rtxStreamZlib.h

00001 /*
00002  * Copyright (c) 2003-2009 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00016  * This software is an unpublished work subject to a confidentiality agreement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 rtxStreamZlib.h 
00026  */
00027 #ifndef _RTXSTREAMZLIB_H_
00028 #define _RTXSTREAMZLIB_H_
00029 
00030 #include "rtxsrc/osSysTypes.h"
00031 #include "rtxsrc/rtxExternDefs.h"
00032 #include "rtxsrc/rtxStream.h"
00033 
00034 #ifdef __cplusplus
00035 extern "C" {
00036 #endif
00037 
00038 /*
00039  * This function initializes a zlib compressed stream. This function should
00040  *  be called first before any operation with a zlib compressed stream.
00041  *
00042  * @param pctxt        Pointer to context structure variable.
00043  * @param flags        Specifies the access mode for the stream: 
00044  *                       - OSRTSTRMF_INPUT = input (reading) stream;
00045  *                       - OSRTSTRMF_OUTPUT = output (writing) stream.
00046  * @return             Completion status of operation: 0 (0) = success,
00047  *                       negative return value is error.
00048  */
00049 EXTERNRT int rtxStreamZlibAttach (OSCTXT* pctxt, OSUINT16 flags);
00050 
00051 /*
00052  * This function finish compressed block. Stream switched to transparent mode.
00053  *
00054  * @param pctxt        Pointer to context structure variable.
00055  * @return             Completion status of operation: 0 (0) = success,
00056  *                       negative return value is error.
00057  */
00058 EXTERNRT int rtxStreamZlibEnd (OSCTXT* pctxt);
00059 
00060 /*
00061  * This function free a zlib compressed stream and restore underlying stream. 
00062  *
00063  * @param pctxt        Pointer to context structure variable.
00064  * @return             Completion status of operation: 0 (0) = success,
00065  *                       negative return value is error.
00066  */
00067 EXTERNRT int rtxStreamZlibFree (OSCTXT* pctxt);
00068 
00069 /*
00070  * This function finish compressed block and start new block. 
00071  * Stream remained in compressed mode.
00072  *
00073  * @param pctxt        Pointer to context structure variable.
00074  * @return             Completion status of operation: 0 (0) = success,
00075  *                       negative return value is error.
00076  */
00077 EXTERNRT int rtxStreamZlibReset (OSCTXT* pctxt);
00078 
00079 /*
00080  * This function start compression parameters. 
00081  *
00082  * @param pctxt        Pointer to context structure variable.
00083  * @param level        Set compression level 0..9.
00084  *                       0 - Z_NO_COMPRESSION
00085  *                       1 - Z_BEST_SPEED
00086  *                       9 - Z_BEST_COMPRESSION
00087  *                      -1 - Z_DEFAULT_COMPRESSION - like level 6
00088  * @param windowBits   Set decompression window size.
00089  *                       8..15 - ZLIB header (RFC 1950)
00090  *                       -8..-15 - header is absent (RFC 1951)
00091  *                       (8..15) + 16 - GZIP header (RFC 1952)
00092  * @param memLevel     Set memory usage level 1..9.
00093  *                       1 - use minimum memory
00094  *                       9 - use maximum memory
00095  * @param strategy     Set copression algorithm.
00096  *                       0 - Z_DEFAULT_STRATEGY - common method any data
00097  *                       other possible values defined in zlib.h
00098  * @return             Completion status of operation: 0 (0) = success,
00099  *                       negative return value is error.
00100  */
00101 EXTERNRT int rtxStreamZlibSetDeflateParams 
00102 (OSCTXT* pctxt, int level, int windowBits, int memLevel, int strategy);
00103 
00104 /*
00105  * This function start decompression parameter. 
00106  *
00107  * @param pctxt        Pointer to context structure variable.
00108  * @param windowBits   Set decompression window size.
00109  *                       8..15 - ZLIB header (RFC 1950)
00110  *                       -8..-15 - header is absent (RFC 1951)
00111  *                       (8..15) + 16 - GZIP header (RFC 1952)
00112  * @return             Completion status of operation: 0 (0) = success,
00113  *                       negative return value is error.
00114  */
00115 EXTERNRT int rtxStreamZlibSetInflateParams 
00116 (OSCTXT* pctxt, int windowBits);
00117 
00118 /*
00119  * This function start compressed block. 
00120  *
00121  * @param pctxt        Pointer to context structure variable.
00122  * @return             Completion status of operation: 0 (0) = success,
00123  *                       negative return value is error.
00124  */
00125 EXTERNRT int rtxStreamZlibStart (OSCTXT* pctxt);
00126 
00127 #ifdef __cplusplus
00128 }
00129 #endif
00130 
00131 #endif /* _RTXSTREAMZLIB_H_ */
00132