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

   1 /*
   2  * Copyright (c) 2006 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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.  The rights granted to you under the
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30
  31 /*
  32         File:           comp.c
  33
  34         Contains:       NULL compression. Kernel version of Yarrow assumes
  35                                 incoming seed data is truly random.
  36 */
  37 #include "dev/random/YarrowCoreLib/include/WindowsTypesForMac.h"
  38 #include "comp.h"
  39
  40 #ifdef  YARROW_KERNEL
  41
  42 /* null compression */
  43 comp_error_status comp_init(__unused COMP_CTX* ctx)
  44 {
  45         return COMP_SUCCESS;
  46 }
  47
  48
  49 comp_error_status comp_add_data( __unused COMP_CTX* ctx,
  50                                                                  __unused Bytef* inp,
  51                                                                  __unused uInt inplen )
  52 {
  53         return COMP_SUCCESS;
  54 }
  55
  56 comp_error_status comp_get_ratio( __unused COMP_CTX* ctx,float* out )
  57 {
  58         *out = 1.0;
  59         return COMP_SUCCESS;
  60 }
  61
  62 comp_error_status comp_end( __unused COMP_CTX* ctx )
  63 {
  64         return COMP_SUCCESS;
  65 }
  66
  67 #else
  68
  69 /* original Yarrow compression, must be linked with zlib */
  70
  71 #if             defined(macintosh) || defined(__APPLE__)
  72 #include "WindowsTypesForMac.h"
  73 #include "yarrowUtils.h"
  74 #include <string.h>
  75 #include <stdlib.h>
  76 #else
  77 #include <windows.h>
  78 #endif
  79 #include <math.h>
  80 #include "comp.h"
  81
  82 /* Check that the pointer is not NULL */
  83 #define PCHECK(ptr)  if(ptr==NULL) {return COMP_ERR_NULL_POINTER;}
  84 #define MMPCHECK(mmptr) if(mmptr==MM_NULL) {return COMP_ERR_NULL_POINTER;}
  85 /* Check that the important parts of the context are ok */
  86 #define CTXCHECK(ctx) \
  87 PCHECK(ctx)                             \
  88 MMPCHECK(ctx->buf)
  89
  90 /* Might want to vary these by context */
  91 #define BUFSIZE  16384 /* 16K */
  92 #define OUTBUFSIZE 16800 /* = inbufsize*1.01 + 12 (See zlib docs) */
  93 #define SHIFTSIZE 4096 /* BUFSIZE/4 */
  94
  95 #define _MIN(a,b) (((a)<(b))?(a):(b))
  96
  97
  98 /* Initialize these routines */
  99 comp_error_status comp_init(COMP_CTX* ctx)
 100 {
 101         ctx->buf = mmMalloc(BUFSIZE);
 102         if(ctx->buf == MM_NULL) {goto cleanup_comp_init;}
 103         ctx->spaceused = 0;
 104
 105         return COMP_SUCCESS;
 106
 107 cleanup_comp_init:
 108         mmFree(ctx->buf);
 109
 110         return COMP_ERR_LOW_MEMORY;
 111 }
 112
 113
 114 comp_error_status comp_add_data(COMP_CTX* ctx,Bytef* inp,uInt inplen)
 115 {
 116         uInt shifts;
 117         uInt blocksize;
 118         BYTE* buf;
 119
 120         CTXCHECK(ctx);
 121         PCHECK(inp);
 122
 123         buf = (BYTE*)mmGetPtr(ctx->buf);
 124
 125         if(inplen+SHIFTSIZE>BUFSIZE)
 126         {
 127                 blocksize = _MIN(inplen,BUFSIZE);
 128                 memmove(buf,inp,blocksize);
 129                 ctx->spaceused = blocksize;
 130         }
 131         else
 132         {
 133                 if(inplen+ctx->spaceused>BUFSIZE)
 134                 {
 135                         shifts = (uInt)ceil((inplen+ctx->spaceused-BUFSIZE)/(float)SHIFTSIZE);
 136                         blocksize = _MIN(shifts*SHIFTSIZE,ctx->spaceused);
 137                         memmove(buf,buf+blocksize,BUFSIZE-blocksize);
 138                         ctx->spaceused = ctx->spaceused - blocksize;
 139                 }
 140                 memmove(buf+ctx->spaceused,inp,inplen);
 141                 ctx->spaceused += inplen;
 142         }
 143
 144         return COMP_SUCCESS;
 145 }
 146
 147 comp_error_status comp_get_ratio(COMP_CTX* ctx,float* out)
 148 {
 149         Bytef *inbuf,*outbuf;
 150         uLong insize,outsize;
 151         int resp;
 152
 153         *out = 0;
 154
 155         CTXCHECK(ctx);
 156         PCHECK(out);
 157
 158         if(ctx->spaceused == 0) {return COMP_SUCCESS;}
 159
 160         inbuf = (Bytef*)mmGetPtr(ctx->buf);
 161         outbuf = (Bytef*)malloc(OUTBUFSIZE);
 162         if(outbuf==NULL) {return COMP_ERR_LOW_MEMORY;}
 163
 164         insize = ctx->spaceused;
 165         outsize = OUTBUFSIZE;
 166
 167         resp = compress(outbuf,&outsize,inbuf,insize);
 168         if(resp==Z_MEM_ERROR) {return COMP_ERR_LOW_MEMORY;}
 169         if(resp==Z_BUF_ERROR) {return COMP_ERR_LIB;}
 170
 171         *out = (float)outsize/(float)insize;
 172
 173         /* Thrash the memory and free it */
 174         trashMemory(outbuf, OUTBUFSIZE);
 175         free(outbuf);
 176
 177         return COMP_SUCCESS;
 178 }
 179
 180 comp_error_status comp_end(COMP_CTX* ctx)
 181 {
 182         if(ctx == NULL) {return COMP_SUCCESS;} /* Since nothing is left undone */
 183
 184         mmFree(ctx->buf);
 185         ctx->buf = MM_NULL;
 186
 187         return COMP_SUCCESS;
 188 }
 189
 190 #endif  /* YARROW_KERNEL */
 191