osfmk/prng/YarrowCoreLib/src/comp.c

   1 /*
   2  * Copyright (c) 1999, 2000-2013 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_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. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 /*
  30         File:           comp.c
  31
  32         Contains:       NULL compression. Kernel version of Yarrow assumes
  33                                 incoming seed data is truly random.
  34 */
  35 #include "prng/YarrowCoreLib/include/WindowsTypesForMac.h"
  36 #include "comp.h"
  37
  38 #ifdef  YARROW_KERNEL
  39
  40 /* null compression */
  41 comp_error_status comp_init(__unused COMP_CTX* ctx)
  42 {
  43         return COMP_SUCCESS;
  44 }
  45
  46
  47 comp_error_status comp_add_data( __unused COMP_CTX* ctx,
  48                                                                  __unused Bytef* inp,
  49                                                                  __unused uInt inplen )
  50 {
  51         return COMP_SUCCESS;
  52 }
  53
  54 comp_error_status comp_get_ratio( __unused COMP_CTX* ctx,float* out )
  55 {
  56         *out = 1.0;
  57         return COMP_SUCCESS;
  58 }
  59
  60 comp_error_status comp_end( __unused COMP_CTX* ctx )
  61 {
  62         return COMP_SUCCESS;
  63 }
  64
  65 #else
  66
  67 /* original Yarrow compression, must be linked with zlib */
  68
  69 #if             defined(macintosh) || defined(__APPLE__)
  70 #include "WindowsTypesForMac.h"
  71 #include "yarrowUtils.h"
  72 #include <string.h>
  73 #include <stdlib.h>
  74 #else
  75 #include <windows.h>
  76 #endif
  77 #include <math.h>
  78 #include "comp.h"
  79
  80 /* Check that the pointer is not NULL */
  81 #define PCHECK(ptr)  if(ptr==NULL) {return COMP_ERR_NULL_POINTER;}
  82 #define MMPCHECK(mmptr) if(mmptr==MM_NULL) {return COMP_ERR_NULL_POINTER;}
  83 /* Check that the important parts of the context are ok */
  84 #define CTXCHECK(ctx) \
  85 PCHECK(ctx)                             \
  86 MMPCHECK(ctx->buf)
  87
  88 /* Might want to vary these by context */
  89 #define BUFSIZE  16384 /* 16K */
  90 #define OUTBUFSIZE 16800 /* = inbufsize*1.01 + 12 (See zlib docs) */
  91 #define SHIFTSIZE 4096 /* BUFSIZE/4 */
  92
  93 #define _MIN(a,b) (((a)<(b))?(a):(b))
  94
  95
  96 /* Initialize these routines */
  97 comp_error_status comp_init(COMP_CTX* ctx)
  98 {
  99         ctx->buf = mmMalloc(BUFSIZE);
 100         if(ctx->buf == MM_NULL) {goto cleanup_comp_init;}
 101         ctx->spaceused = 0;
 102
 103         return COMP_SUCCESS;
 104
 105 cleanup_comp_init:
 106         mmFree(ctx->buf);
 107
 108         return COMP_ERR_LOW_MEMORY;
 109 }
 110
 111
 112 comp_error_status comp_add_data(COMP_CTX* ctx,Bytef* inp,uInt inplen)
 113 {
 114         uInt shifts;
 115         uInt blocksize;
 116         BYTE* buf;
 117
 118         CTXCHECK(ctx);
 119         PCHECK(inp);
 120
 121         buf = (BYTE*)mmGetPtr(ctx->buf);
 122
 123         if(inplen+SHIFTSIZE>BUFSIZE)
 124         {
 125                 blocksize = _MIN(inplen,BUFSIZE);
 126                 memmove(buf,inp,blocksize);
 127                 ctx->spaceused = blocksize;
 128         }
 129         else
 130         {
 131                 if(inplen+ctx->spaceused>BUFSIZE)
 132                 {
 133                         shifts = (uInt)ceil((inplen+ctx->spaceused-BUFSIZE)/(float)SHIFTSIZE);
 134                         blocksize = _MIN(shifts*SHIFTSIZE,ctx->spaceused);
 135                         memmove(buf,buf+blocksize,BUFSIZE-blocksize);
 136                         ctx->spaceused = ctx->spaceused - blocksize;
 137                 }
 138                 memmove(buf+ctx->spaceused,inp,inplen);
 139                 ctx->spaceused += inplen;
 140         }
 141
 142         return COMP_SUCCESS;
 143 }
 144
 145 comp_error_status comp_get_ratio(COMP_CTX* ctx,float* out)
 146 {
 147         Bytef *inbuf,*outbuf;
 148         uLong insize,outsize;
 149         int resp;
 150
 151         *out = 0;
 152
 153         CTXCHECK(ctx);
 154         PCHECK(out);
 155
 156         if(ctx->spaceused == 0) {return COMP_SUCCESS;}
 157
 158         inbuf = (Bytef*)mmGetPtr(ctx->buf);
 159         outbuf = (Bytef*)malloc(OUTBUFSIZE);
 160         if(outbuf==NULL) {return COMP_ERR_LOW_MEMORY;}
 161
 162         insize = ctx->spaceused;
 163         outsize = OUTBUFSIZE;
 164
 165         resp = compress(outbuf,&outsize,inbuf,insize);
 166         if(resp==Z_MEM_ERROR) {return COMP_ERR_LOW_MEMORY;}
 167         if(resp==Z_BUF_ERROR) {return COMP_ERR_LIB;}
 168
 169         *out = (float)outsize/(float)insize;
 170
 171         /* Thrash the memory and free it */
 172         trashMemory(outbuf, OUTBUFSIZE);
 173         free(outbuf);
 174
 175         return COMP_SUCCESS;
 176 }
 177
 178 comp_error_status comp_end(COMP_CTX* ctx)
 179 {
 180         if(ctx == NULL) {return COMP_SUCCESS;} /* Since nothing is left undone */
 181
 182         mmFree(ctx->buf);
 183         ctx->buf = MM_NULL;
 184
 185         return COMP_SUCCESS;
 186 }
 187
 188 #endif  /* YARROW_KERNEL */
 189