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(COMP_CTX* ctx)
  36 {
  37         return COMP_SUCCESS;
  38 }
  39
  40
  41 comp_error_status comp_add_data(COMP_CTX* ctx,Bytef* inp,uInt inplen)
  42 {
  43         return COMP_SUCCESS;
  44 }
  45
  46 comp_error_status comp_get_ratio(COMP_CTX* ctx,float* out)
  47 {
  48         *out = 1.0;
  49         return COMP_SUCCESS;
  50 }
  51
  52 comp_error_status comp_end(COMP_CTX* ctx)
  53 {
  54         return COMP_SUCCESS;
  55 }
  56
  57 #else
  58
  59 /* original Yarrow compression, must be linked with zlib */
  60
  61 #if             defined(macintosh) || defined(__APPLE__)
  62 #include "WindowsTypesForMac.h"
  63 #include "yarrowUtils.h"
  64 #include <string.h>
  65 #include <stdlib.h>
  66 #else
  67 #include <windows.h>
  68 #endif
  69 #include <math.h>
  70 #include "comp.h"
  71
  72 /* Check that the pointer is not NULL */
  73 #define PCHECK(ptr)  if(ptr==NULL) {return COMP_ERR_NULL_POINTER;}
  74 #define MMPCHECK(mmptr) if(mmptr==MM_NULL) {return COMP_ERR_NULL_POINTER;}
  75 /* Check that the important parts of the context are ok */
  76 #define CTXCHECK(ctx) \
  77 PCHECK(ctx)                             \
  78 MMPCHECK(ctx->buf)
  79
  80 /* Might want to vary these by context */
  81 #define BUFSIZE  16384 /* 16K */
  82 #define OUTBUFSIZE 16800 /* = inbufsize*1.01 + 12 (See zlib docs) */
  83 #define SHIFTSIZE 4096 /* BUFSIZE/4 */
  84
  85 #define _MIN(a,b) (((a)<(b))?(a):(b))
  86
  87
  88 /* Initialize these routines */
  89 comp_error_status comp_init(COMP_CTX* ctx)
  90 {
  91         ctx->buf = mmMalloc(BUFSIZE);
  92         if(ctx->buf == MM_NULL) {goto cleanup_comp_init;}
  93         ctx->spaceused = 0;
  94
  95         return COMP_SUCCESS;
  96
  97 cleanup_comp_init:
  98         mmFree(ctx->buf);
  99
 100         return COMP_ERR_LOW_MEMORY;
 101 }
 102
 103
 104 comp_error_status comp_add_data(COMP_CTX* ctx,Bytef* inp,uInt inplen)
 105 {
 106         uInt shifts;
 107         uInt blocksize;
 108         BYTE* buf;
 109
 110         CTXCHECK(ctx);
 111         PCHECK(inp);
 112
 113         buf = (BYTE*)mmGetPtr(ctx->buf);
 114
 115         if(inplen+SHIFTSIZE>BUFSIZE)
 116         {
 117                 blocksize = _MIN(inplen,BUFSIZE);
 118                 memmove(buf,inp,blocksize);
 119                 ctx->spaceused = blocksize;
 120         }
 121         else
 122         {
 123                 if(inplen+ctx->spaceused>BUFSIZE)
 124                 {
 125                         shifts = (uInt)ceil((inplen+ctx->spaceused-BUFSIZE)/(float)SHIFTSIZE);
 126                         blocksize = _MIN(shifts*SHIFTSIZE,ctx->spaceused);
 127                         memmove(buf,buf+blocksize,BUFSIZE-blocksize);
 128                         ctx->spaceused = ctx->spaceused - blocksize;
 129                 }
 130                 memmove(buf+ctx->spaceused,inp,inplen);
 131                 ctx->spaceused += inplen;
 132         }
 133
 134         return COMP_SUCCESS;
 135 }
 136
 137 comp_error_status comp_get_ratio(COMP_CTX* ctx,float* out)
 138 {
 139         Bytef *inbuf,*outbuf;
 140         uLong insize,outsize;
 141         int resp;
 142
 143         *out = 0;
 144
 145         CTXCHECK(ctx);
 146         PCHECK(out);
 147
 148         if(ctx->spaceused == 0) {return COMP_SUCCESS;}
 149
 150         inbuf = (Bytef*)mmGetPtr(ctx->buf);
 151         outbuf = (Bytef*)malloc(OUTBUFSIZE);
 152         if(outbuf==NULL) {return COMP_ERR_LOW_MEMORY;}
 153
 154         insize = ctx->spaceused;
 155         outsize = OUTBUFSIZE;
 156
 157         resp = compress(outbuf,&outsize,inbuf,insize);
 158         if(resp==Z_MEM_ERROR) {return COMP_ERR_LOW_MEMORY;}
 159         if(resp==Z_BUF_ERROR) {return COMP_ERR_LIB;}
 160
 161         *out = (float)outsize/(float)insize;
 162
 163         /* Thrash the memory and free it */
 164         trashMemory(outbuf, OUTBUFSIZE);
 165         free(outbuf);
 166
 167         return COMP_SUCCESS;
 168 }
 169
 170 comp_error_status comp_end(COMP_CTX* ctx)
 171 {
 172         if(ctx == NULL) {return COMP_SUCCESS;} /* Since nothing is left undone */
 173
 174         mmFree(ctx->buf);
 175         ctx->buf = MM_NULL;
 176
 177         return COMP_SUCCESS;
 178 }
 179
 180 #endif  /* YARROW_KERNEL */
 181