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dashley |
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//$Header$ |
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//------------------------------------------------------------------------------------------------- |
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//This file is part of "David T. Ashley's Shared Source Code", a set of shared components |
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//integrated into many of David T. Ashley's projects. |
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//------------------------------------------------------------------------------------------------- |
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//This source code and any program in which it is compiled/used is provided under the MIT License, |
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//reproduced below. |
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//------------------------------------------------------------------------------------------------- |
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//Permission is hereby granted, free of charge, to any person obtaining a copy of |
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//this software and associated documentation files(the "Software"), to deal in the |
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//Software without restriction, including without limitation the rights to use, |
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//copy, modify, merge, publish, distribute, sublicense, and / or sell copies of the |
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//Software, and to permit persons to whom the Software is furnished to do so, |
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//subject to the following conditions : |
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// |
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//The above copyright notice and this permission notice shall be included in all |
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//copies or substantial portions of the Software. |
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// |
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//THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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//IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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//FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE |
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//AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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//LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
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//OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
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//SOFTWARE. |
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//------------------------------------------------------------------------------------------------- |
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//This software module is concerned with functions to support the generation |
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//of CRCs and hash functions. CRCs and hash functions are similar in that they |
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//provide an abstraction of a large amount of data, although CRCs may have better |
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//(or different) statistical properties than hash functions. These functions |
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//are split out from any specific application for maximum reusability of the |
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//code. |
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#ifndef CRCHASHFUNCS_H_INCLUDED |
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#define CRCHASHFUNCS_H_INCLUDED |
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#ifdef MODULE_CRCHASHFUNCS |
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#define DECMOD_CRCHASHFUNCS |
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#else |
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#define DECMOD_CRCHASHFUNCS extern |
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#endif |
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//Define the state object that holds CRC-32 intermediate results as the CRC is |
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//being formed. This is conceptually private for the caller. |
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// |
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struct CRCHASHFUNCS_Crc32StateStruct |
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{ |
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unsigned crc; |
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//This is the only state for now. |
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}; |
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//All CRC32 functions are courtesy of Richard A. Ellingson |
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//from the Internet. |
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// |
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//Checks the CRC-32 table for integrity, returns non-zero if |
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//the table is OK, or 0 if the table is corrupted. The table |
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//is a table of constants in memory--it is not known how |
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//much protection the "const" keyword can give it, i.e. if |
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//the tools can put it in a memory segment where some kind |
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//of protection is afforded by the OS. |
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DECMOD_CRCHASHFUNCS |
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int CRCHASHFUNCS_Crc32TableCheck(void); |
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//Initializes the CRC formation structure. |
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DECMOD_CRCHASHFUNCS |
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void CRCHASHFUNCS_Crc32StateStructOpen(struct CRCHASHFUNCS_Crc32StateStruct *arg); |
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//Adds data to it. |
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DECMOD_CRCHASHFUNCS |
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void CRCHASHFUNCS_Crc32StateStructAddData(struct CRCHASHFUNCS_Crc32StateStruct *arg, |
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void *data, |
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unsigned len); |
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//Reads the CRC out at any time. |
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DECMOD_CRCHASHFUNCS |
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unsigned CRCHASHFUNCS_Crc32Extract(struct CRCHASHFUNCS_Crc32StateStruct *arg); |
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//Closes the structure. |
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DECMOD_CRCHASHFUNCS |
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void CRCHASHFUNCS_Crc32StateStructClose(struct CRCHASHFUNCS_Crc32StateStruct *arg); |
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DECMOD_CRCHASHFUNCS const char *CRCHASHFUNCS_cvcinfo(void); |
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DECMOD_CRCHASHFUNCS const char *CRCHASHFUNCS_hvcinfo(void); |
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//Definition of the version of the H file, used for providing version control |
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//information to external callers. |
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#define CRCHASHFUNCS_H_VERSION ("$Header$") |
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#endif |
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//End of crchashfuncs.h. |