rtxStreamCtxtBuf.h
00001 /* 00002 * Copyright (c) 2003-2010 Objective Systems, Inc. 00003 * 00004 * This software is furnished under a license and may be used and copied 00005 * only in accordance with the terms of such license and with the 00006 * inclusion of the above copyright notice. This software or any other 00007 * copies thereof may not be provided or otherwise made available to any 00008 * other person. No title to and ownership of the software is hereby 00009 * transferred. 00010 * 00011 * The information in this software is subject to change without notice 00012 * and should not be construed as a commitment by Objective Systems, Inc. 00013 * 00014 * PROPRIETARY NOTICE 00015 * 00016 * This software is an unpublished work subject to a confidentiality agreement 00017 * and is protected by copyright and trade secret law. Unauthorized copying, 00018 * redistribution or other use of this work is prohibited. 00019 * 00020 * The above notice of copyright on this source code product does not indicate 00021 * any actual or intended publication of such source code. 00022 * 00023 *****************************************************************************/ 00024 /* 00025 * @file rtxStreamCtxtBuf.h 00026 * Stream functions that work directly with the context buffer. 00027 */ 00028 #ifndef _RTXSTREAMCTXTBUF_H_ 00029 #define _RTXSTREAMCTXTBUF_H_ 00030 00031 #ifndef _NO_STREAM 00032 00033 #include "rtxsrc/osSysTypes.h" 00034 #include "rtxsrc/rtxExternDefs.h" 00035 #include "rtxsrc/rtxStream.h" 00036 00037 #ifdef __cplusplus 00038 extern "C" { 00039 #endif 00040 00041 /* 00042 * This function create and initializes a context-buffered stream. This 00043 * function should be called first before any operation with the stream. 00044 * 00045 * @param pctxt Pointer to context structure variable. 00046 * @return Completion status of operation: 0 (0) = success, 00047 * negative return value is error. 00048 */ 00049 EXTERNRT int rtxStreamCtxtBufCreate (OSCTXT* pctxt); 00050 00051 /* 00052 * This function pre-reads a 'size' number of octets of data from the input 00053 * stream into the internal stream buffer. This functions blocks until all 00054 * necessary data is read, end of file is detected, or another error 00055 * occurs. This function guarantees that the internal buffer will contain at 00056 * least the 'size' number of octets. Thus, it is possible to obtain direct 00057 * access to the memory buffer with pre-read data by using the 'buffer' field 00058 * of the OSCTXT context block. 00059 * 00060 * @param pctxt Pointer to a context structure variable that has 00061 * been initialized for stream operations. 00062 * @param size Number of octets to be pre-read. 00063 * @return Completion status of operation: 0 (0) = success, 00064 * negative return value is error. 00065 */ 00066 EXTERNRT int rtxStreamCtxtBufPreRead (OSCTXT* pctxt, size_t size); 00067 00068 /* 00069 * This function checks if the stream is already context-buffered or not. 00070 * If not, the stream will be created above the existing stream. 00071 * If the stream cannot be opened, an error code is returned. 00072 * 00073 * @param pctxt Pointer to a context structure variable that has 00074 * been initialized for stream operations. 00075 * @return Completion status of operation: 0 (0) = success, 00076 * negative return value is error. 00077 */ 00078 EXTERNRT int rtxStreamCtxtBufCheck (OSCTXT* pctxt); 00079 00080 /* 00081 * This function frees a context-buffered stream and restores the underlying stream. 00082 * 00083 * @param pctxt Pointer to context structure variable. 00084 * @return Completion status of operation: 0 (0) = success, 00085 * negative return value is error. 00086 */ 00087 EXTERNRT int rtxStreamCtxtBufFree (OSCTXT* pctxt); 00088 00089 #ifdef __cplusplus 00090 } 00091 #endif 00092 00093 #endif /* _NO_STREAM */ 00094 #endif /* _RTXSTREAMCTXTBUF_H_ */ 00095