.
 */
OS_API c_char* cmx_writerSnapshotRead      (const c_char* snapshot);

/**
 * Takes one sample from the supplied snapshot. The result format depends on the
 * data type of the samples in the snapshot.
 * 
 * @param snapshot The snapshot to take a sample from.
 * @return The XML representation of the taken sample or NULL if no sample was
 *         available.
 */
OS_API c_char* cmx_writerSnapshotTake      (const c_char* snapshot);

#undef OS_API

#if defined (__cplusplus)
}
#endif

#endif /* CMX_WRITERSNAPSHOT*/
