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  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22
  23 /*
  24         File:           comp.c
  25
  26         Contains:       NULL compression. Kernel version of Yarrow assumes
  27                                 incoming seed data is truly random.
  28 */
  29 #include "dev/random/YarrowCoreLib/include/WindowsTypesForMac.h"
  30 #include "comp.h"
  31
  32 #ifdef  YARROW_KERNEL
  33
  34 /* null compression */
  35 comp_error_status comp_init(__unused COMP_CTX* ctx)
  36 {
  37         return COMP_SUCCESS;
  38 }
  39
  40
  41 comp_error_status comp_add_data( __unused COMP_CTX* ctx,
  42                                                                  __unused Bytef* inp,
  43                                                                  __unused uInt inplen )
  44 {
  45         return COMP_SUCCESS;
  46 }
  47
  48 comp_error_status comp_get_ratio( __unused COMP_CTX* ctx,float* out )
  49 {
  50         *out = 1.0;
  51         return COMP_SUCCESS;
  52 }
  53
  54 comp_error_status comp_end( __unused COMP_CTX* ctx )
  55 {
  56         return COMP_SUCCESS;
  57 }
  58
  59 #else
  60
  61 /* original Yarrow compression, must be linked with zlib */
  62
  63 #if             defined(macintosh) || defined(__APPLE__)
  64 #include "WindowsTypesForMac.h"
  65 #include "yarrowUtils.h"
  66 #include <string.h>
  67 #include <stdlib.h>
  68 #else
  69 #include <windows.h>
  70 #endif
  71 #include <math.h>
  72 #include "comp.h"
  73
  74 /* Check that the pointer is not NULL */
  75 #define PCHECK(ptr)  if(ptr==NULL) {return COMP_ERR_NULL_POINTER;}
  76 #define MMPCHECK(mmptr) if(mmptr==MM_NULL) {return COMP_ERR_NULL_POINTER;}
  77 /* Check that the important parts of the context are ok */
  78 #define CTXCHECK(ctx) \
  79 PCHECK(ctx)                             \
  80 MMPCHECK(ctx->buf)
  81
  82 /* Might want to vary these by context */
  83 #define BUFSIZE  16384 /* 16K */
  84 #define OUTBUFSIZE 16800 /* = inbufsize*1.01 + 12 (See zlib docs) */
  85 #define SHIFTSIZE 4096 /* BUFSIZE/4 */
  86
  87 #define _MIN(a,b) (((a)<(b))?(a):(b))
  88
  89
  90 /* Initialize these routines */
  91 comp_error_status comp_init(COMP_CTX* ctx)
  92 {
  93         ctx->buf = mmMalloc(BUFSIZE);
  94         if(ctx->buf == MM_NULL) {goto cleanup_comp_init;}
  95         ctx->spaceused = 0;
  96
  97         return COMP_SUCCESS;
  98
  99 cleanup_comp_init:
 100         mmFree(ctx->buf);
 101
 102         return COMP_ERR_LOW_MEMORY;
 103 }
 104
 105
 106 comp_error_status comp_add_data(COMP_CTX* ctx,Bytef* inp,uInt inplen)
 107 {
 108         uInt shifts;
 109         uInt blocksize;
 110         BYTE* buf;
 111
 112         CTXCHECK(ctx);
 113         PCHECK(inp);
 114
 115         buf = (BYTE*)mmGetPtr(ctx->buf);
 116
 117         if(inplen+SHIFTSIZE>BUFSIZE)
 118         {
 119                 blocksize = _MIN(inplen,BUFSIZE);
 120                 memmove(buf,inp,blocksize);
 121                 ctx->spaceused = blocksize;
 122         }
 123         else
 124         {
 125                 if(inplen+ctx->spaceused>BUFSIZE)
 126                 {
 127                         shifts = (uInt)ceil((inplen+ctx->spaceused-BUFSIZE)/(float)SHIFTSIZE);
 128                         blocksize = _MIN(shifts*SHIFTSIZE,ctx->spaceused);
 129                         memmove(buf,buf+blocksize,BUFSIZE-blocksize);
 130                         ctx->spaceused = ctx->spaceused - blocksize;
 131                 }
 132                 memmove(buf+ctx->spaceused,inp,inplen);
 133                 ctx->spaceused += inplen;
 134         }
 135
 136         return COMP_SUCCESS;
 137 }
 138
 139 comp_error_status comp_get_ratio(COMP_CTX* ctx,float* out)
 140 {
 141         Bytef *inbuf,*outbuf;
 142         uLong insize,outsize;
 143         int resp;
 144
 145         *out = 0;
 146
 147         CTXCHECK(ctx);
 148         PCHECK(out);
 149
 150         if(ctx->spaceused == 0) {return COMP_SUCCESS;}
 151
 152         inbuf = (Bytef*)mmGetPtr(ctx->buf);
 153         outbuf = (Bytef*)malloc(OUTBUFSIZE);
 154         if(outbuf==NULL) {return COMP_ERR_LOW_MEMORY;}
 155
 156         insize = ctx->spaceused;
 157         outsize = OUTBUFSIZE;
 158
 159         resp = compress(outbuf,&outsize,inbuf,insize);
 160         if(resp==Z_MEM_ERROR) {return COMP_ERR_LOW_MEMORY;}
 161         if(resp==Z_BUF_ERROR) {return COMP_ERR_LIB;}
 162
 163         *out = (float)outsize/(float)insize;
 164
 165         /* Thrash the memory and free it */
 166         trashMemory(outbuf, OUTBUFSIZE);
 167         free(outbuf);
 168
 169         return COMP_SUCCESS;
 170 }
 171
 172 comp_error_status comp_end(COMP_CTX* ctx)
 173 {
 174         if(ctx == NULL) {return COMP_SUCCESS;} /* Since nothing is left undone */
 175
 176         mmFree(ctx->buf);
 177         ctx->buf = MM_NULL;
 178
 179         return COMP_SUCCESS;
 180 }
 181
 182 #endif  /* YARROW_KERNEL */
 183