bsd/dev/random/YarrowCoreLib/src/comp.c

   1 /*
   2  * Copyright (c) 1999, 2000-2001 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 /*
  25         File:           comp.c
  26
  27         Contains:       NULL compression. Kernel version of Yarrow assumes
  28                                 incoming seed data is truly random.
  29 */
  30 #include "dev/random/YarrowCoreLib/include/WindowsTypesForMac.h"
  31 #include "comp.h"
  32
  33 #ifdef  YARROW_KERNEL
  34
  35 /* null compression */
  36 comp_error_status comp_init(__unused COMP_CTX* ctx)
  37 {
  38         return COMP_SUCCESS;
  39 }
  40
  41
  42 comp_error_status comp_add_data( __unused COMP_CTX* ctx,
  43                                                                  __unused Bytef* inp,
  44                                                                  __unused uInt inplen )
  45 {
  46         return COMP_SUCCESS;
  47 }
  48
  49 comp_error_status comp_get_ratio( __unused COMP_CTX* ctx,float* out )
  50 {
  51         *out = 1.0;
  52         return COMP_SUCCESS;
  53 }
  54
  55 comp_error_status comp_end( __unused COMP_CTX* ctx )
  56 {
  57         return COMP_SUCCESS;
  58 }
  59
  60 #else
  61
  62 /* original Yarrow compression, must be linked with zlib */
  63
  64 #if             defined(macintosh) || defined(__APPLE__)
  65 #include "WindowsTypesForMac.h"
  66 #include "yarrowUtils.h"
  67 #include <string.h>
  68 #include <stdlib.h>
  69 #else
  70 #include <windows.h>
  71 #endif
  72 #include <math.h>
  73 #include "comp.h"
  74
  75 /* Check that the pointer is not NULL */
  76 #define PCHECK(ptr)  if(ptr==NULL) {return COMP_ERR_NULL_POINTER;}
  77 #define MMPCHECK(mmptr) if(mmptr==MM_NULL) {return COMP_ERR_NULL_POINTER;}
  78 /* Check that the important parts of the context are ok */
  79 #define CTXCHECK(ctx) \
  80 PCHECK(ctx)                             \
  81 MMPCHECK(ctx->buf)
  82
  83 /* Might want to vary these by context */
  84 #define BUFSIZE  16384 /* 16K */
  85 #define OUTBUFSIZE 16800 /* = inbufsize*1.01 + 12 (See zlib docs) */
  86 #define SHIFTSIZE 4096 /* BUFSIZE/4 */
  87
  88 #define _MIN(a,b) (((a)<(b))?(a):(b))
  89
  90
  91 /* Initialize these routines */
  92 comp_error_status comp_init(COMP_CTX* ctx)
  93 {
  94         ctx->buf = mmMalloc(BUFSIZE);
  95         if(ctx->buf == MM_NULL) {goto cleanup_comp_init;}
  96         ctx->spaceused = 0;
  97
  98         return COMP_SUCCESS;
  99
 100 cleanup_comp_init:
 101         mmFree(ctx->buf);
 102
 103         return COMP_ERR_LOW_MEMORY;
 104 }
 105
 106
 107 comp_error_status comp_add_data(COMP_CTX* ctx,Bytef* inp,uInt inplen)
 108 {
 109         uInt shifts;
 110         uInt blocksize;
 111         BYTE* buf;
 112
 113         CTXCHECK(ctx);
 114         PCHECK(inp);
 115
 116         buf = (BYTE*)mmGetPtr(ctx->buf);
 117
 118         if(inplen+SHIFTSIZE>BUFSIZE)
 119         {
 120                 blocksize = _MIN(inplen,BUFSIZE);
 121                 memmove(buf,inp,blocksize);
 122                 ctx->spaceused = blocksize;
 123         }
 124         else
 125         {
 126                 if(inplen+ctx->spaceused>BUFSIZE)
 127                 {
 128                         shifts = (uInt)ceil((inplen+ctx->spaceused-BUFSIZE)/(float)SHIFTSIZE);
 129                         blocksize = _MIN(shifts*SHIFTSIZE,ctx->spaceused);
 130                         memmove(buf,buf+blocksize,BUFSIZE-blocksize);
 131                         ctx->spaceused = ctx->spaceused - blocksize;
 132                 }
 133                 memmove(buf+ctx->spaceused,inp,inplen);
 134                 ctx->spaceused += inplen;
 135         }
 136
 137         return COMP_SUCCESS;
 138 }
 139
 140 comp_error_status comp_get_ratio(COMP_CTX* ctx,float* out)
 141 {
 142         Bytef *inbuf,*outbuf;
 143         uLong insize,outsize;
 144         int resp;
 145
 146         *out = 0;
 147
 148         CTXCHECK(ctx);
 149         PCHECK(out);
 150
 151         if(ctx->spaceused == 0) {return COMP_SUCCESS;}
 152
 153         inbuf = (Bytef*)mmGetPtr(ctx->buf);
 154         outbuf = (Bytef*)malloc(OUTBUFSIZE);
 155         if(outbuf==NULL) {return COMP_ERR_LOW_MEMORY;}
 156
 157         insize = ctx->spaceused;
 158         outsize = OUTBUFSIZE;
 159
 160         resp = compress(outbuf,&outsize,inbuf,insize);
 161         if(resp==Z_MEM_ERROR) {return COMP_ERR_LOW_MEMORY;}
 162         if(resp==Z_BUF_ERROR) {return COMP_ERR_LIB;}
 163
 164         *out = (float)outsize/(float)insize;
 165
 166         /* Thrash the memory and free it */
 167         trashMemory(outbuf, OUTBUFSIZE);
 168         free(outbuf);
 169
 170         return COMP_SUCCESS;
 171 }
 172
 173 comp_error_status comp_end(COMP_CTX* ctx)
 174 {
 175         if(ctx == NULL) {return COMP_SUCCESS;} /* Since nothing is left undone */
 176
 177         mmFree(ctx->buf);
 178         ctx->buf = MM_NULL;
 179
 180         return COMP_SUCCESS;
 181 }
 182
 183 #endif  /* YARROW_KERNEL */
 184