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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 | #ifndef _LZRW3_H #define _LZRW3_H /* * $Source: /homes/cvs/ftape-stacked/ftape/compressor/lzrw3.h,v $ * $Revision: 1.1 $ * $Date: 1997/10/05 19:12:30 $ * * include files for lzrw3. Only slighty modified from the original * version. Assembles the three include files compress.h, port.h and * fastcopy.h from the original lzrw3 package. * */ #include <linux/types.h> #include <linux/string.h> /******************************************************************************/ /* */ /* COMPRESS.H */ /* */ /******************************************************************************/ /* */ /* Author : Ross Williams. */ /* Date : December 1989. */ /* */ /* This header file defines the interface to a set of functions called */ /* 'compress', each member of which implements a particular data compression */ /* algorithm. */ /* */ /* Normally in C programming, for each .H file, there is a corresponding .C */ /* file that implements the functions promised in the .H file. */ /* Here, there are many .C files corresponding to this header file. */ /* Each comforming implementation file contains a single function */ /* called 'compress' that implements a single data compression */ /* algorithm that conforms with the interface specified in this header file. */ /* Only one algorithm can be linked in at a time in this organization. */ /* */ /******************************************************************************/ /* */ /* DEFINITION OF FUNCTION COMPRESS */ /* =============================== */ /* */ /* Summary of Function Compress */ /* ---------------------------- */ /* The action that 'compress' takes depends on its first argument called */ /* 'action'. The function provides three actions: */ /* */ /* - Return information about the algorithm. */ /* - Compress a block of memory. */ /* - Decompress a block of memory. */ /* */ /* Parameters */ /* ---------- */ /* See the formal C definition later for a description of the parameters. */ /* */ /* Constants */ /* --------- */ /* COMPRESS_OVERRUN: The constant COMPRESS_OVERRUN defines by how many bytes */ /* an algorithm is allowed to expand a block during a compression operation. */ /* */ /* Although compression algorithms usually compress data, there will always */ /* be data that a given compressor will expand (this can be proven). */ /* Fortunately, the degree of expansion can be limited to a single bit, by */ /* copying over the input data if the data gets bigger during compression. */ /* To allow for this possibility, the first bit of a compressed */ /* representation can be used as a flag indicating whether the */ /* input data was copied over, or truly compressed. In practice, the first */ /* byte would be used to store this bit so as to maintain byte alignment. */ /* */ /* Unfortunately, in general, the only way to tell if an algorithm will */ /* expand a particular block of data is to run the algorithm on the data. */ /* If the algorithm does not continuously monitor how many output bytes it */ /* has written, it might write an output block far larger than the input */ /* block before realizing that it has done so. */ /* On the other hand, continuous checks on output length are inefficient. */ /* */ /* To cater for all these problems, this interface definition: */ /* > Allows a compression algorithm to return an output block that is up to */ /* COMPRESS_OVERRUN bytes longer than the input block. */ /* > Allows a compression algorithm to write up to COMPRESS_OVERRUN bytes */ /* more than the length of the input block to the memory of the output */ /* block regardless of the length of the output block eventually returned. */ /* This allows an algorithm to overrun the length of the input block in the */ /* output block by up to COMPRESS_OVERRUN bytes between expansion checks. */ /* */ /* The problem does not arise for decompression. */ /* */ /* Identity Action */ /* --------------- */ /* > action must be COMPRESS_ACTION_IDENTITY. */ /* > p_dst_len must point to a longword to receive a longword address. */ /* > The value of the other parameters does not matter. */ /* > After execution, the longword that p_dst_len points to will be a pointer */ /* to a structure of type compress_identity. */ /* Thus, for example, after the call, (*p_dst_len)->memory will return the */ /* number of bytes of working memory that the algorithm requires to run. */ /* > The values of the identity structure returned are fixed constant */ /* attributes of the algorithm and must not vary from call to call. */ /* */ /* Common Requirements for Compression and Decompression Actions */ /* ------------------------------------------------------------- */ /* > wrk_mem must point to an unused block of memory of a length specified in */ /* the algorithm's identity block. The identity block can be obtained by */ /* making a separate call to compress, specifying the identity action. */ /* > The INPUT BLOCK is defined to be Memory[src_addr,src_addr+src_len-1]. */ /* > dst_len will be used to denote *p_dst_len. */ /* > dst_len is not read by compress, only written. */ /* > The value of dst_len is defined only upon termination. */ /* > The OUTPUT BLOCK is defined to be Memory[dst_addr,dst_addr+dst_len-1]. */ /* */ /* Compression Action */ /* ------------------ */ /* > action must be COMPRESS_ACTION_COMPRESS. */ /* > src_len must be in the range [0,COMPRESS_MAX_ORG]. */ /* > The OUTPUT ZONE is defined to be */ /* Memory[dst_addr,dst_addr+src_len-1+COMPRESS_OVERRUN]. */ /* > The function can modify any part of the output zone regardless of the */ /* final length of the output block. */ /* > The input block and the output zone must not overlap. */ /* > dst_len will be in the range [0,src_len+COMPRESS_OVERRUN]. */ /* > dst_len will be in the range [0,COMPRESS_MAX_COM] (from prev fact). */ /* > The output block will consist of a representation of the input block. */ /* */ /* Decompression Action */ /* -------------------- */ /* > action must be COMPRESS_ACTION_DECOMPRESS. */ /* > The input block must be the result of an earlier compression operation. */ /* > If the previous fact is true, the following facts must also be true: */ /* > src_len will be in the range [0,COMPRESS_MAX_COM]. */ /* > dst_len will be in the range [0,COMPRESS_MAX_ORG]. */ /* > The input and output blocks must not overlap. */ /* > Only the output block is modified. */ /* > Upon termination, the output block will consist of the bytes contained */ /* in the input block passed to the earlier compression operation. */ /* */ /******************************************************************************/ /******************************************************************************/ /* */ /* PORT.H */ /* */ /******************************************************************************/ /* */ /* This module contains macro definitions and types that are likely to */ /* change between computers. */ /* */ /******************************************************************************/ #ifndef DONE_PORT /* Only do this if not previously done. */ #ifdef THINK_C #define UBYTE unsigned char /* Unsigned byte */ #define UWORD unsigned int /* Unsigned word (2 bytes) */ #define ULONG unsigned long /* Unsigned word (4 bytes) */ #define BOOL unsigned char /* Boolean */ #define FOPEN_BINARY_READ "rb" /* Mode string for binary reading. */ #define FOPEN_BINARY_WRITE "wb" /* Mode string for binary writing. */ #define FOPEN_TEXT_APPEND "a" /* Mode string for text appending. */ #define REAL double /* USed for floating point stuff. */ #endif #if defined(LINUX) || defined(linux) #define UBYTE __u8 /* Unsigned byte */ #define UWORD __u16 /* Unsigned word (2 bytes) */ #define ULONG __u32 /* Unsigned word (4 bytes) */ #define LONG __s32 /* Signed word (4 bytes) */ #define BOOL is not used here /* Boolean */ #define FOPEN_BINARY_READ not used /* Mode string for binary reading. */ #define FOPEN_BINARY_WRITE not used /* Mode string for binary writing. */ #define FOPEN_TEXT_APPEND not used /* Mode string for text appending. */ #define REAL not used /* USed for floating point stuff. */ #ifndef TRUE #define TRUE 1 #endif #endif #define DONE_PORT /* Don't do all this again. */ #define MALLOC_FAIL NULL /* Failure status from malloc() */ #define LOCAL static /* For non-exported routines. */ #define EXPORT /* Signals exported function. */ #define then /* Useful for aligning ifs. */ #endif /******************************************************************************/ /* End of PORT.H */ /******************************************************************************/ #define COMPRESS_ACTION_IDENTITY 0 #define COMPRESS_ACTION_COMPRESS 1 #define COMPRESS_ACTION_DECOMPRESS 2 #define COMPRESS_OVERRUN 1024 #define COMPRESS_MAX_COM 0x70000000 #define COMPRESS_MAX_ORG (COMPRESS_MAX_COM-COMPRESS_OVERRUN) #define COMPRESS_MAX_STRLEN 255 /* The following structure provides information about the algorithm. */ /* > The top bit of id must be zero. The remaining bits must be chosen by */ /* the author of the algorithm by tossing a coin 31 times. */ /* > The amount of memory requested by the algorithm is specified in bytes */ /* and must be in the range [0,0x70000000]. */ /* > All strings s must be such that strlen(s)<=COMPRESS_MAX_STRLEN. */ struct compress_identity { ULONG id; /* Identifying number of algorithm. */ ULONG memory; /* Number of bytes of working memory required. */ char *name; /* Name of algorithm. */ char *version; /* Version number. */ char *date; /* Date of release of this version. */ char *copyright; /* Copyright message. */ char *author; /* Author of algorithm. */ char *affiliation; /* Affiliation of author. */ char *vendor; /* Where the algorithm can be obtained. */ }; void lzrw3_compress( /* Single function interface to compression algorithm. */ UWORD action, /* Action to be performed. */ UBYTE *wrk_mem, /* Working memory temporarily given to routine to use. */ UBYTE *src_adr, /* Address of input data. */ LONG src_len, /* Length of input data. */ UBYTE *dst_adr, /* Address of output data. */ void *p_dst_len /* Pointer to a longword where routine will write: */ /* If action=..IDENTITY => Adr of id structure. */ /* If action=..COMPRESS => Length of output data. */ /* If action=..DECOMPRESS => Length of output data. */ ); /******************************************************************************/ /* End of COMPRESS.H */ /******************************************************************************/ /******************************************************************************/ /* fast_copy.h */ /******************************************************************************/ /* This function copies a block of memory very quickly. */ /* The exact speed depends on the relative alignment of the blocks of memory. */ /* PRE : 0<=src_len<=(2^32)-1 . */ /* PRE : Source and destination blocks must not overlap. */ /* POST : MEM[dst_adr,dst_adr+src_len-1]=MEM[src_adr,src_adr+src_len-1]. */ /* POST : MEM[dst_adr,dst_adr+src_len-1] is the only memory changed. */ #define fast_copy(src,dst,len) memcpy(dst,src,len) /******************************************************************************/ /* End of fast_copy.h */ /******************************************************************************/ #endif |