1/*
2 * Copyright (c) 1999, 2000-2001 Apple Computer, 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 "dev/random/YarrowCoreLib/include/WindowsTypesForMac.h"
36#include "comp.h"
37
38#ifdef	YARROW_KERNEL
39
40/* null compression */
41comp_error_status comp_init(__unused COMP_CTX* ctx)
42{
43	return COMP_SUCCESS;
44}
45
46
47comp_error_status comp_add_data( __unused COMP_CTX* ctx,
48								 __unused Bytef* inp,
49								 __unused uInt inplen )
50{
51	return COMP_SUCCESS;
52}
53
54comp_error_status comp_get_ratio( __unused COMP_CTX* ctx,float* out )
55{
56	*out = 1.0;
57	return COMP_SUCCESS;
58}
59
60comp_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) \
85PCHECK(ctx)				\
86MMPCHECK(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 */
97comp_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
105cleanup_comp_init:
106	mmFree(ctx->buf);
107
108	return COMP_ERR_LOW_MEMORY;
109}
110
111
112comp_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
145comp_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
178comp_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
190